21 ms·

This should not come as a surprise, and it was largely predictable from the outset. The flu has a base reproduction number (R0) less than 2 (https://www.vdh.vi

This should not come as a surprise, and it was largely predictable from the outset. The flu has a base reproduction number (R0) less than 2 (https://www.vdh.virginia.gov/coronavirus/2020/12/07/covid-19-and-influenza-surveillance/ https://www.vdh.virginia.gov/coronavirus/2020/12/07/covid-19...). Covid has an R0 in the vicinity of 2.5 (https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scena...). In the meantime, public health measures like masking and distancing will work against both viruses. If people become reluctant to socialize because of covid (whether or not there be legal restrictions), they will also not spread the flu. As a broad conclusion, if public health measures reduce the effective reproduction number of Covid to about 1 (stabilizing exponential growth), they will also reduce the effective reproduction number of the flu to something substantially below 1. Since the flu would have also had a low baseline prevalence in the summer of 2020, it is no wonder that we failed to see a flu season. There's really no need for conspiracy theorizing.

DoingIsLearning 5y ago
Non virologist naive question, if we apply all these measures targeting SARS-COV2 and it also creates a massive negative pressure on flu viruses, is there a risk that this applies an adaptive pressure to select for a future uber infectious new flu strain?
- Majromax 5y ago
  I don't see any reason to expect it would. Summer months, for example, already apply a strong negative pressure on the flu virus (that is, we have a flu season), yet we have not seen a year-round flu. Diseases always face selection pressure to spread more easily and rapidly. When that selection pressure is caused by broad factors like "people aren't congregating together," it's hard to imagine how any simple evolution could overcome that barrier. Covid itself is instructive here. Some of the variants of concern are more transmissible than the originally-distributed variant as of March of last year, but those mutations don't uniquely overcome masks or social distancing. They would have always result in a more transmissible virus (because SARS-CoV-2 appears to be a zoonotic virus not originally perfectly-adapted to humans), and we are seeing them now because each infected person is a new roll of the mutation dice. Applying that lesson to the flu, the less prevalent the virus the less likely we are to see variations, not more. Alas, for influenza itself we always have the asterisk that we regularly see new variations cross to humans from animal reservoirs, so we're unlikely to eliminate it through only (nonpharmaceutical) human-health measures. (It'd be nice to get a universal flu vaccine, though.)
  - juloo 5y ago
    > yet we have not seen a year-round flu. We had. And it may have killed 3% to 5% of the world population in about 2 years: https://en.wikipedia.org/wiki/Spanish_flu https://en.wikipedia.org/wiki/Spanish_flu That's also why we are so afraid of this one and constantly monitor it: https://en.wikipedia.org/wiki/Avian_influenza https://en.wikipedia.org/wiki/Avian_influenza
- daanlo 5y ago
  My layman understanding is that it doesn‘t work that way. Less spread = less chance of mutation = less chance of uber infectious new flu strain.
  - collyw 5y ago
    It's potentially the opposite. Say you have a population of 1000. If one person infects ten others. Then its going to be 3 generations before 1000 are infected and full immunity is reached. We go for a suppression strategy instead.If 1 person infects 1 other person (as we seem to be trying to achieve with corna) it is going to take 1000 generations before full immunity is achieved. There is going to be far more chance of mutations in 1000 generations of viral replication than in 3 generations.
    - teachingassist 5y ago
      If everybody has had the disease, what's the purpose of having full immunity? However, I think this is right in one sense: an implicit or explicit strategy of keeping R0 as close as possible to 1 would be the strategy with the highest risk of significant mutations, as we have seen. UK government ministers literally stated this to be their strategy.
      - collyw 5y ago
        It was just an example to make the theory easier to understand.
    - daanlo 5y ago
      That is a really interesting thought. But isn‘t the chance of mutation per viral replication (which happens million-fold in each human per infection) and not per human? What I meant was that if we contain the virus to only ever get 1% of the population sick then there is a lower chance of mutation than if it gets 70% sick.
    - kaba0 5y ago
      Your second paragraph assumes that a suppressed virus will not go extinct. If the suppression is effective, with eg. vaccines it can be done with quickly, with no higher chance of mutations.
- Fomite 5y ago
  It's unlikely. Most of the major "uber infectious" influenza strains don't emerge via ordinary mutation (antigenic drift) but the reassortment of two viral genomes that have infected the same host (antigenic shift). Given pigs and wild birds aren't social distancing, there's no reason to believe there's a distinctly high amount of additional pressure one way or the other.
- kaba0 5y ago
  Chance of mutation depends mostly on the number of infected —- applying antibiotics is problematic because it is a repeated process, and the net amount of cell divisions is huge with iterating killing and “letting go”. With effective and strict measures, the pandemic could quickly die out with basically minimal chance of a super-mutation. The current some half of the world somewhat protected, while other parts are breeding grounds is a pretty bad state to be at, with a potential mutation turning up and endangering the protected people as well again.
timr 5y ago
> This should not come as a surprise, and it was largely predictable from the outset....the flu has a base reproduction number (R0) less than 2....Covid has an R0 in the vicinity of 2.5....In the meantime, public health measures like masking and distancing will work against both viruses....there's really no need for conspiracy theorizing. Assuming that this is due to "masking and distancing" and the small difference in R0 is crude thinking. It's unlikely to be anything of the sort. First, R0 is not a fixed constant. It varies by context and location, and we've seen influenza decline everywhere. Second, R0 is an estimated value. There are big error bars on all of these estimates -- the overlap is far greater than the 0.5 you're using to claim causality. Third, rhinovirus has not gone away (estimated R0 < 2). Nor has adenovirus (estimated R0 ~2.3) [1,2] There's something far more interesting going on here, it is surprising, and it isn't a "conspiracy theory" to talk about it. It's science. (FWIW, my current favored hypothesis is that the closure of schools, and possibly travel, significantly affected the spread of flu. Unlike Covid, kids are a significant vector of spread for influenza. It's one of those little facts about Covid that is...politically incorrect...to acknowledge right now. But I am speculating, and there are problems with this theory as well.) [1] https://syndromictrends.com/metric/panel/rp/percent_positivity/organism/main https://syndromictrends.com/metric/panel/rp/percent_positivi... [2] https://www.medrxiv.org/content/10.1101/2020.02.04.20020404v1.full.pdf https://www.medrxiv.org/content/10.1101/2020.02.04.20020404v...
