As many countries gingerly start lifting their lockdown measures, experts worry that a further surge of the coronavirus in under-developed regions with shaky health systems could undermine efforts to halt the pandemic, and they say more realistic options are needed.

Brazil, Mexico, South Africa, India and Pakistan are among countries easing tight restrictions, not only before their outbreaks have peaked but also before any detailed surveillance and testing system is in place to keep the virus under control. That could ultimately have devastating consequences, health experts warn.