The government has technically hit its 19 July target of offering all adults in the UK a Covid-19 vaccine. But although all adults have been offered a first dose, not all of them have had it, and a significant number have had only one dose, not two. Only 68% of UK adults are fully vaccinated. If you include under-18s, only 54% of the total population is fully vaccinated. For this reason, some scientists say 19 July is too soon for “freedom day”, when the government will lift almost all restrictions on mask use and social distancing in England. Authorities should wait until more people are vaccinated before lifting public health restrictions, says Christina Pagel, director of UCL’s Clinical Operational Research Unit. “There is no disadvantage to more people being vaccinated.” She suggests a different target: that before England unlocks all adults and over-12s should be offered two doses, not just one. “We should wait until at least we’ve finished our primary vaccination programme and offered two doses to adolescents too,” she says. Others, however, back the government’s decision to unlock now. “This virus is not going away,” says Paul Hunter, professor in medicine at the University of East Anglia. “We will most likely see a surge whenever we lift restrictions now, in the autumn or next spring, it has to be one of these three options.” Hunter, like the UK government, points to lower rates of hospitalisation and severe disease as the key benefit of the vaccination programme. He also cites the potential for immunity to wane six months after vaccination as a reason to unlock now, rather than wait. As things stand, less than one in four of the under-30s will have full vaccine protection on 19 July. Many younger groups have only recently become eligible for vaccines, so have not been able to get a second dose. Older age groups were jabbed first, so have much higher rates of vaccination. However, even in groups that have been eligible for vaccines for months, there remains a proportion of people who are not fully vaccinated. This is lowest among the over-70s: only 6% of those aged 70-79 in England have not had both doses. However, for 50- to 54-year-olds, who have been eligible for vaccines since mid-March, the number not fully vaccinated stands at 19%. As it takes two weeks for vaccines to become effective, we have used vaccination figures from two weeks before 19 July. Has vaccine take-up slowed? Vaccine take-up was high during the second Covid wave in the early months of 2021, with older age groups getting the jab in large numbers. But there is concern that younger people, who are less worried about serious illness, will not get vaccinated as quickly. The chart below shows first dose take-up flattening out at a lower level for younger age cohorts. What vaccines do, and don’t do Full vaccination of every adult and adolescent in England will not get rid of coronavirus as vaccines are not 100% effective: they reduce but do not remove the effects of the disease. As the diagram below shows, people who are fully vaccinated can still become sick with coronavirus. A single dose of any vaccine does not offer much protection against getting symptoms of coronavirus but it does significantly reduce the risk of hospital admission. For Hunter, the fact that we cannot fully vaccinate our way out of coronavirus means that we need to allow natural infections in an “exit wave” to top up vaccine immunity. He believes it is now safer to do so because the most vulnerable people are vaccinated and at much less risk. “Like the other coronaviruses we will find an equilibrium, with or without vaccines, and then suffer reinfections every few years for the rest of our lives, though within a few years [infections will be] mostly either like the common cold or completely asymptomatic. Each reinfection will act like a booster dose, in effect.” But for Pagel, the fact we cannot rely only on vaccines means that we should supplement vaccines with public health measures such as restrictions. “You can’t rely on only vaccination to keep infections in check. You could still keep some measures, such as masks, or contact tracing, or heavily invest in ventilation etc. Together they might well be able to reach herd immunity if you have enough people vaccinated.” Even if the government ploughs on with its current “exit wave” strategy, a delay to allow more vaccination (and possibly a booster programme for vulnerable people) will make that wave smaller and less dangerous, Pagel says. “That [exit wave] would be much smaller with more people vaccinated.”