CONCLUSIONS
In summary, a booster BNT162B2 shot in previous recipients of CoronaVac induced IgM and IgG antibodies against Spike protein. Although immunization with two doses of CoronaVac and a booster dose with BNT162b2 vaccine provided limited protection against symptomatic disease during the last wave of COVID-19 in Brazil, the vaccines induced an immune memory 6 months after the booster shot. In addition, a SARS-CoV-2 infection after vaccination boosted the antibodies against Nucleocapsid protein.