Although COVID-19 research is still in its early stages, a new study News released on Monday indicated that there may not be a need for enhanced injections for years.

Scientists found that Pfizer and Moderna vaccines produced a strong immune response that can last for several years-as long as the virus does not evolve into a new form, “New York Times” reported.

If the virus or one of its variants changes significantly, the components of the vaccine need to be adjusted and added to the booster injection of the vaccine.

Currently, the COVID-19 vaccine can prevent the Delta variant because it is still structurally similar to the original virus.

The study published in the journal Nature only focused on mRNA vaccines, such as Pfizer and Moderna, and did not follow Johnson & Johnson’s vaccines.

“This is a good sign and shows how durable this vaccine is against our immunity,” Said Ali Ellebedy, an immunologist at Washington University in St. Louis who led the study..

Dr. Ellebedy said that previous research has shown Lasting immune response Among patients recovering from COVID-19. At least 8 months after infection, immune cells that recognize the virus are found in the patient’s bone marrow, and “memory B cells” mature and strengthen within at least one year after infection. This indicates that the immunity of the vaccine itself may last for several years.

The team studied the lymph nodes, where immune cells are ready to recognize and fight infections such as the COVID-19 virus in a structure called the germinal center. They recruited 41 people, 8 of whom had previously been infected with COVID-19, and then they were fully vaccinated with Pfizer to test the activity level of their germinal centers.

The researchers collected lymph node samples from 14 participants at 3, 4, 5, 7 and 15 weeks after receiving the first dose. They found that 15 weeks after the first injection, the body’s immune response was still very strong, the number of memory cells did not decrease, and the germinal center was also very active.

Normally, the germinal centers peaked one to two weeks after vaccination, but the mRNA vaccine stimulated these centers, and they are still very vigorous.

Marion Pepper, an immunologist at the University of Washington in Seattle, told the New York Times that this shows that B cells are evolving and will eventually protect the virus from continuing to evolve.

However, older people and people with weakened immune systems may still need boosters because of their weakened immune systems.

It is not clear how long the protective effect of mRNA will last, but scientists say that if there is no mutation, it may last a lifetime. Because we know that mutations are spreading around the world, researchers say that vaccine immunity is better than no protection.

If the virus has evolved far enough from the original structure of the virus, it may be necessary to intensify injections.