A study conducted in the United States says Pfizer’s two-dose COVID-19 vaccine is less effective at protecting young children than it is for older children and adults.
Researchers from New York state’s Department of Health compared data collected from more than 850,000 kids ages 12 to 17 with data collected from children between 5 and 11 years old who were fully vaccinated between December 13, 2021 and January 30 of this year, when the country was struggling with the surge of the omicron variant.
The study shows the vaccine’s effectiveness against severe illness and hospitalization in the younger group declined from 100 percent to 48 percent, compared to a decline from 85 percent to 73 percent among the older children.
The vaccine’s effectiveness against infection plunged from 68 percent to just 12 percent among the 5 to 11 year old group, while declining from 66 percent to 51 percent among the 12 to 17 set. The study has not been peer-reviewed.
Researchers noted that the younger children were inoculated with a dose containing just 10 micrograms, while the older children received 30 micrograms, the same dose given to adults.
The U.S. Food and Drug Administration last month delayed its review of the Pfizer COVID-19 vaccine for under-5-year-olds because initial testing showed its two-dose series was not working well against the omicron variant.
Pfizer and its German-based partner, BioNTech, are currently testing a three-dose regimen of its vaccine among children under 5 years old and those ages 5 to 11, based on studies in adults that suggest an extra shot may provide the needed level of protection against omicron.
Monday’s release of the New York study comes just days after the U.S. Centers for Disease Control and Prevention issued new guidelines that allow most Americans to abandon wearing face masks.