After the first injection has been administered, the second dose is given 21 days after as a booster.
The Pfizer/BioNTech vaccine is a type of mRNA vaccine, like many of the other covid vaccines currently in development.
MRNA vaccines differ from the more traditional forms of vaccine, which may use weakened or inactive forms of viruses to cause an immune response.
These vaccines introduce an mRNA sequence into the body, which contains instructions to make a “spike protein”.
Source: | Daily Express