Today the FDA Vaccines and Related Biological Products Advisory Committee approved the Moderna COVID-19 vaccine. The results are not surprising given the positive review of the Pfizer vaccine a week ago and the FDA’s very positive review of Moderna’s phase three data that was published two days ago.
There were some similar concerns as were raised in the Pfizer discussion, but there were more votes in favor of approval — 20 for approval with only one abstention. The biggest difference was that the approval was only for recipients 18 years and older. The four no votes in the Pfizer review were due to the inclusion of 16- and 17-year-old recipients of the vaccine in the approval.
The Moderna vaccine will aid tremendously in the COVID-19 suppression effort since Moderna has manufactured more of the vaccine (reportedly 6 million doses) than Pfizer and has less strenuous refrigeration requirements for distribution. This makes the vaccine much more useful for institutions like nursing homes where commercial chains such as CVS and Walgreens will be performing the immunizations.
One issue that has arisen is the allergic reactions to these vaccines. There are now reports of four allergic reactions, two in Great Britain and two in the United States. While the individuals in Great Britain were reported to have had prior histories of allergic reactions and each carried an EpiPen, neither of the health care workers immunized in Alaska had a prior history of allergic reactions.
The cause of these reactions is unclear. There is one component of the vaccine present in varying forms as a stabilizer in many drugs and other vaccines. This component, called PEG (polyethylene glycol), has been implicated in allergic reactions, but it is not clear that it is the cause in these cases. While additional study is necessary to clarify these reactions, they remain rare events since there have been several hundred thousand administrations of the vaccine so far.
The frequency of these reactions is not high enough to alter the recommendations for the vaccine and most administration sites will have equipment and supplies necessary to treat individuals with allergic reactions.