World Health Organization Warns Against Mixing Covid-19 Vaccines

The World Health Organization’s chief clinical scientist has advised governments and individuals against mixing and matching COVID-19 vaccines from different manufacturers, saying such decisions should be left to public health authorities.

“It’s a little bit of a dangerous trend here,” Dr Soumya Swaminathan told an online briefing on Monday after a question about booster shots. “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.

“Individuals should not decide for themselves, public health agencies can, based on available data,” she said in the tweet. “Data from mix and match studies of different vaccines are awaited – immunogenicity and safety both need to be evaluated.”

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 clinical trial led by the University of Oxford in the UK is ongoing to investigate mixing and matching the regimen of AstraZeneca and Pfizer vaccines. The trial was recently expanded to include the Moderna Inc and Novavax Inc vaccines.

Meanwhile, Thailand’s Prime Minister Gen Prayut Chan-o-cha changed his stance on the mixing of Covvd-19 Vaccines Sinovac and AstraZeneca as the second dose. On Wednesday Gen Prayut told the Public Health department to kick off its mix-and-match vaccine strategy to combat the fast-spreading Delta variant, despite WHO concerns.

Gen Prayut also ordered the collection of data related to the jabs, especially in relation to the elderly and people with chronic conditions. “The government will look for the best way to tackle the spread of the Delta variant and will also boost public awareness,” a Government spokesperson said.

He added that Gen Prayut had never sought to suspend the mix-and-match vaccine strategy giving people who received the first dose of China’s Sinovac vaccine a second dose with AstraZeneca.

“The prime minister has asked all parties to listen to the National Communicable Disease Committee’s comments on the new strategy,” the spokesperson added.

Source: Reuters, CTN News