As the number of people living with the coronavirus in the United States decreases, so does the immunity of individuals. Various studies have shown that although MRNA vaccines They have been effective in preventing hospitalization and death, but their ability to prevent infection has declined. Therefore, first Pfizer and then Moderna applied to the US Food and Drug Administration for a second boost dose of the Corona vaccine. But do we really need the fourth dose, and if so, when should we get it?
Researchers and scientists disagree on whether to prescribe a fourth dose of corona vaccine have. “I do not think everyone is the same right now,” said Dr. Yvonne Maldonado, a pediatric infectious disease specialist at Stanford University. Booster dose No longer need. “But there is no ban on reviewing available data.”
Who is eligible for the fourth dose of Corona vaccine?
So far, the only people diagnosed with the fourth dose of the vaccine are those with weakened immune systems. This group includes Youth And Elderly They have had organ transplants, are undergoing chemotherapy, suffer from advanced or untreated HIV, or are taking immunosuppressive drugs.
The Food and Drug Administration is likely to set up a committee next month to authorize a fourth dose for everyone. adults Make decisions. “We know that people over the age of 65, even if they are vaccinated, are at a higher risk of death than people under the age of 65,” said Dr. Carlos del Rio, an infectious disease specialist at Amory University. [ولی] “By injecting a booster dose, this risk is significantly reduced.”
Elderly immune system with age Weaker It can and cannot produce as many antibodies as young people. On the other hand, the elderly usually have other diseases that increase the risk of acute coronary heart disease.
Pfizer and Biontec in their request for a booster dose of Corona vaccine for individuals Over 65 years The results of two studies have been emphasized. These studies show that people who have received only three doses of the vaccine are much less likely to get the virus with a fourth dose.
Researchers in a preprint study published health records of about 1.1 million Citizens over 60 were compared to those who had been vaccinated with three or four doses. The result was that the incidence and severity of the disease were lower in people who received four doses of the vaccine. However, the researchers stressed that the available data are preliminary and it is not possible to say how long the effect of the fourth dose will last.
How should the fourth dose injection schedule be set?
Due to the limited data available, experts are careful not to make precise recommendations about when to receive a fourth dose. If another wave of coronary heart disease occurs in the near future, a fourth dose may be helpful. But if the next wave does not occur until the summer or fall of this year, if the fourth dose is injected now, the effect will be until the next wave. Low will be. In addition, current vaccines are based on the original Corona strain and may not be as effective against future strains.
“If we knew when the next wave was coming, we would have vaccinated people on time,” said Dr. Amy Sherman, an infectious disease specialist at Brigham and Women’s Hospital in Boston. “But I think we have not yet reached the point where we are aware of the seasonal waves or the rhythm and status of the new Covid species.”
What happens to other people?
Experts believe that three doses are enough for healthy people under 65 years. For example, people in their 20s or 30s who have received three doses of the vaccine only slightly boost their immune systems with the fourth dose. “Maybe a fourth dose will be recommended later, but for now I think the focus should be on injections,” said Dr. Christine Gibler, an immunology researcher at Rockefeller University. The third dose “Be.”
“Concerns about millions of people who have not been vaccinated or received full doses are much more serious,” said Dr. Del Rio.
“We have to be very careful about vaccination strategies,” says Dr. Sherman. As a society, we need to see what our goal is with the vaccine and its boosting doses, because none of the vaccines can completely prevent the spread of the disease. “We need to see how well we can cope with the asymptomatic or mild outbreak of the disease and at the same time be able to protect vulnerable people.”