Moderna says infant Covid vaccine succeeded in trial

US biotech firm Moderna on Wednesday said it was pursuing regulatory approval for its Covid vaccine in children under six years old after the two-shot regimen was found to be safe and produced a strong immune response.

Specifically, two doses of 25 micrograms given to babies, toddlers and preschoolers generated similar levels of antibodies to two doses of 100 micrograms given to young people aged 18-25, indicating there would be similar levels of protection.

Children under six are the only age group that has yet to gain access to a Covid-19 vaccine in the US.

Based on the data, Moderna said it would submit authorisation requests to the US Food and Drug Administration (FDA), European Medicines Agency (EMA) and other global regulators in the coming weeks.

The results “are good news for parents of children under six years of age,” said CEO Stephane Bancel in a statement.

“We now have clinical data on the performance of our vaccine from infants six months of age through older adults.”

The company did however find relatively low vaccine efficacy against infection, with its trial taking place during the Omicron wave.

Vaccine efficacy in children six months up to age two was 43.7%, and efficacy was 37.5% in the two to five years age group.

The majority of these cases were mild and the two doses still provided very strong protection against severe outcomes. There were no hospitalisations or deaths.

Moderna said this was consistent with what had been observed among adults, and the company was evaluating a third dose as a booster, to increase efficacy against Omicron infection.

The trial included 4,200 aged two to six years and 2,500 aged six months to two years.

Side effects were generally mild and consistent with those seen in older age groups.

Rates of fever greater than 38 degrees Celsius were around the same as commonly used and recommended paediatric vaccines: 17% in the six months to two years group, and 15% in the two years to six years group.

The company added that, after consulting with the FDA, it is also applying to be authorised among children six to 11 for two doses of 50 micrograms, and updating its application for authorisation in kids aged 12 through 17.

The EMA and other regulators have already authorised the Moderna vaccine in these age groups.

Last month, the FDA postponed a meeting of a panel to consider the Pfizer-BioNTech Covid vaccine for children younger than five, saying it required additional data on third doses. The companies said they expected that data to be ready by April.