This week, social media was flooded with a series of headlines documenting a seemingly disturbing case of COVID-19 to a San Diego nurse who became ill about a week after receiving her first dose of vaccine. from Pfizer against coronavirus.
However, experts said that his disease is not unexpected: it is known that the protective effects of vaccines take at least a few weeks to materialize. And they noted that the disease before completing the two-dose vaccine regimen should not diminish the effectiveness of Pfizer, which has reached the final stage of successful clinical trials.
Reporting that a person who has not received the full dose of vaccine has COVID-19, “it’s like saying someone came out in the middle of a storm without an umbrella and got wet,” said Taison Bell, an intensive care physician at the University. from Virginia. Bell received the first dose of Pfizer vaccine on December 15 and will soon receive the second dose.
The 45-year-old California nurse, identified as Matthew W. in an ABC10 News report, received her first injection of the Pfizer vaccine on December 18th. According to the news, six days later he began to feel mild symptoms, including chills, muscle aches and fatigue. The day after Christmas, it tested positive for the virus.
Megan Ranney, an emergency physician at Brown University, said this should not cause concern. “So what ???” wrote on Twitter on Wednesday in response to a Reuters article about the nurse’s illness. “It’s a two-dose vaccine.” Ranney received his first dose of Pfizer vaccine on December 18th.
Ranney pointed out in an interview that the fact that the nurse’s illness is news implies that it was something that did not live up to expectations … and that there should have been protection about a week after the first dose of vaccine. By no means is this the case.
Vaccines take at least a few days to develop their protective effects. The Pfizer formula is designed around a molecule called messenger RNA or mRNA, which, once injected, enters human cells and instructs them to make a coronavirus protein called a peak. None of these components are infectious and cannot cause COVID-19. But they act as impostors of the coronavirus and teach the body to recognize the real virus and fight it if it ever enters.
Peak production is thought to occur within a few hours of the first dose. But the body needs at least a few days to memorize the material before it can unload its entire arsenal of weapons of defense against the virus. This time it takes immune cells to analyze the protein, mature, multiply and sharpen their reflexes to identify the tip.
Data from Pfizer clinical trials indicate that the vaccine may begin to protect its recipients from the disease about a week or two after the first dose. A second injection of mRNA, given three weeks after the first, helps the immune cells remember the most important features of the virus, which strengthens the protection process.
Ranney noted that the chronology of the nurse’s illness in California fits very well with the vulnerability window after vaccination. It is also very likely that you were infected with the virus close to the date you were vaccinated, maybe even earlier. If people develop symptoms of COVID-19, they may start to feel them two to fourteen days after they become infected with the coronavirus.
A similar situation occurred recently with Mike Harmon, the state auditor in Kentucky, who this week tested positive for the virus a day after receiving the first dose of an unspecified coronavirus vaccine.
“It seems that, without knowing it, I could have been exposed to the virus and I caught it shortly before or after I received the first dose of vaccine on Monday,” he said in a statement. Harmon reaffirmed his “total confidence in the vaccine and the need for as many people as possible to receive it as soon as possible.”
Jerica Pitts, a spokeswoman for Pfizer, said the vaccine’s protective effects are “substantially improved after the second dose, supporting the need for a two-dose series of vaccines.”
“People may have contracted the disease before or immediately after vaccination,” he said.
When given the full two-dose regimen of Pfizer vaccine, it was found to be 95% effective in preventing symptomatic cases of COVID-19, which was received as very good news now that coronavirus cases have increased. However, this leaves a small percentage of people who will not be protected after vaccination, Ranney said. “There is no vaccine that is 100% effective.”
It is also unknown how well Pfizer can protect against asymptomatic infection or whether it will significantly reduce the ability of the virus to pass from one person to another. This means that measures such as masking or social distancing are still essential, even after full vaccination.
The information collected by Pfizer during end-stage clinical trials suggested that the vaccine may provide at least some protection after a single dose. But the purpose of the study was not to specifically test how effective a single injectable treatment would be.
Krutika Kuppalli, an infectious disease doctor at the University of South Carolina School of Medicine, said two of her colleagues tested positive shortly after their first dose. “Given the speed with which cases are growing, none of this surprises me,” he said. As the effects of the vaccine are not expected to be immediate, “this should not be considered a vaccine failure”. Kuppalli, who received the first dose of vaccine from Pfizer on December 15, added that contracting COVID-19 between doses of the vaccine should not discourage anyone from receiving the second dose after consultation with a healthcare professional. .
In recent weeks, more than 2.7 million people in the United States have received the first dose of vaccine from Pfizer or a similar one from Moderna. Both vaccines consist of two photos, and as more and more people reach them, it’s important to maintain good communication about how and when vaccines work, Bell said.
“For now, we have to stick to the doses that were determined in the studies,” he said. “This will give us maximum efficiency.”