LONDON (Reuters) - Prime Minister Boris Johnson said Britain was ready to roll out a mass COVID-19 vaccination programme but it was too early to rely on a vaccine as a solution to the coronavirus pandemic. “I must stress that these are very, very early days, and we’ve talked for a long time, right about the distant bugle of the scientific cavalry coming over the brow of the hill,” Johnson told a media conference after Pfizer said its experimental COVID-19 vaccine was more than 90% effective. “I can tell you that tonight that today that toot, that bugle is louder, but it’s still some way off. We absolutely cannot rely on this news, as a solution.”