100% protection against severe disease. this second shot, whether it s a johnson & johnson, or a moderna, pfizer, is really important because we want to get that efficacy up high. reporter: a new study shows that vaccinations helped reduce more than a quarter million covid cases. 107,000 hospitalizations, and 39,000 deaths among seniors. tonight, the bells at the national cathedral rang to honor the 700,000 americans who have dayed from covid. moderna has also smipted an application 7 asking the f.d.a. to authorize a booster shot. next week an f.d.a. panel will discuss both the j&j and moderna applications, and then later this month, they will discuss whether to authorize covid-19 vaccinations for younger children. norah. o donnell: meg oliver, thank you. the pandemic has taken a devastating toll on police