An independent advisory panel to the US Food and Drug Administration has unanimously recommended that people over 65 years old, or at high risk of severe illness, may receive a booster dose of the ModernaCovid-19 vaccine.
The FDA will now consider the recommendation; while it is not obligated to follow the recommendation, it usually does.
Officials are expected to reach a decision within days as to whether to roll out a Moderna booster program for those who were vaccinated at least six months ago.
Almost 70 million Americans have received both doses of the Moderna vaccine. The booster shot would be a half dose.
The Vaccines and Related Biological Products Advisory Committee was asked to vote on whether available data supports giving a 50 microgram booster dose to three high-risk groups — those over 65 years of age; people aged 18 to 64 at high risk of severe Covid-19; and adults whose frequent institutional or occupational exposure to Covid, such as medical staff, puts them at high risk of contracting the virus and developing serious complications.
An advisory committee to the Centers for Disease Control and Prevention which gives recommendations as to how vaccines should be deployed is scheduled to meet on Wednesday.
When Pfizer put forward its case for people to be administered booster shots, the pharmaceutical company said that its efficacy appeared to wane over time. This claim was backed up by CDC research which found efficacy against hospitalisation fell from 91 per cent to 77 per cent after four months.
However, Moderna’s efficacy holds up better, so the company made its argument for booster shots based on the vaccine’s ability to prevent infection and lessen symptoms in mild to moderate cases.
Five months after a second dose, research by Moderna shows that the vaccine remains highly protective, with an efficacy of 93 per cent in preventing any illness, and 98 per cent in preventing severe illness.
In a research trial, a half dose restored antibodies that had diminished in the six to eight months since the second dose.
Additionally, recipients of the vaccine in 2020’s clinical trial, before emergency use authorisation was granted, showed an uptick of breakthrough infections approximately a year after receiving their second dose — more so than those in the trial who had received the placebo and were therefore vaccinated more recently.
Johnson & Johnson has asked the FDA to consider a booster for recipients of its vaccine, and the same panel will vote about that on Friday.
They will also discuss whether recipients of the one-shot J&J vaccine might be better off receiving a dose of either the Pfizer or Moderna vaccine, but no vote on that will be held yet.