Mix and matching some COVID vaccines gives high immunity: Study | Al Jazeera

A major British study into mixing COVID-19 vaccines has found that people had a better immune response when they received a first dose of AstraZeneca or Pfizer-BioNTech shots followed by Moderna nine weeks later, according to the results.

“We found a really good immune response across the board … in fact, higher than the threshold set by Oxford-AstraZeneca vaccine two doses,” Matthew Snape, the Oxford professor behind the Com-COV2 trial, told the Reuters news agency on Monday.

The findings supporting flexible dosing will offer some hope to low- and middle-income countries that may need to mix vaccines for first and second doses if supplies run low or become unstable.

“I think the data from this study will be especially interesting and valuable to low- and middle-income countries where they’re still rolling out the first two doses of vaccines,” Snape said.

“We’re showing … you don’t have to stick rigidly to receiving the same vaccine for a second dose … and that if the programme will be delivered more quickly by using multiple vaccines, then it is OK to do so.”

If the AstraZeneca-Oxford vaccine is followed by a Moderna or Novavax shot, higher antibodies and T-cell responses were induced versus two doses of AstraZeneca-Oxford, according to researchers at the University of Oxford.

The study of 1,070 volunteers also found that a dose of the Pfizer-BioNTech vaccine followed by a Moderna shot was better than two doses of Pfizer-BioNTech.