The advisors have since admitted that they didn't plug a South Korea-style test-trace-isolate programme into their models, as Britain lacked the required testing infrastructure, not least because testing was centralized, instead of, like Germany, employing university and private labs.
There's been reports of researchers being optimistic of a vaccine by the Autumn, but we'll see. Wouldn't be surprised to see one earlier than 18 months -- amazing what you can do with relaxed regulations and near-unlimited resources -- but can't be relied on. Even if SARS-CoV-2 can't be eradicated without a vaccine, aggressive elimination programmes could both save Iives, and make vaccination much easier when one arrives.
The underlying principle with both vaccination and quarantine's the same: destroy a virus in the general population by starving it of hosts. The two are, ultimately, facets of the same strategy, and one another's constant allies.