Mary Wilson
Well-known member
Published: 26 July 2021
DOI: https://doi.org/10.1038/s41591-021-01463-x
Meagan E. Deming & Kirsten E. Lyke
Heterologous dosing with the adenovirus-based ChAdOx1 (AstraZeneca) vaccine followed by an mRNA vaccine induced stronger immune responses than did the homologous ChAdOx1 vaccine series, according to recent immunogenicity studies.
Despite the development of multiple successful vaccines against the coronavirus SARS-CoV-2, the continued emergence of variants of concern and the sporadic worldwide distribution of vaccines have limited and will continue to limit vaccine effectiveness. A new wrinkle in the global vaccine effort has been the occurrence of rare events such as thrombosis and thrombocytopenia syndrome associated with adenovirus-based vaccines. This triggered cessation of the distribution of AstraZeneca’s ChAdOx1 nCoV-19 (ChAd) vaccine in many countries, as well as a surge in vaccine hesitancy in risk-averse populations[SUP]1[/SUP].
In this issue of Nature Medicine, studies by Barros-Martins et al.[SUP]2[/SUP] and Schmidt et al.[SUP]3[/SUP] capitalize on the ad hoc heterologous prime–boost vaccination that resulted from the halting of vaccination with ChAd in several European countries, which left partially vaccinated people the option of completing their vaccinations with an mRNA vaccine (BNT162b2 (BNT), from Pfizer–BioNTech); or mRNA-1273, from Moderna). Barros-Martins et al. report that, compared with results obtained by homologous ChAd–ChAd dosing, the ChAd–BNT dosing strategy resulted in significantly greater immunoglobulin G (IgG) and IgA immune responses directed against the SARS-CoV-2 spike protein and robust, 20- to >60-fold greater titers of neutralizing antibody against the Alpha (B.1.1.7), Beta (B.1.351) and Gamma (P.1) SARS-CoV-2 variants of concern[SUP]2[/SUP]. These neutralizing titers were approximately threefold higher than those in serum from the groups dosed with BNT–BNT (albeit with differing intervals between dose 1 and dose 2), with higher titers of the IgG and IgA subclasses.
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https://www.nature.com/articles/s41591-021-01463-x#citeas
DOI: https://doi.org/10.1038/s41591-021-01463-x
Meagan E. Deming & Kirsten E. Lyke
Heterologous dosing with the adenovirus-based ChAdOx1 (AstraZeneca) vaccine followed by an mRNA vaccine induced stronger immune responses than did the homologous ChAdOx1 vaccine series, according to recent immunogenicity studies.
Despite the development of multiple successful vaccines against the coronavirus SARS-CoV-2, the continued emergence of variants of concern and the sporadic worldwide distribution of vaccines have limited and will continue to limit vaccine effectiveness. A new wrinkle in the global vaccine effort has been the occurrence of rare events such as thrombosis and thrombocytopenia syndrome associated with adenovirus-based vaccines. This triggered cessation of the distribution of AstraZeneca’s ChAdOx1 nCoV-19 (ChAd) vaccine in many countries, as well as a surge in vaccine hesitancy in risk-averse populations[SUP]1[/SUP].
In this issue of Nature Medicine, studies by Barros-Martins et al.[SUP]2[/SUP] and Schmidt et al.[SUP]3[/SUP] capitalize on the ad hoc heterologous prime–boost vaccination that resulted from the halting of vaccination with ChAd in several European countries, which left partially vaccinated people the option of completing their vaccinations with an mRNA vaccine (BNT162b2 (BNT), from Pfizer–BioNTech); or mRNA-1273, from Moderna). Barros-Martins et al. report that, compared with results obtained by homologous ChAd–ChAd dosing, the ChAd–BNT dosing strategy resulted in significantly greater immunoglobulin G (IgG) and IgA immune responses directed against the SARS-CoV-2 spike protein and robust, 20- to >60-fold greater titers of neutralizing antibody against the Alpha (B.1.1.7), Beta (B.1.351) and Gamma (P.1) SARS-CoV-2 variants of concern[SUP]2[/SUP]. These neutralizing titers were approximately threefold higher than those in serum from the groups dosed with BNT–BNT (albeit with differing intervals between dose 1 and dose 2), with higher titers of the IgG and IgA subclasses.
...
https://www.nature.com/articles/s41591-021-01463-x#citeas