Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2025 Jul 22;80(Supplement_1):S37-S46.
doi: 10.1093/cid/ciaf130.

Immunogenicity and Safety of Heterologous Versus Homologous Prime-Boost Regimens With BBIBP-CorV and Ad26.COV2.S COVID-19 Vaccines: A Multicentric, Randomized, Observer-Blinded Non-inferiority Trial in Madagascar and Mozambique

Patrícia Ramgi  1 , Mohamadou Siribie  2   3 , Njariharinjakamampionona Rakotozandrindrainy  4 , Odete Bule  1 , Harshvardhan Shrivastava  2 , Lígia Chambule  1 , Eun Lyeong Park  2 , Carina Fernando  1 , Jéssica Boque  1 , Rezelda Macuiana  1 , Ravomialisoa Razafimanantsoa  4 , Ndrainaharimira Rakotozandrindrainy  4 , Tsiriniaina J L Razafindrabe  4 , Antenaina N Rakotoarisoa  4 , Tiana M Raminosoa  4 , Herinirina L Derandrainy  4 , Masinirina M Rakotoson  4 , Cynthia S S de Silva  1 , Mirna Mutombene  1 , Carmélia Massinga  1 , José P Langa  1 , Tobin Guarnacci  2 , Sophie S Y Kang  2 , Sue Kyoung Jo  2 , Hyon Jin Jeon  2   4   5 , Jean-Louis Excler  2 , Yunkai Yang  6 , Shiyu Wang  6 , Jonathan D Sugimoto  2   7 , Jae Seung Yang  2 , Byoung-Shik Shim  2 , Tabea Binger  2 , Igor U Capitine  1 , Asma B Aziz  2 , Ju Yeon Park  2 , Deok Ryun Kim  2 , Raphaël Rakotozandrindrainy  4 , Ilesh V Jani  1 , Birkneh Tilahun Tadesse  2   8   9 , Florian Marks  2   4   5   10   11
Affiliations
Randomized Controlled Trial

Immunogenicity and Safety of Heterologous Versus Homologous Prime-Boost Regimens With BBIBP-CorV and Ad26.COV2.S COVID-19 Vaccines: A Multicentric, Randomized, Observer-Blinded Non-inferiority Trial in Madagascar and Mozambique

Patrícia Ramgi et al. Clin Infect Dis. .

Abstract

Background: Data on immunogenicity and safety of heterologous prime-boost (HePB) regimens using the BBIBP-CorV and Ad26.COV2.S have not yet been reported in sub-Saharan Africa.

Methods: We conducted a randomized, observer-blinded, non-inferiority trial assessing the immunogenicity and safety of HePB regimens using BBIBP-CorV and Ad26.COV2.S, in adults aged 18-65 years. Participants enrolled, were stratified by baseline severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serostatus, and randomized into four arms in a 1:1:1:1 ratio: A1 (BBIBP-CorV, Ad26.COV2.S), A2 (BBIBP-CorV, BBIBP-CorV), B1 (Ad26.COV2.S, BBIBP-CorV), and B2 (placebo, Ad26.COV2.S), administered at 28-day intervals. Fifteen participants in each arm were randomized separately in the immunology subset at a ratio of 1:1:1:1. Primary endpoints were the geometric mean titers (GMTs) of anti-SARS-CoV-2 neutralizing antibodies (nAbs) against SARS-CoV-2 Omicron variant BA.1 and safety at 4 weeks after second vaccination. The non-inferiority margin was 0.67 fold difference in geometric mean ratio (GMR) between the ratio of GMTs in the heterologous versus corresponding homologous arms.

Results: A total of 369 participants were randomized, and 367 of them received at least one dose of vaccine. Participants were between 18 and 65 years of age. Four weeks after second dose, GMT of nAbs in arms A1 and A2 was 802.7 (95% confidence interval [CI]: 635.3-1014.3) and 202.6 (95% CI: 150.8-272.1), respectively, with an adjusted GMR of 4.2 (2-sided 95% CI: 2.9-5.9). GMTs were 603.6 (95% CI: 446.1-816.7) and 725.7 (95% CI: 539.5-976.1) in arms B1 and B2, respectively, with an adjusted GMR of 0.8 (2-sided 95% CI: .5-1.2). Three serious adverse events were reported and none of them were related to the vaccination.

Conclusions: The noninferiority criterion was met only in arm A1 versus A2. HePB regimens were safe and well tolerated.

Clinical trials registration: NCT04998240.

Keywords: Ad26.COV2.S; BBIBP-CorV; SARS-CoV-2; heterologous; homologous.

PubMed Disclaimer

Conflict of interest statement

Potential conflicts of interest. All authors: No reported conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest.

Figures

Figure 1.
Figure 1.
Trial profile showing the disposition of the study participants to each of the 4 study arms.
Figure 2.
Figure 2.
Solicited local and common systemic reactions that occurred respectively within 7 days and 14 days of first vaccination, by severity and study arm. Abbreviation: AE, adverse event.
Figure 3.
Figure 3.
Solicited local and common systemic reactions that occurred respectively within 7 days and 14 days of second vaccination, by severity and study arm. Abbreviation: AE, adverse event.
See this image and copyright information in PMC

References

    1. Kumar A, Singh R, Kaur J, et al. Wuhan to world: the COVID-19 pandemic. Front Cell Infect Microbiol 2021; 11:596201. - PMC - PubMed
    1. Choi EM. COVID-19 vaccines for low- and middle-income countries. Trans R Soc Trop Med Hyg 2021; 115:447–56. - PMC - PubMed
    1. Wei X, Li L, Zhang F. The impact of the COVID-19 pandemic on socio-economic and sustainability. Environ Sci Pollut Res Int 2021; 28:68251–60. - PMC - PubMed
    1. Josephson A, Kilic T, Michler JD. Socioeconomic impacts of COVID-19 in low-income countries. Nat Hum Behav 2021; 5:557–65. - PubMed
    1. Msemburi W, Karlinsky A, Knutson V, Aleshin-Guendel S, Chatterji S, Wakefield J. The WHO estimates of excess mortality associated with the COVID-19 pandemic. Nature 2023; 613:130–7. - PMC - PubMed

Publication types

MeSH terms

Associated data