Moderna said that the current version of the Covid vaccine will continue to be its first line of defence against Omicron, despite the fact that a booster dose of the vaccine appeared to protect against the fast-spreading Omicron variant in laboratory testing.
The decision to focus on the current vaccine was made because of how quickly the variant is spreading. The company plans to develop a vaccine to protect against Omicron, which it hopes to begin clinical trials early next year.
Dr Paul Burton is Moderna's chief medical officer. It is highly effective and safe. I think it will protect people during the holiday period and during the winter when Omicron will be at its most severe.
The company said that a booster dose increased neutralising antibodies against the variant by 37 times. A higher, 100g booster dose of the same vaccine drove levels even higher.
The blood from people who had received the vaccine against the pseudoviruses was tested. It is similar to data discussed by the top US infectious disease expert.
It would be for governments and regulators to decide if they wanted the enhanced level of protection that a 100g dose would confer.
The company said the 100g dose was safe and well-tolerated, but there was a tendency to have more frequent adverse reactions.
The results were similar when Moderna tested the vaccine's effectiveness against its prototype boosters that target multiple previous variant of concern.
The 50g booster of Moderna's vaccine was approved by the US regulators. The first two shots are 100g.
The Moderna and Pfizer/BioNTech vaccines have been linked to rare cases of heart inflammation in young men. Moderna's vaccine may cause that side-effect at a higher rate.
The World Health Organization says that Omicron has raced around the world and been reported in 89 countries.
The number of Omicron cases was doubling in a few days in areas with community transmission, but there were still many unknowns about the variant.
