The team of experts say that there is a need to develop COVID-19 vaccines that have high impact on prevention of infection and transmission.
The technical advisory group on COVID-19 vaccine composition (TAG-CO-VAC) of the World Health Organisation (WHO) has said that the composition of current COVID-19 vaccines may need to be updated.
The group said this in an interim statement on COVID-19 vaccines in the context of the circulation of the Omicron SARS-CoV-2 variant.
The WHO team of experts says that this is needed “to ensure that COVID-19 vaccines continue to provide WHO-recommended levels of protection against infection and disease by variants of concern, including Omicron and future variants.”
The technical advisory group also considers that there is a need to develop COVID-19 vaccines that have high impact on prevention of infection and transmission, in addition to the prevention of severe disease and death.
The TAG-CO-VAC said that it will consider a change in vaccine composition to ensure that vaccines continue to meet the criteria established in WHO’s Target Product Profile for COVID-19 vaccines, including protection against severe disease and, to improve vaccine-induced protection.
WHO has established TAG-CO-VAC to review and assess the public health implications of emerging SARS-CoV-2 variants of concern on the performance of COVID-19 vaccines and to provide recommendations to WHO on COVID-19 vaccine composition.
Repeated booster doses of the original vaccine unlikely to be appropriate
In the context of the circulation of the Omicron variant, currently sweeping across the world, the TAG-CO-VAC has urged for a broader access of the existing COVID-19 vaccines for primary and booster doses across the globe. This, it hopes, will help mitigate the emergence and impact of new variants of concern.
TAG-CO-VAC was established by the WHO in September 2021 as a multidisciplinary group of 18 experts to review and assess the public health implications of emerging variants of concern on the performance of COVID-19 vaccines and provide recommendations on COVID-19 vaccine composition.
Since its emergence, the SARS-CoV-2 virus has continued to evolve and WHO has designated five variants as SARS-CoV-2 variants of concern to date – namely Alpha, Beta, Gamma, Delta and Omicron – due to their impact on transmission, disease severity, or capacity for immune escape.
“While the Omicron variant is spreading rapidly across the world, the evolution of SARS-CoV-2 is expected to continue and Omicron is unlikely to be the last variant of concern,” says the interim statement of the WHO group of experts.
On the oft-iterated issues of vaccine equity, the experts have argued that “a vaccination strategy based on repeated booster doses of the original vaccine composition is unlikely to be appropriate or sustainable.”
It argues that equity in vaccine distribution is necessary to achieve global public health goals. It says that steps towards distributing the vaccine to developing nations is also necessary bearing in mind the evolution of the virus.
In the interim, the TAG-CO-VAC encourages COVID-19 vaccine manufacturers to generate and provide data on performance of current and Omicron-specific COVID-19 vaccines.
“These data will be considered in the context of the framework mentioned above to inform the TAG-CO-VAC decisions when changes to vaccine composition may be required,” the technical advisory group says in its statement.
Image: WHO – who.int