11 ms·

Is one vaccine dose enough if you’ve had Covid? What the science says

32 points by dsr12 5y ago

the_laka 5y ago
I wish there was an easier way to figure out if you had COVID. As someone who's only got one dose so far, I would gladly skip the second one if I knew for certain I had COVID before, so someone else could get my second dose.
- crazygringo 5y ago
  Did you not get an antibody test at some point prior to the vaccine? That would have given you an answer with 99% certainty if you used a good one.
  - briefcomment 5y ago
    I think they are relatively expensive, ~$200. Probably worth it though. We would need some form of official recognition of antibody tests though. Pretty sure most places that require vaccination don't accept antibody test results.
    - alkonaut 5y ago
      Antibody tests at the supermarket clinic here is $40. Unsure if that’s a crappy test or if any subsidy is provided. $40 vs $200 does seem like the usual EU vs US markup too I guess
      - briefcomment 5y ago
        Ah, not bad
    - colospoin 5y ago
      I believe the Red Cross tests for the antibody when you give blood, as well.
    - crazygringo 5y ago
      Antibody tests have been widely made available for free across the developed world. In NYC, for example, they've been available for free at a ton of different sites. It may always be as convenient or quick, but it's free.
  - bpodgursky 5y ago
    Antibody tests were only widely available in July-August, so people who got COVID in Feb or March often didn't have high enough antibody counts by that point to flag positive on the tests.
    - crazygringo 5y ago
      That's not true. The half-life of antibody levels has been estimated at 73 days. The antibody tests are quite sensitive, time has not been enough of a factor yet to produce false negatives. In a year or two it might be. The only time concern is that you need to wait 2-3 weeks until after you recover from COVID to ensure you test positive.
- bootlooped 5y ago
  Don't some antibody tests do this? I think antibody tests that detect antibodies to the nucleocapsid should be unaffected by the vaccines, which only spur resistance to the spike protein. See the section called "Binding Antibody Tests" here: https://creakyjoints.org/living-with-arthritis/coronavirus/covid-19-vaccines/antibody-testing-covid-19-vaccine-immunocompromised/ https://creakyjoints.org/living-with-arthritis/coronavirus/c...
  - DiogenesKynikos 5y ago
    This is true of some - but not all - of the vaccines. The whole inactivated virus vaccines contain more than the spike, but the mRNA and vector vaccines only contain the spike.
- dataflow 5y ago
  [never mind]
  - sologoub 5y ago
    The article is not advocating doing anything unsafe or otherwise endangering others. The scientific question is quite valid - do we have to use our limited vaccine supply to ensure all get two doses or can we save a dose on those who already had COVID and give it to someone who needs it? First paragraph of the article: “Many people who’ve been infected with the coronavirus might be able to safely skip the second jab of any two-dose vaccine regimen, a growing number of studies suggest. These results could help to stretch scarce vaccine supplies and are already influencing vaccination policies in some countries.” US might have enough for everyone, and wouldn’t it be also great if we didn’t need as many doses and could share with hard hit places like India? I see this as a net positive if true.
  - taxicabjesus 5y ago
    The US is in desperate need of people who are willing to take all the vaccines the government has purchased for us. What’s the shelf life on the mRNA products? Looks like Moderna’s lasts for six months in the freezer. Pfizer for 30 days on dry ice, another 30 days in a regular freezer? Lots of doses are going to get tossed. Most the people who are going to get the shot have gotten it already.
- nikstar 5y ago
  A test for antibodies against N protein will tell you if you had COVID or not.
- johtso 5y ago
  T-cell tests are available in some places now. https://www.tspotcovid.com/ https://www.tspotcovid.com/
djrogers 5y ago
> Research shows that a previous coronavirus infection plus one dose of vaccine provides powerful protection — but concerns linger This is one thing that’s been incredibly frustrating throughout this whole pandemic. Studies and research will show B, with no sign of A, however inertia/politics/fear/ignorance will continue to push A to the point of harm. An example - a local store was insisting on wiping down the entire checkout conveyor with alcohol between every single customer until very recently, when we’ve know for a long time that you won’t get COVID from that.
- konschubert 5y ago
  Security theatre. It’s about feeling safe, not about being safe.
- avian 5y ago
  > a local store was insisting on wiping down the entire checkout conveyor with alcohol between every single customer until very recently, when we’ve know for a long time that you won’t get COVID from that. As someone from a country where running orders are still to disinfect often-touched surfaces (switches, door handles, office desks, etc.) I was surprised by this. I went to check what CDC from US recommends. It turns out it's pretty much the same: > Clean high touch surfaces daily. This includes tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks. (from https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-si...) So maybe wiping down the belt between every customer is a bit excessive, but it seems my sources don't agree with the "you don't get COVID from that" part.
  - unpolloloco 5y ago
    https://www.nature.com/articles/d41586-021-00251-4 https://www.nature.com/articles/d41586-021-00251-4 Cleaning for an airborne illness is just theater. Upgrading air handlers, increasing airflow, and spacing people further apart matter. Cleaning stuff randomly just makes people feel better (but can make good business sense because of this!)
sigstoat 5y ago
