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covid every 2.5 years
2022-03-09 23:49I just read this brilliant paper. https://www.nature.com/articles/s41591-020-1083-1
A long term AIDS study has been sampling the same people's blood every 3 months for 35 years. The authors used those samples to look at re-infections by seasonal coronaviruses (a few of the 200 culprits that give us "the common cold"). There are four "dissimilar" species. Re-infections were measured by jumps in antibody levels vs. one of the species.
The results? Re-infection by the same species could happen within 6 months, though that was rare. The most common interval was 12 months. The mean time was 30 months for the two most common species and overall, and 55 months (I judge from the graph) for the slowest species.
Covid-19 is yet another species, but given similar results across four different species, and them + covid-19 all being fast respiratory viruses where transmission can only be stopped by high levels of mucosal antibodies, I think we can reasonably assume something similar for it. If we treat covid as "endemic" and just rely on immunity from old vaccinations and infection, you can bet on getting it every few years, with many people getting it again within a year.
How to avoid that? Probably either vaccination at least every 6 months, to keep antibody levels high, or NPIs like masking consistently outside the household, at least during surges (and enough testing, wastewater or random sampling to know when a surge is happening!)
A long term AIDS study has been sampling the same people's blood every 3 months for 35 years. The authors used those samples to look at re-infections by seasonal coronaviruses (a few of the 200 culprits that give us "the common cold"). There are four "dissimilar" species. Re-infections were measured by jumps in antibody levels vs. one of the species.
The results? Re-infection by the same species could happen within 6 months, though that was rare. The most common interval was 12 months. The mean time was 30 months for the two most common species and overall, and 55 months (I judge from the graph) for the slowest species.
Covid-19 is yet another species, but given similar results across four different species, and them + covid-19 all being fast respiratory viruses where transmission can only be stopped by high levels of mucosal antibodies, I think we can reasonably assume something similar for it. If we treat covid as "endemic" and just rely on immunity from old vaccinations and infection, you can bet on getting it every few years, with many people getting it again within a year.
How to avoid that? Probably either vaccination at least every 6 months, to keep antibody levels high, or NPIs like masking consistently outside the household, at least during surges (and enough testing, wastewater or random sampling to know when a surge is happening!)