Medical community anxiously awaits COVID-19 booster shots

MANILA, Philippine — Frontline healthcare workers are anxiously awaiting the green light for the rollout of booster or third shots of the COVID-19 vaccine as added protection, especially for people exposed to the coronavirus like them and for individuals vulnerable to breakthrough infections because they have comorbidities or are immunocompromised.

Doctors representing various medical societies who spoke this week at a roundtable discussion with reporters explained the need for another jab in the wake of studies and reports of breakthrough infections, or infections among those fully vaccinated.

But even prior to Thursday’s meeting, one of them, Dr. Rontgene Solante, an officer of the Philippine College of Physicians (PCP), already argued for a booster shot months after the government rolled out the national vaccination drive in March.

“With waning protection after six months, the population at risk are those health-care workers due to occupational exposure, elderly and immunocompromised due to poor immune response,” he told the Inquirer.

Solante said that a booster dose for health-care workers and a third dose for the elderly and immunocompromised would continue to protect them from getting infected or suffering from severe infection.

“Because of the above risk, I fully support giving them the booster and third dose the soonest time possible,” he said.

Who are at risk?

Dr. Carlo Trinidad, diplomate of the Philippine Society of Nephrology and a PCP fellow, said people who are immunocompromised are those with weakened immune system that could not effectively defend them against infections like COVID-19. Their immune system had been altered by, among others, drugs and diseases, such as diabetes, HIV, cancer, lupus and congenital disorders, he said.

Comorbidities refer to the presence of illnesses that are usually chronic or long term.

People with comorbidities who are at risk for breakthrough infection and a severe case are those with cardiovascular disease, type 2 diabetes mellitus, chronic kidney disease, HIV infection and cancer, Trinidad said.

He said an August 2021 study published by the US Centers for Disease Control and Prevention showed that 40 percent to 44 percent of breakthrough cases were immunocompromised individuals.

The study also found that the effectiveness of a two-dose vaccine was lower at 59 percent to 72 percent among immunocompromised people versus 90 percent to 94 percent among those who are not.

In the Philippines, the Food and Drug Administration (FDA) reported 642 breakthrough cases out of 20.3 million fully vaccinated as of Sept. 26. It said that 126 were infected 14 days after they got their second shot, the rest more than 14 days after full inoculation.

Studies have shown that antibodies against COVID-19 usually waned after several months and the protection provided by some vaccines also declined, Solante told reporters.

Mix and match

To prevent breakthrough cases, administering booster or third doses and the “mix and match” of vaccines must be done to optimize vaccine schedules and to enhance protection for the vulnerable population, he said.

“Evidence shows that the use of AstraZeneca or Pfizer as third dose to Sinovac resulted in higher antibody levels than a third dose of Sinovac to Sinovac,” Solante said.

He said the mixing and matching of Pfizer, Moderna and Johnson & Johnson also showed similar or higher antibody levels than getting the primary vaccine series (first and second dose) of the same jab.

Solante also said that other studies found no serious adverse events in the mix and match of Pfizer, AstraZeneca and Sinovac.

The Strategic Advisory Group of Experts of the World Health Organization has advised seniors inoculated with the China-made Sinovac and Sinopharm jabs to get a third dose.

Health Undersecretary Maria Rosario Vergeire on Friday said the Department of Health (DOH) had filed an application for an emergency use authorization for booster and additional shots.

More than 101 million doses of various brands of vaccines have been delivered to the Philippines as of Oct. 29. About 38 million doses are in storage in Metro Manila and elsewhere in the country ready for distribution.

According to Dr. Ted Herbosa, an adviser to the National Task Force Against COVID-19, the government will use the “just in time” system for the vaccines where the doses would be delivered to local governments that would be able to immediately administer the jabs.423 more deaths

Interior Secretary Eduardo Año challenged local government officials to fully vaccinate 70 percent of their constituents by the end of the year to achieve herd immunity.

The DOH on Saturday reported that the COVID-19 death toll breached the 43,000 mark, with 423 new fatalities raising it to 43,044.

The DOH recorded 4,008 new infections, increasing the total cases to 2,783,896.

Active infections numbered 47,690. About 74 percent were mild cases, 11.3 percent were moderate, 6.5 percent severe, 5.1 percent asymptomatic and 2.7 critical.

The 6,887 who recovered brought the total number of survivors to 2,693,162.

Of the 50,776 individuals tested, 3,961 were positive for the coronavirus, or a positivity rate of 7.8 percent.

—WITH REPORTS FROM LEILA B. SALAVERRIA, DEXTER CABALZA AND INQUIRER RESEARCH