A US nurse has tested positive for COVID-19 eight days after having received a Pfizer vaccine shot. Matthew W, who works as an ER nurse at two hospitals in San Diego, received the jab on December 18.
Speaking to ABC 10News, he said that - after receiving the vaccine, his arm was sore for a day but he suffered no other side effects.
However, six days later, the 45-year-old became sick while working a shift in the COVID-19 unit. He got the chills and later came down with muscle aches and fatigue, ABC reported. The next day, he tested positive for COVID-19.
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As per the report, Matthew's condition has improved since his symptoms peaked on Christmas Day but still feels fatigued.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
Dr Christian Ramers, an infectious disease specialist with Family Health Centers of San Diego, said that such cases were not unexpected because ur was "exactly what we would expect to happen if someone was exposed."
Read: From the lab to the jab: How BioNTech-Pfizer won the vaccine race
Ramers, who serves on the clinical advisory panel for the US' vaccine rollout, said, "It is possible that Matthew was infected before receiving the vaccine, as the incubation period may be as much as two weeks. Additionally, we know from the vaccine clinical trials that it is going to take about 10 to 14 days to develop protection from the vaccine."
Read: You're infected with the coronavirus. But how infected?
He further said that he knew of several other local cases where health care workers became infected around the time they received the vaccine.
"All cases illustrate the fact that results aren’t immediate. Even after you start receiving some protection, it won't be full protection," Ramers said, adding that the first dose gives around 50 percent protection and second dose up to 95 percent.
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, has been found to be 95 percent effective in preventing the disease.
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It must be stored at -70 degrees Celsius (-94 degrees Fahrenheit), a temperature much lower than standard freezers and which forced the company to develop special containers for transport.
Over a dozen countries have already approved the vaccine for use, including Britain, Canada, Mexico, Saudi Arabia and Bahrain. Pfizer has also sought EUA for the jab in India, and has submitted an application to the Drugs Controller General of India (DCGI).
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