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
. 2021 Aug 25;10(17):3817.
doi: 10.3390/jcm10173817.

An Immunogenicity Report for the Comparison between Heterologous and Homologous Prime-Boost Schedules with ChAdOx1-S and BNT162b2 Vaccines

Alexandre Vallée  1 , Marc Vasse  2   3 , Laurence Mazaux  2 , Brigitte Bonan  4 , Carline Amiel  5 , Sara Zia-Chahabi  2 , Aurélie Chan-Hew-Wai  4 , Eric Farfour  2 , Eve Camps  4 , Pauline Touche  1 , Flavie Barret  1 , François Parquin  6 , David Zucman  7 , Erwan Fourn  7
Affiliations

An Immunogenicity Report for the Comparison between Heterologous and Homologous Prime-Boost Schedules with ChAdOx1-S and BNT162b2 Vaccines

Alexandre Vallée et al. J Clin Med. .

Abstract

Background: There is a small amount of immunological data on COVID-19 heterologous vaccination schedules in humans. We assessed the immunogenicity of BNT162b2 (Pfizer/BioNTech) administered as a second dose in healthcare workers primed with ChAdOx1-S (Vaxzevria, AstraZeneca).

Methods: 197 healthcare workers were included in a monocentric observational study in Foch hospital, France, between June and July 2021. The main outcome was the immunogenicity measured by serum SARS-CoV-2 IgG antibodies.

Results: 130 participants received the ChAdOx1-S/BNT vaccine and 67 received the BNT/BNT vaccine. The geometric mean of IgG antibodies was significantly higher in the BNT/BNT vaccine group compared to the ChAdOx1-S/BNT vaccine group, namely 10,734.9, 95% CI (9141.1-12,589.3) vs. 7268.6, 95% CI (6501.3-8128.3), respectively (p < 0.001). However, after adjustment for time duration between the prime and second vaccinations, no significant difference was observed (p = 0.181). A negative correlation between antibody levels and time duration between second dose and serology test was observed for the BNT/BNT vaccine (p < 0.001), which remained significant after adjustment for all covariates (p < 0.001), but not for the ChAdOx1-S/BNT vaccine (p = 0.467).

Conclusions: Heterologous and homologous schedules of ChAdOx1-S and BNT vaccines present robust immune responses after the second vaccination. The results observed were equivalent after adjustment for covariates and emphasize the importance of flexibility in deploying mRNA and viral vectored vaccines. Nevertheless, applying the ChAdOx1-S schedule vaccination for the heterologous second dose of BNT was associated with decreased IgG antibody levels compared to the homologous BNT/BNT vaccination.

Keywords: BNT162b2; COVID-19; COVID-19 vaccine; ChAdOx1-S; immunogenicity.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
IgG antibody levels in overall population according to BNT/BNT and ChAdOx1-S/BNT (A) and according to gender (B).
Figure 2
Figure 2
Association between IgG antibody levels and time duration aspects and age. (A) Association between IgG antibody levels and time duration between second vaccination and serology test for BNT/BNT and ChAdOx1-S/BNT. (B) Association between IgG antibody levels and time duration between prime and second vaccinations for BNT/BNT and ChAdOx1-S/BNT. (C) Association between IgG antibody levels and time duration between prime vaccination and serology test for BNT/BNT and ChAdOx1-S/BNT. (D) Association between IgG antibody levels and age of healthcare workers for BNT/BNT and ChAdOx1-S/BNT. * Significant models after adjustment for all covariates.
See this image and copyright information in PMC

References

    1. Khoury D.S., Cromer D., Reynaldi A., Schlub T.E., Wheatley A.K., Juno J.A., Subbarao K., Kent S.J., Triccas J.A., Davenport M.P. Neutralizing Antibody Levels Are Highly Predictive of Immune Protection from Symptomatic SARS-CoV-2 Infection. Nat. Med. 2021;27:1205–1211. doi: 10.1038/s41591-021-01377-8. - DOI - PubMed
    1. Fontanet A., Cauchemez S. COVID-19 Herd Immunity: Where Are We? Nat. Rev. Immunol. 2020;20:583–584. doi: 10.1038/s41577-020-00451-5. - DOI - PMC - PubMed
    1. Cushman M. Epidemiology and Risk Factors for Venous Thrombosis. Semin. Hematol. 2007;44:62–69. doi: 10.1053/j.seminhematol.2007.02.004. - DOI - PMC - PubMed
    1. Østergaard S.D., Schmidt M., Horváth-Puhó E., Thomsen R.W., Sørensen H.T. Thromboembolism and the Oxford–AstraZeneca COVID-19 Vaccine: Side-Effect or Coincidence? Lancet. 2021;397:1441–1443. doi: 10.1016/S0140-6736(21)00762-5. - DOI - PMC - PubMed
    1. Vallée A., Chan-Hew-Wai A., Bonan B., Lesprit P., Parquin F., Catherinot É., Choucair J., Billard D., Amiel-Taieb C., Camps È., et al. Oxford-AstraZeneca COVID-19 Vaccine: Need of a Reasoned and Effective Vaccine Campaign. Public Health. 2021;196:135–137. doi: 10.1016/j.puhe.2021.05.030. - DOI - PMC - PubMed

LinkOut - more resources