LONDON • One morning in March, not long after the coronavirus sent her country into lockdown and brought an abrupt end to life as she had known it, Mrs Hazell Jacobs, 86, awoke in her south London home ready to start something new.

For weeks, Mrs Jacobs, a widow living alone, had ventured no farther than her garden. Benevolent neighbours brought her groceries and she had regular phone check-ins from her daughters and grandchildren, but a minor stroke weeks earlier had sent her into lockdown before most, and a chronic eye condition was eroding her sight.