Study shows Sinovac shot safe for kids as young as 3

(File photo from REUTERS)

Sinovac’s COVID-19 vaccine was found to be safe and effective against COVID-19 infection and could provide protection against the Delta and Omicron variants to children as young as 3 years old, according to vaccine and infectious disease experts.

Dr. Liza Gonzales of the Philippine Pediatric Society said during an online Kapihan on Thursday that CoronaVac, the brand name of Chinese company Sinovac’s vaccine, was “well-tolerated and safe” among children age 3 to 17 years, based on a clinical trial conducted in the Chinese province of Hebei. The study based on this trial was published in June last year in the medical journal Lancet.

A two-dose regimen composed of 3 micrograms each was found to induce higher neutralizing antibodies compared to a 1.5-microgram vaccine shot, Gonzales said.

“They need to find which is the optimal dose that will be able to give the best humoral and cellular immune response. With other vaccine platforms, dosage is reduced due to safety concerns. But with Sinovac, they did not find anything with regards to safety,” Gonzales told reporters.

Another clinical trial, this time in Chile, showed that Sinovac provided “mild or modest protection” against the Omicron and Delta variants, according to Gonzales, who is an infectious disease specialist.

The safety trial, which was participated by 963 Chilean kids and teens age 3 to 17, showed that neutralizing antibodies and T cells, or the white blood cells that fight infection, “recognized” Delta and Omicron variants of SARS-CoV2, the virus that causes COVID-19.

But Gonzales said that further studies have yet to be made regarding these findings because the Chilean trial used a “pseudovirus neutralization assay,” a virological tool developed for the evaluation of antibodies against coronavirus in laboratories.

“We don’t know yet how (Sinovac) will do in the real world. That’s what we’re waiting for. But at least we know that there are neutralizing antibodies as well as T cell responses against these variants. We need further studies before we can say it is really effective,” Gonzales said.

Panel review

The studies were presented as the Department of Health awaits the review of the Health Technology Assessment Council (HTAC), an independent advisory body created under the Republic Act 11223 or the Universal Health Care Act, on the use of the Sinovac jab for age 6 and up.

The Food and Drug Administration (FDA) last week approved the amendment to the emergency use authorization (EUA) of Sinovac to include the pediatric population as an eligible recipient of the Chinese vaccine.

Dr. Nina Gloriani, Vaccine Expert Panel (VEP) chair, explained that the current recommendation to administer Sinovac to 6 to 17 years old was based on a separate large-scale study in Chile. It covered two million kids and teens of the same age group who received two shots of either Pfizer or Sinovac.

It found that Sinovac’s effectiveness against COVID-19 infection was at 74.12 percent 14 days after the second dose. However, this was lower than Pfizer’s effectiveness at 84.94 percent.

Sinovac was also 90.24-percent effective against hospitalization and 100-percent effective in preventing intensive care unit (ICU) admission and death.

“We have data only for vaccine effectiveness for 6 to 17 years old. The study did not include effectiveness [of Sinovac] to 3 to 5 years old, so that became our basis. If they provide us data on effectiveness for the other age groups, the recommendation could be amended,” Gloriani said.

The government last month started giving COVID-19 jabs to children aged 5 to 11 with or without comorbidities following regulatory approval by the local FDA. Pediatric specialists have said that children did not have a “natural resistance” to the coronavirus.

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