Coronavirus and hydroxychloroquine: What do we know?

US President Donald Trump has said he's taking the malaria drug hydroxychloroquine as a preventative measure against Covid-19, although scientists have warned about side effects. Studies are underway to examine if hydroxychloroquine (and a related drug chloroquine) are effective against the coronavirus. We've looked at what we know so far about these drugs. Who's raised concerns about using them? The World Health Organization has said it's concerned by reports of individuals self-medicating and causing the…