Slumber angels, rejoice! Who doesn’t love sleep? Researchers just gave us another excuse to be a homebody this weekend. A new study suggests that deep sleep may have a long-term influence on your immune system. Previous studies have shown that sleep boosts psychological long-term memory, but researchers speculate that it could significantly improve biological long-term memory as well. In fact, one study showed there was a distinct connection between long-term increases in memory T cells (aka your immune system’s memory bank) and deep long-wave sleep. So, next time you’re due for a vaccine update, be sure to get your beauty sleep to amp up the effect!