FDA could delay decision on AstraZeneca COVID-19 vaccine
The combination of uncertainty about the safety of AstraZeneca’s COVID-19 vaccine and confidence in supplies of three FDA-authorized vaccines could lead FDA and the company to find ways to delay a decision about making the AstraZeneca vaccine available in the U.S., current and former HHS officials told BioCentury.
The precedents set with the first three COVID-19 vaccines from Pfizer Inc. (NYSE:PFE) and its partner BioNTech SE (NASDAQ:BNTX), Moderna Inc. (NASDAQ:MRNA), and Johnson & Johnson (NYSE:JNJ) are unlikely to be replicated with the vaccine from AstraZeneca plc (LSE:AZN; NASDAQ:AZN), the officials said. In those cases, HHS urged the companies to file EUAs quickly after data meeting FDA’s criteria were available. FDA then scrambled to review the data, convene advisory committee meetings, and issue EUAs within days of the meetings, and HHS acted to get the vaccines into the arms of vulnerable individuals as quickly as possible.
In contrast, FDA’s review of the AstraZeneca vaccine, Vaxzevria, will include assessment of postmarket data, including adverse event reports that have caused consternation in Europe.
FDA is under less pressure to act quickly because supplies of the three authorized COVID-19 vaccines are expected to be sufficient for the entire U.S. population. HHS has shifted its COVID-19 vaccine focus to expanding indications to pediatric populations and developing vaccines that are optimized to protect against SARS-CoV-2 variants, officials told BioCentury.
If FDA decides to slow-walk the AstraZeneca vaccine, it could request that the company submit a BLA, a requirement that could take several months to fulfill. FDA requires a median of six months of safety data for a COVID-19 vaccine BLA versus two months of safety data for an EUA. A BLA must also contain more extensive data about manufacturing.
The company has been forced to relocate U.S. manufacturing after a quality control failure led the U.S. government to dedicate a facility solely to producing the J&J vaccine rather than continue to manufacture both the AstraZeneca and J&J vaccines.
If FDA accepts an EUA from AstraZeneca, it could suggest that the company defer submission until more postmarket safety data are available, or the agency could take longer to complete its review than it has with prior COVID-19 vaccines, current and former HHS officials told BioCentury.
Mixed messages in Europe
Speculation about the fate of Vaxzevria in the U.S. follows mixed signals from European regulators and health ministries, which have acknowledged that it may increase the risk of rare blood clotting events, especially in younger populations, but also state that its benefits outweigh its risks.
On Wednesday, MHRA recommended that individuals ages 18-30 be offered Comirnaty from Pfizer and BioNtech or COVID-19 Vaccine Moderna, but it is not prohibiting individuals in this age group from receiving AZ's vaccine.
EMA’s PRAC stated Wednesday that the rare thromboembolic events with low platelet counts should be listed as side effects of AZ’s vaccine.
EMA has not made recommendations or taken regulatory actions for any specific populations to avoid the vaccine. Several European health agencies, however, have acted to prevent or discourage younger people from receiving Vaxzevria.
Associate Editor Paul Bonanos and Assistant Editor Sandi Wong contributed to this story.