Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections

Heba N. Altarawneh et al. No notable differences were observed in the effectiveness against BA.1 and BA.2 of previousinfection, vaccination, and hybrid immunity. Protection from previous infection with variants other than omicron against reinfection was moderate and durable, but protection of primary-series vaccination against infection was negligible by 6 months after the second dose. Recent […]