The Philippines will continue observing a three-week interval between the first and second doses of the reformulated Pfizer vaccine for children aged 5 to 11, despite new data from the World Health Organization (WHO) that shows the second dose should be given four to eight weeks after the first.
“We have to review the data to see if there is a better immune response if it is given after eight weeks,” said Dr. Nina Gloriani, chairman of the Vaccine Expert Panel. “Right now it is three weeks at least, or four weeks. Right now, we still have no data.”
According to WHO, longer interval between doses is “associated with higher vaccine effectiveness and potentially lower risk of myocarditis or pericarditis,” Gloriani said in an online forum by the Department of Health.
However, the status quo will be followed until the study is reviewed by the Vaccine Expert Panel.
The Philippines followed the shorter interval between doses to “balance the effect” of the Omicron variant of COVID-19, Gloriani said.
The Philippines recorded an increase in cases attributed to the more infectious Omicron variant in January, with peaks surpassing those of the Delta variant surge in 2021.
The Center for Disease Control and Prevention still recommends a two-dose series separated by 21 days for the reformulated Pfizer COVID-19 vaccine intended for children aged 5-11 years.
On the other hand, Dr. Wilda Silva, DOH National Immunization Campaign program manager, said that while myocarditis (inflammation of the heart muscle) were noted after receiving mRNA COVID-19 vaccines such as Pfizer, cases are very rare.
“Most people with myocarditis after vaccination can recover with simple treatment. However, if you get it from a viral infection, this can be very severe,” Silva warned.
The risk of getting myocarditis from a COVID-19 infection is four to eight times higher for unvaccinated individuals, Silva added.
There is only a 1 in 200,000 chance of getting myocarditis after COVID-19 vaccination.
She reiterated that most adverse effects following immunization among the 5 to 11 age group are mild and treatable, such as headaches, rashes, and fever.
The use of antipyretic or drugs against fever was more frequent after the second dose, according to Silva.
Pfizer’s jab among children ages 5 to 11 is 90.7 percent effective, Gloriani said. The 10-microgram dose was chosen for the said age group as it produces nearly the same amount of neutralizing antibodies as that of the 20-microgram dose for adults, she added.
The public is urged to observe minimum public health standards alongside vaccination, Silva said.
“Go out and get vaccinated; get your loved ones, children vaccinated against COVID-19. We have routine [non-COVID-19] vaccines for children under 1 year and they’re given for free,” she said. “It’s a proven fact: vaccination saves lives.”
The Philippines has inoculated against COVID-19 some 48,615 children ages 5 to 11 and 9.3 million children aged 12 to 17 as of Tuesday.