Cumulative incidence of SARS-CoV-2 infection after third-dose CoronaVac or BNT162b2 vaccination in adults who previously received two doses of CoronaVac (A) or BNT162b2 (B) within 4–6 months after vaccination and when the omicron BA.2 subvariant was locally circulating
respiratory illness, COPD, fever
ADVERSE REACTIONS, SARS-COV-2 INFECTION, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, MAY, COPD
COVID-19 was identified by rapid antigen test or PCR between third-dose vaccination (administered from Nov 12, 2021, to Jan 27, 2022) until May 31, 2022. The four study groups included participants who previously received two doses of CoronaVac and were randomly assigned to receive a third dose of CoronaVac (CC-C) or BNT162b2 (CC-B), and participants who previously received two doses of BNT162b2 and were randomly assigned to receive a third dose of CoronaVac (BB-C) or BNT162b2 (BB-B). Data from 378 (84%) of 451 participants who agreed to participate in active surveillance for respiratory illness were included. The date of a positive test for the first SARS-CoV-2 infection identified in these participants was Feb 11, 2022. HR=hazard ratio.Baseline characteristicsData are n (%) or mean (SD). The four study groups included participants who previously received two doses of CoronaVac and were randomly assigned to receive a homologous third dose of CoronaVac (CC-C) or a heterologous third dose of BNT162b2 (CC-B), and participants who previously received two doses of BNT162b2 and were randomly assigned to receive a heterologous third dose of CoronaVac (BB-C) or a homologous third dose of BNT162b2 (BB-B). NA=not applicable. COPD=chronic obstructive pulmonary disease.Solicited local and systemic reactions during the 7 days after third-dose CoronaVac or BNT162b2 vaccinationData are n (%), mean (SD), or median (IQR). The four study groups included participants who previously received two doses of CoronaVac and were randomly assigned to receive a third dose of CoronaVac (CC-C) or BNT162b2 (CC-B), and participants who previously received two doses of BNT162b2 and were randomly assigned to receive a third dose of CoronaVac (BB-C) or BNT162b2 (BB-B). Data from 424 (94%) of 451 participants who reported adverse reactions for at least 7 days post vaccination were included. According to the stratified randomisation, comparison was made between CC-C and CC-B groups, and separately between BB-C and BB-B groups. No participants in the CC-C and BB-C groups reported fever.