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Replies to post #369575 on Innovation Pharmaceuticals Inc (IPIX)
08/09/21 5:24 PM
08/09/21 9:34 PM
If someone has had COVID-19, why should they get vaccinated? Don’t they already have immunity?
If you’ve been infected, you have some protection. But that immunity has limits. The biggest limit is that it doesn’t last as long as we would like it to.
Studies have shown that people who have been infected can benefit significantly from vaccination. It gives them a strong, lasting immunity boost. After receiving the first dose of the Pfizer or Moderna vaccine, they have immunity levels comparable to those of uninfected people who have received their second dose.
We’re still trying to better understand why immunity lasts longer for some people than others. Underlying factors like obesity or age appear to play a role in how long immunity lasts.
Reinfection with SARS-CoV-2 has been documented, but the scientific understanding of natural infection-derived immunity is still emerging (5). The duration of immunity resulting from natural infection, although not well understood, is suspected to persist for ≥90 days in most persons.** The emergence of new variants might affect the duration of infection-acquired immunity, and laboratory studies have shown that sera from previously infected persons might offer weak or inconsistent responses against several variants of concern (2,6). For example, a recent laboratory study found that sera collected from previously infected persons before they were vaccinated provided a relatively weaker, and in some cases absent, neutralization response to the B.1.351 (Beta) variant when compared with the original Wuhan-Hu-1 strain (1). Sera from the same persons after vaccination showed a heightened neutralization response to the Beta variant, suggesting that vaccination enhances the immune response even to a variant to which the infected person had not been previously exposed. Although such laboratory evidence continues to suggest that vaccination provides improved neutralization of SARS-CoV-2 variants, limited evidence in real-world settings to date corroborates the findings that vaccination can provide improved protection for previously infected persons. The findings from this study suggest that among previously infected persons, full vaccination is associated with reduced likelihood of reinfection, and, conversely, being unvaccinated is associated with higher likelihood of being reinfected.
