As long as there is data available showing that a coronavirus disease (COVID-19) vaccine can extend its original shelf life, it can be allowed, the Food and Drug Administration (FDA) said on Monday, Dec. 13.

"Ang naibibigay lang namin talaga na expiration date o shelf life ay iyong mayroon po talagang scientific evidence to show na at that month, usually po six months, ay useful pa siya (The expiration date or shelf life that we usually provide is the one that is backed up by scientific evidence showing that at that month, usually six months, it is still useful)," FDA Director-General Eric Domingo explained during the Laging Handa press briefing.

"So kapag ini-extend po ang shelf life, halimbawa, mas tumatagal na iyong mga bakuna tapos tini-testing at naipakita na useful pa sila, kapag mayroon po talagang data to show na useful pa sila after six months for example, puwede nating i-extend iyon shelf life (So if we extend the shelf life, for example, vaccines last longer when they are tested and have shown that they are still useful, if there is actual data to show that it is still useful after six months, we can extend the shelf life)," he added.

Domingo said that only Pfizer-BioNTech and Sinovac have submitted an amendment to their Emergency Use Authorization (EUA) to update the shelf life of their vaccines. For Pfizer-BioNTech, Domingo said that its shelf life was extended to nine months from the original six months, while Sinovac extended its shelf life to 12 months.

Astrazeneca has yet to submit an amendment to its EUA and its shelf life remains at six months.

Vaccine manufacturers, according to Domingo, are required to apply for an EUA amendment where they would disclose the data or evidence which would state that the extension of the vaccine's shelf life would ensure that it will remain useful, safe, and in good quality.