The US Food and Drug Administration (FDA) on Friday authorised emergency use of the Moderna Covid-19 Vaccine and the Pfizer-BioNTech vaccine for the prevention of Covid-19 in children down to 6 months of age.
For the Moderna Covid vaccine, the FDA amended the emergency use authorisation (EUA) to include use of the vaccine in individuals 6 months to 17 years of age.
The vaccine had been authorised for use in adults 18 years of age and older.
For the Pfizer-BioNTech vaccine, the FDA amended the EUA to include use of the vaccine in individuals 6 months to 4 years of age.
The vaccine had been authorised for use in individuals 5 years of age and older.
The agency said in a statement that the known and potential benefits of the Moderna and Pfizer-BioNTech COVID-19 vaccines outweigh the known and potential risks in the paediatric populations authorised for use for each vaccine.
"Many parents, caregivers and clinicians have been waiting for a vaccine for younger children and this action will help protect those down to 6 months of age," said FDA Commissioner Robert M Califf.
"As we have seen with older age groups, we expect that the vaccines for younger children will provide protection from the most severe outcomes of Covid-19, such as hospitalisation and death," Califf added.
The Moderna vaccine is administered as a primary series of two doses, one month apart, to individuals 6 months to 17 years of age.
The vaccine is also authorised to provide a third primary series dose at least one month following the second dose for individuals in this age group who have been determined to have certain kinds of immunocompromise.
The Pfizer-BioNTech vaccine is administered as a primary series of three doses in which the initial two doses are administered three weeks apart followed by a third dose administered at least eight weeks after the second dose in individuals 6 months to 4 years of age.
"As with all vaccines for any population, when authorising Covid-19 vaccines intended for paediatric age groups, the FDA ensures that our evaluation and analysis of the data is rigorous and thorough," said Peter Marks, Director of the FDA's Center for Biologics Evaluation and Research.
The effectiveness and safety data evaluated and analysed by the FDA for the Moderna vaccine to support the EUA for these paediatric populations were generated in two ongoing, randomised clinical trials in the US and Canada which enrolled infants, children and adolescents.
Children 6 months to 5 years of age received a two-dose primary series of the Moderna vaccine at 25 micrograms (mcg) of messenger RNA (mRNA) per dose.
In the FDA analyses, the immune response to the vaccine, of both age groups of children, was comparable to the immune response of the adults.
On the other hand, the effectiveness and safety data evaluated and analysed by the FDA for the Pfizer-BioNTech COVID-19 vaccine were also generated in an ongoing and randomised clinical trial in the US and internationally, which enrolled infants and children.
"The effectiveness data to support the EUA in children 6 months to 4 years of age is based on a comparison of immune responses following three doses of the Pfizer-BioNTech vaccine in a subset of children in this age group to the immune responses among adults 16 to 25 years of age," said the US FDA.
The immune response to the vaccine for both age groups of children was comparable to the immune response of the older participants.
The FDA and CDC safety surveillance systems have previously identified increased risks of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of tissue surrounding the heart) following vaccination with the Moderna vaccine and the Pfizer-BioNTech vaccine, particularly following the second dose.
"The observed risk is highest in males 18 to 24 years of age for the Moderna vaccine and in males 12 to 17 years of age for the Pfizer-BioNTech vaccine," said the FDA.