- mmmrtl 5y ago
  Possible explanations include: - More asymptomatic transmission of rhinovirus/enterovirus and adenoviruses than influenza. People often don't notice these illnesses, so wouldn't assume it is COVID and quarantine like they would for influenza. - More fomite spread than influenza. They may be more stable on surfaces or in food
  - timr 5y ago
    These are reasonable theories as well. Though the second one would really have to be "SARS-CoV2 has more fomite spread than flu" to explain the observations. In general though, any sort of explanation that focuses on differences in transmission is more plausible than hand-wavy theories involving R0 and masks. People just desperately want to find evidence that the stuff we did this year made a huge difference.
deleted 5y ago
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havewetsalt 5y ago
It's conspiracy theory by definition if it falls outside the official narrative. So even science can be a conspiracy theory. In fact, real science has a tendency to be viewed (by non-scientists, it should go without saying) as conspiracy theory insofar as it challenges the official narrative, and invokes complicated explanations, rather than a nice simple answer.
- realreality 5y ago
  You need a conspiracy for it to be a conspiracy theory. Without that, it's just a theory (or, more likely, a hypothesis).
  - havewetsalt 5y ago
    No, the modern sense is literally just a euphemism for dissent. (of course the modern sense of literal is literally figurative.)
- Majromax 5y ago
  No, a conspiracy theory "by definition" requires collaboration between several human agents. In this overall thread, the idea that the "disappearance" of flu is driven by political desire to label all respiratory illnesses as covid cases would be an example of a conspiracy theory. Another commenter brings up the idea of 'viral interference.' This is not an example of a conspiracy theory, but I do not give the idea great credence on Occam's Razor grounds.
  - havewetsalt 5y ago
    No, that's just your definition. While I may personally agree the viral interference comment is not (in my definition) a conspiracy theory, it is regarded as a conspiracy theory in many (again, non-scientific) contexts. The conspiracy is not the collaboration, it is the belief.
  - didericis 5y ago
    > the idea that the "disappearance" of flu is driven by political desire to label all respiratory illnesses as covid cases would be an example of a conspiracy theory. You’d also have to claim that mislabelling was done deliberately for it to be conspiratorial. I don’t think politically motivated distortions of perception are conspiratorial if those who are prone to mislabel things due to their belief system do so without realizing. Not saying that’s an applicable explanation for the disappearance of flu, as it seems way too universal, just going further into semantics.
tryonenow 5y ago
>In the meantime, public health measures like masking and distancing will work against both viruses That's not necessarily true. COVID appears to be aerosolized, whereas typical flu is not. That means that masks will work to catch viral flu particles in ejected fluids (talking, coughing, sneezing, etc), but the same cannot be assumed for COVID, given that viral particles are orders of magnitude smaller than pores in cloth and surgical masks. And this assertion is supported by at least two studies (one Danish I believe) which showed negligible effect of mask wearing on COVID spread.
MeinBlutIstBlau 5y ago
How can you explain people getting covid but not the flu when nothing changed when places started opening up? It sounds more like poor data reporting more than anything else and I will take that to my grave.
- Majromax 5y ago
  > How can you explain people getting covid but not the flu when nothing changed when places started opening up? Covid starts from a higher baseline level of cases, and it has a higher transmission rate. When societies "open up" (resume social contacts; it's more than just government lockdowns), then we'd expect to see covid cases climb before flu cases. In fact, seeing the opposite would be very surprising.
- Godel_unicode 5y ago
  > ...and I will take that to my grave "When the Facts Change, I Change My Mind. What Do You Do, Sir?"
  - luxuryballs 5y ago
    Real answer? Ask how much faith you have in your religion of “facts”.
    - boredtofears 5y ago
      So how exactly does your system of belief work?
- kevin_thibedeau 5y ago
  The CDC doesn't accurately measure flu deaths. It's largely done by assessing death certificate data rather than positively identifying a flu infection. Deaths by pneumonia during the designated flu season months are counted in the tally of annual flu deaths. It is very likely that a portion of deaths attributed to COV19 over the winter were in fact from flu.
- teachingassist 5y ago
fullshark 5y ago
> This should not come as a surprise, and it was largely predictable from the outset. That explains all these news stories telling me what to expect: https://www.nbcnews.com/news/us-news/experts-warn-twindemic-covid-cases-rise-flu-seasons-looms-n1240623 https://www.nbcnews.com/news/us-news/experts-warn-twindemic-... https://www.usatoday.com/story/news/health/2020/09/19/covid-flu-experts-fear-twindemic-200-k-deaths-us/5697848002/ https://www.usatoday.com/story/news/health/2020/09/19/covid-... https://www.scientificamerican.com/article/how-we-can-avoid-a-twindemic-of-covid-and-flu/ https://www.scientificamerican.com/article/how-we-can-avoid-... etc: https://www.google.com/search?q=twindemic&tbs=cdr:1,cd_min:9/1/2020,cd_max:11/30/2020&tbm=nws&sxsrf=ALeKk00iO50BpGwVTpp8Ljzsbx03jyzdhw:1619728667669&ei=GxmLYOesKM-r0PEPltytwAI&start=20&sa=N&ved=0ahUKEwinpvm-p6TwAhXPFTQIHRZuCyg4ChDw0wMImgE&biw=1309&bih=695&dpr=2.2 https://www.google.com/search?q=twindemic&tbs=cdr:1,cd_min:9...
- jb775 5y ago
  Where's all the people that were saying Covid is a completely separate thing from the flu?...and every "Covid Death" was a separate death on top of the normal flu death rate? Occam's Razor: Covid isn't a "pandemic", it's a strong flu
  - dijit 5y ago
    Covid transmits the same way as flu but is more infectious. Measures against Covid work against flu. It’s nice to know that our flu deaths are declining. But our Covid deaths are many times more.
    - achenatx 5y ago
      covid might not be more infectious, it might just be less people have any existing partial resistance to sars-cov-2. Each year the flu mutates but it still has overlap with prior variants. As sars-cov-2 mutates seasonal covid might end up less bad than the seasonal flu. Though there is no way to tell.
      - 5y ago
fallingfrog 5y ago
I actually told people at the outset of the covid lockdowns, “at least we won’t have a flu season this year.” Then later on I saw people online floating this as some kind of conspiracy and I thought, “wait, this wasn’t obvious to everyone?”
