Scientists from Britain are investigating whether lower doses of Covid vaccine can be used in booster programs. This is in the hope that it will increase global supply.
As a means of protecting against the virus, fractional doses have been suggested as a way to ensure that scarce supplies are available in areas where there is shortage.
The idea is being considered by several members of the Joint Committee on Vaccination and Immunisation, which advises UK government. In times of shortage, lower doses of vaccines have been used to treat other diseases.