Pfizer said it would share the results with regulators in the U.S. and other countries and seek emergency use authorization in the U.S. as early as the end of the month.

The companies said the two-dose shot was found to be safe and well tolerated among the children in the study. The vaccine generated levels of antibodies that were similar to those of younger adults, meeting the study’s measurements of success, according to the companies.

Pfizer and BioNTech said they hadn’t yet determined vaccine efficacy—how well it protects against Covid-19—for children in the age group. The companies provided the results in a press release. They haven’t been peer reviewed by independent experts or published in a medical journal.

“We are eager to extend the protection afforded by the vaccine to this younger population, subject to regulatory authorization, especially as we track the spread of the Delta variant and the substantial threat it poses to children,” Pfizer Chief Executive Albert Bourla said in a statement.

Many parents have been awaiting vaccines to give to young children, hoping to protect them as the school year starts.

Young children are at lower risk of severe disease and hospitalization than adults, according to health experts, and when they are infected, they tend to experience milder symptoms. Yet young children are going to the hospital in greater numbers than earlier in the pandemic because of Delta’s spread primarily among unvaccinated people.

Doctors and health authorities say it will be important to vaccinate children, not only to protect them from the virus but also to help protect children around them and their family members.

The Pfizer-BioNTech vaccine is cleared for use in the U.S. for children as young as 12. Some parents with younger children have enrolled them in clinical trials to potentially get the shot as soon as possible. Others have pressed to get vaccinations for youngsters after the Food and Drug Administration issued full approval for the shot, even though the label specifies use only for people aged 16 years and older.

After studying the shot in a small number of children to settle on a dose, Pfizer expanded the size of the study in June to enroll about 4,500 subjects. Two-thirds of the subjects received two doses of the vaccine—in a smaller dosage than adults—three weeks apart, with the rest getting a placebo.

Pfizer said a review of data for 2,268 children in the trial showed that those who received two 10 microgram doses had antibody levels one month after the second dose similar to those found in people aged 16 to 25 years who received 30 microgram doses in a separate Pfizer study.

Neutralizing antibodies, which prevent the virus from entering cells and replicating, play a key role in the body’s immune response against Covid-19.

There appeared to be fewer side effects such as fever and chills among younger children who got the vaccine compared with 16-25 year olds, according to Pfizer. There also were no cases of myocarditis, an inflammatory heart condition that has so far been found to be a rare side effect primarily in young men.

Pfizer said that results of a study of younger children, aged 6 months to under 5 years could come by the fourth quarter this year.

This story has been published from a wire agency feed without modifications to the text