COVID-19 vaccination strongly protected 12- to 18-year-olds during Delta

Photo: Pramote Polyamate/Getty Images

Two new studies report that COVID-19 vaccination strongly protects against both infection and serious illness among adolescents ages 12 to 18. Both covered periods when the highly contagious Delta variant was the predominant circulating strain.

A study supported by the U.S. Centers for Disease Control and Prevention, led by Boston Children's Hospital and published in the Morbidity & Mortality Weekly Report on October 19, focused on severe COVID-19 disease requiring hospitalization. It found that two doses of the Pfizer-BioNTech COVID-19 vaccine were 93% effective at preventing COVID-19 hospitalization.

The investigation used a case-control design. The cases were 179 vaccine-eligible patients hospitalized for COVID-19, ages 12-18. The 285 controls, matched for age, tested negative for COVID-19 or had asymptomatic infections and were hospitalized for other reasons. 

All patients were hospitalized in 16 U.S. states from June 1 to September 30, a period when pediatric hospitalizations were surging, especially in the southern U.S., where 61% of the cases were enrolled.

Of the 179 patients hospitalized for COVID-19, only 3% were vaccinated, versus 33% of controls. Of the adolescents hospitalized for COVID-19, 43% were admitted to an intensive care unit, 16% required life support, and two died.

All patients requiring ICU care or life support, including the two who died, were unvaccinated. Of the 3% of vaccinated adolescents hospitalized for COVID-19, none developed critical illness.

Boston Children's also collaborated on a large study of 12- to 18-year-olds in Israel, led by the Clalit Research Institute. This focused on COVID-19 infection in general. Using health record databases, the investigators compared 94,354 Pfizer-vaccinated adolescents with 94,354 matched unvaccinated controls from June 8 through September 14.

Fully vaccinated adolescents had a 93% decreased risk for symptomatic COVID-19 and a 90% decreased risk for documented infection. The findings are published as a letter in The New England Journal of Medicine.

WHAT'S THE IMPACT?

The findings show that COVID-19 is not a benign disease among younger populations, underscoring the importance of vaccinating adolescents to provide them with a more robust level of protection.

Both teams of researchers hope the new data will help ease vaccine hesitancy. To date, COVID-19 vaccination rates have been relatively low in U.S. adolescents. As of October 12, only 45% of 12- to 15-year-olds in the U.S. and 53% of 16- to 17-year-olds were fully vaccinated against the coronavirus, according to the CDC's COVID Data Tracker.

THE LARGER TREND

In order to address the public health need, the U.S. Food and Drug Administration announced this week that it would allow the mixing and matching of COVIS-19 booster shots, meaning those who received the Pfizer shots can get a Moderna booster, and vice versa. Those who received either can also get a Johnson and Johnson booster.

The Biden Administration has released its plan to distribute doses to children at doctors' offices, pharmacies and schools, after federal regulators give the expected approvals for the shots for children ages 5-11.

On Tuesday, the White House said that the start of the vaccination program for children ages 5-11 will depend on the independent FDA and Centers for Disease Control and Prevention timeline. The FDA's advisory committee meets Tuesday, October 26, and the CDC's independent advisory committee meeting is scheduled for November 2-3.

Rates of hospitalization among children are higher than earlier in the pandemic due to the highly transmissible Delta variant, and public health authorities plan to offer shots in settings more familiar for children than the mass sites used for many adults, according to The Wall Street Journal.

Twitter: @JELagasse
Email the writer: jeff.lagasse@himssmedia.com