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The majority of adults are now vaccinated in many developed countries.
That could soon change.
Pfizer-BioNTech expects to hand over crucial data about the efficacy of its vaccine in the 5-11 age group within weeks to regulators in the US.
So when will the vaccine be available to them?
The National explains.
Which ages is the vaccine being trialled in children?
The vaccine has already been approved in children age 12 and above, and it is currently in trials for those as young as six months.
Pfizer-BioNTech administered the first doses in young children in March to study the vaccine in three age groups: children aged 5 to 11 years, 2 to 5 years, and 6 months to 2 years.
Younger children are receiving a lower dose of the vaccine compared with adults.
A scientist involved in the trials for children said it appeared children mounted a “very strong immune response” to the vaccine, despite the lower doses.
"So one-third of the dose that we're giving adults, or even one-third of the dose that was used in 12-year-olds and above, was just as immunogenic,” Dr Bob Frenck, director of the Vaccine Research Centre at Cincinnati Children's Hospital told CNN.
“We got just as good an immune response as the 30-microgram dose and there were less side effects.
"So because of that, for the 5-12-year-old dosing we are looking at 10 micrograms, and then, in the younger kids, under 5, even going down further to 3 micrograms."
When will the trial reports be available?
The results of the trials in ages between 5 and 11 will be available first, sometime at the end of September and subsequently, Pfizer is expected to file an emergency use application for its use. The US Food and Drug Administration will then need time to assess it.
It is not known how long that will take, but Pfizer’s application for 12 year-olds and above was approved about a month after the company submitted it.
Experts have said that means approval could follow in October if the vaccine proves safe and effective.
"We're hoping to have authorisation – depending on both results and, of course, a few decisions – not too long after the school year starts," Dr Phil Dormitzer, chief scientific officer for viral vaccines at Pfizer, told America's National Public Radio.
Data for younger groups will follow slightly later.
Results for children aged 2 to 5 will be ready soon after the 5-11 age group.
And results for the youngest group, age 6 months to 2 years, are expected in October or November.
It is not known when the vaccines will be approved in the UAE.
But approval in the UAE followed shortly after the vaccine got the green light in the US for the 12-15 age group in May.
Are children at risk from the virus?
The overwhelming majority of children suffer only mild symptoms, or none at all. However, they can and do catch the virus and transmit it, and a very small number become very sick or die as a result.
More than four million children are known to have suffered from the virus since the onset of the pandemic in the US. At least 346 have died.
However, a recent study reported in the journal Pediatrics showed Covid-19 led to more symptoms and complications than the flu in children, with underlying health conditions such as asthma and obesity presenting bigger risks.
According to the research, pneumonia and hypoxia, or a lack of oxygen, occurred more frequently in Covid than seasonal flu.
Children can also suffer from long Covid.
Data released by the UK’s Office of National Statistics in February and April showed 9.8 per cent of children aged from 2 to 11 years and 13 per cent aged 12–16 years reported at least one lingering symptom five weeks after a positive diagnosis.