Duque warns vs mixing and matching vaccine doses, cites insufficient data

Health Secretary Francisco Duque prepares to inject vaccine into the arm of a health worker in Dagupan City. WILLIE LOMIBAO

MANILA, Philippines — Citing insufficient data, Health Secretary Francisco Duque said Friday that for now, he does not advocate “mixed-use vaccines” or giving a person a second shot using a vaccine made by a different drugmaker.

Duque made the remark during a hearing in the House of Representatives on Friday where he was asked regarding the so-called combo-vaccination, or combining vaccines in two-dose inoculation for greater efficacy against the coronavirus disease.

“I do not advocate for this as of yet, there is no sufficient data to force the claim that a mixed vaccine policy works,” Duque said.

Duque said a problem may arise if a vaccinee experiences adverse side effects following a mixed use vaccination.

“Kapag nagbigay ka ng ibang bakuna sa first dose, halimbawa Sinovac, then second dose mo AstraZeneca, pag nagkaroon ng problema, adverse event following immunization, serious side effect, paano mo ituturo ‘yung siya ba ay first dose, Sinovac, or second dose, AstraZeneca?” Duque said by way of an example.

“Unless science comes forward with convincing evidence and data to show for example na vaccine Pfizer and Moderna na both using MRNA platform, baka doon pwede,” the health secretary added.

Health Undersecretary Maria Rosario Vergeire has maintained the position of both the Department of Health (DOH) and the Food and Drug Administration that the first and second doses of an administered vaccine should be of the same brand.

Despite this, due to low supply and the uncertainty of the next deliveries, the government’s Vaccine Expert Panel (VEP) has begun studying the possibility of allowing a person to be vaccinated with two different brands of COVID-19 jabs for the first and second doses.

In London, a study using different COVID-19 vaccines in two-dose inoculations is being expanded to include shots made by Moderna and Novavax.

The trial, known as the Com-Cov study, was first launched in February to look at whether giving the first dose of one type of COVID-19 shot and the second dose of another elicits an immune response that is as good as using two doses of the same vaccine.

EDV