Pfizer Inc. said on Friday the COVID-19 pandemic could extend through next year and announced plans to develop a three-dose vaccine regimen for children ages 2 to 16, a move that could delay its authorization.

The U.S. pharmaceutical company made its comments as European countries geared up for further travel and social restrictions and a study warned that the rapidly spreading omicron coronavirus variant was five times more likely to reinfect people than its predecessor, delta.

Pfizer executives said the company believed that by 2024, the disease should be endemic around the globe, meaning it would no longer be a pandemic. The company projected that "COVID will transition to an endemic state potentially by 2024."