Booster dose of BNT162b2 after two doses of CoronaVac improves neutralization of SARS-CoV-2 Omicron variant

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Campos, Guilherme R. F. ; Almeida, Nathalie Bonatti Franco ; Filgueiras, Priscilla Soares ; Corsini, Camila Amormino ; Gomes, Sarah Vieira Contin ; de Miranda, Daniel Alvim Pena ; de Assis, Jessica Vieira ; Silva, Thais Barbara de Souza ; Alves, Pedro Augusto ; Fernandes, Gabriel da Rocha ; de Oliveira, Jaquelline Germano ; Rahal, Paula ; Grenfell, Rafaella Fortini Queiroz ; Nogueira, Mauricio L.

• Document type: Journal article
• Source: COMMUNICATIONS MEDICINE; v. 2, n. 1, p. 4-pg., 2022-07-22.

Abstract

Campos et al. assessed the impact of a booster dose of BNT162b2 on antibody neutralization against the SARS-CoV-2 Omicron variant, following two doses of the CoronaVac vaccine. Neutralization mean titers against Omicron decrease over time following two doses of CoronaVac but increase again after the BNT162b2 booster, as does seroconversion. Plain language summaryThe high transmission rates of SARS-CoV-2 favor the appearance of variants of the virus bearing a high number of changes in the genetic material, such as the Omicron variant. These changes might impact the efficacy of COVID-19 vaccines. Here, we evaluated the ability, of a highly adopted vaccination scheme in Brazil, of producing neutralizing antibodies, proteins present in the human body that bind to the virus and prevent infection, against the Omicron variant. This scheme consisted in two doses of the CoronaVac vaccine followed by an additional dose of the BNT162b2 vaccine. Our analysis showed that, before the additional dose, the number of individuals presenting neutralizing antibodies against Omicron was low and decreased over time. However, the production of neutralizing antibodies increased significantly after the BNT162b2 dose. Our findings support that this vaccination scheme improves the neutralization of Omicron. BackgroundThe emergence of the new SARS-CoV-2 Omicron variant, which is known to have a large number of mutations when compared to other variants, brought to light the concern about vaccine escape, especially from the neutralization by antibodies induced by vaccination.MethodsBased on viral microneutralization assays, we evaluated in 90 individuals the impact on antibody neutralization induction, against Omicron variant, by a booster dose of BNT162b2 mRNA vaccine after the CoronaVac primary vaccination scheme.ResultsHere we show that the percentage of seroconverted individuals 30 and 60 days after CoronaVac scheme was 16.6% and 10%, respectively. After booster dose administration, the seroconvertion rate increased to 76.6%. The neutralization mean titer against Omicron in the CoronaVac protocol decreased over time, but after the booster dose, the mean titer increased 43.1 times.ConclusionsThese results indicate a positive impact of this vaccine combination in the serological immune response against SARS-CoV-2 Omicron variant. (AU)

• FAPESP's process: 20/07419-0 - Clinical and epidemiological study of SARS-CoV-2 in a prospective population and hospitalar cohorts in SJ Rio Preto, SP, Brazil in 2020
• Grantee: Guilherme Rodrigues Fernandes Campos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 20/04836-0 - Clinical and epidemiological study of SARS-CoV-2 in a prospective population and hospitalar cohorts in São José do Rio Preto, SP, Brazil in 2020
• Grantee: Maurício Lacerda Nogueira
• Support Opportunities: Regular Research Grants