Dynamics of SARS-CoV-2 Antibody Response to CoronaVac followed by Booster Dose of BNT162b2 Vaccine

Abstract

We evaluated the longitudinal dynamics of antibody response to the SARS-CoV-2 vaccine CoronaVac and the effect of a booster dose of BNT162b2 vaccine. We found a robust antibody response after the second dose of Coro-naVac that wanes over time. The response was recovered by BNT162b2, which boosted anti-spike antibody titers.

Antibody response 6 months after the booster dose of Pfizer in previous recipients of CoronaVac

“…In Brazil, the CoronaVac (Sinovac) was the first vaccine approved for emergency use, and the third dose was administered, preferably, with the BNT162b2 vaccine (Pfizer/BioNTech). Previously, we showed that the third dose with the BNT162b2 vaccine boosted the anti‐spike (S) antibody titers in recipients of CoronaVac 5 . In the current cohort, we evaluated the antibody levels after 6 months of the booster dose and whether the omicron wave in Brazil impacted the antibody response.…”

“…Previously, we showed that the third dose with the BNT162b2 vaccine boosted the anti‐spike (S) antibody titers in recipients of CoronaVac. 5 In the current cohort, we evaluated the antibody levels after 6 months of the booster dose and whether the omicron wave in Brazil impacted the antibody response.…”

Antibody response following the fourth SARS‐CoV‐2 vaccine dose during the Omicron wave in Brazil

“…To evaluate the antibody waning over time, antibody F I G U R E 1 Antibody response over time in a cohort of healthcare workers vaccinated with two doses of CoronaVac (Sinovac), a third dose with BNT162b2 (Pfizer), and a fourth dose with ChAdOx1 nCoV-19 (AstraZeneca). (A) N IgG levels after the fourth dose, comparing the same cohort published by Fonseca et al 14 and Silva et al 15 (B) S IgG levels. Shading corresponds to COVID-19 waves and the main variant strains in the state of Ceará, Brazil; orange (Gamma-P1/B.1.1.28.1); blue (Delta-B.1.671.2), and gray (Omicron-BA.4 and BA.5).…”

“…Previously we showed that CoronaVac (Sinovac) induced an antibody response against both the viral S and N proteins of SARS-CoV-2 that declined over time. 13 The third dose of BNT162b2 (Pfizer) recalled the S-IgG response, 14 but the antibodies waned after 6 months. 15 Here, we investigated in the current cohort, the impact of the fourth dose with ChAdOx1 nCoV-19 (AstraZeneca), on the humoral immune response to SARS-CoV-2 during a 9-month follow-up period in which Omicron was the predominant variant in Brazil.…”

Persistent SARS-COV-2 infection in vaccinated individual with three doses of COVID-19 vaccine

“…Over these two pandemic years, many studies have evaluated the response of vaccines and their effect under clinical conditions [6] . Our group monitored the profile of immunological responses to different vaccine protocols [7] , [8] , [9] . The persisting positive diagnosis with maintenance of Cq values in SARS-CoV-2 (E gene) could be an interesting insight to infer the differences between the development of disease and how the immune system can respond over the time.…”