The request for the license that was submitted is for two doses of three micrograms, which would give parents “the opportunity to direct a series of vaccinations against Covid-19 for their children pending a possible license for a third dose,” according to what Pfizer Director General Albert Borla announced in a statement.
The US drug giant chose a dose of three micrograms per injection for children aged six months to five years. It is 10 times lower than the dose given to adults (30 mcg), and lower than the dose for children aged five to 11 years (10 mcg).
A dose of 10 micrograms caused more fever symptoms in children aged 2 to less than 5 years than in the older groups, prompting the company to opt for a lower dose.
It was found that two doses of three micrograms provoked a weaker immune response than recorded in boys and young adults.
Therefore, Pfizer decided to amend its clinical trial protocol, to include a third dose to be injected “at least two months after the second,” according to what it said in a statement that also explained that the second dose is given three weeks after the first.
The booster dose has been shown to boost immunity in older groups.