Vaccine mix study anchors on Sinovac as first dose

MANILA, Philippines — The Department of Science and Technology (DOST) is studying how the Chinese-developed Sinovac jabs will work with other vaccine brands.

DOST Undersecretary for research and development Rowena Cristina Guevara said yesterday Sinovac was chosen as the first dose to be administered because of its stable supply in the country. The second doses will be Sputnik V, AstraZeneca, Pfizer and Moderna.

Guevara noted that all these vaccines have been granted emergency use authorization by the Food and Drug Administration (FDA).

“A total of 3,000 participants will be recruited from eight study sites nationwide. Eligible participants are those included in the A1 to A4 priority groups in line with the DOH (Department of Health) and COVAX Facility guidelines. Participants will also be screened based on the inclusion and exclusion criteria of the study,” Guevara said.

“The study aims to determine the safety and immunogenicity of completing the vaccination with available COVID-19 vaccines in the Philippines in those given Sinovac as the first dose,” she added.

The proposed study sites are Antipolo or Marikina, Manila, Pasig, Makati or Pasay, Muntinlupa, Quezon City, Cebu and Davao.

There is an ongoing major trial in the United Kingdom to examine whether different COVID-19 vaccines can safely be used for two-dose regimens.

The DOST has provided a funding of P133 million for the vaccine mix-and-match study to be led by the Philippine Society for Allergy, Asthma and Immunology.

The study is expected to start this month once the DOST receives the go-signal from the FDA and Philippine Health Research Ethics Board. It will run for 18 months.

The DOST also funded another study on the efficacy of the national COVID-19 vaccination program to be undertaken by the University of the Philippines - Manila, with a budget of P114.9 million.

Group A will study the same vaccines under the same brand. Group B will study the vaccines to be interchanged and Group C the special high-risk group to be given a booster dose.

Under Group A, the completion of the Sinovac-Sinovac and AstraZeneca-AstraZeneca vaccination series will be studied to act as the control of the study. For Group B, the vaccines to be combined after the first Sinovac dose are the other vaccines that have been given EUA.

Group C will match the same set of vaccines but as a third dose.

“This means that after the completion of the vaccination of Sinovac, AstraZeneca, Sputnik V, Pfizer and Moderna will be administered to act as a booster dose,” Guevara said.

“Aside from determining the safety and immunogenicity of interchanging vaccine brands to complete COVID-19 vaccine series, the study also aims to determine if the high-risk population who already completed the dosing regimen of the Sinovac vaccine would elicit a better immune response after the immunization of a booster dose from a different vaccine brand,” she added.

Guevara said the vaccine mix-and-match trial would not include people under 17 years of age.

“The clinical trial will only include participants aged 18 and above. The vaccine expert panel would also like to enroll those 70 and above,” she said.