Pharmaceutical giant Pfizer predicted Friday that the COVID-19 pandemic may not end until 2024, Reuters reports. Also on Friday, the company and its partner BioNTech SE announced plans to delay request for authorization of their COVID-19 vaccine in children ages 2 to 5 "after the shot generated a weaker than expected immune response in a key study," writes The Wall Street Journal. In a presentation to investors, Pfizer Chief Scientific Officer Mikael Dolsten explained the company "expects some regions to continue to see pandemic levels of COVID-19 cases over the next year or two," per Reuters. Meanwhile, he said, other countries might simultaneously experience COVID on more of an "endemic" level, with "low, manageable caseloads." By 2024, however, COVID-19 should be endemic globally, Pfizer forecasted. "When and how exactly this happens will depend on evolution of the disease, how effectively society deploys vaccines and treatments, and equitable distribution to places where vaccination rates are low," Dolsten said. "The emergence of new variants could also impact how the pandemic continues to play out." Regarding a vaccine for kids ages 2 to 5, Pfzier and BioNTech said they would "begin testing the addition of a third dose in the children, and if successful, would ask U.S. health regulators to authorize use sometime during the first half of 2022," per the Journal.