/ q7 K, c0 B2 V- x" G) AScientists are concerned that measures to combat Covid-19 have weakened the immune systems of young children who have not been able to build up resistance to common bugs, leaving them vulnerable when mask-wearing and social distancing eventually end. 1 Z% ]* t0 f( I/ ^7 S1 ?, khttps://www.theguardian.com/soci ... -system-experts-say " T4 ~* h# y4 I0 u4 P* d+ ELockdown最受害的是儿童。