The emergence of variants of SARS-CoV-2, the virus that causes COVID-19, serve as a powerful reminder that viruses by their very nature mutate, and that the scientific response may need to adapt to remain effective against them, according to COVAX statement on new variants of SARS-CoV-2.
In light of recent news stories regarding the preliminary data on minimal effectiveness of the AstraZeneca/Oxford vaccine at preventing mild to moderate COVID-19 disease caused by the viral variant B.1.351, it is important to note that primary analysis of data from Phase III trials has so far shown – in the context of viral settings without this variant – that the AstraZeneca/Oxford vaccine offers protection against severe disease, hospitalisation and death. This means it is vitally important now to determine the vaccine’s effectiveness when it comes to preventing more severe illness caused by the B.1.351 variant.
Additional studies will also allow us to confirm the optimal vaccination schedule and its impact on vaccine efficacy. CEPI has announced funding for additional clinical research to optimize and extend the use of existing vaccines, which could include “mix-and-match” studies of different vaccines used in combinations that may improve the quality and strength of the immune response. Such studies could be useful in optimizing the use of available vaccines, including the AstraZeneca/Oxford vaccine.
The WHO Strategic Advisory Group of Experts on Immunization (SAGE) convened today to review evidence on the AstraZeneca/Oxford vaccine, including emerging evidence on performance against viral variants, and to consider the demonstrated impact of the product and the risk-benefit assessment for use cases with limited data. These recommendations for use of the AstraZeneca product are being finalised and will be presented to the WHO Director-General on 9 Feb 2021.
Even though this recent news on effectiveness of the AstraZeneca/Oxford vaccine against the B.1.351 variant is based on a limited study size which focused on low-risk participants and used interval doses that were not optimized for immunogenicity, these results confirm we must do everything possible to reduce the circulation of the virus, prevent infections and reduce the opportunities for the SARS-CoV-2 to evolve resulting in mutations that may reduce the efficacy of existing vaccines