People may have hidden immunity against COVID-19

Research has shown that the immunity of antibodies to COVID-19 can only last for a few months, leaving people at risk for secondary infections.

But there is now hope that T cells, the warrior lymphocyte cells in our bodies, may offer some protection against the disease now and in the future. And the good news is that many of us have T cells that already recognize the coronavirus and can fend off an attack. This so-called hidden immunity may also be one of the keys to developing a vaccine against the disease.

According to BBC Future, T cells, not antibodies, may be the vital link in the fight against COVID-19. T cells are white blood cells that identify and kill potential invaders of pathogens. The researchers say these cells have long-term memory and can even identify enemies from the past to generate a quick and effective response to an attacking virus.

Surprisingly, the researchers found that people had T cells that attacked the surface of the COVID-19 virus in blood samples taken before the pandemic began. In fact, 40-60% of these individuals had specific T cells that attacked the protein surfaces of the coronavirus. Scientists at the La Jolla Institute of Immunology in California found T cells that recognized and responded to SARS-CoV-2 in blood samples collected between 2015 and 2018.

Experts say prior exposure to cold viruses may be how our immune systems develop T cells that respond to COVID-19. According to BBC Future, this means that T cells can provide protection for years and should be part of the overall plan to develop a vaccine.

“There really is a huge spectrum of vaccine design,” said Adrian Hayday, professor of immunobiology at King’s College London, adding that he was encouraged by the fact that our immune system readily recognizes the virus. “And that really emphasizes how incredibly important these cells are, and that the antibodies alone won’t help you.”