DOST starts clinical trials for ‘mix-and-match’ COVID-19 vaccines

MANILA, Philippines — The Department of Science and Technology (DOST) on Saturday said the dry run for the “mix-and-match” clinical trials for COVID-19 vaccines has started this month to determine the efficacy of various brands of vaccines that might be administered as third or booster shots.

Speaking at the televised Laging Handa public briefing, DOST Undersecretary for Research and Development Rowena Guevara said the first dry run took place in Marikina City last Oct. 18, to be followed in Muntinlupa City and Davao City on Oct. 25 and 29.

“In the mix and match, we will know if you can have a third dose of a vaccine type that is different from that of your first two shots. We want to know the effectivity of the [third dose], its safety, and if [the results] would be acceptable to us,” she said.

Guevara said the dry run was in preparation for the pilot launches for the study, which would take place in yet-to-be disclosed facilities in the three cities.

The DOST official said the results of the study would be available by the first quarter of next year when the government would have considered the possibility of administering third or booster shots to the population.

Although some countries such as the United States are now administering booster shots to the elderly and persons with comorbidities, the World Health Organization (WHO) has called for a moratorium on distributing boosters until next year, considering that more than half of the world’s population, especially in the poorer countries, have not yet even received a single dose.

The WHO experts’ group later recommended additional doses for those who were immunocompromised or have weak immune systems who were susceptible to breakthrough or postvaccination infection of COVID-19.

The Department of Health agreed with the WHO, adding that the recommended additional dose was different from a booster shot.

The country’s vaccine czar, Secretary Carlito Galvez Jr., earlier this month said the government was planning a “revaccination” program lasting six to eight months.

He added that vaccine supplies would be enough to start giving booster shots to healthcare workers starting either next month or in January.

Plant-based relief

Meanwhile, Guevara said that aside from virgin coconut oil (VCO), the DOST was already considering the use of medicines derived from the local herb “tawa-tawa” and the aromatic plant “lagundi” to ease symptoms of people with COVID-19.

She said that while studies had encouraging results, the final or definitive test must be conducted using live virus cultures. This would be done abroad since it required a biosafety level 3 facility, which the Philippines did not have.

“The clinical studies we made have not established directly the antiviral properties of [the medicines derived from] these three [plants]. What was established was what they do to the COVID-19 symptoms,” he said.

Guevara noted, however, that VCO has been approved by the Food and Drug Administration as “functional food,” lagundi as herbal medicine, and tawa-tawa as herbal supplement.

“We can say that these three locally available [products] can provide symptomatic relief for COVID-19,” she said.

The DOST official said that in vitro trials involving VCO showed its compounds decreased the viral load of people with mild COVID-19 cases by 60 to 90 percent.

For lagundi, she said a study concluded in August showed COVID-19 patients who took the plant-based medicine had lesser degrees of symptoms, including anosmia or loss of smell, compared to those who did not take the medicine.

For tawa-tawa, she disclosed that feedback from 172 patients-respondents with mild to moderate COVID who were given food supplements derived from the herb showed that their symptoms disappeared three to five days later.