- psychlops 5y ago
  Covid was this years flu season.
  - fallingfrog 5y ago
    That is not correct: they are two different viruses. Even if you’re making a loose analogy that’s still a poor comparison.
- fallingfrog 5y ago
  I’m not lying you know. I did say this, and everyone I said it too either said that they had also had the same thought, or if they hadn’t, they still agreed after thinking about it for a moment. That includes conservatives. Anyone could have seen it coming, and many did. It was only after that fact that the conspiracy memes started going around.
haecceity 5y ago
Will the flu come back after covid ends? If covid ends?
- ddingus 5y ago
  I think that depends a lot on how people live.
- justtemporary 5y ago
  Yes, the flu virus has a natural reservoir amongst the bird population.
fny 5y ago
To quell discussions of no/low testing. Looking at two weeks: - Week of December 5, 2020: 40/22,474 flu tests were positive - Week of December 7, 2019: 631/1,508 flu tests were positive Cumulative #s: - Cumulative through Week 14 2021: 1,739/891,717 - Cumulative through Week 14 2019: 37,155/69,291 So we've been testing wayyy more often with wayyy fewer positives. https://www.cdc.gov/flu/weekly/pastreports.htm https://www.cdc.gov/flu/weekly/pastreports.htm
xyzzy21 5y ago
Or....(and without any conspiracy theories - never mind MOST conspiracy theories of the last 30 years have entirely become true - conspiracy TRUTHS). Everything that was flu was labeled as COVID since doctors, hospitals and medical professions were PAID a bounty on COVID. Multiple this by PCR testing being 99% fraudulent due to high cycle counts which enable cold viruses and even flu viruses to to test positive because you've reached the "noise floor" of the test at 10-15 cycles (most testing was done with 30-40 cycles). This helped "fulfill" the bounties and take all the attention away from conventional diseases both infective and others like heart disease, cancer, etc. (which got counted as COVID as well, just like traffic accidents and other definitely-not-COVID deaths that occurred). The same bounty system shut down the entire surveillance system for flu as well as because non-essential workers included anything not COVID related or providing shallowly defined "essential" services.
- sebmellen 5y ago
  I’m 100% sure that “MOST” conspiracy theories of the last 30 years have not been proven true.
- deleted 5y ago
  [deleted]
- SamBam 5y ago
  > since doctors, hospitals and medical professions were PAID a bounty on COVID. You what? Do you actually believe this? Seriously?
  - seattle_spring 5y ago
    Oh man I gotta figure out how to get my wife backpay for all the bounties she must be owed!
audessuscest 5y ago
https://twitter.com/ianmSC/status/1387864442386325504 https://twitter.com/ianmSC/status/1387864442386325504
- ceejayoz 5y ago
  Sweden didn't mandate strict measures. Plenty of folks still took them on their own volition.
  - audessuscest 5y ago
    No mask, public transports, restaurant, schools open, etc doesn't matter if even 20% of the population (which is a very high estimate) use some of these measures. You can't explain that the evolution is exactly the same as a Norway...
    - ceejayoz 5y ago
      You can, though. If you get a disease's R0 below one, it goes away. Enough people changed their behavior in both countries to make flu go away, because it no longer spread quickly enough to sustain itself.
alexnewman 5y ago
I believe there’s been placebo controlled studies that show that masks to not stop the spread of influenza . I haven’t read the papers, just something I’ve seen mentioned on medcram.
zackees 5y ago
The problem with this logic is the presumption that wearing masks was a widespread phenomenon. As someone who traveled a lot this year I can assure you that there a many states and areas that mostly ignored the lockdowns happening in the city areas. For these places, we would expect the flu to continue on as normal. Instead it’s disappeared. How strange.
rconti 5y ago
I remember reading a conspiracy theory back in ~ April 2020 that said "what happened to the flu" / "why are flu cases down so sharply?" It was literally so stupid that it took me a minute or two to understand that the implication was that conspiracy theorists think flu cases were being categorized as covid.
- audessuscest 5y ago
  https://twitter.com/ianmSC/status/1387864442386325504 https://twitter.com/ianmSC/status/1387864442386325504
- nickalaso 5y ago
  Could you explain why this is "literally so stupid" when this appears to be what is happening? If lockdown measures, social distancing, mask wearing, etc. were the true cause of the massive reduction in flu cases, we would expect to also see that countries and US states that failed to enact measures would be reporting high flu numbers to the WHO. This doesn't appear to be happening. Instead, "the drop-off in flu numbers was both swift and universal." (article quote) This universality suggests a data problem to me rather than an environmental change.
  - kaba0 5y ago
    > we would expect to also see that countries and US states that failed to enact measures would be reporting high flu numbers to the WHO. I don’t think so. Even without government policies in place, people become much much more vary of hygiene - that alone could account for a serious drop in new flu cases. The other factor as others mentioned is that someone with a weaker immune system who would have a pretty bad case of flu, had now a much higher chance of getting covid instead (due to covid quickly overtaking the number of cases due to its higher R number), so in a way covid being more infectious, sort of suffocated the flu.
  - xxxxxxx12 5y ago
    There's a good clip from CBC in 2012 about flu surveillance and how it's an unverified estimate with very large bounds: https://www.youtube.com/watch?v=mViFHqDD9hI https://www.youtube.com/watch?v=mViFHqDD9hI
cheeri0 5y ago
> In the meantime, public health measures like masking and distancing will work against both viruses. Yeah but there are numerous studies that show these things don't work. Also, I'm confused why you think someone cannot get both covid-19 and the flu.
nanis 5y ago
> In the meantime, public health measures like masking and distancing will work against both viruses. This argument does not make sense because of the timing of the disappearance of the flu. For example, NYS was having a really bad flu season before the Covid panic hit[1]. I am posting a link to my screenshot first because NYS flu tracker[1] is one of the stupidest web pages out there. Click on the "compare with previous seasons" heading on the page to get the current table. The noteworthy part is the drop in flu cases between the 6th and 7th weeks during what seems like an exceptionally bad flu season. Note also "Regulation for Prevention of Influenza Transmission by Healthcare and Residential Facility and Agency Personnel"[3]: > As of December 5, 2019, influenza is prevalent in NYS. > At this time, Section 2.59 of the New York State Sanitary Code (10 NYCRR § 2.59) requires all health care and residential facilities and agencies regulated pursuant to Article 28, 36, or 40 of the Public Health Law to ensure that all personnel, as defined in the regulation, not vaccinated against influenza for the current influenza season wear a surgical or procedure mask while in areas where patients or residents are typically present. > This page will be updated when the status changes. which apparently has not been updated since December 5, 2019. [1]: https://twitter.com/sinan_unur/status/1368882698966667265 https://twitter.com/sinan_unur/status/1368882698966667265 [2]: https://nyshc.health.ny.gov/web/nyapd/new-york-state-flu-tracker https://nyshc.health.ny.gov/web/nyapd/new-york-state-flu-tra... [3]: https://www.health.ny.gov/diseases/communicable/influenza/seasonal/providers/prevention_of_influenza_transmission/ https://www.health.ny.gov/diseases/communicable/influenza/se... (archived <https://archive.is/wde1c https://archive.is/wde1c>)
