9 July

I promised to talk about chickens. This isn’t a chicken doing the splits, it’s a chicken with Marek’s DIsease. A type of herpes virus. It’s deadly to pretty much any chicken who catches it. I’m telling this story because originally Marek’s DIsease wasn’t that deadly, and how it became that is a story for us, during Covid times. There’s a vaccination for Marek’s Disease, and commercial chooks get it. It’s successful at stopping them dying, though it does little to stop them passing it on to other chickens (ringing any bells yet?) Over the years of using this vaccine, strains of the virus that would normally not have survived because they’re lethal (if a chicken dies, it can’t pass it on), survived because the vaccine kept the chicken alive. This caused the gradual natural selection of strands of Marek’s that are lethal to any chicken who isn’t vaccinated. Without constant vaccination, all chickens would die. This is the danger of vaccinating with a vaccine that doesn’t stop transmission, only severe disease, and then not controlling spread of a virus. It will tend to push that virus to ever-more lethal variants. Covid vaccines are pretty good against severe disease, and pretty hopeless now at stopping transmission. And we’re not stopping transmission with other measures, we’re happily all out getting repeatedly infected. I’m sure you can join the dots and write the ending yourself.