Simply put, COVID-19 infections weaken our immune systems. This makes us more prone to reinfection with SARS-CoV-2, infections with other viruses (e.g. RSV), reactivation of dormant viral infections (e.g. shingles, Herpes-Zoster virus), bacterial infections (Group A strep,TB) and even rare fungal infections. To make matters worse, the infections themselves may also be more severe. Being infected with SARS-CoV-2 and other viruses or bacteria at the same time can also make things worse, in adults as well as children.