What is Herd Immunity and How Can We Achieve It With COVID-19? Post date April 16, 2020 ← Coronavirus ‘is the Big One … I hope never to see bigger’: Harvard epidemiologist → Johnson & Johnson Announces a Lead Vaccine Candidate for COVID-19; Landmark New Partnership with U.S. Department of Health & Human Services; and Commitment to Supply One Billion Vaccines Worldwide for Emergency Pandemic Use