Moderna announced Wednesday that it has administered the first doses of a modified vaccine designed to fight coronavirus variants to study participants.
The company said it is observing the efficacy of two different modified vaccines in a small study of 60 people who had already received the original vaccine.
Some participants will receive a booster dose of a modified vaccine specifically designed to combat a variant of the virus first identified in South Africa. This variant has been shown to reduce to some extent the immune response elicited by the original Moderna vaccine.
Other participants receive a booster dose that combines the modified vaccine with the original vaccine to produce a “multivalent” vaccine designed to fight multiple strains simultaneously.
The studies are part of the company’s strategy to prepare for variants of the virus as needed.
Moderna says studies have shown that the original vaccine can protect against the variants, but there is still a six-fold reduction in the level of antibodies produced against the South African strain.
As a result, the company has said “with an abundance of caution” that it is preparing a booster dose specifically directed against that species, if necessary.
Pfizer has also prepared for the possibility of needing booster doses.
In addition, Moderna said the National Institutes of Health will be conducting a study of the modified vaccine in participants who have not yet received the original vaccine.