Pfizer begins trials of COVID-19 vaccine in children under 12

Pfizer said Thursday that it began a clinical trial testing its COVID-19 vaccine in children under 12 this week, another milestone in expanding access to vaccinations beyond adults.

The company began a phase one trial this week, which will determine the correct dose of the vaccine, in a small group of 144 participants, children six months through 11 years of age. Phase two and three trials in larger groups of participants will follow.

Trials in children 12 and over have already started, and results are expected in the next few weeks, said Sharon Castillo, a company spokesperson.

The process for children under 12 is further behind, but widespread vaccinations in that group could start early next year.

Moderna likewise said it was moving forward with trials for children under 12 earlier this month.

Pfizer said it is “encouraged” by the data from children age 12 to 15 and hopes to share results on that group “soon.”