By vaccinating SARS-CoV-2 naïve individuals who have already received two doses of COVID-19 vaccines, we aimed to investigate whether a heterologous prime-boost strategy, using vaccines of different platforms as the booster dose, can enhance the immune response against SARS-CoV-2 virus variants. Participants were assigned into four groups, each receiving different combination of vaccinations: two doses of BNT162b2 followed by one dose of BNT162b2 booster (B-B-B); Combination of BNT162b2 (first dose) and CoronaVac (second dose) followed by one dose of BNT162b2 booster (B-C-B); two doses of CoronaVac followed by one dose of CoronaVac booster (C-C-C); two doses of CoronaVac followed by one dose of BNT162b2 booster (C-C-B). The neutralizing antibody in sera against the virus was determined with live virus microneutralization assay (vMN). The B-B-B group and C-C-B group demonstrated significantly higher immunogenicity against SARS-CoV-2 Wild type (WT), Beta variant (BV) and Delta variant (DV). In addition, the B-B-B group and C-C-B group showed reduced but existing protection against Omicron variant (OV). Moreover, A persistent rise in vMN titre against OV was observed 3 days after booster dose. Regarding safety, a heterologous prime-boost vaccine strategy is well tolerated. In this study, it was demonstrated that using vaccines of different platforms as booster dose can enhance protection against SARS-CoV-2 variants, offering potent neutralizing activity against wild-type virus (WT), Beta variant (BV), Delta variant (DV) and some protection against the Omicron variant (OV). In addition, a booster mRNA vaccine results in a more potent immune response than inactivated vaccine regardless of which platform was used for prime doses.
【저자키워드】 COVID-19, Vaccines, Omicron variant, 【초록키워드】 neutralizing antibody, SARS-CoV-2, Vaccine, immune response, mRNA vaccine, variant, CoronaVac, omicron, delta variant, virus, Neutralizing activity, COVID-19 vaccines, SARS-CoV-2 variants, Inactivated vaccine, sera, Beta, booster dose, platform, booster, Live virus, microneutralization, Combination, dose, heterologous prime-boost, second dose, first dose, participant, titre, wild-type virus, four groups, doses, ENhance, was used, addition, receiving, reduced, was determined, demonstrated, significantly higher, assigned, naïve individual, of BNT162b2, SARS-CoV-2 virus variants, 【제목키워드】 CoronaVac, omicron, response, of BNT162b2,