COVAX, an initiative to encourage the equitable distribution of COVID-19 vaccines, said more research is needed to determine how to potentially modify vaccines to respond to variants of SARS-CoV-2 that have emerged recently, according to a news release.
The statement followed an announcement that South Africa was pausing the rollout of the Astra Zeneca/Oxford vaccine after preliminary data showed minimal effectiveness in preventing mild-to-moderate COVID-19 caused by the variant B.1.351, which first emerged in South Africa and has since spread around the world.
COVAX said, “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.”
COVAX also said that the Coalition for Epidemic Preparedness Innovations (CEPI) has announced funding for studies about how 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 World Health Organization (WHO) Strategic Advisory Group of Experts on Immunization (SAGE) has convened 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. The advisory group’s recommendations for use of the AstraZeneca vaccine will be presented to the WHO on February 9.
The WHO has said it expects to decide “in the next few days” on whether to grant emergency use listing for the AstraZeneca/Oxford vaccine. The organization also said it is enhancing an existing mechanism for tracking and evaluating variants that may affect vaccine composition and expanding that mechanism to provide guidance to manufacturers and countries on changes that may be needed for vaccines.
COVAX said recently that it plans to distribute at least 150 million doses of the AstraZeneca vaccine.