- nanis 5y ago
  I find the downvotes interesting. Do you think the web page is actually well done? Or do you disagree with the observation that the drop between weeks 6 and 7 in 2020 (in the midst of a bad flu season) looks different? % ch in flu cases between weeks 6 and 7 in NYS 2017: -8% 2018: +9% 2019: +9% 2020: -17% 2021: -31% (really low absolute numbers) What caused flu cases to start falling in mid-February _before_ so called "public health measures"?[1] > The acceleration phase of a pandemic is complex and requires a multifaceted and rapidly adapting public health response. During a 3-week period in late February to early March, the number of U.S. COVID-19 cases increased more than 1,000-fold. Various community mitigation interventions were implemented with the aim of reducing further spread and controlling the impact on health care capacity. So, between CDC weeks 7 to 10, the a bad flu season disappears while COVID-19 cases increase 1,000-fold. What are the "public health measures" that explain this divergence? March 21, 2020[2]: > "To be clear, the state has the legal authority to overrule any locality's decision to issue an order of mass quarantine or shut down. No locality will be closing down. The mass transit system is not shutting down. These rumors, caused by undue anxiety, are just that - rumors." March 7, 2020[3]: > During a briefing on the novel coronavirus, Governor Andrew M. Cuomo today declared a state of emergency to help New York more quickly and effectively contain the spread of the virus. February 29, 2020[4]: > "We'll start testing immediately here in New York, so we can handle more tests, more volume, turn them around faster, and we are ready to go and literally we can start testing immediately We have mobilized for emergencies before, and we're going to do it again." February 27, 2020[5]: > Governor Andrew M. Cuomo today announced the total number of flu cases in New York State has eclipsed the record number of seasonal cases since the New York State Department of Health began tracking flu cases during the 1998-99 season. [1]: https://www.cdc.gov/mmwr/volumes/69/wr/mm6918e2.htm https://www.cdc.gov/mmwr/volumes/69/wr/mm6918e2.htm [2]: https://www.governor.ny.gov/news/statement-secretary-governor-melissa-derosa-regarding-rumors-new-york-city-and-mass-transit https://www.governor.ny.gov/news/statement-secretary-governo... [3]: https://www.governor.ny.gov/news/novel-coronavirus-briefing-governor-cuomo-declares-state-emergency-contain-spread-virus https://www.governor.ny.gov/news/novel-coronavirus-briefing-... [4]: https://www.governor.ny.gov/news/video-audio-rush-transcript-governor-cuomo-delivers-update-coronavirus https://www.governor.ny.gov/news/video-audio-rush-transcript... [5]: https://www.governor.ny.gov/news/governor-cuomo-announces-record-breaking-total-number-flu-cases-new-york-even-number-flu-cases https://www.governor.ny.gov/news/governor-cuomo-announces-re...
Fomite 5y ago
Some of this is actually a surprise - we don't have a good handle on how influenza seasonality works, and some of the "Just So" stories for it should have promoted influenza transmission, like increased indoor crowding above even the usual levels in the winter. The dynamics of influenza could have been expected to change, and I would have put money on they decreasing, but it is never the less not pre-ordained nor attributable to an obvious cause (for example, one of the original reasons people didn't push mask orders is the limited suggestion that they were effective for flu).
darkerside 5y ago
I'm really excited to see this thread on HN because I've got a question about flu vs COVID, and I feel like this is my only (slim) chance to get a non-politicized answer to it. It's a simple question. Flu deaths in the US have dropped precipitously. This past flu season resulted in (very roughly) ~1% of the deaths of previous seasons. It seems obvious that this is primarily due to social distancing efforts as you say. To naive little me, this implies that COVID deaths are also likely to have been reduced to ~1% from what they would have been without said measures. In the US, that implies that we may have steered into 500K deaths instead of a stunning potential 50M deaths. Based on my admittedly naive calculations, I'm sure this is inaccurate, but I don't even know in which direction, could have been potentially even more. Did we really avert 50M deaths by social distancing?
- caturopath 5y ago
  > Did we really avert 50M deaths by social distancing? No, not even close. > this implies that COVID deaths are also likely to have been reduced to ~1% from what they would have been without said measures I don't think it implies that. There is nothing that says that the anti-COVID measures are about as effective at preventing spread of COVID as spread of flu. > 500K deaths Closer to 600k :( This is among 32MM cases reported to the CDC, probably more like 80MM cases total. Ignoring lots of factors, our ceiling for COVID is more like 4-10x what we've experienced, not 100X.
  - darkerside 5y ago
    I feel like you misunderstand the meaning of "implies", which is to suggest without explicitly saying. I think it is reasonable to assume that social distancing measures would have a similar effect, and in the absence of other data, the best estimate might be to assume they are proportional. Fortunately there are a couple of other answers in thread that answered this at a level of detail that I could understand.
- jjeaff 5y ago
  That extrapolation only works if the flu is equally as contagious as covid and also has identical methods of transmission (for example, it may be that covid transmits through the air more readily than the flu). But we know that covid is actually quite a bit more contagious, so you can't really make a linear extrapolation like that.
anonymouse008 5y ago
Has anyone given the consideration that many of the positive tests have been common coronavirus colds or other things that may resemble flu and be diagnosed as such in a ICD10/CPT data dump ?
lifeformed 5y ago
Does this mean the excess death rate is undercounting covid then? Since the baseline death rate is counting normal flu deaths.
troyvit 5y ago
XKCD saw it coming :) https://xkcd.com/2306/ https://xkcd.com/2306/
CodeWriter23 5y ago
Nope. Has everything to do with P&I death figures being expanded to CP&I (coronavirus, pneumonia & influenza). Thanks for playing.

