A new study has found that even the sickest Covid-19 patients produce T cells that help fight the virus. T cells are a key component of the immune system and their roles include killing infected host cells, activating other immune cells, and regulating the immune response. The study cites its findings as further evidence that a Covid-19 vaccine (whenever developed) will need to elicit T cells to work alongside antibodies.
The new research was published in the journal Science Immunology on Friday.
The researchers followed 10 severely ill Covid-19 patients who were on ventilators at Erasmus University Medical Center, Netherlands. Two of the patients eventually died. An in-depth look at their immune system responses showed that all 10 patients produced T cells that targeted the SARS-CoV-2 virus. These T cells worked alongside antibodies in trying to clear the virus and stopping the infection.
The researchers note that these findings are in line with a recent study, published in Cell, that showed a robust T cell response in individuals with moderate cases of Covid-19. In both studies, the T cells in these patients prominently targeted the “spike” protein on SARS-CoV-2, according to La Jolla Institute for Immunology, researchers from which are involved in both studies. It is the spike protein that the coronavirus uses to enter human cells. The new study adds to growing evidence that the spike protein is a promising target. Accroding to La Jolla, it also confirms that the immune system can also mount strong responses to other targets on the virus.
“This is good news for those making a vaccine using spike, and it also suggests new avenues to potentially increase vaccine potency,” researcher Daniela Weiskopf, first author of the new study, said in a statement.
While the Cell paper followed San Diego residents, the new paper follows Dutch patients—and the T cell responses were consistent in both populations. “This study is important because it shows this immune response in patients thousands of miles apart. The same observation has now been strongly reproduced in different continents and different studies,” Weiskopf said.
— Source: La Jolla Institute for Immunology