Scientists look beyond antibodies in virus immunity hunt

Could the ghosts of your previous colds help protect you from COVID-19, even if you have never been infected by the new coronavirus spreading across the planet? 

Scientists are investigating a poorly-understood immune mechanism in the body that they hope could help efforts to curb the pandemic. 

At the moment, people who think they have had the virus might get a serological test to check for antibodies. 

These proteins help fight off infection and may prevent them from getting the disease again in the future - but there are signs that with COVID-19 they could fade away within weeks. 

This leaves the other instrument in the body's toolkit - T lymphocytes - a type of white blood cell responsible for the second part of the immune response.

With little yet known about how they operate against COVID-19, scientists are racing to fill in the gaps in our knowledge. 

One hypothesis is that these T cells might help give people a level of cross-immunity protection from COVID-19 because they "remember" previous infections by other viruses in the same family, four of which cause common colds.

"The immune system is complex," said Andreas Thiel, who co-authored a study that looked at the...