Covid-19 Vaccines or Natural Immunity – Do Both Protect?
September 10, 2021
In the current circumstances of disturbingly high rates of infection by the Delta variant and the concerns over obtaining effective vaccine coverage, the degree of protection provided to SARS-CoV-2 infected convalescent people is of clear relevance for natural immunity. Pei et al. estimate that 30% of the population in the United States have already been infected(1). Potency and durability of protection are the two critical considerations. What is the relative potency and duration of protection provided by previous infection compared with that provided by vaccination? Are there differences in the mechanisms of protection? Would vaccination of those previously infected boost protective immunity? Additionally, not all vaccines may be equally effective, and protection in convalescent patients may depend upon the type of predominantly circulating variants at the time of infection.