Abstract
Limited data are available on the responses to heterologous vaccine regimens for SARS-CoV-2, especially among countries using inactivated and adenoviral-vectored vaccines. A total of 77 participants who received heterologous inactivated COVID-19 vaccine (CoronaVac) and adenoviral-vectored vaccine (AZD1222) were enrolled in our study. There were two comparison groups vaccinated with the homologous CoronaVac (N = 79) and AZD1222 (N = 78) regimen. All sera samples were tested for anti-receptor-binding-domain IgG (anti-RBD IgG) using a chemiluminescent microparticle immunoassay (CMIA). The neutralizing activity in a subset of serum samples was tested against the original Wuhan strain and variants of concern, B.1.1.7, B.1.617.2 and B.1.351, using an enzyme-linked immunosorbent assay (ELISA)-based surrogate virus neutralization test (sVNT). The heterologous CoronaVac/AZD1222 vaccine induced higher levels of anti-RBD IgG than that of two-dose homologous CoronaVac or AZD1222 vaccines (p < 0.001). Sera samples of the CoronaVac/AZD1222 vaccine recipients elicited higher neutralizing antibody activity against the original Wuhan and all variants of concern than in the recipients of the two-dose CoronaVac. The heterologous CoronaVac followed by AZD1222 is an alternative regimen to combat with the SARS-CoV-2 variants in case of vaccine shortage with improved immunogenicity compared to the homologous CoronaVac regimen.
Keywords: AZD1222; COVID-19; CoronaVac; Heterologous; Vaccine.
【저자키워드】 COVID-19, Vaccine, CoronaVac, AZD1222, Heterologous, 【초록키워드】 neutralizing antibody, SARS-CoV-2, IgG, Vaccine, COVID-19 vaccine, B.1.351, variant, CoronaVac, variants of concern, B.1.617.2, variants, ELISA, immunoassay, enzyme-linked immunosorbent assay, Neutralizing activity, AZD1222, SARS-CoV-2 variants, B.1.1.7, CMIA, sera, virus neutralization test, response, neutralization test, Wuhan, group, homologous, Heterologous, surrogate virus neutralization test, inactivated, heterologous vaccine, Anti-RBD IgG, regimen, followed by, serum samples, recipients, enzyme, sVNT, participant, Wuhan strain, recipient, serum sample, Microparticle, country, adenoviral-vectored vaccine, adenoviral-vectored vaccines, enzyme-linked immunosorbent, enrolled, tested, elicited, subset, Limited, the SARS-CoV-2, was tested, 【제목키워드】 immunogenicity, inactivated,