Amid the uncertainty surrounding eligibility for and access to the latest Covid-19 vaccine, a new study has found that a common nasal spray could help prevent infection. This randomized placebo-controlled trial examined the effectiveness of the nasal spray azelastine in preventing Covid-19 infection, as published in the journal JAMA Internal Medicine on September 2. Researchers concluded that the chance of developing Covid-19 was about three times lower in the azelastine group compared with the placebo group.