Three doses of Pfizer-BioNTech’s Covid-19 vaccine for the youngest children were 80 percent effective against the omicron variant of the coronavirus, according to early data the company released Monday. 

The long-awaited findings bring the vaccine one step closer to a reality for parents of children ages 6 months to 4 years 

Results from the company’s Phase 2/3 clinical trial also found that the vaccine — which uses a dosage one-tenth the level used for adults — generated a strong immune response and that it was safe

The 80 percent efficacy figure may change as the company gathers more data. It is based on 10 symptomatic cases of Covid that occurred seven days after the third dose of the vaccine as of April 29. A formal analysis will be performed once there are at least 21 positive cases in the clinical trial. The safety and immune response data are finalized, the company said.

The first two doses of the vaccine are given three weeks apart, followed by a third dose at least two months later.

The findings were announced in a news release, and the full data haven’t been made available for outside experts to review. 

Dr. Isaac Bogoch, an infectious disease specialist at the University of Toronto, said that while the findings