DoingIsLearning 5y ago

Non virologist naive question, if we apply all these measures targeting SARS-COV2 and it also creates a massive negative pressure on flu viruses, is there a risk that this applies an adaptive pressure to select for a future uber infectious new flu strain?

Majromax 5y ago
I don't see any reason to expect it would. Summer months, for example, already apply a strong negative pressure on the flu virus (that is, we have a flu season), yet we have not seen a year-round flu. Diseases always face selection pressure to spread more easily and rapidly. When that selection pressure is caused by broad factors like "people aren't congregating together," it's hard to imagine how any simple evolution could overcome that barrier. Covid itself is instructive here. Some of the variants of concern are more transmissible than the originally-distributed variant as of March of last year, but those mutations don't uniquely overcome masks or social distancing. They would have always result in a more transmissible virus (because SARS-CoV-2 appears to be a zoonotic virus not originally perfectly-adapted to humans), and we are seeing them now because each infected person is a new roll of the mutation dice. Applying that lesson to the flu, the less prevalent the virus the less likely we are to see variations, not more. Alas, for influenza itself we always have the asterisk that we regularly see new variations cross to humans from animal reservoirs, so we're unlikely to eliminate it through only (nonpharmaceutical) human-health measures. (It'd be nice to get a universal flu vaccine, though.)
- juloo 5y ago
  > yet we have not seen a year-round flu. We had. And it may have killed 3% to 5% of the world population in about 2 years: https://en.wikipedia.org/wiki/Spanish_flu https://en.wikipedia.org/wiki/Spanish_flu That's also why we are so afraid of this one and constantly monitor it: https://en.wikipedia.org/wiki/Avian_influenza https://en.wikipedia.org/wiki/Avian_influenza
daanlo 5y ago
My layman understanding is that it doesn‘t work that way. Less spread = less chance of mutation = less chance of uber infectious new flu strain.
- collyw 5y ago
  It's potentially the opposite. Say you have a population of 1000. If one person infects ten others. Then its going to be 3 generations before 1000 are infected and full immunity is reached. We go for a suppression strategy instead.If 1 person infects 1 other person (as we seem to be trying to achieve with corna) it is going to take 1000 generations before full immunity is achieved. There is going to be far more chance of mutations in 1000 generations of viral replication than in 3 generations.
  - teachingassist 5y ago
    If everybody has had the disease, what's the purpose of having full immunity? However, I think this is right in one sense: an implicit or explicit strategy of keeping R0 as close as possible to 1 would be the strategy with the highest risk of significant mutations, as we have seen. UK government ministers literally stated this to be their strategy.
    - collyw 5y ago
      It was just an example to make the theory easier to understand.
  - daanlo 5y ago
    That is a really interesting thought. But isn‘t the chance of mutation per viral replication (which happens million-fold in each human per infection) and not per human? What I meant was that if we contain the virus to only ever get 1% of the population sick then there is a lower chance of mutation than if it gets 70% sick.
  - kaba0 5y ago
    Your second paragraph assumes that a suppressed virus will not go extinct. If the suppression is effective, with eg. vaccines it can be done with quickly, with no higher chance of mutations.
Fomite 5y ago
It's unlikely. Most of the major "uber infectious" influenza strains don't emerge via ordinary mutation (antigenic drift) but the reassortment of two viral genomes that have infected the same host (antigenic shift). Given pigs and wild birds aren't social distancing, there's no reason to believe there's a distinctly high amount of additional pressure one way or the other.
kaba0 5y ago
Chance of mutation depends mostly on the number of infected —- applying antibiotics is problematic because it is a repeated process, and the net amount of cell divisions is huge with iterating killing and “letting go”. With effective and strict measures, the pandemic could quickly die out with basically minimal chance of a super-mutation. The current some half of the world somewhat protected, while other parts are breeding grounds is a pretty bad state to be at, with a potential mutation turning up and endangering the protected people as well again.

timr 5y ago

> This should not come as a surprise, and it was largely predictable from the outset....the flu has a base reproduction number (R0) less than 2....Covid has an R0 in the vicinity of 2.5....In the meantime, public health measures like masking and distancing will work against both viruses....there's really no need for conspiracy theorizing. Assuming that this is due to "masking and distancing" and the small difference in R0 is crude thinking. It's unlikely to be anything of the sort. First, R0 is not a fixed constant. It varies by context and location, and we've seen influenza decline everywhere. Second, R0 is an estimated value. There are big error bars on all of these estimates -- the overlap is far greater than the 0.5 you're using to claim causality. Third, rhinovirus has not gone away (estimated R0 < 2). Nor has adenovirus (estimated R0 ~2.3) [1,2] There's something far more interesting going on here, it is surprising, and it isn't a "conspiracy theory" to talk about it. It's science. (FWIW, my current favored hypothesis is that the closure of schools, and possibly travel, significantly affected the spread of flu. Unlike Covid, kids are a significant vector of spread for influenza. It's one of those little facts about Covid that is...politically incorrect...to acknowledge right now. But I am speculating, and there are problems with this theory as well.) [1] https://syndromictrends.com/metric/panel/rp/percent_positivity/organism/main https://syndromictrends.com/metric/panel/rp/percent_positivi... [2] https://www.medrxiv.org/content/10.1101/2020.02.04.20020404v1.full.pdf https://www.medrxiv.org/content/10.1101/2020.02.04.20020404v...