seems like there's some consensus on two "exposures" worth of immunity being valuable. any data on second shots for folks who took the J&J?
- lol768 5y ago
  I don't think they've published any data relating to ENSEMBLE 2 yet.
- Scoundreller 5y ago
  The cynical part of me thinks that J&J is only 1 shot because your body develops strong immunity to it adenovirus-26 vector, so a 2nd shot would get immediately killed off before its spike protein payload could take any action. Until your immunity to it wanes anyway.
  - Throwawayaerlei 5y ago
    This is suspected to be a problem with the Oxford vaccine which also uses one virus vector for both doses. Like Sputnik V, J&J's Janssen unit's Ebola vaccine uses two different virus vectors. And Janssen is doing an ENSEMBLE 2 Phase III clinical trial with two doses eight weeks apart that lol768 mentions. But their primary objective stated from the very beginning was to create the most effective single dose vaccine possible, and vaccinated a billion people in 2021. They appear to have achieved the former, although Sputnik Lite with the same Ad26 based vector could be a competitor, the latter goal is failing due to inherent issues with using cell culturing to make something, a strained supply chain for that which is also required to make Oxford's Sputnik V, and Novavax's vaccine (bug cell grown protein plus adjuvant), and being forced to use the dangerously incompetent Emergent BioSolutions as a subcontractor.
    - Scoundreller 5y ago
      Was J&J the most effective vaccine after 1 dose? Sure they don't have much competition if you only compare against 'approved' schedules, but mRNA vaccines seem better after 1 dose than J&J is. But yeah, there's just not a lot of trial data out there for 1dose mRNA or Oxford vaccine since they're (officially) pretty quick to get you to 2 doses. Emergent BioSolutions was contamination between the J&J side of production with the Oxford/AstraZeneca vaccine side of production...
Scoundreller 5y ago
> France, Germany and Italy, among other countries, now advise only one dose of vaccine for people with a healthy immune system and a confirmed previous diagnosis. Many scientists who have studied immune responses to vaccination say such policies are a sensible way to make the most of limited supplies in countries that are racing to inoculate their populations. At least for France, their Infectious Disease professionals go further. They're of the opinion that a second dose in someone that's been infected (within a certain range of time) is subjecting them to unnecessary treatment, wasted time and side effects for no/limited benefit. It's not to make the most of limited supplies. Auto-translation (with some readability tweaks): > If the second dose of vaccine has already been administered to people with a history of infection with SARS-Cov-2, the data available to date do not show any difference in the safety profile apart from the occurrence of more common systemic reactions. https://www.has-sante.fr/jcms/p_3237271/en/strategie-de-vaccination-contre-le-sars-cov-2-vaccination-des-personnes-ayant-un-antecedent-de-covid-19 https://www.has-sante.fr/jcms/p_3237271/en/strategie-de-vacc... But questioning the value of a vaccine under any circumstances is ban-worthy in a lot of places.
kriskrunch 5y ago
The study used 26 participants? Did I read that right? What is the preferred sample size to back these sorts of claims?
- Scoundreller 5y ago
  Not sure why they'd focus on a study out this week, there have been several others, e.g. the first 5 references in this Letter published a month ago: https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(21)00194-8/fulltext https://www.thelancet.com/journals/ebiom/article/PIIS2352-39...
  - kriskrunch 5y ago
    Thank you. Five studies referenced in there, with "limited participants" but complimentary results. Very cool. I often hear from people that recovered from Covid that they don't need the vaccine, Rand Paul is one notable example, due to their natural antibodies. I'm curious to know what the average antibody titer level of previously infected people is to start. Or how much more protection do they get once vaccinated?
123pie123 5y ago
Why doesn't getting Covid and then allowing your body to produce your own immunity not protect you from getting it again? As I understand the variants are not like the flu or the cold (yet!)
- crazygringo 5y ago
  It probably does. We just haven't had enough time to prove it yet, or to investigate the differences between variants.
  - raarts 5y ago
    According to this (preprint) paper(n=52000), recovering from covid-19 protects just as well (or even slightly better) than getting vaccinated. Also note that vaccines focus on the Spike protein only, and you're immunesystem takes the entire virus into account, which might offer better protection against variants. https://www.medrxiv.org/content/10.1101/2021.06.01.21258176v3 https://www.medrxiv.org/content/10.1101/2021.06.01.21258176v...
    - thedrbrian 5y ago
      PHE are doing one too:- https://www.gov.uk/government/news/past-covid-19-infection-provides-some-immunity-but-people-may-still-carry-and-transmit-virus https://www.gov.uk/government/news/past-covid-19-infection-p... >>PHE scientists working on the study have concluded naturally acquired immunity as a result of past infections provide 83% protection against reinfection, compared to people who have not had the disease before. This appears to last at least for 5 months from first becoming sick.
- uryga 5y ago
  iirc for some reason the amount of antibodies you have falls sharply after 1-3 months and you're vulnerable again. anecdotally, a friend of a friend (EMT) had covid like 4 times before vaccines were available.
  - 5y ago
macinjosh 5y ago
Natural immunity is way better than any vaccine. You don’t need a vaccine if you already have antibodies.
ac42 5y ago
If infection rates were double digit, the "think of what we could save" argument might perhaps deserve some consideration. But as it stands, I feel the only warranted concern is the well-being of Covid survivors.

