Pfizer’s data on COVID-19 vaccine for children under 5 is based in science

U.S. Rep. Chip Roy, a Republican from Texas who is running for reelection in Texas' 21st Congressional District, was not pleased to see news that Pfizer is requesting the U.S. Food and Drug Administration to authorize its COVID-19 vaccine for children under the age of 5.

In a Feb. 1 Tweet, Roy wrote, "Literally using the force of government and the culture of fear to jab children under 5 — with zero basis in science — to make billions of dollars. Shameful, @pfizer."

Roy linked to a Jan. 31 New York Times article reporting this move ahead of Pfizer and BioNTech's expected request. Pfizer is seeking authorization for a two-dose regimen while evaluating how well three doses work.

Does Pfizer's effort to seek authorization for its vaccine for the youngest children have "zero basis in science"? We took a look at that part of the claim.

A spokesperson from Roy's office wrote in a Feb. 3 email: "Rep. Roy’s tweet was intended to bring attention to the fact that, not only there is not a pressing need to vaccinate children — who are extremely low risk for hospitalization and death from COVID-19 — but, according to CNN, Pfizer’s initial trials on a two-dose regimen for children under 5 did not provide sufficient immunity, causing them to begin a new trial adding a third dose."

The Dec. 17 CNN article cited is about adding a third dose to trials after the vaccine for children ages 2 to 5 did not provide expected immunity.

So, Roy is concerned with authorizing emergency use when the data for the third dose is still being collected.

The spokesperson also wrote that there is a low demographic risk level when you compare Centers for Disease Control and Prevention COVID-19 mortality statistics between age groups. The spokesperson highlighted "an extreme disparity between children and the elderly" because there were 393 deaths for children under age 5 and more than 166,000 deaths for those ages 65 to 74 as of Feb. 2.

A Dec. 17 press statement — same day as that CNN article — from Pfizer indicated the company was evaluating a third 10-microgram dose for children ages 5 to 12 after an effective three-dose regimen for people ages 16 and older.

Pfizer described its trial for children ages 6 months to 4 years in its Feb. 1 news release about requesting authorization. The trial initially enrolled 4,500 children ages 6 months to under 12 years old in the U.S., Finland, Poland, and Spain at more than 90 clinical trial sites. Children under age 5 received a lower dose compared to children ages 5 to 12.

The trial grew to 8,300 children as of Feb. 1 following the study's amendments, according to that release. The trials evaluate vaccine safety and effectiveness.

That Feb. 1 Pfizer press release indicated the two-dose regimen did not produce the expected immune response for children ages 2 to 5 but did for children up to age 2.

In a Feb. 4 email, Pfizer spokesperson Sharon J. Castillo wrote that Pfizer and BioNTech’s application is for authorization of the first two three-microgram doses of a planned three-dose series for children up to age 4.

"Data on a third dose, given at least 8 weeks after completion of the second dose, are expected in the coming months and will be submitted to the FDA to support a potential expansion of this requested EUA," Castillo wrote.

In clinical trials, researchers track side effects, immune response and antibody levels compared to adults and teens. The journey to a vaccine is often a long process.

Dr. Joseph Cantey at The University of Texas Health Science Center at San Antonio said that the steps that vaccines go through to be safe and effective is very rigorous. Companies did not take shortcuts on that process even with the urgency of the pandemic.

"What we have seen is a streamlining of all the steps that have to happen so those steps can happen without long delays in between them. So, in non-pandemic settings, a drug company might have an idea for a new vaccine or new mechanism, and they would do what we call pre-clinical trials," he said.

Then there would be a gap in years between pre-clinical trials and clinical trials, Cantey explained, as a vaccine developer secured funding or went through the regulatory hoops. Then they would start studies while the drug company might work on other products or different priorities.

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"The main thing that happened with the COVID vaccine is not that the Phase 1 or Phase 2 or Phase 3 studies were any shorter or less rigorous," Cantey said. "It was all that downtime in between got eliminated, because there's such an urgency for these vaccines that companies went through Phase 1 to Phase 2 to Phase 3 in a matter of months instead of a manner of years or a decade."

For the Pfizer COVID-19 vaccine, mRNA enter the muscle cells and instruct the cells to produce a harmless spike protein — the same that is found on the virus that causes COVID-19, according to the CDC. The body's immune response to this spike protein teaches the body how to fight the virus.

