13. COVID Immunity
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
Not everyone keeps detectable IgG after asymptomatic or even symptomatic infection
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
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).
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
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 Study not peer reviewed at time of podcast posting Full Text Link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