How long does immunity last after a COVID infection? News reports of two recent studies suggest that it wanes quickly and that some patients may never have immunity at all. In this episode, we take a look at those studies and explain why they don’t exactly say what is being said about them.
Take home points
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Not everyone keeps detectable IgG after asymptomatic or symptomatic infection
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If you have asymptomatic COVID-19 infection, you are less likely to have detectable IgG at 8 weeks compared to someone who had symptoms
What we still don’t know
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Does this drop or absence of IgG correlate to decreased immunity? The reflex answer would seem to be ‘yes’ but we still don’t understand the COVID-19 correlates of protection (blood tests that can show whether or not someone has immunity).
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The likelihood of those who have had COVID-19 getting reinfected. The studies discussed in this podcast evaluated parts of the immune system that are involved in immunity, but we haven’t answered the real question: what is the likelihood of having a repeat illness (or repeat asymptomatic infection).
Mentioned in this show
The Stimulus COVID Podcast Page: Click Here
References
Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections.” Nature medicine (2020): 1-5 Full Text Link
Liu, Tao, et al. “Prevalence of IgG antibodies to SARS-CoV-2 in Wuhan-implications for the ability to produce long-lasting protective antibodies against SARS-CoV-2.”medRxiv (2020). Study not peer reviewed at time of podcast posting Full Text Link
Plotkin, Stanley A. “Correlates of protection induced by vaccination.”Clinical and vaccine immunology17.7 (2010): 1055-1065. Full Text Link
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