Studies suggest that people with Covid should be vaccinated once

Almost 30 million people In the United States, and perhaps many other people who have never been diagnosed with the disease, have been infected with the coronavirus. Should these people still be vaccinated?

Two new studies highlight and answer that question.

In fact, this study suggests that a single dose of vaccine is sufficient for these people to supercharge antibodies and destroy the coronavirus and even some more infectious mutants. I have.

The results of these new studies Survey results of the other two Published over the past few weeks. In summary, this study suggests that people infected with Covid-19 should be vaccinated, but a single dose of the vaccine may be sufficient.

“I think the reason why people previously infected with Covid should be vaccinated is a very strong reason,” said Jennifer Gommerman, an immunologist at the University of Toronto who was not involved in the new study.

A person’s immune response to natural infections is very diverse. Most people make large amounts of antibodies that last for months. However, some people with or without mild symptoms of Covid-19 produce very little antibody. Antibodies drop to undetectable levels immediately.

The vaccine is “even in the stadium,” Dr. Gomerman said, saying that anyone who recovers from Covid-19 produces enough antibodies to protect it from the virus.

The· Latest researchHas not yet been published in a scientific journal, but analyzed blood samples of people infected with Covid-19. The findings suggested that their immune system had problems evading the first identified coronavirus variant in South Africa, B.1.351.

However, one shot of either the Pfizer-BioNTech or Moderna vaccine changed the situation significantly. It amplified the amount of antibody in the blood 1000 times.Cancer Research Center In Seattle, where I led the research.

When flushed with antibodies, samples from all participants may neutralize not only B.1.351, but also the coronavirus that caused the SARS outbreak in 2003.

In fact, the antibody did not have Covid and seemed to perform better than those who had been vaccinated twice. Studies suggest that the Pfizer-BioNTech and Moderna vaccines are about one-fifth less effective against mutants.

The researchers obtained blood samples from 10 volunteers. Seattle Covid Cohort Study People who have been vaccinated several months after being infected with the coronavirus. Seven of the participants received the Pfizer-BioNTech vaccine and three received the Moderna vaccine.

Blood collected approximately 2-3 weeks after vaccination showed a significant increase in antibody levels compared to samples collected prior to vaccination. Researchers still don’t know how long the increase in antibody levels will last, but “hopefully they will last longer,” Dr. McGuire said.

Researchers also saw an increase in immune cells that remember and fight the virus, Dr. McGuire said. “It looks pretty obvious that we are boosting their existing immunity,” he said.

To Another new studyResearchers at New York University have found that a second dose of the vaccine has no benefit to people with Covid-19, a phenomenon that has also been observed with vaccines of other viruses.

In that study, most people were infected with the coronavirus eight or nine months ago, but the first dose of the vaccine showed an increase in antibodies 100- to 1000-fold. However, after the second dose, antibody levels did not increase any further.

“A significant increase in a single dose is a true testament to the strength of immunological memory,” said Dr. Mark J. Mulligan, director of the NYU Langone Vaccine Center and lead author of the study. I am.

In some parts of the world, including the United States, a significant minority of the population is already infected, Dr. Mulligan said. “They should definitely be vaccinated,” he said.

It is unclear whether spikes of 1000 times the antibody levels recorded in the lab will occur in the actual settings. Nonetheless, Florian Kramer, an immunologist at Mount Sinai School of Medicine in New York, shows that a single injection is sufficient to significantly increase antibody levels.

Dr. hug led Another new studyThis indicates that people infected with Covid-19 and vaccinated once have more severe side effects and more antibodies than those who have never been infected before.

“If you put all four papers together, a single vaccination will give you pretty good information about people who are already infected,” said Dr. Krammer.

He and other researchers are trying to convince scientists at the Centers for Disease Control and Prevention to recommend a one-time dose to those who have recovered from Covid-19.

Dennis R. Burton, an immunologist at the Scripps Research Institute in La Jolla, California, ideally said these people after the first shot in case antibody levels plummeted after weeks or months. Should be monitored.

The fact that overcharged antibodies observed in a new study can fight the 2003 SARS virus is that a single dose of the vaccine is a “widespread neutralizing antibody” to the volunteer body, a wide range of related immune molecules. It suggests that it may have prompted you to attack. Virus, Dr. Burton said.

For decades, he and other scientists have investigated whether widely neutralizing antibodies can tackle multiple versions of HIV at once. HIV mutates faster than any other virus and evades most antibodies quickly.

The new coronavirus mutates much more slowly, but there are now multiple variants of the virus that appear to be more contagious or evolved to interfere with the immune system.New research may provide clues as to how to do it Make a single vaccine This stimulates the production of extensively neutralizing antibodies that can destroy all variants of the coronavirus, Dr. Burton said.

Without such a vaccine, scientists would have to tweak the vaccine every time the virus changed significantly. “You’re stuck with a kind of whac-a-mole approach,” he said. It will probably take months, if not more, to develop and test such a vaccine against the coronavirus, but “it’s a longer-term way to approach this virus.”