According to a published study, Pfizer Inc (NYSE:PFE) and BioNTech SE's (NASDAQ:BNTX) two-dose COVID-19 vaccine provided very little protection for children aged 5 to 11 years during the wave of omicron infection in New York.
The vaccine's efficacy against infection among those children declined to 12% at the end of January from 68% in mid-December compared to kids who did not get vaccinated, according to the study, which has not yet been peer-reviewed.
For those aged 12 to 17, the vaccine's protection against infection fell to 51% in late January from 66% in mid-December.
Also See: Pfizer, Moderna COVID-19 Boosters Effectiveness Wanes After Four Months: CDC Study.
The data showed that the vaccine was around 48% effective in keeping the younger age group out of the hospital, with 73% efficacy against hospitalization among adolescents last month.
That was down from effectiveness of 100% and 85% against hospitalization for the two age groups as of mid-December.
Pfizer said it is studying a three-dose vaccine schedule in the pediatric population.
Related: FDA Postpones Adcomm For Pfizer's COVID-19 Vaccine For Youngest Kids.
Price Action: PFE shares are down 1.69% at $46.15, and BNTX stock is down 0.95% at $149.38 during the market session on the last check Tuesday.