32 points by dsr12 5y ago

I wish there was an easier way to figure out if you had COVID. As someone who's only got one dose so far, I would gladly skip the second one if I knew for certain I had COVID before, so someone else could get my second dose.

crazygringo 5y ago
Did you not get an antibody test at some point prior to the vaccine? That would have given you an answer with 99% certainty if you used a good one.
- briefcomment 5y ago
  I think they are relatively expensive, ~$200. Probably worth it though. We would need some form of official recognition of antibody tests though. Pretty sure most places that require vaccination don't accept antibody test results.
  - alkonaut 5y ago
    Antibody tests at the supermarket clinic here is $40. Unsure if that’s a crappy test or if any subsidy is provided. $40 vs $200 does seem like the usual EU vs US markup too I guess
    - briefcomment 5y ago
      Ah, not bad
  - colospoin 5y ago
    I believe the Red Cross tests for the antibody when you give blood, as well.
  - crazygringo 5y ago
    Antibody tests have been widely made available for free across the developed world. In NYC, for example, they've been available for free at a ton of different sites. It may always be as convenient or quick, but it's free.
- bpodgursky 5y ago
  Antibody tests were only widely available in July-August, so people who got COVID in Feb or March often didn't have high enough antibody counts by that point to flag positive on the tests.
  - crazygringo 5y ago
    That's not true. The half-life of antibody levels has been estimated at 73 days. The antibody tests are quite sensitive, time has not been enough of a factor yet to produce false negatives. In a year or two it might be. The only time concern is that you need to wait 2-3 weeks until after you recover from COVID to ensure you test positive.
bootlooped 5y ago
Don't some antibody tests do this? I think antibody tests that detect antibodies to the nucleocapsid should be unaffected by the vaccines, which only spur resistance to the spike protein. See the section called "Binding Antibody Tests" here: https://creakyjoints.org/living-with-arthritis/coronavirus/covid-19-vaccines/antibody-testing-covid-19-vaccine-immunocompromised/ https://creakyjoints.org/living-with-arthritis/coronavirus/c...
- DiogenesKynikos 5y ago
  This is true of some - but not all - of the vaccines. The whole inactivated virus vaccines contain more than the spike, but the mRNA and vector vaccines only contain the spike.
dataflow 5y ago
[never mind]
- sologoub 5y ago
  The article is not advocating doing anything unsafe or otherwise endangering others. The scientific question is quite valid - do we have to use our limited vaccine supply to ensure all get two doses or can we save a dose on those who already had COVID and give it to someone who needs it? First paragraph of the article: “Many people who’ve been infected with the coronavirus might be able to safely skip the second jab of any two-dose vaccine regimen, a growing number of studies suggest. These results could help to stretch scarce vaccine supplies and are already influencing vaccination policies in some countries.” US might have enough for everyone, and wouldn’t it be also great if we didn’t need as many doses and could share with hard hit places like India? I see this as a net positive if true.
- taxicabjesus 5y ago
  The US is in desperate need of people who are willing to take all the vaccines the government has purchased for us. What’s the shelf life on the mRNA products? Looks like Moderna’s lasts for six months in the freezer. Pfizer for 30 days on dry ice, another 30 days in a regular freezer? Lots of doses are going to get tossed. Most the people who are going to get the shot have gotten it already.
nikstar 5y ago
A test for antibodies against N protein will tell you if you had COVID or not.
johtso 5y ago
T-cell tests are available in some places now. https://www.tspotcovid.com/ https://www.tspotcovid.com/

