Do vaccines make pandemics worse?

Now Joe Rogan is claiming that vaccinating during a pandemic makes the pandemic worse because leaky vaccines cause new variants.

Rogan’s claims come from an old study of a virus in chickens, but his conclusion is wrong. Some people have used this study to wrongly say that “leaky” vaccines are making COVID turn into stronger and more dangerous variants.

The study was published in 2015 and focused on a chicken illness called Marek’s disease, which is a serious viral infection in chickens. The researchers looked at how the virus could still change over time even when chickens were vaccinated.

The vaccine in the study was called a “leaky vaccine,” which means it does not completely stop the virus from spreading, but it still helps protect animals from getting very sick. Even with this type of vaccine, vaccination greatly reduced how much the disease spread and how many chickens died. In fact, deaths from Marek’s disease dropped by 99% between 1970 and 2006 because of vaccines.

Some have tried to use this chicken study to claim that COVID vaccines caused the mutations and variants we have seen. But that is not true. A variant is a new version of a virus that forms when the virus changes over time. One major variant, Delta, appeared before COVID vaccines were even available.

The main author of the study, Andrew Read, has said that people are misunderstanding his research. He explained that vaccines do not cause viruses to mutate. Viruses mutate when they replicate, meaning when they make copies of themselves inside the body. Since vaccines reduce how much a virus spreads and replicates, they can actually lower the chance of new mutations forming.