KEY POINTS

  • The country has administered more than 18 million Sinovac vaccine doses
  • The Philippines FDA said more time is needed to determine whether the vaccine's protections wane over time
  • The Philippines set a new record of COVID-19 cases Thursday

The majority of breakthrough COVID-19 infections in the Philippines occurred in people who received the Chinese-made SinoVac COVID-19 vaccine, according to government data. 

The Philippine government administered a total of 35,838,964 doses of COVID-19 vaccines as of Sept. 5. Of the total number of doses, 18,583,548 were of the two-dose SinoVac vaccine, data from the country’s National COVID-19 Vaccination Dashboard showed. 

Filipino health officials confirmed that as of Aug. 29, a total of 242 cases of breakthrough COVID-19 infections have been recorded in the country. Of the total number, 180 or 74% received the SinoVac vaccine. At least four died. 

Despite the number of breakthrough cases, Philippines Food and Drug Administration Director-General Eric Domingo said it is too early to conclude whether the effectiveness of the SinoVac shots waned over time. 

“Our numbers are still small and we have to get more data in the coming months,” Domingo said in a press conference, GMA Network reported. “The data for September and October might give us an indication, but as of this time, five months after the vaccination, information is not yet convincing that there is waning protection.”

In a study published in July, Chinese researchers found that antibodies triggered by the SinoVac COVID-19 vaccine declined below a threshold six months after participants between the ages of 18 and 59 received the second shot. 

An expert in Singapore also said that SinoVac produced significantly lower levels of antibodies compared to the Pfizer-BioNTech COVID-19 vaccine shots. 

Antibody levels in people who completed the two-dose Pfizer shots were between 1,300 and 2,000 international units per milliliter. In people who received the SinoVac shots, the antibody levels were zero to 40.

Chinese researchers from the Shanghai Fosun Pharmaceutical (Fosun Pharma) have since partnered with BioNTech to develop an mRNA booster vaccine to increase antibody levels in people who received the less effective SinoVac shots.

It is unclear whether the Philippine government plans to administer booster shots, even after authorities on Thursday reported 22,820 new cases — the highest the country has recorded since the beginning of the pandemic. 

As of Thursday, the Philippines reported 2,134,005 COVID-19 infections and 34,672 deaths, according to Johns Hopkins University's data. 

The EU drug regulator has listed the neurological disorder Guillain-Barre syndrome as a 'very rare' possible side effect of the AstraZeneca Covid-19 vaccine The EU drug regulator has listed the neurological disorder Guillain-Barre syndrome as a 'very rare' possible side effect of the AstraZeneca Covid-19 vaccine Photo: AFP / Ben STANSALL