Covid-19 vaccination 'incubation period' for 10-14 days before second dose

File picture of a person receiving the Pfizer-BioNTech vaccine. 

A US nurse has tested positive for Covid-19 a week after receiving the vaccine, it has been reported.

However, an infectious disease expert has stated that this is not unexpected and is in line with what is known about the jab. 

According to ABC News, Matthew W - an ER nurse in San Diego - got the Pfizer/BioNTech vaccine on December 18.

On Christmas Eve, after working a shift in a Covid ward, he became unwell.

The nurse reportedly developed some symptoms of Covid-19 and went to a drive-up hospital testing site and later tested positive for the virus.

Infectious disease expert Dr Christian Ramers told the news outlet that it is “not unexpected at all”.

The Pfizer/BioNTech vaccine requires two doses to be taken and Dr Ramers highlighted that the case shows that results are not immediate.

According to the Health Service Executive in Ireland, the vaccine requires two doses “at least 21 days apart”.

Dr Ramers said: “If you work through the numbers, this is exactly what we’d expect to happen if someone was exposed.” 

The doctor said it was possible that Matthew W had been infected prior to getting the vaccine, adding that the incubation period may be as much as two weeks.

He added that even if Matthew was infected after getting the virus, it is still in line with what is known about the vaccine. 

“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,” Dr Ramers said.

Dr Ramers told ABC News: “That first dose we think gives you somewhere around 50%, and you need that second dose to get up to 95%.” 

The first reported US case of the Covid-19 variant that has been seen in the United Kingdom has been discovered in Colorado, Governor Jared Polis announced.

The coronavirus variant was found in a man in his 20s who is in isolation south east of Denver and has no travel history, state health officials said.

The headline of this story has been changed by the Irish Examiner editorial team to better reflect the content of the article.