Briefly

COViD edition:

• T-cells. Recent research has found some people already have a T-cell immune response to the COViD virus — in some cases due to getting SARS Classic,  nearly two decade ago, and in some cases probably from animal coronaviruses. That’s encouraging for the prospects  of a vaccine.  But in the  US there are people saying this means those people are immune and we’re near the herd immunity threshold.  That’s completely untrue. The infectiousness of the virus was estimated from how fast it spreads in real populations — so if 50% of people are immune, that just means the virus is twice as infectious as we thought, and the herd immunity threshold is higher.
• T-cells: Some people have T-cell responses already, but we don’t actually know those people are immune, or even less susceptible. As Ed Yong explains “Immunology is where intuition goes to die“
• If you want to know about vaccine candidates for COVID: first, read the introduction by Siouxsie Wiles and Toby Morris, then look at the blogs of Hilda Bastian and Derek Lowe. Hilda is an expert on evidence in health and started out as a healthcare consumer advocate. Derek  is a pharmaceutical chemist.
• What is genome sequencing for the virus and why? Basic introduction from Siouxsie and Toby at The Spinoff, more from David Welch’s op ed at Stuff
• Why we need randomised trials: The Mayo Clinic, in the US, has given plasma from recovered COVID cases to more than 35,000 people and they still don’t really know if it works.
• And now for something completely different: there’s an IMDB entry for the 1pm Covid Briefing, and reviews of season 2 are starting to stream in.