Moderna announced Wednesday that it has administered the first doses of a modified vaccine designed to combat coronavirus variants to participants.
The company said it was observing the efficacy of two different modified vaccines in a small study involving 60 people who had already received the original vaccine.
Some of the participants receive an increased 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 the immune response caused by the original Moderna vaccine to some extent.
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 form part of the company’s strategy to prepare, if necessary, for the variants of the virus.
Moderna says studies have shown that the original vaccine can protect against the variants, but there is still a sixfold reduction in the level of antibodies produced against the South African strain.
Therefore, the company said ‘out of caution’ that they are preparing a booster dose specifically targeted to the stress, if necessary.
Pfizer also prepared for the possibility of requiring booster doses.
In addition, Moderna said the National Institutes of Health will conduct a study with its modified vaccine in participants who have not yet received the original vaccine.