Virus Challenge


Anchor lead: Volunteers in the UK plan to allow themselves to be infected with Sars-CoV2 following vaccination, Elizabeth Tracey reports

How can you tell if a Sars-CoV2 vaccine works? Most studies inject two groups of people, one of whom gets the vaccine and the other a placebo. Then researchers wait to see whether the vaccinated group experiences less infection than the other, a process that takes some time. Now researchers in the UK say they are planning to expose some of their vaccine volunteers to the virus to see if the vaccine works, called a challenge. Brian Garibaldi, a critical care medicine expert at Johns Hopkins, comments.

Garibaldi: It’s very difficult to do live virus challenges. This is something we don’t commonly do and there’s been a healthy ethical debate in the US about whether or not we would consider doing this for vaccine studies that are taking place here. Very interested to see what happens with those studies but there is, even though we do have some therapies against Covid-19 and we hope that these vaccines are going to be effective at providing at least some measure of protection there is some obvious risk to being in these types of studies, and very anxious to see what happens.  :29

At Johns Hopkins, I’m Elizabeth Tracey.