(Reuters) – Moderna (NASDAQ:) Inc stated that it was informed Sunday by the U.S. Food and Drug Administration of the need to take additional time in order to assess the COVID-19 vaccine company produces for adolescents 12-17 years old.

Moderna was told by FDA in a statement that they may not have completed the review prior to January 2022. This could impact the time of an EUA (emergency use authorization) for this age group.

Moderna Chief Executive Stephane Bancel told Reuters last week https://www.reuters.com/business/healthcare-pharmaceuticals/exclusive-moderna-covid-19-shot-could-start-being-used-children-teens-within-2021-10-27 that based on conversations with the agency, he believed the vaccine would be authorized for those 12 to 17 in the next few weeks.

According to the U.S.-based biotech firm, it received a late Friday notification that FDA required additional time for international assessments of myocarditis risk after vaccination. This rare side effect has mostly affected young men.

Moderna stated that it will be reviewing new analyses from outside sources on myocarditis risks in people younger than 18 as soon as possible.

Moderna requested U.S. approval for its shot for children aged 12-17 in June.

The COVID-19 vaccination is available to all Americans over the same age. Pfizer After being cleared by FDA and Centers for Disease Control and Prevention, Inc and BioNTech SE (NASDAQ) in May, it has been approved.

Moderna stated that it would delay its EUA request for the half-strength 50-microgram vaccine dose for children aged 6-11 until the FDA has reviewed the 12-17 file.