Findings based on two doses three weeks apart are first to show shot remains effective for many months
The coronavirus vaccine developed by Pfizer and its German partner BioNTech protects against symptomatic Covid for up to six months, an updated analysis of clinical trial data has found.
In a statement released on Thursday, the companies reported efficacy of 91.3% against any symptoms of the disease in participants assessed up to six months after their second shot. The level of protection is only marginally lower than the 95% achieved soon after vaccination.
The Pfizer/BioNTech Covid jab is an mRNA vaccine. Essentially, mRNA is a molecule used by living cells to turn the gene sequences in DNA into the proteins that are the building blocks of all their fundamental structures. A segment of DNA gets copied (“transcribed”) into a piece of mRNA, which in turn gets “read” by the cell’s tools for synthesising proteins.
