Mixing-matching Covid vaccines ‘dangerous’: WHO chief scientist

Washington: Dr Soumya Swaminathan, WHO’s chief scientist, has warned against mixing and matching of Covid-19 vaccines by different manufacturers for the first and second doses.

She called it a “dangerous trend” and said that there was a lack of data about the impact of the process.

“There are people who are thinking about mixing and matching. We receive a lot of queries from people who say they have taken one [dose] and are planning to take another one (doses). It’s a little bit of a dangerous trend here. We are in a data-free, evidence-free zone as far as mix and match,” Swaminathan said in an online briefing.

Mixing and matching of Covid-19 vaccines is a method of immunization using two doses of the shot from different manufacturers.

Most vaccines, including Pfizer-BioNTech, Moderna, University of Oxford-AstraZeneca, Bharat Biotech as well as the Russian Sputnik V, are all required to be administered in two doses with the prescribed intervals between the shots differing for each vaccine.

Sputnik V also has a single-dose vaccine named Sputnik V Lite and the jab by Johnson & Johnson is a single-dose vaccine too.

“There is limited data on mix and match. There are studies going on, we need to wait for that. Maybe it will be a very good approach. But, at the moment we only have data on the Oxford-AstraZeneca vaccine, followed by Pfizer. It will be a chaotic situation in countries if citizens start deciding when and who will be taking a second, a third and a fourth dose,” she said.

She also stressed the need for equal distribution of the vaccine globally.

“We have four countries that have announced booster programs and a few more that are thinking about it. If 11 high and upper-middle-income countries decide that they will go for a booster for their population, or even sub-groups, this will require an additional 800 million doses of vaccine,” she said.

Image courtesy of (latestly.com)

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