REGARDING THE COVID-19 PANDEMIC, IS MAREK’S DISEASE A CAUTIONARY TALE?

Abstract

Marek’s disease (MD) is a deadly viral disease of chickens. Prior to 1960 MD was a relatively mild disease, with a low mortality rate. By 1970 large scale corporate mega farms were dominating the chicken industry, and MD became more threatening. A vaccine for MD was, therefore, introduced in the early 1970s. Vaccinated chickens rarely become ill with MD. However, over the past 50 years the MD virus has become increasingly deadly, such that 100% of unvaccinated chickens die within 2 weeks when exposed to the most virulent strains, which are shed by the vaccinated chickens. The MD vaccine is a sub optimal vaccine in that it reduces symptoms but does not prevent infection or transmission of the virus. Studies have strongly suggested that, because it is a sub optimal vaccine, the MD vaccine enables and drives evolution of increasingly virulent strains of the virus. The COVID vaccines are also sub optimal vaccines. This raises concern that the COVID vaccines might enable and drive evolution of increasingly virulent strains of the SARS-CoV-2 virus and cause the global population to become increasingly dependent on COVID vaccines, which may eventually fail, due to evolution of vaccine resistance.