As 38.4 million Americans prepare to travel this Thanksgiving weekend (according to AAA estimates), officials with the Centers for Disease Control and Prevention are urging them not to bring the H1N1 flu home for the holidays.

“We want you to stay healthy and safe and travel well,” said Rear Adm. Anne Schuchat, MD, director of the CDC’s National Center for Immunization and Respiratory Diseases.

In addition to the usual recommendations to wash hands, cover coughs and get the vaccine when available, the CDC recommends people who are sick avoid travel to reduce the risk of transmitting the virus in close quarters, such as a crowded airplane cabin.

According to public health officials, the holiday travel season could produce a temporary spike in influenza activity, despite reported decreases throughout the first half of November.

Schuchat also reported a “worrisome” increase in invasive pneumococcal infections in persons under 65. Influenza makes the body more susceptible to this secondary bacterial infection, which is especially dangerous for persons with underlying medical conditions, such as  heart disease or neurological problems.

Pneumococcal infection can be prevented by one-time vaccine available at most doctor’s offices. However, Shuchat said only one in four high risk adults bothers to get the vaccine.