Experts open to mixing Covid vaccine brands

The country’s vaccine expert panel is considering holding possible trials of mixing different Covid-19 vaccines of either the same or different platforms to see if the mix would contribute to additional immune response against the virus.

This comes after comments made by an official of the Chinese Center for Disease Control and Prevention claiming that its vaccines had “lower efficacy” and would need additional booster shots using a different platform such as messenger ribonucleic acid or mRNA.

But in a subsequent statement on state-owned Global Times, Dr. Gao Fu said his remarks were “misunderstood,” rather, he said “the vaccination process should be adjusted to improve vaccine efficacy.”

Dr. Nina Gloriani, panel chairman, said mixing vaccines under the same platform would not have any possible issues in terms of possible immunological conflicts with different vaccines of the same or different platform.

“Wala naman dapat isyu; it’s like, ‘yung isang subunit, spike ang laman, tapos ‘yung isang gusto mong palitan, Sinovac, which is inactivated. Nauna si spike at second mo ‘yung buong virus, ang mabu-boost n’ya ay ‘yung spike, pero it will have its own response to the other vaccine components na nasa virus (There should be no issue; it’s like the other subunit contained [the] spike [protein] and the one that you want to change, Sinovac, is inactivated. It will boost the spike protein and the second will be the entire vaccine, but it will have its own response to the vaccine components in the virus),” Gloriani told reporters in a briefing on Tuesday.

She said the United States and some countries in Europe are already doing trials on inoculating people using different vaccine brands.

According to Gloriani, mixing vaccines of different platforms can be done as long as there are guidelines regarding the administration of different vaccines.

She said mixing different vaccine brands or mixing different viral platforms is also a “reasonable and practical” move because of the scarcity of vaccine supplies in the country.

“Because it is a very practical or realistic scenario that we may be looking at… hindi pwedeng i-delay for too long ‘yung second dose (We cannot delay the second dose for too long),” Gloriani added.

In a forum organized by the Management Association of the Philippines, infectious diseases specialist Dr. Benjamin Co said it is possible to take different vaccine brands, as there is no such thing as a “vaccine overdose.”

“But I probably would wait for some of the data, kasi wala pang isang taon ang clinical trials ng mga vaccines (as the clinical trials of the vaccines have not yet reached a full year), so maybe we can wait for the vaccines that are forthcoming as they are created as boosters for variants of concern,” Co added.

Former Health secretary Dr. Esperanza Cabral agreed with Co, saying it is possible to take different vaccine brands for the same vaccine-preventable disease.

Gloriani said clinical trials for the Sinovac vaccine among senior citizens have not yet started as they plan to amend their trial protocol of taking the placebo versus the vaccine that will not affect the current rollout among the group.

Meanwhile, Johnson & Johnson subsidiary Janssen Pharmaceuticals has already recruited 700 subjects in the clinical trial of the JNJ-78436735 vaccine using a two-dose regimen.

Gloriani said the manufacturer is now monitoring the participants in the study and a preliminary interim data for efficacy may be released within the next few months.

She added that the interim data from the double-dose regimen might be considered by the Food and Drug Administration in its evaluation of the vaccine, which applied for emergency use authorization in March.