WASHINGTON — Brett Giroir, the assistant secretary for health who coordinates the administration’s coronavirus testing, said Sunday that there is no evidence that hydroxychloroquine is an “effective” treatment for COVID-19, despite President Donald Trump’s repeated boosting of the drug over objections from experts. In an interview on “Meet the Press,” Giroir did not specifically mention the president, but he made clear that the scientific consensus is that the drug does not help treat the disease. “Most physicians and prescribers are evidence-based and they’re not influenced by whatever is on Twitter or anything else. And the evidence just does not show...