mmmrtl 5y ago
Possible explanations include: - More asymptomatic transmission of rhinovirus/enterovirus and adenoviruses than influenza. People often don't notice these illnesses, so wouldn't assume it is COVID and quarantine like they would for influenza. - More fomite spread than influenza. They may be more stable on surfaces or in food
- timr 5y ago
  These are reasonable theories as well. Though the second one would really have to be "SARS-CoV2 has more fomite spread than flu" to explain the observations. In general though, any sort of explanation that focuses on differences in transmission is more plausible than hand-wavy theories involving R0 and masks. People just desperately want to find evidence that the stuff we did this year made a huge difference.

deleted 5y ago

[deleted]

havewetsalt 5y ago

It's conspiracy theory by definition if it falls outside the official narrative. So even science can be a conspiracy theory. In fact, real science has a tendency to be viewed (by non-scientists, it should go without saying) as conspiracy theory insofar as it challenges the official narrative, and invokes complicated explanations, rather than a nice simple answer.

realreality 5y ago
You need a conspiracy for it to be a conspiracy theory. Without that, it's just a theory (or, more likely, a hypothesis).
- havewetsalt 5y ago
  No, the modern sense is literally just a euphemism for dissent. (of course the modern sense of literal is literally figurative.)
Majromax 5y ago
No, a conspiracy theory "by definition" requires collaboration between several human agents. In this overall thread, the idea that the "disappearance" of flu is driven by political desire to label all respiratory illnesses as covid cases would be an example of a conspiracy theory. Another commenter brings up the idea of 'viral interference.' This is not an example of a conspiracy theory, but I do not give the idea great credence on Occam's Razor grounds.
- havewetsalt 5y ago
  No, that's just your definition. While I may personally agree the viral interference comment is not (in my definition) a conspiracy theory, it is regarded as a conspiracy theory in many (again, non-scientific) contexts. The conspiracy is not the collaboration, it is the belief.
- didericis 5y ago
  > the idea that the "disappearance" of flu is driven by political desire to label all respiratory illnesses as covid cases would be an example of a conspiracy theory. You’d also have to claim that mislabelling was done deliberately for it to be conspiratorial. I don’t think politically motivated distortions of perception are conspiratorial if those who are prone to mislabel things due to their belief system do so without realizing. Not saying that’s an applicable explanation for the disappearance of flu, as it seems way too universal, just going further into semantics.

tryonenow 5y ago

>In the meantime, public health measures like masking and distancing will work against both viruses That's not necessarily true. COVID appears to be aerosolized, whereas typical flu is not. That means that masks will work to catch viral flu particles in ejected fluids (talking, coughing, sneezing, etc), but the same cannot be assumed for COVID, given that viral particles are orders of magnitude smaller than pores in cloth and surgical masks. And this assertion is supported by at least two studies (one Danish I believe) which showed negligible effect of mask wearing on COVID spread.

MeinBlutIstBlau 5y ago

How can you explain people getting covid but not the flu when nothing changed when places started opening up? It sounds more like poor data reporting more than anything else and I will take that to my grave.

Majromax 5y ago
> How can you explain people getting covid but not the flu when nothing changed when places started opening up? Covid starts from a higher baseline level of cases, and it has a higher transmission rate. When societies "open up" (resume social contacts; it's more than just government lockdowns), then we'd expect to see covid cases climb before flu cases. In fact, seeing the opposite would be very surprising.
Godel_unicode 5y ago
> ...and I will take that to my grave "When the Facts Change, I Change My Mind. What Do You Do, Sir?"
- luxuryballs 5y ago
  Real answer? Ask how much faith you have in your religion of “facts”.
  - boredtofears 5y ago
    So how exactly does your system of belief work?
kevin_thibedeau 5y ago
The CDC doesn't accurately measure flu deaths. It's largely done by assessing death certificate data rather than positively identifying a flu infection. Deaths by pneumonia during the designated flu season months are counted in the tally of annual flu deaths. It is very likely that a portion of deaths attributed to COV19 over the winter were in fact from flu.
teachingassist 5y ago

fullshark 5y ago

> This should not come as a surprise, and it was largely predictable from the outset. That explains all these news stories telling me what to expect: https://www.nbcnews.com/news/us-news/experts-warn-twindemic-covid-cases-rise-flu-seasons-looms-n1240623 https://www.nbcnews.com/news/us-news/experts-warn-twindemic-... https://www.usatoday.com/story/news/health/2020/09/19/covid-flu-experts-fear-twindemic-200-k-deaths-us/5697848002/ https://www.usatoday.com/story/news/health/2020/09/19/covid-... https://www.scientificamerican.com/article/how-we-can-avoid-a-twindemic-of-covid-and-flu/ https://www.scientificamerican.com/article/how-we-can-avoid-... etc: https://www.google.com/search?q=twindemic&tbs=cdr:1,cd_min:9/1/2020,cd_max:11/30/2020&tbm=nws&sxsrf=ALeKk00iO50BpGwVTpp8Ljzsbx03jyzdhw:1619728667669&ei=GxmLYOesKM-r0PEPltytwAI&start=20&sa=N&ved=0ahUKEwinpvm-p6TwAhXPFTQIHRZuCyg4ChDw0wMImgE&biw=1309&bih=695&dpr=2.2 https://www.google.com/search?q=twindemic&tbs=cdr:1,cd_min:9...

jb775 5y ago
Where's all the people that were saying Covid is a completely separate thing from the flu?...and every "Covid Death" was a separate death on top of the normal flu death rate? Occam's Razor: Covid isn't a "pandemic", it's a strong flu
- dijit 5y ago
  Covid transmits the same way as flu but is more infectious. Measures against Covid work against flu. It’s nice to know that our flu deaths are declining. But our Covid deaths are many times more.
  - achenatx 5y ago
    covid might not be more infectious, it might just be less people have any existing partial resistance to sars-cov-2. Each year the flu mutates but it still has overlap with prior variants. As sars-cov-2 mutates seasonal covid might end up less bad than the seasonal flu. Though there is no way to tell.
    - 5y ago

fallingfrog 5y ago

I actually told people at the outset of the covid lockdowns, “at least we won’t have a flu season this year.” Then later on I saw people online floating this as some kind of conspiracy and I thought, “wait, this wasn’t obvious to everyone?”

psychlops 5y ago
Covid was this years flu season.
- fallingfrog 5y ago
  That is not correct: they are two different viruses. Even if you’re making a loose analogy that’s still a poor comparison.
fallingfrog 5y ago
I’m not lying you know. I did say this, and everyone I said it too either said that they had also had the same thought, or if they hadn’t, they still agreed after thinking about it for a moment. That includes conservatives. Anyone could have seen it coming, and many did. It was only after that fact that the conspiracy memes started going around.

