From the dusty highlands of Bolivia to the Brazilian metropolis of São Paulo, the pandemic has swamped underfunded healthcare systems after spreading fast across nations where many people survive hand-to-mouth and have been unable to enter lockdown. U.S. CDC looking into heart inflammation in some young vaccine recipients Some teenagers and young adults who received COVID-19 vaccines experienced heart inflammation, a U.S. Centers for Disease Control and Prevention advisory group said, recommending further study of the rare condition.