The immune response generated by previous exposure to common colds could protect against Covid-19, according to a new peer reviewed study published in Nature Communications Monday, an early but promising finding researchers say could pave the way to more long-lasting vaccines that protect against current and future variants of coronavirus.
People with high levels of T cells—a type of white blood cell that is a key part of the immune system—from other coronavirus infections like the common cold are less likely to contract the virus that causes Covid-19, according to a study by researchers at Imperial College London.
For the study, which took place in September 2020 (before most in the U.K. had been infected or vaccinated against Covid-19), the researchers followed 52 people living with someone who had Covid-19, half of whom went on to contract the disease.
For the half that did not get infected, blood samples taken shortly after exposure revealed higher levels of T cells from previous coronavirus infections, such as colds, that could also recognize proteins in the virus that causes Covid-19, the researchers said.
Professor Ajit Lalvani, the study’s senior author, said the findings provide “the clearest evidence to date that T cells induced by common cold coronaviruses play a protective role against” Covid and could hold the key to developing a universal vaccine that protects against current and future variants
The study said the T Cells attack proteins inside the virus, rather than the spike protein (targeted by most widely-used vaccines) on its surface, which Lalvani said mutate much less and make for more “broadly protective vaccines” between various variants.