A new study raises concerns about the mRNA vaccines' effectiveness revealing that Pfizer COVID-19 vaccine is only 42% effective against the Delta variant.
A new preprint study (read below) that raises concerns about the mRNA vaccines' effectiveness against Delta — particularly Pfizer's — has already grabbed the attention of top US administration officials.
The study found the Pfizer vaccine was only 42% effective against infection in July, when the Delta variant wa...