haecceity 5y ago

Will the flu come back after covid ends? If covid ends?

ddingus 5y ago
I think that depends a lot on how people live.
justtemporary 5y ago
Yes, the flu virus has a natural reservoir amongst the bird population.

fny 5y ago

To quell discussions of no/low testing. Looking at two weeks: - Week of December 5, 2020: 40/22,474 flu tests were positive - Week of December 7, 2019: 631/1,508 flu tests were positive Cumulative #s: - Cumulative through Week 14 2021: 1,739/891,717 - Cumulative through Week 14 2019: 37,155/69,291 So we've been testing wayyy more often with wayyy fewer positives. https://www.cdc.gov/flu/weekly/pastreports.htm https://www.cdc.gov/flu/weekly/pastreports.htm

xyzzy21 5y ago

Or....(and without any conspiracy theories - never mind MOST conspiracy theories of the last 30 years have entirely become true - conspiracy TRUTHS). Everything that was flu was labeled as COVID since doctors, hospitals and medical professions were PAID a bounty on COVID. Multiple this by PCR testing being 99% fraudulent due to high cycle counts which enable cold viruses and even flu viruses to to test positive because you've reached the "noise floor" of the test at 10-15 cycles (most testing was done with 30-40 cycles). This helped "fulfill" the bounties and take all the attention away from conventional diseases both infective and others like heart disease, cancer, etc. (which got counted as COVID as well, just like traffic accidents and other definitely-not-COVID deaths that occurred). The same bounty system shut down the entire surveillance system for flu as well as because non-essential workers included anything not COVID related or providing shallowly defined "essential" services.

sebmellen 5y ago
I’m 100% sure that “MOST” conspiracy theories of the last 30 years have not been proven true.
deleted 5y ago
[deleted]
SamBam 5y ago
> since doctors, hospitals and medical professions were PAID a bounty on COVID. You what? Do you actually believe this? Seriously?
- seattle_spring 5y ago
  Oh man I gotta figure out how to get my wife backpay for all the bounties she must be owed!

audessuscest 5y ago

https://twitter.com/ianmSC/status/1387864442386325504 https://twitter.com/ianmSC/status/1387864442386325504

ceejayoz 5y ago
Sweden didn't mandate strict measures. Plenty of folks still took them on their own volition.
- audessuscest 5y ago
  No mask, public transports, restaurant, schools open, etc doesn't matter if even 20% of the population (which is a very high estimate) use some of these measures. You can't explain that the evolution is exactly the same as a Norway...
  - ceejayoz 5y ago
    You can, though. If you get a disease's R0 below one, it goes away. Enough people changed their behavior in both countries to make flu go away, because it no longer spread quickly enough to sustain itself.

alexnewman 5y ago

I believe there’s been placebo controlled studies that show that masks to not stop the spread of influenza . I haven’t read the papers, just something I’ve seen mentioned on medcram.

zackees 5y ago

The problem with this logic is the presumption that wearing masks was a widespread phenomenon. As someone who traveled a lot this year I can assure you that there a many states and areas that mostly ignored the lockdowns happening in the city areas. For these places, we would expect the flu to continue on as normal. Instead it’s disappeared. How strange.

rconti 5y ago

I remember reading a conspiracy theory back in ~ April 2020 that said "what happened to the flu" / "why are flu cases down so sharply?" It was literally so stupid that it took me a minute or two to understand that the implication was that conspiracy theorists think flu cases were being categorized as covid.

audessuscest 5y ago
https://twitter.com/ianmSC/status/1387864442386325504 https://twitter.com/ianmSC/status/1387864442386325504
nickalaso 5y ago
Could you explain why this is "literally so stupid" when this appears to be what is happening? If lockdown measures, social distancing, mask wearing, etc. were the true cause of the massive reduction in flu cases, we would expect to also see that countries and US states that failed to enact measures would be reporting high flu numbers to the WHO. This doesn't appear to be happening. Instead, "the drop-off in flu numbers was both swift and universal." (article quote) This universality suggests a data problem to me rather than an environmental change.
- kaba0 5y ago
  > we would expect to also see that countries and US states that failed to enact measures would be reporting high flu numbers to the WHO. I don’t think so. Even without government policies in place, people become much much more vary of hygiene - that alone could account for a serious drop in new flu cases. The other factor as others mentioned is that someone with a weaker immune system who would have a pretty bad case of flu, had now a much higher chance of getting covid instead (due to covid quickly overtaking the number of cases due to its higher R number), so in a way covid being more infectious, sort of suffocated the flu.
- xxxxxxx12 5y ago
  There's a good clip from CBC in 2012 about flu surveillance and how it's an unverified estimate with very large bounds: https://www.youtube.com/watch?v=mViFHqDD9hI https://www.youtube.com/watch?v=mViFHqDD9hI

cheeri0 5y ago

> In the meantime, public health measures like masking and distancing will work against both viruses. Yeah but there are numerous studies that show these things don't work. Also, I'm confused why you think someone cannot get both covid-19 and the flu.

nanis 5y ago

> In the meantime, public health measures like masking and distancing will work against both viruses. This argument does not make sense because of the timing of the disappearance of the flu. For example, NYS was having a really bad flu season before the Covid panic hit[1]. I am posting a link to my screenshot first because NYS flu tracker[1] is one of the stupidest web pages out there. Click on the "compare with previous seasons" heading on the page to get the current table. The noteworthy part is the drop in flu cases between the 6th and 7th weeks during what seems like an exceptionally bad flu season. Note also "Regulation for Prevention of Influenza Transmission by Healthcare and Residential Facility and Agency Personnel"[3]: > As of December 5, 2019, influenza is prevalent in NYS. > At this time, Section 2.59 of the New York State Sanitary Code (10 NYCRR § 2.59) requires all health care and residential facilities and agencies regulated pursuant to Article 28, 36, or 40 of the Public Health Law to ensure that all personnel, as defined in the regulation, not vaccinated against influenza for the current influenza season wear a surgical or procedure mask while in areas where patients or residents are typically present. > This page will be updated when the status changes. which apparently has not been updated since December 5, 2019. [1]: https://twitter.com/sinan_unur/status/1368882698966667265 https://twitter.com/sinan_unur/status/1368882698966667265 [2]: https://nyshc.health.ny.gov/web/nyapd/new-york-state-flu-tracker https://nyshc.health.ny.gov/web/nyapd/new-york-state-flu-tra... [3]: https://www.health.ny.gov/diseases/communicable/influenza/seasonal/providers/prevention_of_influenza_transmission/ https://www.health.ny.gov/diseases/communicable/influenza/se... (archived <https://archive.is/wde1c https://archive.is/wde1c>)

