Modern (NASDAQ: MRNA) said on Tuesday it was investigating some cases where patients appeared to have allergic reactions to the coronavirus vaccine. All reported incidents, in which people experienced reactions after their first injection of mRNA-1273, occurred at a vaccination clinic in San Diego. (The vaccine is administered in a two-dose regimen, with injections given 21 days apart.)
The California Department of Health did not specify the exact number of people in the group who experienced these reactions, but California state epidemiologist Dr. Erica S. Pan said there were fewer than 10 individuals in a 24-hour period.
In each of these cases, the vaccine came from a batch – No. 41L20A, which contained more than 1.27 million doses, distributed in approximately 1,700 vaccination posts in 37 states. More than 330,000 of them went to California. It is not known exactly how many of them have already been used. So far, no similar group of allergic reactions has been reported.
Image source: Getty Images.
Following reports on the San Diego cluster on Sunday, Dr. Pan – in a decision she said she made “[o]with extreme caution “- issued a formal recommendation for health professionals to immediately stop using the vaccines in the batch in question. Pan promised that he would provide an update as his department learned more about the incidents.
As for Moderna, the company said it is working with federal health officials to investigate the possible causes of the reactions in California. He added that he is unaware of similar groups of incidents elsewhere.
So far, mRNA-1273 remains one of only two coronavirus vaccines that have received emergency use authorization from the Food and Drug Administration. Like the other, Pfizer and BioNTechof BNT162b2, is being distributed throughout the country and the available supply is being administered to populations at greater risk of COVID-19.
The vaccine implantation process has been slower than expected, however, and new President Joe Biden has promised to accelerate the pace in the coming weeks and months.