Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, on Wednesday said it would be challenging to distribute vaccines that use messenger RNA based technology in developing countries, owing to their cold storage requirements.
The comments come days after Pfizer Inc said its experimental COVID-19 vaccine is more than 90 per cent effective based on initial trial results and that it expects to file for US emergency authorization this month.
The vaccine candidate uses synthetic messenger RNA to activate the immune system against the virus and needs to be kept at minus 70 degrees Celsius (-94 F) or below.
"It does have cold-chain challenges as it were. In a country like the UK and the United States we can address them and it still would be challenging. But, probably much more challenging in countries in the developing world," Mr Fauci said at the Financial Times' global pharmaceutical and biotechnology conference.
Moderna Inc's experimental vaccine, which is on track to report early data from a late-stage trial later this month, also uses mRNA technology and needs to be stored at minus 20 degrees Celsius (-4 F).
"That's the reason why when we put together our plan ... we want to have a diversity of what we call vaccine platforms. It is not just mRNA ... there are three separate platforms that are being looked at in the United States," Mr Fauci said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
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