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Randomized Controlled Trial
. 2024 Dec 31;20(1):2301632.
doi: 10.1080/21645515.2023.2301632. Epub 2024 Jan 11.

SCB-2019 protein vaccine as heterologous booster of neutralizing activity against SARS-CoV-2 Omicron variants after immunization with other COVID-19 vaccines

Camilo C Roa Jr  1 , Mari Rose A de Los Reyes  2 , Eric Plennevaux  3 , Igor Smolenov  4 , Branda Hu  4 , Faith Gao  4 , Hannalyn Ilagan  4 , Donna Ambrosino  5 , George Siber  6 , Ralf Clemens  7 , Htay Htay Han  4
Affiliations
Randomized Controlled Trial

SCB-2019 protein vaccine as heterologous booster of neutralizing activity against SARS-CoV-2 Omicron variants after immunization with other COVID-19 vaccines

Camilo C Roa Jr et al. Hum Vaccin Immunother. .

Abstract

We assessed the non-inferiority of homologous boosting compared with heterologous boosting with the recombinant protein vaccine, SCB-2019, in adults previously immunized with different COVID-19 vaccines. Three equal cohorts (N ~ 420) of Philippino adults (18-80 years) previously immunized with Comirnaty, CoronaVac or Vaxzevria COVID-19 vaccines were randomized 1:1 to receive homologous or heterologous (SCB-2019) boosters. Neutralizing antibodies against prototype SARS-CoV-2 (Wuhan-Hu-1) were measured in all participants and against Delta variant and Omicron sub-lineages in subsets (30‒50 per arm) 15 days after boosting. Participants recorded solicited adverse events for 7 days and unsolicited and serious adverse events until Day 60. Prototype SARS-CoV-2 neutralizing responses on Day 15 after SCB-2019 were statistically non-inferior to homologous Vaxzevria boosters, superior to CoronaVac, but lower than homologous Comirnaty. Neutralizing responses against Delta and Omicron BA.1, BA.2, BA.4 and BA.5 variants after heterologous SCB-2019 were higher than homologous CoronaVac or Vaxzevria, but lower than homologous Comirnaty. Responses against Omicron BF.7, BQ.1.1.3, and XBB1.5 following heterologous SCB-2019 were lower than after homologous Comirnaty booster but significantly higher than after Vaxzevria booster. SCB-2019 reactogenicity was similar to CoronaVac or Vaxzevria, but lower than Comirnaty; most frequent events were mild/moderate injection site pain, headache and fatigue. No vaccine-related serious adverse events were reported. Heterologous SCB-2019 boosting was well tolerated and elicited neutralizing responses against all tested SARS-COV-2 viruses including Omicron BA.1, BA.2, BA.4, BA.5, BF.7, BQ.1.1.3, and XBB1.5 sub-lineages that were non-inferior to homologous boosting with CoronaVac or Vaxzevria, but not homologous Comirnaty booster.

Keywords: COVID-19; Comirnaty; CoronaVac; Delta; Omicron; SCB-2019; Vaccine; Vaxzevria; heterologous booster; homologous booster.

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Conflict of interest statement

Eric Plennevaux, Igor Smolenov, Branda Hu, Faith Gao, Hannalyn Ilagan and Htay Htay Han are full-time employees of the study sponsor. George Siber has served as a Scientific Advisory Board Member and received consulting fees from Clover Biopharmaceuticals, AdVaccine, CanSino, Everest Medicines, Valneva, Senda and Vaxart and owns equities in Clover, AdVaccine, Vaxxinity and Everest Medicines. Donna Ambrosino has received consulting fees from Clover Biopharmaceuticals, Vaxxinity, Everest Medicines, Senda, and served as a Scientific Advisory Board Member for Clover Biopharmaceuticals, Vaxxinity, Senda, Everest Medicines, and Inventprise, and served as a board member for Clover Biopharmaceuticals and Inventprise and owns stock in Clover, Everest Medicine, and Inventprise. Ralf Clemens has received funding from the Bill & Melinda Gates Foundation, consulting fees from Icosavax, Hillevax, honoraria from AstraZeneca, served as a board member for Clover Biopharmaceuticals, Curevac, IVI, Inventprise and owns stocks in Icosavax, HilleVax, Curevac, Novartis, Roche, GSK, and Clover Biopharmaceuticals. Camilo C. Roa, Jr. and Mari Rose A. de Los Reyes have no competing interests to declare.

Figures

Figure 1.
Figure 1.
Disposition of participants in Safety Set and per protocol immunogenicity sets of the three study phases.
Figure 2.
Figure 2.
Anti-prototype SARS-CoV-2 neutralizing GMTs (IU/mL) with 95% CI at Days 1 and 15 in the three parts of the study according to baseline immunity (Per Protocol Set). Participants are grouped as low (25% with lowest titers), medium (50% with medium titers) and high (25% with highest titers) baseline. Heterologous to homologous GMT ratios (95% CI) at Day 15 are shown above columns; values at bases of columns show numbers of participants per group.
Figure 3.
Figure 3.
neutralizing GMTs (95% CI) against prototype SARS-CoV-2 and variants at Days 1 and 15 in subsets from the three parts of the study (Omicron BF.7, BQ.1.1.3 and XBB1.5 were not tested in the CoronaVac cohort).
Figure 4.
Figure 4.
Reactogenicity as proportions of each group in the three parts of the study with solicited local reactions and systemic adverse events, shown with severity.
See this image and copyright information in PMC

References

    1. Callaway E. Are COVID surges becoming more predictable? New Omicron variants offer a hint. Nature. 2022;605(7909):204–11. doi:10.1038/d41586-022-01240-x. - DOI - PubMed
    1. Candido KL, Eich CR, de Fariña LO, Kadowaki, MK, da Conceição Silva, JL, Maller, A, Simão, RD. Spike protein of SARS-CoV-2 variants: a brief review and practical implications. Braz J Microbiol. 2022;53(3):1133–57. doi:10.1007/s42770-022-00743-z. - DOI - PMC - PubMed
    1. Murano K, Guo Y, Siomi H. The emergence of SARS-CoV-2 variants threatens to decrease the efficacy of neutralizing antibodies and vaccines. Biochem Soc Trans. 2021;49(6):2879–90. doi:10.1042/BST20210859. - DOI - PMC - PubMed
    1. Noor R, Shareen S, Billah M. COVID-19 vaccines: their effectiveness against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its emerging variants. Bull Natl Res Cent. 2022;46:96. doi:10.1186/s42269-022-00787-z. - DOI - PMC - PubMed
    1. Florentino PTV, Millington T, Cerqueira-Silva T, Robertson C, de Araújo Oliveira V, Júnior JBS, Alves FJO, Penna GO, Katikireddi SV, Boaventura VS, et al. Vaccine effectiveness of two-dose BNT162b2 against symptomatic and severe COVID-19 among adolescents in Brazil and Scotland over time: a test-negative case-control study. Lancet Infect Dis. 2022;22(11):1577–86. doi:10.1016/S1473-3099(22)00451-0. - DOI - PMC - PubMed

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