Sleep plays a vital role in our immune system functioning. Without enough good quality sleep, we get sick more easily and take longer to recover. As adults we should be aiming for 7 to 8 hours of good quality sleep every night. Adolescents should be aiming for 9 to 10 hours, and younger children should be getting closer to 10 or more hours of sleep every night.
Our immune systems produce infection-fighting antibodies and cells during sleep, and proteins called cytokines. Some cytokines are effective sleep promoters and others form part of the immune and stress responses. If you don’t sleep enough, or sleep well enough, your immune system will not be producing the cytokines, antibodies and cells necessary to fight off infections.
During the COVID crisis, high anxiety and stress or high workloads may be making it hard to squeeze in a full 8 hours every night. This may be necessary for a short time. But just how low can you let it go?
Research repeatedly points to the magic figure of 6 hours of sleep per night as the threshold where all sorts of bad stuff starts to happen. For example, Dr. Aric Prather, a leader in psychoneuroimmunology research from the University of California, San Francisco and his team found that if you drop your sleep to 6 hours or less for as little as 5 days in a row, you are 4.24 times as likely to catch the common cold after being exposed to the virus as people who sleep more than 7 hours per night.
 Prather, A., Janicki-Deverts, D., Hall, M., Cohen, S. (2015). Behaviorally assessed sleep and susceptibility to the common cold. Sleep, 38(9), 1353-1359.