DOH warns vs mixing vaccine brands

MANILA, Philippines — The country’s treatment czar yesterday expressed caution over the possibility of inoculating with two different brands of COVID-19 vaccines for the first and second doses.

Health Undersecretary Leopoldo Vega said that at this time, there is no scientific data on the safety of injecting different vaccine brands as protection for an individual against COVID.

“It’s uncertain. It didn’t go through a study. There is no scientific basis,” Vega said in a radio interview, noting that vaccines have different platforms and, thus, using two brands may not be a good idea.

AstraZeneca, Gamaleya and Janssen vaccines use viral vector while Sinovac and Bharat use inactivated virus. Pfizer-BioNTech uses messenger ribonucleic acid (mRNA).

Philippine Foundation for Vaccination executive director Lulu Bravo backed Vega’s position that there is still no scientific basis to mix COVID-19 vaccines.

“No company has done a study on mixing vaccines with others. It remains to be investigated,” Bravo said in a public briefing. “It is possible that the efficacy may increase, decrease, or stay the same. It remains to be seen. But it won’t be harmful if we try.”

Amid the uncertainty of the next deliveries, the Vaccine Expert Panel (VEP) is already studying the possibility of allowing a person to be vaccinated with two different brands of COVID-19 vaccines.