. INDIANAPOLIS — A blue card sat on the windshield of Josh Woolvin's black Hyundai Tucson on Tuesday, a spot of color in the sunshine at Indianapolis Motor Speedway. It signaled to nurses at this drive-by immunization clinic that Woolvin and his mother, Debbie Shipp, wanted Johnson & Johnson's single-dose coronavirus vaccine, not their other choice, Pfizer-BioNTech's two-shot regimen. Both selected Johnson & Johnson for its one-and-done convenience, a preference that outweighed their concerns about the extremely rare blood clots that prompted a 10-day pause in use of the vaccine. "I'd rather deal with the side effects than die" of COVID-19, Woolvin said. There is no government data yet on whether health authorities' ten-day halt in administration of the Johnson & Johnson vaccine soured people on the product, and the company declined to discuss the matter. But in spot checks across the country, people seeking vaccines and officials dispensing them appear eager to resume using the vaccine, which is also easier to store and transport.