According to scientists, “Since immunity against the novel coronavirus is contributed by both the antibodies and cells of the immune system, simpler, standardised lab tests to assess the T cell response in COVID-19 patients may help unravel more mysteries about the disease”.
Immunologist Satyajit Rath stated that “the two major components of immunity specific for any infection are the T cell responses, and those mediated by the immune system’s B cells along with the antibody proteins they produce.”
He said, “Antibody responses are easier to measure, especially on a large scale, and they have traditionally been the protective components of vaccine-induced immunity. Therefore, they always tend to be focused upon, as is true in the ongoing pandemic as well”. He added that the T cell responses “are very important” and “technically much harder to study, particularly in human communities.”
He explained that a subset CD8 T cells are responsible for eliciting a major antiviral immune response which is likely to have an important part to play, especially in those people whose antibody responses are likely to be short-lived.
Daniel Altmann, Professor of Immunology at the University College London in the UK, said, “One of the best indicators of the importance of T cell immunity comes from reports of people who have made full recovery from COVID-19 despite the complete absence of antibodies”.
Rath added, “Another subset of the T cells — called CD4 T cells — help the B cell-antibody response become more efficient and long-lived.” He commented that these must be analysed in order to understand the efficiency of antibody responses and how long they function.
According to the NII immunologist, “CD4 T cell responses also contribute anti-viral functions as well as causing tissue and organ damage”. That means CD8 T cell responses have the potential to eliminate virus-infected cells of the body and to also stop the growth of the virus.