Pfizer and BioNTech said Monday that preliminary results from clinical trials in children under the age of five have shown that their coronavirus vaccines have developed strong enough immunity to meet the three-dose regulatory approval criteria.
In a press release, the companies announced the results of a subset of tests on 1,678 children aged 6 months to 4 years, saying the three-dose method was 80 percent effective in preventing significant infections. No supporting information was released, and companies did not say how many children were on the subset. A Pfizer spokesman said the trial results would be released next month.
Both Pfizer and Moderna are hoping to get approval to vaccinate the country’s youngest children soon. About 18 million children under the age of 5 are the only Americans who are not yet eligible to be vaccinated against the coronavirus, and parents’ expectations about when to be shot have been repeatedly dashed.
Pfizer and its partner Bioentech said the number of children on the test who fell ill with covid was too small to make a definitive statement about their effectiveness. Only 10 children participating in the trial fell ill in Kovid after being given the third dose of the vaccination group. Clinical trial protocols specify that at least 21 covid cases are required for vaccine efficacy analysis. The companies said that the final data of efficacy, a secondary end point for clinical trials, would be shared “once available”.
The Biden administration had hoped to give a dose of the vaccine to those under 5 years of age in early February. The Food and Drug Administration initially pressured Pfizer to submit data on how well the two doses worked for young children, but Pfizer says the two doses have been delayed because they are not effective enough in preventing significant infections from highly contagious Omicron variants.
But Pfizer said new results show that three doses, the third given at least two months after the second, stimulated the immune system to defend itself strongly against the virus without any security concerns. The researchers said that the immune response of the subsets of the trial participants, measured one month after the third dose, was more favorable than that of the 16- to 25-year-olds who received the two doses.
Pfizer CEO Dr Albert Borla said: “We are pleased that our formulation for the youngest child, which we carefully selected as one tenth of the dose energy for adults, was well tolerated and developed a strong immune system.” Pfizer chief executive said in a statement. Ugur Sahin said companies would complete their FDA application for urgent approval of the baby vaccine this week.
New discoveries heat up a competition between Moderna and Pfizer as to which company will create the best vaccine for the youngest Americans. Moderna is proposing a two-dose regimen for children under 6, using a quarter of its adult dose. The agency said it estimates a third dose would be needed as a booster shot, but has not yet submitted any information to the government.
The question of which vaccine works best will be put to a committee of advisers outside the FDA scheduled for June 15. Both Pfizer and Moderna have proposed different dosage approaches for younger children and presented the results of different clinical trials. Whether a vaccine should be approved or both are exempt may affect regulators.
In late April, Moderna sought urgent approval of her pediatric vaccine when interim results showed that participants in clinical trials had similar immunity to young adults when given one-fourth stronger doses.
Like Pfizer, the firm says its results meet the criteria for clinical trials for success. Moderna said its vaccine was found to be 51 percent effective against significant infections in children under 2 years of age and 37 percent effective between 2 and 5 years of age.
If the results of Pfizer are revealed by the following data, then its effectiveness will be better than that of Moderna. Both companies say their vaccines produce similar side effects to other pediatric vaccines used for decades.
Adel Hasan Contributing Reporting.