To make flu shots effective, sleep specialist Matthew Walker, author of “Why We Sleep,” told CNN’s Christiane Amanpour practicing good sleep hygiene is important.

Insufficient sleep in the week before getting a flu shot can lead to the production of less than 50% of the normal antibody response — a reaction that would render the flu shot largely ineffective, Walker told Amanpour. Walker specializes in the relationship between sleep and human health at the University of California, Berkeley.

Walker cited a 2002 study published by the Journal of the American Medical Association, and a 2020 study in the International Journal of Behavioral Medicine supports those findings, suggesting that sleep on nights prior to vaccination could be critical to vaccine efficacy.

Get the full story at cnn.com.