Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Several vaccines have demonstrated efficacy against SARS-CoV-2 mediated disease, yet there is limited data on the immune response induced by heterologous vaccination regimens using alternate vaccine modalities. Here, we present a detailed description of the immune response, in mice, following vaccination with a self-amplifying RNA (saRNA) vaccine and an adenoviral vectored vaccine (ChAdOx1 nCoV-19/AZD1222) against SARS-CoV-2. We demonstrate that antibody responses are higher in two-dose heterologous vaccination regimens than single-dose regimens. Neutralising titres after heterologous prime-boost were at least comparable or higher than the titres measured after homologous prime boost vaccination with viral vectors. Importantly, the cellular immune response after a heterologous regimen is dominated by cytotoxic T cells and Th1+ CD4 T cells, which is superior to the response induced in homologous vaccination regimens in mice. These results underpin the need for clinical trials to investigate the immunogenicity of heterologous regimens with alternate vaccine technologies.

Original publication

DOI

10.1038/s41467-021-23173-1

Type

Journal article

Journal

Nat Commun

Publication Date

17/05/2021

Volume

12

Keywords

Animals, Antibodies, Neutralizing, Antibodies, Viral, COVID-19, COVID-19 Vaccines, Immunization, Secondary, Immunogenicity, Vaccine, Mice, RNA, Viral, SARS-CoV-2, Spike Glycoprotein, Coronavirus, T-Lymphocytes, Cytotoxic, Th1 Cells, Vaccination, Vaccines, Synthetic