It has long been predicted that once Britain reopened there would be another wave of coronavirus cases. One reason is that the vaccination programme, despite good headway, is not yet available to everyone — in England those aged between 25 and 29 were only invited to book their first jabs this week. Even when fully vaccinated the shots cannot offer complete protection. Vaccine hesitancy has been limited in the UK, yet a resurgence of infections when Britons began to socialise again was almost certain.

There have also been failures of border control — the government was slow to put India on the “red list” despite a jump in cases and has generally dragged its feet over travel quarantining. That allowed the more transmissible Delta variant to spread and become the dominant form of the virus. Cases are now rising exponentially, as is the number of people in hospitals with the virus, albeit at a slower pace.

For this reason the full relaxation of restrictions, scheduled in England for June 21, should be delayed for at least a fortnight and replaced with a partial reopening. That would provide breathing room for already-stretched hospitals and allow time for substantially more people to get the second dose of the vaccine. The data so far suggests that receiving one dose offers less protection against catching the Delta variant compared with others circulating in Britain.

While the government has acted too incautiously in the past — waiting until the last moment to introduce lockdowns or trying to “have its cake and eat it” on restrictions — the context is different this time. The progress of the vaccination programme may have broken the tight link between cases, hospitalisations and deaths. Vulnerable groups who have received both doses of vaccination are relatively more protected — much of the current rise in cases is among the unvaccinated young who have stronger immune systems.

Nevertheless, the young can still get seriously ill and a surge in infections could overwhelm hospitals, already dealing with a backlog of delayed operations and treatments from previous lockdowns. Delaying could also prevent the country from going backwards and being forced to return to a more restricted society.

The remaining restrictions undeniably impose high costs on businesses. Nightclubs are closed, as are most theatres — composer Andrew Lloyd Webber has said that the government will have to arrest him to prevent his theatres opening. While Britons can already socialise outside, visit pubs and go to some theatres and sporting venues, they must still do so while social distancing — this reduces capacity and raises costs. Many have not reopened, believing that it would be unprofitable in such conditions.

Eventually vaccination certificates may provide a way out of the bind, allowing those who have received both doses of the vaccine to attend indoor venues en masse. For now, the idea is a divisive distraction: questions over discrimination can be more easily rebutted once everyone has had the chance to be jabbed, though privacy concerns may persist. In the meantime, nightclubs will struggle without the under-30s, as will many pubs.

Depending on the data, including the results of trials of “Covid-secure” events, some restrictions could still be eased on June 21. The lifting of others should be delayed, especially the least intrusive measures such as wearing masks indoors. Prime Minister Boris Johnson told England in February that the country was travelling on a “one-way road to freedom”: it is far better to go carefully than to go backwards.