djrogers 5y ago

> Research shows that a previous coronavirus infection plus one dose of vaccine provides powerful protection — but concerns linger This is one thing that’s been incredibly frustrating throughout this whole pandemic. Studies and research will show B, with no sign of A, however inertia/politics/fear/ignorance will continue to push A to the point of harm. An example - a local store was insisting on wiping down the entire checkout conveyor with alcohol between every single customer until very recently, when we’ve know for a long time that you won’t get COVID from that.

konschubert 5y ago
Security theatre. It’s about feeling safe, not about being safe.
avian 5y ago
> a local store was insisting on wiping down the entire checkout conveyor with alcohol between every single customer until very recently, when we’ve know for a long time that you won’t get COVID from that. As someone from a country where running orders are still to disinfect often-touched surfaces (switches, door handles, office desks, etc.) I was surprised by this. I went to check what CDC from US recommends. It turns out it's pretty much the same: > Clean high touch surfaces daily. This includes tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks. (from https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-si...) So maybe wiping down the belt between every customer is a bit excessive, but it seems my sources don't agree with the "you don't get COVID from that" part.
- unpolloloco 5y ago
  https://www.nature.com/articles/d41586-021-00251-4 https://www.nature.com/articles/d41586-021-00251-4 Cleaning for an airborne illness is just theater. Upgrading air handlers, increasing airflow, and spacing people further apart matter. Cleaning stuff randomly just makes people feel better (but can make good business sense because of this!)

sigstoat 5y ago

seems like there's some consensus on two "exposures" worth of immunity being valuable. any data on second shots for folks who took the J&J?

lol768 5y ago
I don't think they've published any data relating to ENSEMBLE 2 yet.
Scoundreller 5y ago
The cynical part of me thinks that J&J is only 1 shot because your body develops strong immunity to it adenovirus-26 vector, so a 2nd shot would get immediately killed off before its spike protein payload could take any action. Until your immunity to it wanes anyway.
- Throwawayaerlei 5y ago
  This is suspected to be a problem with the Oxford vaccine which also uses one virus vector for both doses. Like Sputnik V, J&J's Janssen unit's Ebola vaccine uses two different virus vectors. And Janssen is doing an ENSEMBLE 2 Phase III clinical trial with two doses eight weeks apart that lol768 mentions. But their primary objective stated from the very beginning was to create the most effective single dose vaccine possible, and vaccinated a billion people in 2021. They appear to have achieved the former, although Sputnik Lite with the same Ad26 based vector could be a competitor, the latter goal is failing due to inherent issues with using cell culturing to make something, a strained supply chain for that which is also required to make Oxford's Sputnik V, and Novavax's vaccine (bug cell grown protein plus adjuvant), and being forced to use the dangerously incompetent Emergent BioSolutions as a subcontractor.
  - Scoundreller 5y ago
    Was J&J the most effective vaccine after 1 dose? Sure they don't have much competition if you only compare against 'approved' schedules, but mRNA vaccines seem better after 1 dose than J&J is. But yeah, there's just not a lot of trial data out there for 1dose mRNA or Oxford vaccine since they're (officially) pretty quick to get you to 2 doses. Emergent BioSolutions was contamination between the J&J side of production with the Oxford/AstraZeneca vaccine side of production...

