Korea’s National Medical Center says it intends to make the most out of Pfizer vaccines by extracting up to seven doses from a vial using special syringes. As standard, each Pfizer vial yields five to six doses.

Dr. Oh Myoung-don, heading the NMC’s COVID-19 immunization program, said on Wednesday in a text message response to a question from The Korea Herald that “wasting the extra dose could not be justified when the vaccines do so much to save lives.”

“When we can get seven doses out of a single vial, we are going to use them,” he said.

The Pfizer vaccine, which is trickier to store and prepare, is being administered at select institutions across Korea. The NMC is among them, and became the first to give the Pfizer vaccine to around 300 health care workers on Saturday.

But drawing the additional doses out of Pfizer vials is “not officially recommended,” according to the national health agency’s commissioner Jung Eun-kyeong.

In response to a press question, Jung told a news briefing Monday that it was “not advisable to obtain more doses from the vaccine vials beyond their standard allotment” and issued a particular warning against mixing any leftover vaccine to yield more doses.

Infectious disease specialist Dr. Eom Joong-sik at Gachon University Medical Center said in a statement posted to Facebook Sunday that it would be “impossible to measure by eye that the remaining liquid in each vial is in fact 0.3 milliliters (the amount that makes up one full dose).”

“This is going to put a lot of stress on workers at vaccination sites who are already stressed out as is.”

Dr. Kim Woo-joo, another infectious disease specialist at Korea University Medical Center, said in a phone interview Wednesday that stretching the Pfizer vaccines to seven doses was “prone to errors.”

“Using the occasional seventh dose has been tried in other countries, and then eventually disallowed.” The dose-maximizing syringes are “‘low dead-space syringes’ not ‘zero dead-space syringes,’” after all, he said.

The debate took off after the NMC’s president Dr. Chung Ki-hyun told Prime Minister Chung Sye-kyun that extracting seven doses from Pfizer vaccine vials was “a marvelous discovery” during a press event amid Saturday’s rollout. Chung could not be reached for comment.

By Kim Arin (arin@heraldcorp.com)