Researchers identified a group of healthcare workers who did not become infected during the first wave. They found evidence of pre-existing T-cell immunity, suggesting that not everyone is equally susceptible to Covid.
T-cells from common cold coronaviruses can provide protection against COVID-19, an Imperial College London study has found. But why has it taken 16 months for it to be published?
During a Covid surge, what proportion of the population is exposed? Is it almost everyone, with most being immune, or is it only a small proportion, with everyone else left susceptible? This is the crucial question.
A new study in Nature shows that not only do people infected with SARS-CoV-2 develop lasting T cell immunity, but so too do their close contacts who were never infected. This means herd immunity is closer than we think.
The virus raged on the Diamond Princess cruise ship in February 2020, but only 17% of passengers tested positive, suggesting high levels of pre-existing immunity. Why was that lesson ignored by the modellers?