Scoundreller 5y ago

> France, Germany and Italy, among other countries, now advise only one dose of vaccine for people with a healthy immune system and a confirmed previous diagnosis. Many scientists who have studied immune responses to vaccination say such policies are a sensible way to make the most of limited supplies in countries that are racing to inoculate their populations. At least for France, their Infectious Disease professionals go further. They're of the opinion that a second dose in someone that's been infected (within a certain range of time) is subjecting them to unnecessary treatment, wasted time and side effects for no/limited benefit. It's not to make the most of limited supplies. Auto-translation (with some readability tweaks): > If the second dose of vaccine has already been administered to people with a history of infection with SARS-Cov-2, the data available to date do not show any difference in the safety profile apart from the occurrence of more common systemic reactions. https://www.has-sante.fr/jcms/p_3237271/en/strategie-de-vaccination-contre-le-sars-cov-2-vaccination-des-personnes-ayant-un-antecedent-de-covid-19 https://www.has-sante.fr/jcms/p_3237271/en/strategie-de-vacc... But questioning the value of a vaccine under any circumstances is ban-worthy in a lot of places.

kriskrunch 5y ago

The study used 26 participants? Did I read that right? What is the preferred sample size to back these sorts of claims?

Scoundreller 5y ago
Not sure why they'd focus on a study out this week, there have been several others, e.g. the first 5 references in this Letter published a month ago: https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(21)00194-8/fulltext https://www.thelancet.com/journals/ebiom/article/PIIS2352-39...
- kriskrunch 5y ago
  Thank you. Five studies referenced in there, with "limited participants" but complimentary results. Very cool. I often hear from people that recovered from Covid that they don't need the vaccine, Rand Paul is one notable example, due to their natural antibodies. I'm curious to know what the average antibody titer level of previously infected people is to start. Or how much more protection do they get once vaccinated?

123pie123 5y ago

Why doesn't getting Covid and then allowing your body to produce your own immunity not protect you from getting it again? As I understand the variants are not like the flu or the cold (yet!)

crazygringo 5y ago
It probably does. We just haven't had enough time to prove it yet, or to investigate the differences between variants.
- raarts 5y ago
  According to this (preprint) paper(n=52000), recovering from covid-19 protects just as well (or even slightly better) than getting vaccinated. Also note that vaccines focus on the Spike protein only, and you're immunesystem takes the entire virus into account, which might offer better protection against variants. https://www.medrxiv.org/content/10.1101/2021.06.01.21258176v3 https://www.medrxiv.org/content/10.1101/2021.06.01.21258176v...
  - thedrbrian 5y ago
    PHE are doing one too:- https://www.gov.uk/government/news/past-covid-19-infection-provides-some-immunity-but-people-may-still-carry-and-transmit-virus https://www.gov.uk/government/news/past-covid-19-infection-p... >>PHE scientists working on the study have concluded naturally acquired immunity as a result of past infections provide 83% protection against reinfection, compared to people who have not had the disease before. This appears to last at least for 5 months from first becoming sick.
uryga 5y ago
iirc for some reason the amount of antibodies you have falls sharply after 1-3 months and you're vulnerable again. anecdotally, a friend of a friend (EMT) had covid like 4 times before vaccines were available.
- 5y ago

macinjosh 5y ago

Natural immunity is way better than any vaccine. You don’t need a vaccine if you already have antibodies.

ac42 5y ago

If infection rates were double digit, the "think of what we could save" argument might perhaps deserve some consideration. But as it stands, I feel the only warranted concern is the well-being of Covid survivors.