Thursday 25 February 2021

Vaccines must be able to adapt to new virus variants: Covax

GENEVA, 16 days ago

Covax, a global initiative aimed at equitable access to Covid-19 vaccines, has issued a statement on new Covid-19 variants following reports of minimal effectiveness of the AstraZeneca/Oxford vaccine at preventing the variant found first in South Africa.
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 if they are to remain effective against them, said a statement.
"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," it said. 
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, Covax said.
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 optimise 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 optimising the use of available vaccines, including the AstraZeneca/Oxford vaccine, it said.
The WHO Strategic Advisory Group of Experts on Immunization (SAGE) convened yesterday 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 today (Feb 9).   
Even though the 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 optimised 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. 
This means that additionally:
* Manufacturers must be prepared to adjust to the SARS-CoV-2 viral evolution, including potentially providing future booster shots and adapted vaccines, if found to be scientifically necessary;
* Trials must be designed and maintained to allow any changes in efficacy to be assessed, and to be of sufficient scale and diversity to enable clear interpretation of results;
* Enhanced genomic surveillance must be backed by rapid sharing of genetic and meta-data to allow for global coordination and response;
* Priority should be given to vaccinating high-risk groups everywhere in order to ensure maximum global protection against new strains and minimise the risk of transmission;
* Governments and donors, as well as development banks, should further support Covax in order to ensure equitable access and delivery, as well as meet ongoing research and development costs for next-generation vaccines.
Covax was set up to ensure global equitable access to safe and effective Covid-19 vaccines. With the world’s largest actively managed portfolio of Covid-19 vaccine candidates, the Covax Facility offers its self-financing participants and those eligible for support through the Gavi Covax Advance Market Commitment access to a diverse range of vaccine candidates, suitable for a broad range of contexts and settings. -TradeArabia News Service


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