evidence: Vice President Mike Pence says he is not preemptively taking the malaria drug hydroxychloroquine to ward off COVID-19 like President Donald Trump because his doctor does not recommend using the drug. [...] In April, the Food and Drug Administration (FDA) warned the public to not take the drug outside of a hospital setting, noting that it could cause "potentially life-threatening heart rhythm problems " and had "not been shown to be safe and effective for treating or preventing COVID-19." [...] Recent studies published in the Journal of the American Medical Association and the New England Journal of Medicine also found that hydroxychloroquine had no statistically significant effect on the virus, with one noting that it could increase the risk of patients suffering heart attacks.