nanis 5y ago
I find the downvotes interesting. Do you think the web page is actually well done? Or do you disagree with the observation that the drop between weeks 6 and 7 in 2020 (in the midst of a bad flu season) looks different? % ch in flu cases between weeks 6 and 7 in NYS 2017: -8% 2018: +9% 2019: +9% 2020: -17% 2021: -31% (really low absolute numbers) What caused flu cases to start falling in mid-February _before_ so called "public health measures"?[1] > The acceleration phase of a pandemic is complex and requires a multifaceted and rapidly adapting public health response. During a 3-week period in late February to early March, the number of U.S. COVID-19 cases increased more than 1,000-fold. Various community mitigation interventions were implemented with the aim of reducing further spread and controlling the impact on health care capacity. So, between CDC weeks 7 to 10, the a bad flu season disappears while COVID-19 cases increase 1,000-fold. What are the "public health measures" that explain this divergence? March 21, 2020[2]: > "To be clear, the state has the legal authority to overrule any locality's decision to issue an order of mass quarantine or shut down. No locality will be closing down. The mass transit system is not shutting down. These rumors, caused by undue anxiety, are just that - rumors." March 7, 2020[3]: > During a briefing on the novel coronavirus, Governor Andrew M. Cuomo today declared a state of emergency to help New York more quickly and effectively contain the spread of the virus. February 29, 2020[4]: > "We'll start testing immediately here in New York, so we can handle more tests, more volume, turn them around faster, and we are ready to go and literally we can start testing immediately We have mobilized for emergencies before, and we're going to do it again." February 27, 2020[5]: > Governor Andrew M. Cuomo today announced the total number of flu cases in New York State has eclipsed the record number of seasonal cases since the New York State Department of Health began tracking flu cases during the 1998-99 season. [1]: https://www.cdc.gov/mmwr/volumes/69/wr/mm6918e2.htm https://www.cdc.gov/mmwr/volumes/69/wr/mm6918e2.htm [2]: https://www.governor.ny.gov/news/statement-secretary-governor-melissa-derosa-regarding-rumors-new-york-city-and-mass-transit https://www.governor.ny.gov/news/statement-secretary-governo... [3]: https://www.governor.ny.gov/news/novel-coronavirus-briefing-governor-cuomo-declares-state-emergency-contain-spread-virus https://www.governor.ny.gov/news/novel-coronavirus-briefing-... [4]: https://www.governor.ny.gov/news/video-audio-rush-transcript-governor-cuomo-delivers-update-coronavirus https://www.governor.ny.gov/news/video-audio-rush-transcript... [5]: https://www.governor.ny.gov/news/governor-cuomo-announces-record-breaking-total-number-flu-cases-new-york-even-number-flu-cases https://www.governor.ny.gov/news/governor-cuomo-announces-re...

Fomite 5y ago

Some of this is actually a surprise - we don't have a good handle on how influenza seasonality works, and some of the "Just So" stories for it should have promoted influenza transmission, like increased indoor crowding above even the usual levels in the winter. The dynamics of influenza could have been expected to change, and I would have put money on they decreasing, but it is never the less not pre-ordained nor attributable to an obvious cause (for example, one of the original reasons people didn't push mask orders is the limited suggestion that they were effective for flu).

darkerside 5y ago

I'm really excited to see this thread on HN because I've got a question about flu vs COVID, and I feel like this is my only (slim) chance to get a non-politicized answer to it. It's a simple question. Flu deaths in the US have dropped precipitously. This past flu season resulted in (very roughly) ~1% of the deaths of previous seasons. It seems obvious that this is primarily due to social distancing efforts as you say. To naive little me, this implies that COVID deaths are also likely to have been reduced to ~1% from what they would have been without said measures. In the US, that implies that we may have steered into 500K deaths instead of a stunning potential 50M deaths. Based on my admittedly naive calculations, I'm sure this is inaccurate, but I don't even know in which direction, could have been potentially even more. Did we really avert 50M deaths by social distancing?

caturopath 5y ago
> Did we really avert 50M deaths by social distancing? No, not even close. > this implies that COVID deaths are also likely to have been reduced to ~1% from what they would have been without said measures I don't think it implies that. There is nothing that says that the anti-COVID measures are about as effective at preventing spread of COVID as spread of flu. > 500K deaths Closer to 600k :( This is among 32MM cases reported to the CDC, probably more like 80MM cases total. Ignoring lots of factors, our ceiling for COVID is more like 4-10x what we've experienced, not 100X.
- darkerside 5y ago
  I feel like you misunderstand the meaning of "implies", which is to suggest without explicitly saying. I think it is reasonable to assume that social distancing measures would have a similar effect, and in the absence of other data, the best estimate might be to assume they are proportional. Fortunately there are a couple of other answers in thread that answered this at a level of detail that I could understand.
jjeaff 5y ago
That extrapolation only works if the flu is equally as contagious as covid and also has identical methods of transmission (for example, it may be that covid transmits through the air more readily than the flu). But we know that covid is actually quite a bit more contagious, so you can't really make a linear extrapolation like that.

anonymouse008 5y ago

Has anyone given the consideration that many of the positive tests have been common coronavirus colds or other things that may resemble flu and be diagnosed as such in a ICD10/CPT data dump ?

lifeformed 5y ago

Does this mean the excess death rate is undercounting covid then? Since the baseline death rate is counting normal flu deaths.

troyvit 5y ago

XKCD saw it coming :) https://xkcd.com/2306/ https://xkcd.com/2306/

CodeWriter23 5y ago

Nope. Has everything to do with P&I death figures being expanded to CP&I (coronavirus, pneumonia & influenza). Thanks for playing.