Pfizer vaccine shelf life extended amid wastage fears

Pfizer and UK health regulators have said the two-week extension would have ‘no impact’ on the vaccine’s safety and effectiveness

The National Health Service has extended the shelf life of certain batches of nearly expired Pfizer Covid-19 vaccine shots. The move was prompted by concerns about millions of doses being wasted due to a lackluster booster drive.

In a letter sent to vaccination centers on Monday, NHS England said that “undamaged” vials from 20 batches of Pfizer’s vaccine – known as Comirnaty – could be used up to 45 days after they had been thawed out from ultra-cold freezer storage. This works out at a full two weeks later than their previously recommended post-thaw shelf life, 31 days.

Following “stability assessments,” Pfizer had apparently confirmed that the extension would have “no impact to product quality.” The letter added that the Medicines and Healthcare products Regulatory Agency (MHRA) had “no objection,” since there is “no detrimental impact on the safety, quality or efficacy of the identified vaccine.”

The letter, by NHS England’s vaccine deployment program leaders Dr. Emily Lawson and Dr. Jonathan Leach, noted that Pfizer had “assessed available data” and instructed colleagues to prioritize stocks “nearing expiry.” The extension will “enable more patients to access these critical and life-saving vaccines over the coming days,” they wrote.

The Pfizer vaccine can be stored for up to nine months at temperatures between -80 degrees Celsius and -60 degrees Celsius. It is then shifted to refrigerators, where it can be used during a post-thaw period prior to expiry.

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Based on the “available data,” the MHRA told the Daily Mail it was “satisfied” that the shots would be safe and effective beyond its “authorised expiry date,” but did not confirm whether this was true of the Pfizer vaccine as a whole or the 20 batches in question.

The extension comes amid reports that uptake for Prime Minister Boris Johnson’s much-publicized booster vaccination drive has slowed down dramatically. According to the Daily Mail, only about 116,000 people on average are now getting their booster shot daily across the country.

Flagging vaccination rates have led to concerns about wasted doses – with an unnamed Whitehall insider telling the i news outlet last week that “you plan for a certain number of people to come forward, and if they don’t [then] you have a problem.”

Meanwhile, a source told the Health Service Journal that the booster drive had led to vaccines being pushed out, “irrespective of whether regions wanted it.”