IL10 and streptococcal infection: IL-10 production by regulatory T (T Reg) cells has the potential to induce susceptibility to secondary bacterial infections, and serum levels of IL-1β and IL-10 are elevated in children secondary to Streptococcus pyogenes infection one week after IAV infection, while decreasing with symptom improvement, which seems to indicate that IAV infection and secondary Streptococcus infection also enhance pulmonary toxicity in children, but this needs to be confirmed by further studies (Bedoya et al., 2013; Ochi et al., 2018).