The vaccines from Biontech / Pfizer and Moderna are said to protect against the coronavirus for years. According to a scientific study in "Nature" magazine, they trigger a sustained immune response in the body. The results support the belief that most people immunized with the mRNA vaccines may not need a booster dose as long as the virus and its variants do not progress much beyond their current forms. However, according to the scientists involved in the study, this is not guaranteed.
"It's a good sign of how durable our immunity is after this vaccine," study leader Ali Ellebedy, immunologist at Washington University in St. Louis, told the New York Times about the results. The vaccine from Johnson & Johnson was not taken into account in the study, but he assumes that the immune response is less permanent than that of mRNA vaccines.
A month ago, a research team led by Ellebedy found that people who had survived Covid disease had immune cells against Sars-CoV-2 in the bone marrow even eight months after the infection. Another study showed that so-called memory B cells remain in the body for at least a year after infection. According to the results, researchers believe that people who were infected and later vaccinated may have a lifetime of producing immune cells against the coronavirus. However, it was unclear whether vaccination alone could have a similar long-lasting effect.
After an infection or vaccination, a specialized structure, the germinal center, forms in the lymph nodes. This structure is the basis for B cells (B lymphocytes), which form antibodies against viruses. The longer these B cells remain in the body, the more effectively they can react to virus variants. Dr. Ellebedy found that 15 weeks after the first dose of the vaccine, the germinal center was still highly active in all 14 participants and that the number of memory cells that recognized the coronavirus had not decreased.
Germ centers usually peak one to two weeks after vaccination and then decrease. "Usually there isn't much left after four to six weeks," Deepta Bhattacharya, an immunologist at the University of Arizona, told the newspaper. But the germinal centers stimulated by the mRNA vaccines barely receded months after vaccination. Most of what scientists know about the persistence of germinal centers is based on animal studies, according to Bhattacharya. The new study shows for the first time what happens to people after vaccination.
According to the study, people who are permanently treated with medication and older people with a weak immune system need a booster vaccination. According to the research group around Ellebedy, it is difficult to predict exactly how long the protection of mRNA vaccines will last. Without variants, immunity could theoretically last a lifetime. But the virus is clearly evolving.
https://www.n-tv.de/panorama/Moderna-und-Bion...50635.html
"It's a good sign of how durable our immunity is after this vaccine," study leader Ali Ellebedy, immunologist at Washington University in St. Louis, told the New York Times about the results. The vaccine from Johnson & Johnson was not taken into account in the study, but he assumes that the immune response is less permanent than that of mRNA vaccines.
A month ago, a research team led by Ellebedy found that people who had survived Covid disease had immune cells against Sars-CoV-2 in the bone marrow even eight months after the infection. Another study showed that so-called memory B cells remain in the body for at least a year after infection. According to the results, researchers believe that people who were infected and later vaccinated may have a lifetime of producing immune cells against the coronavirus. However, it was unclear whether vaccination alone could have a similar long-lasting effect.
After an infection or vaccination, a specialized structure, the germinal center, forms in the lymph nodes. This structure is the basis for B cells (B lymphocytes), which form antibodies against viruses. The longer these B cells remain in the body, the more effectively they can react to virus variants. Dr. Ellebedy found that 15 weeks after the first dose of the vaccine, the germinal center was still highly active in all 14 participants and that the number of memory cells that recognized the coronavirus had not decreased.
Germ centers usually peak one to two weeks after vaccination and then decrease. "Usually there isn't much left after four to six weeks," Deepta Bhattacharya, an immunologist at the University of Arizona, told the newspaper. But the germinal centers stimulated by the mRNA vaccines barely receded months after vaccination. Most of what scientists know about the persistence of germinal centers is based on animal studies, according to Bhattacharya. The new study shows for the first time what happens to people after vaccination.
According to the study, people who are permanently treated with medication and older people with a weak immune system need a booster vaccination. According to the research group around Ellebedy, it is difficult to predict exactly how long the protection of mRNA vaccines will last. Without variants, immunity could theoretically last a lifetime. But the virus is clearly evolving.
https://www.n-tv.de/panorama/Moderna-und-Bion...50635.html
