Antibody-rich plasma from people who’ve recovered from COVID-19 is one treatment being researched to help those still battling the virus. But an estimated 360,000 people willing to donate their plasma are not allowed to do so — despite the fact it could save roughly a million Americans. WHYY’s Zoe Read explains why a relic of the 1980s HIV epidemic still limits gay men from giving blood. She says Philly area politicians and LGBTQ advocates are pushing back.