Green light for storing Pfizer shots at refrigerator temperature for a month

The Health Sciences Authority (HSA) has given the green light for Pfizer's Covid-19 vaccine to be stored at standard refrigerator temperatures of between 2 deg C and 8 deg C for up to a month.

The move, which will help facilitate Singapore's nationwide vaccine roll-out, follows a similar decision by the United States Food and Drug Administration last week.

The Pfizer-BioNTech vaccine was approved last December, subject to a strict set of storage conditions. These included long-term storage at minus 70 deg C, with temporary storage at refrigerator temperatures permitted for up to five days.

In February, the HSA said that the vaccine can also be stored at a standard freezer temperature of minus 20 deg C for up to two weeks.

Its latest decision to further revise storage conditions for the vaccine came "after a thorough review of the application and supplemental data submitted by Pfizer", HSA said in a statement yesterday.

The thawed, undiluted vaccine remains stable when stored at refrigerator temperatures for 31 days, the authority said.

"This will greatly facilitate the transportation and local distribution of this vaccine to vaccination centres, as well as its storage and use at the centres, which is important in ensuring the steady progress of our vaccination programme to protect more Singaporeans."

Cartons of the vaccine typically arrive packed in dry ice, in special thermal containers. The vials are then stored in an ultra-low-temperature freezer.

Vaccine doses are thawed before being diluted and injected into a person's arm. Any unused diluted doses must be discarded after six hours.