South Korea on Friday paved the way to approving Pfizer’s mRNA vaccine for COVID-19 as another group of pharmaceutical experts positively opined on the vaccine’s efficacy and safety.

On the same day, Korea received enough Pfizer vaccines to inoculate 58,500 people, sourced from the global COVAX facility. This lot, under special import exemptions, can be used without the Drug Ministry’s emergency approval, with the first round of vaccinations to start Saturday for frontline medical workers.

Coincidentally on Friday, the US Food and Drug Administration issued a more flexible guideline on storage and transportation of both Pfizer’s and Moderna’s mRNA vaccines.

According to the FDA, the latest data submitted by Pfizer attested to a more lenient handling of the undiluted vaccine vials for up to two weeks in conventional freezers. Thawed or diluted vaccines cannot be refrozen, however.

Messenger-RNA vaccines, by their molecular structural nature, had formerly been known to require frigid temperatures of -80 to -60 degrees Celsius. Such ultra-cold freezers have been a point of inconvenience in global vaccine distribution, as they are hard-to-access luxuries in most countries, not to mention being of no use outside of for these vaccines.

The tough storage and distribution requirements put Pfizer and Moderna at a disadvantage against other COVID-19 vaccine makers.

Vaccines made by AstraZeneca, Johnson & Johnson and Novavax only need basic refrigeration between 2 to 8 degrees Celsius.

With the eased FDA guidelines, Pfizer vaccine distribution in Korea may also undergo more flexible storage and transportation, lifting the burden off the management.

Korea’s Drug Ministry said Friday that the data it is currently reviewing for emergency use of the Pfizer vaccine here does not include the latest data set regarding the critical temperatures.

Only after Pfizer Korea submits relevant data can the Drug Ministry consider the new information and relax the domestic distribution plans.

In reviewing a vaccine’s emergency use, the Korean authorities are employing a three-part review process. Friday’s announcement was the second leg.

The committee of pharmacists involved in the second review advised authorities to include a phrase in the approvals document to indicate that the Pfizer vaccine can be used for teenagers aged 16 and 17 despite the lack of specific data, because their immune response does not differ from that of adults. Pfizer’s vaccine can be used for those 16 and up.

The Drug Ministry will finalize the emergency approvals after a third evaluation.

By Lim Jeong-yeo (kaylalim@heraldcorp.com)