COVID shot for young kids is closer, Pfizer aiming for fall

Pfizer released details Tuesday about the progress of its COVID-19 vaccination trials in children, showing that they have completed early testing and are moving forward with lower-dose trials in younger kids.

Children are less likely than adults to have a serious case of COVID-19, so drug companies are trying to minimize vaccine side effects while maximizing benefits.

For now, Pfizer, which collaborates with German biotech BioNTech, is testing its vaccine at lower doses in grade schoolers than adolescents and still lower doses in younger children.

Pfizer and BioNTech already have studied their vaccine in 2,260 adolescents age 12 to and 15 and received authorization to provide them shots in the United States. Their vaccine trials showed that adolescents developed a strong antibody response to the virus. The vaccine prevented infections and did not lead to intolerable side effects.

The companies also have completed early trials in a small number of younger children to show safety and establish relevant vaccine doses.

As is typical with trials in children, volunteers have been divided into three age groups: ages 5 to 11, 2 to 5, and 6 months to 2 years.

The 112 children in those trials received doses of either 10, 20 or 30 micrograms, with an option for 3 micrograms in the youngest children.

Larger trials to evaluate safety and immune response already have begun in 5- to 11-year-olds at 10 micrograms and are expected to begin in the younger age groups in the next few weeks, according to a statement from Pfizer. Children under 5 will receive the 3 microgram dose.

Those trials will include 4,500 volunteers across all three age groups in the U.S., Finland, Poland and Spain. Trial organizers are working to ensure a diversity of trial participants, the company said.

One child will receive a placebo for every two that get the active vaccine. Children who receive the placebo will be given the option to get the active shots if the vaccine is authorized within six months of their participation.

If those trials prove safety and immune response, the companies expect to request federal authorization in September or October to provide the vaccine to children ages 5 to 11, and a little later in the fall for younger children.

At a later date, the companies may consider vaccinating infants once they confirm safety in older children.

As with adults and older teens, the Pfizer-BioNTech vaccine will be given to children with two shots, spaced about three weeks apart.

Unlike adults, the companies will not be required to prove that the vaccines prevent most infections – which is no longer practical because of low rates of infection in the U.S. and even lower rates among children.

Instead, vaccine makers will have to show that their shots produce an equivalent or better immune response than in young people 16 to 25.

Moderna and Johnson & Johnson are testing their shots in children as well.