A year 1990 study in soldiers suggested that T-cells remain protective for about one year after catching one of the four coronaviruses that circulate as what we call “the common colds”.
The findings raised concern that SARS-CoV-2 could infect a person many times and that a vaccine might not generate lasting protection. But the article focused on just one arm of the immune response, the B cells, which produce antibodies that help to clear an infection.
T cells are also key to the immune response against viruses. They play a variety of roles, among them helping B cells to mature into disease-fighting machines. The article by Jose Mateus and colleagues at La Jolla Institute for Immunology is important because it shows that people keep T cells from the milder coronaviruses long enough to potentially interact with a new challenge by SARS-CoV-2 and that those T cells might even recognize SARS-CoV-2 and help to clear the infection. ...snip...
The milder coronaviruses can generate similar antibodies to the ones that are generated by the coronaviruses that cause SARS and Mers. These antibodies are so similar that they nearly tricked a British Columbia care facility into thinking they had an outbreak of SARS after the SARS epidemic had been declared over. In fact, the outbreak was caused by OC43, one of the coronaviruses that causes the common cold.
