Vaccinated US nurse contracts COVID-19, expert says Pfizer shot needed more time to work

More than a week after receiving Pfizer Inc’s vaccine, a nurse in California tested positive for COVID-19 as ABC News affiliate reported on Tuesday, but according to a medical expert and the U.S. drugmaker, the body needs more time to build up protection.

In a statement to Reuters Pfizer said it “will review all available information on this case and all reports of any confirmed diagnosis following vaccination.”

“Based on our Phase 3 safety and efficacy study, the vaccine provides some protection against COVID-19 within about 10 days of the first dose and substantially boosted after the second dose, supporting the need for a 2-dose vaccination series”, it said.

It also added, “Individuals may have contracted disease prior to or right after vaccination”.

Matthew W., 45, a nurse at two different local hospitals, said in a Facebook post on December 18 that he had received the Pfizer vaccine, telling the ABC News affiliate that his arm was sore for a day but that he had suffered no other side-effects.

Six days later on Christmas Eve, he became sick after working a shift in the COVID-19 unit, the report added. 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.

Christian Ramers, an infectious disease specialist with Family Health Centers of San Diego, told the ABC News affiliate 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 added. “That first dose we think gives you somewhere around 50%, and you need that second dose to get up to 95%.”