Clusters of SARS-CoV-2 lineage B.1.1.7 infection after vaccination with adenovirus-vectored and inactivated vaccines
de Souza WM., Muraro SP., Souza GF., Amorim MR., Sesti-Costa R., Mofatto LS., Forato J., Barbosa PP., Toledo-Teixeira DA., Bispo-Dos-santos K., Parise PL., Brunetti NS., Moreira JCO., Costa VA., Cardozo DM., Moretti ML., Barros-Mazon S., Marchesi GF., Ambrosio C., Spilki FR., Almeida VC., Vieira AS., Zambon L., Farias AS., Addas-Carvalho M., Benites BD., Marques RE., Sabino EC., Von Zuben AB., Weaver SC., Faria NR., Granja F., Angerami RN., Proença-Módena JL.
A SARS-CoV-2 B.1.1.7 variant of concern (VOC) has been associated with increased trans-missibility, hospitalization, and mortality. This study aimed to explore the factors associated with B.1.1.7 VOC infection in the context of vaccination. On March 2021, we detected SARS-CoV-2 RNA in nasopharyngeal samples from 14 of 22 individuals vaccinated with a single-dose of ChAdOx1 (outbreak A, n = 26), and 22 of 42 of individuals with two doses of the CoronaVac vaccine (outbreak B, n = 52) for breakthrough infection rates for ChAdOx1 of 63.6% and 52.4% for CoronaVac. The outbreaks were caused by two independent clusters of the B.1.1.7 VOC. The serum of PCR-positive symptomatic SARS-CoV-2-infected individuals had ~1.8–3.4-fold more neutralizing capacity against B.1.1.7 compared to the serum of asymptomatic individuals. These data based on exploratory analysis suggest that the B.1.1.7 variant can infect individuals partially immunized with a single dose of an adenovirus-vectored vaccine or fully immunized with two doses of an inactivated vaccine, although the vaccines were able to reduce the risk of severe disease and death caused by this VOC, even in the elderly.