Pfizer claims Covid-19 vaccine 91% effective in young children

Pfizer says the Covid-19 shot it developed with BioNTech is 90.7% effective against symptomatic cases in children aged five to 11, according to a briefing document posted on the Food and Drug Administration’s (FDA’s) website.

Outside experts on the FDA’s vaccines and related biological products advisory committee will meet next week to evaluate Pfizer and BioNTech’s application for emergency authorisation of their Covid vaccine in young children. If the panel votes to recommend clearance and the FDA agrees, it could pave the way for a Covid vaccine for young children to be available by the beginning of November.

The document was posted on the FDA’s website in advance of the meeting, scheduled for October 26. The efficacy result is based on a trial of about 2,250 children, according to the document.

Pfizer and BioNTech applied for authorisation in the younger children in early October after trial data showed that the lower-dose shot raised antibodies against Covid. The child dose of the companies’ vaccine is one-third of the amount given to adults.  

In the document, Pfizer also released new safety data from an additional 2,250 children enrolled in the trial as part of an expansion of the study requested by US regulators. The data found no new safety problems, and side effects were consistent with what has been previously seen with the vaccine.

In the efficacy portion of the trial, 1,305 children without prior evidence of Covid received two shots, while 663 got placebo injections. Among those who got the vaccine, there were three cases of symptomatic Covid starting a week after the second shot, compared with 16 cases in the placebo group. 

Symptoms were milder in the cases that occurred among vaccinated children, and none developed fevers, according to the document. Most of the cases occurred in August and September.

Though Covid affects children less severely than adults, the disease has been a leading cause of death for those aged five to 14 in 2021. As the new school year in the US coincided with a surge in the Delta variant, infections among youth have picked up. In August and September, Covid cases among children under the age of 18 surged 419% in the US compared with June and July.

The US expects to be able to begin vaccinating young children before Thanksgiving, on November 25. Health officials have said they could be ready to vaccinate children of any age in the first quarter of 2022.

Bloomberg News. More stories like this are available on bloomberg.com