A nurse in California tested positive for Covid-19 nearly a week after receiving Pfizer Inc's vaccine, even as the US drug maker said the vaccine needs more time to prompt build-up of protection, an ABC News affiliate reported on Tuesday.
Matthew W, 45, who works as nurse at two different local hospitals, said in a Facebook post on 18 December that he had received the Pfizer vaccine and that six days after, on Christmas Eve, he became sick after working a shift in the Covid-19 unit.
The ABC News affiliate quoted him as saying that his arm was sore for a full day after the vaccine shot, although he had suffered no other side-effects.
The report also said that following the vaccination, he got the chills and later came down with muscle aches and fatigue.
He went to a drive-up hospital testing site and tested positive for Covid-19 the day after Christmas, the report said.
The ABC News affiliate also quoted Christian Ramers, an infectious disease specialist with Family Health Centers of San Diego, as saying that this scenario was not unexpected.
"We know from the vaccine clinical trials that it's going to take about 10 to 14 days for you to start to develop protection from the vaccine," Ramers said, adding, "That first dose we think gives you somewhere around 50 per cent, and you need that second dose to get up to 95 per cent."
Pfizer, however, said it “will review all available information on this case and all reports of any confirmed diagnosis following vaccination,” the drug maker said in a statement
It may be noted that the Pfizer-BioNTech Covid-19 vaccine has not been approved or licensed by the US Food and Drug Administration (FDA), and has only been authorised for emergency use by FDA under an Emergency Use Authorisation (EUA) to prevent coronavirus disease (COVID-19) for use in individuals 16 years of age and older.
“The emergency use of this product is only authorised for the duration of the declaration that circumstances exist justifying the authorisation of emergency use of the medical product under Section 564(b)(1) of the FD&C Act unless the declaration is terminated or authorisation revoked sooner,” says a website statement issued by Pfizer.