18,000 determined athletes at the fist boston marathon in 2 1/2 years. we were pumped. we were excited to finally have it back, you know, back to the way it used to be. reporter: thousands lining the streets to cheer them on. the field thinned down from years past for social distancing. each runner showing proof of vaccination or a negative test. i was supposed to run this last year. this is my 2020 race, for which i qualified years ago. so we had to wait awhile, but i m glad to be here. reporter: the race coming as the country continues to make positive strides against the virus. cases, hospital admissions and deaths all trending down but officials saying we have not crossed the finish line. i d like to see it well below 10,000 and even much lower than that. but when you re at 95,000, that s still a situation where you have a high degree of dynamic circulation of virus in the community. reporter: still a green light