US biotech firm Moderna said on Thursday it had submitted a request for an emergency use authorisation in the US for its Covid-19 vaccine for babies aged 6 months to children under 6.
Very young children are the only group that are yet to be eligible for the Covid-19 vaccine in the US and in most countries — a source of concern for many parents.
“We believe [this vaccine] will be able to safely protect these children against SARS-CoV-2, which is so important in our continued fight against Covid-19 and will be especially welcomed by parents and caregivers,” the company's chief executive Stephane Bancel said.
In March, the company announced results from a trial that showed the two-shot regimen was found to be safe and produced a strong immune response.
The trial featured 4,200 children aged 2 to 6 years and 2,500 babies aged 6 months to 2 years.
Side effects were generally mild and consistent with those seen in older age groups, said Moderna.
It did, however, find relatively low efficacy, with its trial taking place during the Omicron variant wave.
The current generation of vaccines were designed against the original strain of the virus.
Vaccine efficacy in children 6 months up to age 2 was 51 per cent, and efficacy was 37 per cent in the 2 to 5 years age group, when limiting the analysis to only cases confirmed positive on a positive PCR test.
Moderna said these were similar to vaccine efficacy estimates in adults during Omicron, and it is also currently studying booster doses for all paediatric cohorts.
In February, the Food and Drug Administration postponed a meeting of a panel to consider the Pfizer-BioNTech Covid vaccine for children younger than 5, saying it wanted to see data on how three doses performed before considering the matter.
Pfizer's vaccine, when given as two doses of three micrograms to children aged 6 months to 2 years elicited a similar level of antibodies to the full 30 micrograms given to people aged 16-25, but the same was not true for children between 2 and 4.
This week, Pfizer chief executive Albert Bourla said in an interview that his company was aiming to get the vaccines out by June if regulators agree.
Scientists evaluating a vaccine for infants must closely consider the risk-benefit balance.
New CDC data shows that 75 per cent of US children have had coronavirus so far in the pandemic.
Even when unvaccinated, children under 5 are at very low risk for severe disease, with only 476 US deaths occurring in this age group, according to official data.
Among all US children, there have also been almost 8,000 cases of MIS-C, a post-viral inflammatory condition, resulting in 66 deaths.
Emergency physician Jeremy Faust, of Brigham and Women's Hospital, in Boston, Massachusetts, tweeted that Moderna's results were very positive news, despite the mediocre-sounding efficacy estimates.
“What these vaccines have been shown to really do, over and over, is protect against severe disease and hospitalisation, long-term consequences,” he said, adding the immune response outcomes predicted success on these measures.
“I'll be quite comfortable getting my 4-year-old vaccinated with Moderna.”
AFP contributed reporting