The European Union pharmaceutical regulator said on Monday it had started evaluating a request from Pfizer Inc and BioNTech to extend approval of their coronavirus vaccine to include children between the ages of 12 and 15.

The European Medicines Agency’s Committee for Medicinal Products for Human Use will conduct a fast-track assessment of data submitted by Pfizer and BioNTech and is expected to make a decision in June, unless it requires additional information, the agency said.

In a statement released Friday, the two pharmaceuticals said their request was based on an advanced study of more than 2,000 adolescents that showed their vaccine to be safe and effective. Children will continue to be monitored for longer term protection and safety for another two years.

The companies vaccine is currently approved for use in people 16 years of age and older. Extending this approval to the younger age group could offer younger and less-at-risk populations in Europe access to the vaccine for the first time.

Most of the COVID-19 vaccines approved by authorities around the world are for adults, who are at higher risk, but health officials believe that vaccinating children of all ages will be key to stopping the pandemic. Some research has shown that older children may play a role in the spread of the virus.