Pfizer says its COVID-19 vaccine is effective for children aged 5 to 11: how the trials went and why it matters

The Pfizer vaccine is already available for children aged 12 and older.

The company Pfizer said that its coronavirus vaccine is effective for children aged 5 to 11. It will soon request US approval for this age group. Here is how the vaccine trials for children went and why it matters. 

Vaccine trials

Children were given 10 micrograms with a 21-day interval (the adult dose is 30 mcg). After the second dose, antibody levels against the disease in children aged 5 to 11 were just as high as in teenagers (in May 2021 the company announced 100% efficacy of the vaccine for teenagers aged 12 to 17). 

The side effects are similar: pain at the injection site, fever or body aches. These are the first results of the main trial of the vaccine in the 5 to 11 age group. 

Albert Bourla
Chairman and Chief Executive Officer Pfizer

These trial results provide a solid basis for obtaining approval for our vaccine for children aged 5 to 11, and we plan to submit them to the FDA and other regulators as a matter of urgency. 

In total, 4,500 children aged from 6 months to 11 years took part in the trials in the US, Finland, Poland and Spain, at more than 90 clinical trial sites, with and without signs of coronavirus. The efficacy of the drug was tested in three age groups:

• 5 to 11 years
• 2 to 5 years
• 6 months to 2 years

Children aged 5 to 11 received two doses of 10 mcg each, while children under 5 received 3 mcg each. 

The company's senior vice president, Bill Gruber, told AP News: "I think we have really hit the sweet spot. 

Why it matters

According to the American Academy of Pediatrics, more than 5 million children in the US have contracted coronavirus since the start of the pandemic, and 460 children have died. Infections among children are rising as the Delta strain spreads across the US. 

AP News writes that the studies are not large enough to identify any extremely rare side effects, such as heart inflammation, which sometimes occurs after the second dose (mostly in young people). 

In total, at least one dose of the coronavirus vaccine has been given to more than 200 million people in the US. 170 million people are fully vaccinated, 92 million of them with the Pfizer drug. In mid-August the US authorized a third dose of this vaccine for people with weakened immune systems, who face a particular risk that the disease will be severe. 

The company says a third dose will be needed to protect against new coronavirus strains. Pfizer's report says it increases the number of antibodies fivefold. 

In September it became known that US health officials expect vaccination of children aged 5 to 11 to begin soon. The US Department of Health may make a corresponding decision as early as October 2021.