US nurse tests positive for COVID-19 after receiving Pfizer vaccine
A US nurse has tested positive for COVID-19 just eight days after she received a Pfizer vaccine shot.
ER nurse Matthew W, who worked at two different hospitals in San Diego, received the Pfizer vaccine on December 18. According to Matthew, after receiving the vaccine, his arm got sore for a day with no other side effects.
Six days later, after working a shift in the COVID-19 unit, Matthew felt sick and got the chills following down with muscle aches and fatigue. On December 26, Matthew went to the hospital to get tested for the virus and tested positive for COVID-19.
Matthew said that his symptoms peaked on Christmas Day and he feels a bit fatigued now, but his condition has improved since last week.
Dr Christian Ramers, an infectious disease specialist with Family Health Centre of San Diego, said Matthew's case was surprising but was not unexpected. Ramers said that Matthew might have been infected before receiving the vaccine, as the incubation period may be as much as two weeks. According to the vaccine clinical trials, it takes about 10 to 14 days to develop protection from the vaccine.
Ramers also said that he knew of several other local cases where health care workers became infected around the time they received the vaccine. He added that for the vaccine to be effective, the first dose gives protection from the virus to around 50 per cent and that the second dose is effective to 95 per cent.
The US Food and Drug Administration (FDA) on December 11 approved the Pfizer-BioNTech COVID-19 vaccine for emergency use. US pharmaceutical giant Pfizer developed the vaccine against COVID-19 along with German company BioNTech. The mRNA vaccine candidate, administered in two doses, is 95 per cent effective in preventing the disease. The vaccine must be stored at -70 degrees Celsius (-94 degrees Fahrenheit), a temperature much lower than standard freezers.