The US Food and Drug Administration (FDA) has issued updated guidance for companies developing vaccines, tests and therapeutics to address COVID-19 variants.
There are concerns that existing vaccines may be less effective against new COVID-19 variants and may need to be adapted to address these variants.
In updated guidance, the FDA said that currently authorised vaccines should ‘remain effective’ against the currently circulating variants.
However, the agency added that if a variant emerges in the US that is ‘moderately’ or ‘fully’ resistant to existing vaccines, it may be necessary to modify the vaccines.
In this situation, the FDA said that it expects the manufacturing information to remain generally the same for both an authorised vaccine and a modified vaccine candidate developed by the same manufacturer.
Apart from the manufacturing information, the FDA guidance recommends that clinical data for the effectiveness of modified vaccines should be supported by clinical immunogenicity studies.
Such studies would need to compare an individual’s response to the virus variants induced by the modified vaccine to the immune response induced by the original, authorised vaccine.
The FDA has also encouraged vaccine makers to study the modified vaccine in both non-vaccinated individuals and in people who have previously been vaccinated with the original, authorised jab.
The regulatory agency also added in the guidance that ‘further discussions’ will be required to decide if these potential future, modified COVID-19 vaccines could be authorised without the need for clinical studies.
For COVID-19 tests, the FDA also highlighted a previous safety alert that warns that the presence of viral genetic mutations in a patient sample could potentially alter the performance of diagnostic tests.
In its guidance to test developers, the FDA recommended that companies consider the potential for future viral genetic mutations when designing a test, as well as conducting routine monitoring to evaluate the potential impact of new/emerging variants on the performance of molecular, antigen and serology COVID-19 tests.
Finally, for therapeutics – particularly monoclonal antibodies targeting the virus – the FDA has advised drug developers to continuously monitor genomic databases for emerging COVID-19 variants and evaluate specific variants in the product target that could potentially impact its activity.
“By issuing these guidances, we want the American public to know that we are using every tool in our toolbox to fight this pandemic, including pivoting as the virus adapts,” said Janet Woodcock, acting commissioner of the FDA.
“We need to arm healthcare providers with the best available diagnostics, therapeutics and vaccines to fight this virus. We remain committed to getting these life-saving products to the frontlines,” she added.