Big tech's contact tracing apps won't be a silver bullet to stop COVID-19 — we need more human tracers making actual phone calls (AAPL, GOOGL, GOOG)

· Health experts say contact tracing must be a fundamental part of countries' attempts to reopen amid COVID-19.
· Contact tracing is a tried-and-true technique to find and isolate people who are carrying an illness to slow the virus' spread.
· Some governments are turning to tech giants like Apple and Google that are...