If Priscila Medina had gotten COVID-19 a year ago, she would have had no treatments proven safe and effective to try. But when the 30-year-old nurse arrived at a Long Island hospital last month, so short of breath she could…

If Priscila Medina had gotten COVID-19 a year ago, she would have had no treatments proven safe and effective to try. But when the 30-year-old nurse arrived at a Long Island hospital last month, so short of breath she could…