Pfizer recently announced that its coronavirus vaccine trials for children ages 2 through 5 have not produced the expected immune response.
Despite making headway in other treatments for coronavirus, and vaccinations continuing for children above the age of 5, younger children will likely face a delay in when they will be able to get vaccinated.
Dr. Mark Sawyer, a pediatric infectious disease expert with Rady Children's Hospital and UC San Diego, joined KPBS Midday Edition to talk about what the latest data tells us and what it means for young children.
Researchers are now looking to add a third dose to see if that improves the immune response in the younger age group.
"It has to do with first priming the immune system and then stimulating it over and over again to get the maximum response," Sawyer said.
Regardless, Sawyer said it will add additional time to the development of the vaccine.
"So I'm afraid this is a 3- to 6-month setback in getting younger kids immunized," he said.