The body’s immunity to the coronavirus can last for more than eight months, according to Lahoya researchers.

According to researchers at the La Jolla Institute for Immunology, new data show that almost all COVID-19 survivors have the immune cells needed to fight reinfection for months, if not years. It suggests that.

Survey resultsBased on the analysis of blood samples from 188 COVID-19 patients, the response to coronavirus SARS-CoV-2 (cause of disease) from all major players of the “adaptive” immune system has since been at least The onset of symptoms from the first infection suggests that it may last for 8 months. The adaptive immune system learns to fight specific pathogens.

“Our data suggest that there is an immune response that persists,” said LJI professor Alessandro Sette, who led the study in collaboration with Professor Shane Crotti and Associate Professor Daniela Weiskov. It was.

“We measured antibodies, memory B cells, helper T cells, and killer T cells all at the same time,” says Crotty. “As far as we know, this is the largest study ever on an acute infection that measured all four elements of immune memory.”

Survey results published in the January 6 online version of the journal ScienceMay mean that survivors of COVID-19 have protective immunity against serious coronavirus disease for months, perhaps years, after infection.

The new study will help reveal some of the COVID-19 data from other laboratories that have shown a dramatic reduction in antibodies that fight COVID in the months following infection. Some feared that it might mean that the body was not equipped to protect itself from reinfection.

“Of course, the immune response declines to some extent over time, but that’s normal,” says Sette. “That’s what the immune response does. They have the first stage of standing up, and after their wonderful expansion, the immune response eventually contracts somewhat and becomes steady.”

Researchers have found that virus-specific antibodies remain in the bloodstream for several months after infection. The body also has immune cells called memory B cells. If a person encounters SARS-CoV-2 again, memory B cells may reactivate and produce antibodies to combat reinfection.

SARS-CoV-2 uses its “peplomer” protein to initiate infection of human cells, so researchers searched for memory B cells specific to that spike. They found that spike-specific memory B cells actually increased in the blood 6 months after infection.

Survivors of COVID-19 also had an army of T cells ready to fight reinfection. Memory CD4 + “helper” T cells are protracted and ready to provoke an immune response when SARS-CoV-2 is revisited. Many memory CB8 + “killer” T cells also remain and are ready to destroy infected cells and stop reinfection.

Because various parts of the adaptive immune system work together, antibodies that fight COVID, memory B cells, memory CD4 + T cells, and memory CD8 + T cells can be found in the blood more than 8 months after infection. That’s a good sign, Crotti said.

“This means that people are more likely to have protective immunity, at least for serious illnesses, for that period, perhaps well beyond that,” he said.

The team warned that defensive immunity varies dramatically from person to person. In fact, researchers have seen a hundred-fold range in the size of immune memory. People “at the bottom of their immune memory” may be vulnerable to recurrent COVID-19, Crotti said.

The fact that immune memory against SARS-CoV-2 is possible is also a good sign for vaccine developers, Weiskopf said, and this study is not post-vaccination immune memory, but natural SARS-CoV-2. He emphasized that he followed the response to the infection.

“Immune memory can be just as long-lasting after vaccination, but we have to wait until the data are available,” Weiskopf said. “A few months ago, our study showed that natural infections elicited a strong response, and this study now shows that the response continues. Vaccine research is in its infancy and so far. It is associated with strong defenses, where we expect to see similar long-lasting response patterns for vaccine-induced responses. “

Researchers hope to continue analyzing samples from patients with COVID-19 for the next few months and track their response 12-18 months after the onset of symptoms.

“We’re also doing a much more detailed analysis of what parts of the virus are recognized,” says Sette.

In addition, the team is working to understand how immune memory differs among people of different ages and how it affects the severity of COVID-19 cases. ◆◆