More than two months after he was completely vaccinated against Covid, a doctor in New York woke up with a headache and a pale, heavy feeling of tiredness. A fever and chills soon followed, and his senses of taste and smell began to disappear.
That, he thinks, can not happen. But it was: he tested positive for the coronavirus.
“It was a big shock,” he said. He knew that no vaccine was perfect and that the Pfizer-BioNTech shots he received were found to be 95 percent effective in a large clinical trial. “But in a way, I think it was 100 percent,” he said.
The doctor, who requested anonymity to protect his privacy, is among the few cases reported of people being infected after being partially or even fully vaccinated. Nearly 83 million Americans have received at least one dose of Covid vaccine, and it is unclear how many of them will have a “breakthrough” infection, although two new reports indicate that the number is very small.
One study found that only four out of 8,121 employees who were fully vaccinated at Southwestern Medical Center in Dallas were infected. The other found that only seven out of 14,990 employees at UC San Diego Health and the David Geffen School of Medicine at the University of California, Los Angeles tested positive two or more weeks after taking a second dose of the Pfizer-BioNTech or Modern vaccines received. . Both reports, published Tuesday in the New England Journal of Medicine, show how well the vaccines work in the real world and during a period of intense transmission.
But these breakthrough cases, although fairly rare, are a stark reminder that vaccinated people are not invincible, especially if the virus is widespread.
“We felt very strongly that this data should not make people say, ‘Let us all be vaccinated and then we can all stop wearing masks,'” he said. Led by Francesca J. Torriani, an infectious disease specialist at UC San Diego Health. the California study. “These measures must continue until a larger part of the population is vaccinated.”
Only some of the Covid-positive health workers in the California study showed symptoms, she said, and they tended to be mild, suggesting the vaccines were protective. This reflects data from the vaccination trials indicating that breakthrough infections were mild and did not require hospitalizations. Some people had no symptoms at all, and were only discovered through studies in studies or as part of their medical care.
Doctors at the University of North Carolina, for example, have found some asymptomatic cases in vaccinated patients who were tested for coronavirus before surgery or other medical procedures, according to Dr. David Wohl, the medical director of the center’s vaccination clinic.
He said the absence of symptoms may have meant that the vaccine did exactly what it was supposed to do: prevent people from getting sick, even if it was not possible to infect the virus.
The Centers for Disease Control & Prevention has a small team that studies breakthrough cases, an agency spokeswoman Kristen Nordlund said. One question the researchers are considering is whether specific variants of the coronavirus may play a role in breakthrough cases.
“There is currently no evidence that Covid-19 occurs after vaccination due to changes in the virus,” she said. Nordlund said.
In the next few months, Pfizer and Moderna are expected to release data that should indicate how often vaccinated people become infected with the virus, even if they have no symptoms. The companies tested participants in their vaccine trials for antibodies to a protein called N that is part of the coronavirus but is not part of the vaccine. Finding those antibodies means that a vaccinated person has been infected by the virus. Some volunteers from the studies also have their noses washed regularly to test for an active viral infection.
Another question is how effective the vaccines are in people whose immune systems have been weakened by diseases or medicines, said dr. William Schaffner, an expert in infectious diseases at Vanderbilt University, said. Breakthrough cases can occur in these people because their bodies cannot produce a strong response to a vaccine.
“And it’s amazing how pervasive immunocompromise is,” said Dr. Schaffner said. He calls the condition ‘evidence of modern medicine’, because many patients are successfully treated for conditions they would not have killed so long ago.
The doctor, who became ill despite full vaccination in New York, stayed at home for almost two weeks. He described his illness as relatively mild and said he had been treated with monoclonal antibodies to fight the virus. “If the worst flu is a ten, it was a four,” he said.
Without the vaccine, he said, he believes he would have been sicker.
“I would have been scared of my mortality,” he said. ‘But I did not have a moment’s anxiety. I did not think I was going to die. To think that you are not going to die – that’s quite a big thing. ‘
Apoorva Mandavilli reported.