The Department of Science and Technology (DOST) announced Thursday, June 3, that the Philippines’ study on the safety and efficacy of mixing and matching five coronavirus disease (COVID-19) jabs is expected to start by next month.
DOST Undersecretary for Research and Development Rowena Cristina L. Guevara, who chairs the Task Group on Vaccine Evaluation and Selection (TG-VES, said the 18 month-long clinical trial will involve 3,000 participants who are aged 18 and above and come from A1 to A4 priority groups under the country’s vaccination program.
The study will be conducted by the Philippine Society for Allergy, Asthma, and Immunology (PSAAI), led by Dr. Michelle De Vera.
Before the clinical trial starts, the PSAAI has to secure the approval of the Food and Drug Administration (FDA) and the Philippine Health Research Ethics Board (PHREB).
Guevara said five vaccine brands will be used for the PSAAI study. These are Sinovac, Sputnik V, AstraZeneca, Pfizer and Moderna.
Here are Guevara’s answers to some of the frequently asked questions (FAQs) regarding the clinical trial.
Which vaccine brands will be used for the clinical trial or study on mix and match of vaccines?
The study will evaluate interchanging vaccine brands to complete the vaccination series, with Sinovac as the first dose. Sinovac was chosen as it is considered to be the most stable vaccine supply in the country. All of the vaccines to be mixed and matched with Sinovac are vaccines that have already been given an Emergency Use Authorization (EUA) approval by the Philippine FDA, specifically: AstraZeneca, Sputnik V, Pfizer, and Moderna.
How will the vaccines be matched?
The study will have three groups with a total of 12 study arms. Group A will study the same vaccines under the same platform. Group B will study the vaccines to be interchanged, and Group C will study 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. Meanwhile for Group B, the vaccines to be combined after the first Sinovac dose are vaccines that have already been given an Emergency Use Authorization (EUA) approval by the Philippine FDA, which are specifically: AstraZeneca, Sputnik V, Pfizer, and Moderna.
Group C will match the same set of vaccines but as a third dose. This means that after the completion of the vaccination series of Sinovac, AstraZeneca, Sputnik V, Pfizer, and Moderna will be administered to act as a booster dose.
What about the study on booster doses, is this part of this study?
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 platform or brand.
What are the objectives of this study on mixing and matching vaccine brands?
The study is a multi-site, convenience sampling, unblinded trial which will be spearheaded by Dr. Michelle De Vera of the Philippine Society for Allergy, Asthma, and Immunology (PSAAI). Primarily, the study aims to determine the safety and immunogenicity of completing the vaccination series with available COVID-19 vaccines in the Philippines in those given Sinovac as the first dose.
As mentioned earlier, the trial will also analyze whether those who already completed the dosing regimen for Sinovac will have a better immune response after the immunization of a booster dose from a different vaccine platform or brand.
How many participants are needed and who can participate in the Clinical Trial for Mix and Match?
A total of 3,000 participants will be recruited from 8 proposed study sites nationwide. Eligible participants are those included in the A1 – A4 vaccination priority group in line with the DOH rollout and COVAX facility guidelines. Participants will also be screened based on the inclusion and exclusion criteria of the study.
Will the Mix and Match Clinical Trial include participants ages 17 and below?
No, the clinical trial will only include participants aged 18 years old and above.
The Vaccine Expert Panel (VEP) would also like to enroll those 70 years old and above.
Will the clinical trial affect the limited supply of vaccines in the country?
Local clinical data to be generated from the Filipino people on the interchanging of available COVID-19 vaccines in the Philippines can serve as the basis for deciding which vaccines/vaccine platforms can be mixed, which may be applied by the Department of Health (DOH) for an Emergency Use Authorization (EUA). The relevant data generated may provide basis for the guidelines/policies of the DOH on the vaccination rollout especially during situations of limited vaccine supplies or vaccine shortage.
When will the clinical trial commence?
The study is expected to run for 18 months. It is expected to start in July 2021 to November 2022, as soon as approval from the Ethics Boards and FDA has been sought.