The U.S. Centers for Disease Control and Prevention said on Wednesday it expects to see an increase in levels of COVID-19 and respiratory syncytial virus (RSV) in the country in the coming weeks, as they usually do during the holiday season.

Large gatherings, travel and more time indoors, which typically happen during the holiday season, tend to cause more viruses to spread easily, the health agency said.

CDC expects hospitalizations for flu and COVID-19 to start increasing in the coming weeks. It also sees increased RSV activity, particularly in young children, in the southern and eastern U.S.

The U.S. Food and Drug Administration had approved updated COVID-19 vaccines made by Pfizer and its German partner BioNTech, as well as Moderna in August. The health regulator also granted emergency use authorization for Novavax's traditional protein-based shot.

Currently, there are three FDA-approved RSV vaccines made by GSK, Moderna and Pfizer.

As of Oct. 5, 11.2% of adults aged 18 years or above received an updated COVID-19 vaccine and 36.9% of adults 75 years or older received an RSV shot, according to CDC data.