Pfizer Vaccine 90.7 Percent Effective Against COVID-19 In Clinical Trials In Children

ILLUSTRATION/UNSPLASH

JAKARTA - The Pfizer/BioNTech COVID-19 vaccine showed 90.7 percent efficacy against the coronavirus in clinical trials in children 5-11 years old.

In the trial, 16 children who received placebo developed COVID-19, compared to three children who were vaccinated, Pfizer said in a summary document submitted to the United States Food and Drug Administration (FDA), Friday, October 22.

Since twice as many children were given the vaccine as a placebo in the clinical trial involving 2.268 participants, the efficacy was said to be more than 90 percent.

Pfizer's clinical trials in those aged 5-11 were not designed primarily to measure efficacy against the virus.

Instead, the assay compared the amount of neutralizing antibody induced by the vaccine in children with the response of older recipients in a trial in adults.

Based on those results, Pfizer and BioNTech last month said the COVID-19 vaccine induces a strong immune response in children.

Children aged 5-11 years were given two injections of a 10-microgram dose of the vaccine, one-third the size of the dose given to people 12 years of age and older.

Outside advisers to the FDA are scheduled to meet next week to decide whether to recommend that the agency allow the vaccine for the 5-11 year age group.

FDA staff are expected to publish their review of the evidence submitted by Pfizer after the meeting.

Pfizer also said it had expanded clinical trials to improve its safety data, more than doubling the number of children enrolled.

According to the Pfizer document, the expanded adverse event profile in the pediatric cohort does not indicate any new safety concerns from the vaccine.

The company previously said the safety profile in the age group was generally comparable to that of the 16 to 25-year-olds.

The second group of children has been observed for a shorter time. All had received the second dose, and more than 70 percent more than two weeks after the second dose.

Both the Pfizer/BioNTech and Moderna vaccines have been linked to rare cases of an inflammation of the heart called myocarditis, especially in young men.

Pfizer suggests rates of myocarditis in this age group are likely to be lower than those observed in vaccinated 12 to 15-year-olds.

It is estimated that hospitalizations due to COVID-19 that can be prevented by vaccination are many times the number of potential cases of myocarditis.

Pfizer/BioNTech vaccines already have US regulatory authorization for people aged at least 12, including full FDA approval in August for those aged 16 and over.

About 190 million people in the US are fully vaccinated, including more than 11 million people aged 12-17 who have received the Pfizer vaccine.

If the FDA permits the vaccine for children ages 5-11, a group of U.S. Centers for Disease Control and Prevention (CDC) advisors will meet on November 2 and 3 to make recommendations to the agency on how the injections should be given.

Most states wait for the CDC to sign off on vaccine recommendations before they start giving injections.