The US Centres for Disease Control and Prevention on Tuesday approved the use of Pfizer-BioNTech's Covid-19 vaccine for children between 5 and 11 years old, marking a major milestone in the nation's effort to combat the pandemic.
The backing paves the way for about 28 million children to be inoculated, with many of them already back at school for in-person learning.
Immunisations can begin immediately as Pfizer is already packing and shipping the first orders to states and pharmacies in preparation.
An independent vaccine panel unanimously voted to recommend the use of Pfizer's Covid-19 vaccine for the new age group and CDC director Dr Rochelle Walensky approved the agency's recommendation hours later.
"We know millions of parents are eager to get their children vaccinated and with this decision, we now have recommended that about 28 million children receive a Covid-19 vaccine," Ms Walensky said.
The move also marks the first Covid-19 paediatric vaccine to be approved in the US.
US President Joe Biden agreed it was a "major step forward for [the] nation in our fight to defeat the virus", he said on Tuesday evening.
"It will allow parents to end months of anxious worrying about their kids, and reduce the extent to which children spread the virus to others."
Mr Biden and Dr Walensky said the US paediatric vaccination programme would reach full capacity starting on November 8.
The US Food and Drug Administration gave emergency authorisation for the paediatric vaccine last week.
“Today is a monumental day in the course of this pandemic,” Dr Walensky told the advisory panel before the vote on Tuesday.
She said that while the risk of severe disease and death was lower in young children than adults, it was real – and that Covid-19 has had a profound social, mental health and educational impact on children, including widening disparities in learning.
“There are children in the second grade who have never experienced a normal school year,” Dr Walensky said.
“Paediatric vaccination has the power to help us change all of that.”
Many paediatricians and parents have clamoured for protection for children so they can resume normal childhood activities without risking their own health, or the fear of bringing the virus home to a more vulnerable family member.
One third of parents with children aged between 5 and 11 say their child will be vaccinated “right away” when eligible, a KFF Vaccine Monitor report showed in late September
About one in five said their child would “definitely not” be vaccinated.
Dr Sara Oliver, a scientist with the CDC, told the panel on Tuesday that the agency forecasts vaccinating children aged between 5 and 11 will reduce transmission of coronavirus by 8 per cent, or about 600,000 cases, between November and March of next year.
Dr Oliver said that vaccination of this age group “would dampen, but not eliminate, a new variant emergence” if that were to happen.
More than 8,300 children in this age group have been admitted to hospital with the disease, about a third of them requiring intensive care, government data showed. The CDC has recorded at least 94 deaths in that age range.
Covid-19 has ranked among the top 10 leading deaths for children aged 5 to 14 so far in 2021, a KFF analysis of CDC data showed.
Children receiving the paediatric vaccine will receive their two shots three weeks apart, but their dose will be one third the size of that given to those aged 12 and up.
Pfizer and its partner, BioNTech, said their paediatric vaccine shows 90.7 per cent efficacy against Covid-19 in a clinical trial for children aged 5 to 11.
About one quarter of parents say their child has had to enter quarantine because of possible exposure to Covid-19 at school, KFF said.
Dr Oliver said child vaccinations could lead to stabilisation in the US workforce, as parents might not have to stay home for children who need to be in quarantine.
Agencies contributed to this report