Does COVID-19 Infection Provide Immunity?

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.


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).


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.

One thought on “Does COVID-19 Infection Provide Immunity?”

  1. 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.

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