A persistent question related to COVID-19 is to what extent previous COVID-19 infections protect from future infections. It is not uncommon on social media to see people say that since they previously contracted COVID-19, they are immune and see no reason to get vaccinated.
The CDC notes that there are still a lot of unknowns about how long such protection lasts,
Yes, you should be vaccinated regardless of whether you already had COVID-19. That’s because experts do not yet know how long you are protected from getting sick again after recovering from COVID-19. Even if you have already recovered from COVID-19, it is possible—although rare—that you could be infected with the virus that causes COVID-19 again.
A recently published study that followed more than 16,000 adult health care workers suggests the “natural immunity” may be fleeting at best.
Results
Nine hundred and thirteen (6.12%) participants, including 45 (4.93%) IgG positive participants, experienced COVID-19 infections after study initiation, representing a 51% increased risk of COVID-19 infection among IgG positive participants (IRR = 1.51). Regressions adjusted for documented disparities showed no difference in COVID-19 infection by IgG status (OR=1.19; P = .3117) but significantly greater odds in COVID-19 recurrence among participants with a prior documented COVID-19 infection (OR=1.93; P < .0001).Conclusions
SARS-CoV-2 IgG antibodies and prior COVID-19 infection do not appear to offer meaningful protection against COVID-19 recurrence in healthcare workers. Recurrence would impact decisions regarding ongoing healthcare resource utilization. This study can inform considerations for vaccine administration to vulnerable groups.
Natural infection provides 13x the antibodies, and antibodies better adapted to mutations. I’ve tested for natural antibodies – I never got sick, or at least never had an symptoms, but most people don’t really.