There were almost 194,000 new cases of Covid-19 reported in England last week, which is 35% more than the week before. At the time of writing, 52% of the UK population had been fully vaccinated. Perhaps another 20% have some immunity from one dose of vaccine or previous Covid infection. If this level of population immunity was enough to contain the pandemic alongside public health measures, cases would be falling. They aren’t falling and it isn’t enough.

So cases will keep rising, currently doubling every fortnight or so, until either population immunity is high enough or public health measures are effective enough – or a combination of both – to halt Covid’s spread. The government yesterday announced a removal of all public health measures next Monday, meaning that population immunity has to do all the work. With millions of people still without the protection of full vaccination or previous infection, it is inevitable that a good chunk of that immunity will come from new infection rather than vaccination.

Dr Susan Hopkins, the head of Public Health England, estimated three more doublings of cases before the peak, potentially meaning more than 200,000 cases a day in six weeks’ time. Even the health secretary, Sajid Javid, concedes there are likely to be more than 100,000 cases a day (implying around two more doublings), which would be higher than the highest recorded day in January. This could easily mean another 2 million people infected before cases return to the low levels we saw in early May.

Meanwhile, reports suggest the government is already planning for a fourth wave this autumn due to the return to school and university, colder weather, and some waning of vaccine effectiveness over time. The question then is how much millions more cases matter, given the economic and mental health benefits of further opening.

The prime minister set out two main arguments in favour of further easing. The first is that well over 90% of the most at-risk people are fully vaccinated, greatly weakening the link between new infections and hospitalisations. The second is that it is better to have mass infection now rather than in the winter when the virus spreads more easily and the NHS is more stretched. I think both are wrong.

More than 100 scientists set out why allowing mass infection this summer was a terrible idea in a letter [1] to the Lancet last week. Dr Mike Ryan, the executive director of the World Health Organization’s health emergencies programme, called such a strategy “moral emptiness and epidemiological stupidity”. Healthcare experts for the People’s Covid Inquiry called it a “dangerous experiment”. The British Medical Association, Association of Directors of Public Health, Sage and NHS leaders have all highlighted the danger of allowing mass infection.

First, while we are seeing far fewer hospitalisations than would be the case without a vaccine, hospital admissions are nonetheless rising exponentially. With two or three more doublings, we could be seeing more than 2,000 admissions a day by mid-August – a significant burden on a health service that is already under immense strain, with some hospitals having cancelled elective surgeries and delayed cancer treatment.

The last thing the NHS needs as it tries to cope with its backlog of 5 million patients is a return to giving up wards and ICUs for Covid care.

Second, infections come with a high burden of long Covid. The Office for National Statistics estimates about 1 million people, including 33,000 children, currently live with long Covid in the UK, with 385,000 having symptoms for more than a year and over 600,000 saying it adversely impacts their daily life. With infections falling mainly on the unvaccinated young, we risk burdening a generation with long-term ill health. Both the chief medical officer, Chris Whitty, and the chief executive of NHS Providers, Dr Chris Hopson, have expressed grave concerns over the prospect of hundreds of thousands more cases of long Covid over the coming months.

Third, every new infection presents an opportunity for further mutations of the virus, and any that can better infect the vaccinated will have a large selection advantage. We have already seen the impact of the Delta variant over the past few months – do we really want to work our way through the Greek alphabet?

Fourth, opening further has been billed as “freedom day”, but for many it is anything but. Those living with health conditions that make them more vulnerable to Covid fear a return to shielding indoors as they are no longer protected by low infection rates and measures such as mask-wearing and physical distancing. As even vaccinated people can and do transmit the virus, many of their friends and relatives too will restrict their activities to protect loved ones. For many, lifting the Covid rules will restrict rather than enable their freedom.

Ultimately, all of this is unnecessary. We have safe and highly effective vaccines, approved for use in everyone over the age of 12. We have an excellent vaccination programme. Evidence suggests that immunity derived from vaccination is more robust than immunity from infection, particularly against new variants. We could offer two doses of vaccine to everyone over 12 by the autumn, offering as many people as possible the protection of vaccination rather than the gamble of infection.

The argument that delaying now will only result in more infections later in the winter ignores three things: the protection millions more (including adolescents) can have from vaccination; the potential for vulnerable adults to receive booster shots in autumn; and, crucially, our ability to offset the additional infection risks of winter with public health measures

If you accept that infections both matter and are avoidable, then it’s not about further opening on 19 July, which can only make things worse, but about what we can do now to halt exponential growth and bring down cases. We need to act quickly and act decisively, with strategic testing, contact tracing and supported isolation (including the vaccinated) in all regions, learning from successful efforts in Bolton and Blackburn earlier this summer; a continued requirement to work from home where possible; and with short-lived restrictions, such as a return to outdoor dining, if local directors of public health consider it necessary; and mask-wearing made compulsory again in secondary schools. Any brief return to restrictions must come with financial support for those people and businesses affected.

Infectious diseases are a matter of collective, rather than personal, responsibility. As a society, we could choose to keep in place mask-wearing, some physical distancing and supported isolation of cases and contacts. We could choose to invest in ventilation in business and school buildings – a long-term public health benefit and a key mitigation against Covid. We could choose to suppress this virus over winter and protect our population and our NHS and so provide far more freedom to go about our daily lives. The current government position is that it’s not even going to try. This is not good enough and we have to demand better.

Christina Pagel