Moderna has shipped a new version of its COVID-19 vaccine to testing sites, aimed at a mutation that blunts the shot already in use. The Massachusetts-based company announced the shipment on Feb. 24.
The new vaccine is one piece of a three-part plan to deal with variants that spread more easily. All three pieces test a third dose on top of the two-dose course of Moderna’s vaccine, which holds emergency use authorization from the U.S. Food and Drug Administration (FDA). Volunteers will include people from the early trials of the original vaccine, who were vaccinated six to 12 months ago, and people who have not been vaccinated.
Three studies
The first study adds a third dose of the existing vaccine. Earlier company data showed the original shot still protected against disease from the main known faster-spreading variants, though protection fell somewhat against B.1.351, first identified in South Africa. This study asks whether a third dose can lift virus-fighting antibodies back to the level the two doses gave against the original virus.
The second tests a new vaccine built specifically against B.1.351. It is being tried as the third dose after two doses of the original.
The third combines the original vaccine and the B.1.351 version in one shot, also as a third dose. Moderna said it also plans to study both new vaccines as stand-alone shots in people who are unvaccinated and negative for COVID-19, to see whether they can protect on their own.
The B.1.351 concern
The company said it is running the studies “out of an abundance of caution” and that its original vaccine still gives strong protection against COVID-19 disease. Infectious disease experts are more worried, especially about B.1.351, which seems more resistant to the immune defenses vaccination produces. A Moderna study released in January and later published in the New England Journal in February found a six-fold drop in antibodies able to neutralize B.1.351, compared with the non-mutated virus.
Moderna hopes a third dose, of the same shot or one of the new ones, will make up for that loss. Depending on results, it will work with regulators such as the FDA to decide whether the current authorization needs to change.
Speed and supply
The mRNA technology behind the vaccine lets the company build new versions by changing the genetic information in the shot. The original vaccine was developed in a record 42 days and entered human testing in a record 63 days. The new one took about six to eight weeks.
Alongside the studies, officials committed to an extra 100 million doses of the original vaccine this year, for a total of 700 million doses globally in 2021. Moderna is also looking at ways to fit up to 15 doses in each vial, instead of the current 10.
