MANILA — The Food and Drug Administration said on Tuesday that the the national reference laboratory for emerging diseases will be evaluating rapid antibody test kits as the number of COVID-19 cases in the Philippines continue to rise.

“The Research Institute for Tropical Medicine (RITM) is now ready to evaluate rapid antibody test kits for COVID-19 disease,” FDA Director General Eric Domingo said in a statement.

Domingo said this will allow the RITM to test the reliability of the kits on local samples.

While the FDA has approved rapid antibody test kits, the Department of Health still considers polymerase chain reaction (PCR) test kits as the gold standard for COVID-19 testing.

• READ: Explainer: What’s the difference between PCR-based and rapid test kits for COVID-19?

PCR test kits are able to match patient samples with the genetic material of the virus, while rapid test kits only measure antibodies in a patient’s blood.

The DOH has said that this can be prone to false negatives since a person might not yet produce antibodies at the start of the infection.

But because of the increasing need for testing, the DOH allowed the use of rapid test kits for preliminary screening of patients who will need PCR validation.

• READ: FDA approves 5 COVID-19 rapid test kits despite accuracy concerns; issues guidelines

Domingo said the RITM evaluation “will guide end users in selecting the kits they will use for testing.”

The FDA explained that the RITM was not able to evaluate rapid test kits earlier because of the high volume of PCR testing “and their laboratory’s lack of well-characterized serum samples needed to evaluate the rapid test kits.”

The agency pointed out that while other countries allow the sale of unregistered test kits, in the Philippines, the FDA will only approve test kits registered and approved by counterpart government agencies or pre-qualified by the World Health Organization.

Since the start of the pandemic, the FDA has approved 16 antibody rapid test kits. These test kits have been approved by other countries and had the necessary documentation required by the FDA.

All 16 registered test kits have already been directed by the FDA to submit samples to the RITM within 30 days of receiving a notification for performance evaluation.

“Recent news from other countries reporting poor performance of rapid antibody tests have cast doubts on the accuracy of some kits," Domingo noted.

"As the Philippines embarks on a mass testing strategy using both PCR-based and rapid antibody test kits, validation of rapid kits by the RITM would be helpful in choosing the best products to use as we go forward now and after the end of the ECQ,” he said.