CORONAVIRUS/Taiwan FDA sees 'difficulties' with UBI Asia's new EUA review request

Taipei, Sept. 7 (CNA) Taiwan's Food and Drug Administration (FDA) has voiced its doubts over a bid by Taiwan-based United Biomedical Inc. (UBI) Asia to reapply for emergency use authorization (EUA) for its COVID-19 vaccine.

The company's original EUA request was rejected on Aug. 16 after a measure of its UB-612 vaccine's ability to neutralize the COVID-19 virus failed to meet the Taiwan FDA's standard.

In a statement Monday, however, it said a third dose given to 50 people who participated in its Phase 1 trial 8-10 months after they received a second dose produced strong data, and indicated it would present the new findings to the Taiwan FDA to have its EUA application reviewed again.

Taiwan FDA Director-General Wu Shou-mei (吳秀梅) responded Tuesday that UBI Asia's request for a new review had its "difficulties" because of the very small number of participants who received the third dose and said it might not be persuasive to the experts on the review panel.

Vaccine makers have the right to request a new EUA review, she said, but noted that she had not seen any documents or data from UBI Asia to be reviewed as of noon Tuesday.

If UBI Asia does submit documents, the Taiwan FDA will review the information provided, Wu said, adding that it would be premature to make any other comments on the issue without UBI Asia's submissions.

The controversy over EUA approval in Taiwan is due in part to the fact that local companies with vaccine candidates have not subjected their vaccines to large-scale Phase 3 clinical trials, which are typically used to determine if a vaccine is effective in real life scenarios.

Instead, the government has used the concept of immunobridging, which compares different vaccines based on the strength of neutralizing antibodies generated in the blood of a small sampling of vaccine recipients.

For a vaccine to be granted an EUA by the Taiwan Food and Drug Administration, it had to have geometric mean titers (GMTs) -- an indicator of neutralizing antibodies across a test group -- at least equal to two-thirds the level found in recipients of the AstraZeneca vaccine commonly given in Taiwan.

The testing had to be done in the same lab using the same protocols to ensure the consistency of the results, a necessary step because there is no uniform, globally accepted method for measuring GMTs or how high the GMT level should be to indicate protection.

The UBI Asia vaccine fell short of the 125 GMTs necessary to meet the threshold, and its EUA application was therefore rejected.

Another domestic company, Medigen Vaccine Biologics, had 3.4 times the GMTs found in the AstraZeneca vaccine and was given EUA approval.

UBI Asia has argued, however, that the standard was not comprehensive enough and did not consider the neutralizing effect of antibodies specifically against the Delta variant, which has become increasingly prevalent around the world.

It has also said its vaccine attacks the COVID-19 virus in ways other than through neutralizing antibodies, such as through T-cell and B-cell immune memory response, which was not reflected in the standard adopted by Taiwan's government.

The government ordered 5 million doses each of the Medigen and UBI Asia vaccines before the EUA approval process began, and the Medigen vaccine is currently being administered.