The World Health Organization’s chief scientist has advised individuals against mixing and matching Covid-19 vaccines from different manufacturers, saying such decisions should be left to public health authorities. Chief scientist warns of ‘chaos’ if individual mix vaccine.
- Soumya Swaminathan, the Chief Scientist at the World Health Organization, told an online briefing on Monday after a question about booster shots, “It’s a little bit of a dangerous trend here. 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.”
- Swaminathan had called mixing a “data-free zone” but later clarified her remarks in an overnight tweet. In the tweet, she said: “Individuals should not decide for themselves, public health agencies can be based on available data. Data from mix and match studies of different vaccines are awaited immunogenicity and safety both need to be evaluated.”
- Some studies are showing positive results from mixing vaccines, but these are in the preprint stage and need further studies to support them. Mixing vaccines is seen as an option in some countries where supply is short of one particular vaccine.
- However, WHO is concerned about a situation where individuals decide for themselves which vaccines to get and how far apart to space them without guidance from health authorities.
- The WHO’s Strategic Advisory Group of Experts on vaccines said in June the Pfizer Inc vaccine could be used as a second dose after an initial dose of AstraZeneca, if the latter is not available. A Spanish study found the Pfizer-AstraZeneca combination was highly safe and effective, according to preliminary results.
Meanwhile, preliminary research has found that some vaccine mixtures elicit strong protection, however. Early results from a British vaccine study published June 25 in The Lancet journal found that volunteers who received one dose of the Pfizer vaccine and one dose of the AstraZeneca vaccine produced high levels of antibodies and immune cells.
