COVID-19 vaccine: Pfizer to enroll participants as young as 12 in late-stage trials

Pfizer Inc will enroll participants as young as 12 in its large, late-stage COVID-19 vaccine trial to understand how it works in a wider age group. While severe COVID-19 symptoms are extremely rare in infected children, they can pass on the virus to high-risk groups such as the elderly.

That makes determining the effectiveness of a potential vaccine in children crucial, as vaccines work differently in kids and adults, the FDA said in its guidelines here in June. The U.S. Food and Drug Administration (FDA) granted permission to the drugmaker and German partner BioNTech SE to enroll younger participants this month, according to an update on the U.S. company's website here on Monday.

Last month, Pfizer scaled up its trial to about 44,000 participants, from up to 30,000, to enroll people as young as 16 and those with chronic, stable HIV, hepatitis C and hepatitis B. The company said on Tuesday it would enroll children in its study based on satisfactory safety data in older adolescents and young adults, but did not specify a timeline.

Pfizer is racing to develop a safe and effective vaccine for the new coronavirus with rivals such as Moderna Inc, AstraZeneca Plc and Johnson & Johnson. Late-stage vaccine trials initiated by Moderna, J&J and Novavax Inc are testing their respective candidates only in adults.

AstraZeneca's U.K. vaccine trial, targeting more than 12,000 volunteers, will have one out of 11 subgroups with children 5 to 12 years of age. Chief Executive Officer Pascal Soriot said last month that tests on children had not yet started.