Cantey said it is a matter of calibrating the dosage and ensuring there are no unanticipated side effects.

"Children are definitely not just little adults. You can't say 'well this adult weighs 200 pounds and needs X dose and this child weighs 20 pounds so they need X dose divided by 10.' That's not exactly how it works," Cantey said. "Finding the right dose so that those kids' immune systems can respond to the vaccine in a positive way is a little bit different. But the mechanism itself—the ability of the vaccine to deliver that messenger RNA to cells so that they can make spike proteins, so that the child's immune system can recognize it and protect them from coronavirus—that's the same."

Castillo, the Pfizer spokeswoman, noted Pfizer believes a three-dose series would provide important protection against omicron and future variants. Castillo also noted that series of three doses or more are not uncommon in pediatric vaccines.

The American Academy of Pediatrics said in a Feb. 1 press statement that it is encouraged by the prospect that a vaccine will be available for children under age 5, "pending a rigorous review of Pfizer-BioNTech's scientific data validating its safety and effectiveness by the U.S. Food and Drug Administration, and the Centers for Disease Control and Prevention."

When the Food and Drug Administration authorized the emergency use of the Pfizer-BioNTech vaccine for children ages 5 to 11, the agency had ensured that the authorization was after a "thorough and transparent evaluation of the data" that included expertise of people independent of the FDA committee, according to an Oct. 29 news release. The vaccine's safety was studied in 3,100 children of that age range. The vaccine's immune effectiveness had been measured, and no serious side effects had been detected in that study. 

Children are less likely to have severe symptoms compared to older people, and most COVID-19 deaths in the U.S. have occurred among people age 65 or older, as Rep. Roy's office said. 

Dr. Donald Murphey, member of the Texas Medical Association's COVID-19 Task Force and chair of the Texas Medical Association's Council on Science and Public Health, said he often is asked if children need to get immunized or if children get COVID-19.

"The answer is yes. There's even some recent studies with omicron coming that kids get about the same number of COVID infections that adults do," Murphey said. "They don't get as sick with them, but they do get the same number of infections. If you look for kids who have an asymptomatic infection, they get just as much COVID as adults. And they also spread COVID just as much as adults do."

However, an Oct. 26 FDA advisory committee briefing document about consideration of the vaccine for children ages 5 to 11 noted, "Although the mortality rate for COVID-19 in children is substantially lower than that in adults, COVID-19 was among the top 10 leading causes of death for children 5 to 14 years of age between January and May 2021 in the US."

The emergence of the omicron variant is the reason why the FDA is prioritizing a vaccine for children under age 5, according to the FDA's Feb. 1 news release.

Both the FDA and Pfizer's Feb. 1 press releases acknowledge that the FDA had asked Pfizer and BioNTech to submit its data because of the variant.

In a Jan. 28 news release regarding in-school learning, the American Academy of Pediatrics noted more than 2 million children were infected with COVID-19 in January. Pfizer highlighted in its Feb. 1 statement that hospitalization among children has spiked due to the omicron variant surge.

Parents reserve the right to decide whether their child gets vaccinated. PolitiFact has fact-checked claims, in November and August, on parents or school-aged children being forced to receive the vaccine.

Roy tweeted regarding consideration of authorizing the vaccine for children age 5 and younger: "Literally using the force of government and the culture of fear to jab children under 5 - with zero basis in science - to make billions of dollars. Shameful, @pfizer."

However, the development of the vaccine and subsequent clinical trials, as well as the decision on whether to authorize the vaccine, are based in science.

Pfizer's clinical trial being administered to thousands of children worldwide including in the U.S. is designed to verify the vaccine's safety and effectiveness.

The FDA's decision to authorize emergency use of the vaccine for children under age 5 would be based on the review of the scientific data available. This would likely include both an evaluation of effectiveness and safety, as the data review for children ages 5 to 11 had entailed in October. So the effectiveness of the two-dose course for children under age 5 would be scrutinized in the decision-making process.

The urgency for a vaccine for young children stems from the effect of the omicron variant and its transmissibility. Children could fall sick and/or pass on the virus to others around them. Even with this urgency, the FDA's decision would be rooted in a scientific review.

We rate this claim as Pants on Fire.