A few people ITT talking about starting a new job recently, or increased stress from young kids etc
Aside from diet and illness, the biggest effect on your immune system is stress, this is felt due to the relationship between your sympathetic and parasympathetic nervous systems. Sympathetic is your fight or flight programming and the parasympathetic nervous system dictates your rest and digest. They balance each other when you are healthy, one can get stuck in fight or flight sympathetic nervous system energy
Currently I'm stimulating my vagus nerve to strengthen the parasympathetic nervous system. I started a thread about it. You guys with the increased stress can improve the situation. It's silly but even meditation, breathing techniques, cold plunge can all improve your parasympathetic systems tone. Like me you could just buy a thing to wear for half an hour daily to experience being super chill all the time.
Also I've noticed bad colds etc going around. Just getting over one that's lasted 3 weeks, didn't hit the kids but every teacher and parent got hit bad.