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>Like other respiratory viruses, SARS-Cov-2 is seasonal. There have been three peaks so far, roughly January, May, and late August. So I guess it's seasonal,

>Like other respiratory viruses, SARS-Cov-2 is seasonal. There have been three peaks so far, roughly January, May, and late August. So I guess it's seasonal, if by seasonal you mean it's cycled in winter, spring, and summer so far. Nothing before last winter compared to the three peaks we've had since. So we really have no information on a yearly cycle, especially since vaccination, however it plays out, has affected 2021. Graph: https://www.worldometers.info/coronavirus/ https://www.worldometers.info/coronavirus/ (Daily New Cases)

graeme 5y ago
It’s a respiratory coronavirus. We have decades of info on respiratory viruses and other coronaviruses. They peak November to April in northern hemisphere countries with strong summers. See page 4 here: https://www.annualreviews.org/doi/pdf/10.1146/annurev-virology-012420-022445 https://www.annualreviews.org/doi/pdf/10.1146/annurev-virolo... The late August peak has been a southern US phenomenon, seemingly associated with going inside during warm months for air conditioning. The south states were the ones that peaked early both years. Israel also had an early summer peak last year, associated with a heat wave. In states and countries where people go outside, it is a strong bet that viral transmission will be stronger in the months when coronaviruses are seasonally strong.
- perl4ever 5y ago
  >They peak November to April in northern hemisphere countries with strong summers. In the US, things picked up in July and appear to be peaking now. Which is not November. Conversely, globally, cases were at a lull as March began and near peak by May. I'm not saying I can predict the future, but so far, I don't think the pattern you see exists. >The late August peak has been a southern US phenomenon I think that's a misleading way to put it, unless you accidentally wrote August when you meant May. The late August peak is in the global stats, which I linked to. What seems different for the US is that the spring wave was very attenuated and doesn't show up hardly at all in a graph. We essentially have had two big peaks and not three. https://www.worldometers.info/coronavirus/country/us/ https://www.worldometers.info/coronavirus/country/us/
  - graeme 5y ago
    In 2020 there was a us wave in jul/august. This was strongest in the south. In 2021 there is also a july/august wave, strongest in the south. It is more present in the north than last year’s wave, but not at its biggest there. My prediction is the north will see a bigger wave later in the year as people head inside. You can’t exclude variants either. Alpha was more contagious and got around the world by May, so that trumps seasonality. The May wave also began march/april and peaked later. But for any given variant it would be extremely unusual to see highest activity in summer not winter.

graeme 5y ago

It’s a respiratory coronavirus. We have decades of info on respiratory viruses and other coronaviruses. They peak November to April in northern hemisphere countries with strong summers. See page 4 here: https://www.annualreviews.org/doi/pdf/10.1146/annurev-virology-012420-022445 https://www.annualreviews.org/doi/pdf/10.1146/annurev-virolo... The late August peak has been a southern US phenomenon, seemingly associated with going inside during warm months for air conditioning. The south states were the ones that peaked early both years. Israel also had an early summer peak last year, associated with a heat wave. In states and countries where people go outside, it is a strong bet that viral transmission will be stronger in the months when coronaviruses are seasonally strong.

perl4ever 5y ago
>They peak November to April in northern hemisphere countries with strong summers. In the US, things picked up in July and appear to be peaking now. Which is not November. Conversely, globally, cases were at a lull as March began and near peak by May. I'm not saying I can predict the future, but so far, I don't think the pattern you see exists. >The late August peak has been a southern US phenomenon I think that's a misleading way to put it, unless you accidentally wrote August when you meant May. The late August peak is in the global stats, which I linked to. What seems different for the US is that the spring wave was very attenuated and doesn't show up hardly at all in a graph. We essentially have had two big peaks and not three. https://www.worldometers.info/coronavirus/country/us/ https://www.worldometers.info/coronavirus/country/us/
- graeme 5y ago
  In 2020 there was a us wave in jul/august. This was strongest in the south. In 2021 there is also a july/august wave, strongest in the south. It is more present in the north than last year’s wave, but not at its biggest there. My prediction is the north will see a bigger wave later in the year as people head inside. You can’t exclude variants either. Alpha was more contagious and got around the world by May, so that trumps seasonality. The May wave also began march/april and peaked later. But for any given variant it would be extremely unusual to see highest activity in summer not winter.