We are at the beginning of another wave of Covid – the third in six months. Roughly one in 50 people in England are currently infected, while that figure is as high as one in 30 in Scotland. An estimated 1.4 million people in the UK – more than 2% of the population – would have tested positive last week according to the latest Office for National Statistics (ONS) infection survey. Chances are you know someone who’s got the disease. Covid hospitalisations have also been rising for the past couple of weeks. On Monday there were more than 1,000 admissions in England – the first time we’ve reached that level since April. It’s possible that some of the stark 40% week-on-week rise in prevalence reported last Friday is due to large numbers of people getting together over the extended platinum jubilee weekend. However, scientists who have been monitoring the Covid situation closely have been predicting an uptick for a while now. Two new subvariants – BA.4 and BA.5 – of the Omicron variant have been increasing their share of UK infections for several weeks. Last week they finally overtook the BA.2 version of Omicron responsible for the most recent wave that the UK experienced, in March and April. Although there is no evidence that these new subvariants cause more severe disease, their rise to dominance suggests that they can, at least to some degree, evade existing immunity. There are, however, some reasons for optimism. It’s far from certain that we will see the same level of infections or hospital admissions that we saw in the previous two Omicron waves. Portugal is coming down from a BA.5 wave in which hospitalisations reached 80% of their previous Omicron peak. In contrast, South Africa, which is over the worst of its BA.4/5 wave, hasn’t seen hospitalisations climb anywhere near the levels of the December/January Omicron peak. Another positive is that we are starting from a lower baseline than the most recent wave. Steep falls in infection levels have given hospitals some opportunity to recover from the Covid-related pressures they were experiencing. While it’s important to remember that there is a lag between cases rising and people ending up in the ICU, it is promising to note that steep rises in hospital admissions have not yet been accompanied by commensurate rises in the number of Covid patients in mechanical-ventilation beds. Nevertheless, hospitals are still under severe strain with waits for ambulances far above their targets; accident and emergency waiting times are through the roof; and almost one in nine people in the UK are waiting to start NHS treatment. As well as the potential impact on hospitals and the inevitable increase in the nearly 200,000 people who have lost their lives to Covid, any rise in infection levels will necessarily lead to more people with long Covid. About 2 million people in the UK are living with self-reported long Covid, according to the latest ONS survey. Almost 400,000 of these suggest it has a significant impact on their day-to-day activities. With the recent tribunal ruling that long Covid is a disability, we must start to ask questions about the long-term economic viability of continually and repeatedly allowing huge swathes of our population to become infected with a potentially disabling virus. Surely, we must start to invest in technology, like ventilation and air filtration, which will help to make schools and workplaces safer. We should also seriously consider improving sick pay so that people can afford to self-isolate when they are unwell, rather than going into work and infecting their colleagues. When Boris Johnson suggested in his February “living with Covid” strategy that we should learn lessons from our German counterparts, who are “much more disciplined about not going to work if you’re sick”, he neglected to mention that Germany has one of the best and most comprehensive sick-pay policies in the OECD, whereas the UK has one of the worst. The other bad news regarding this wave relates to its timing – in the middle of a patch of good summer weather. If ever there were a period when we would hope to see sustained falls in the levels of Covid it would be now, when it’s more attractive to meet in low-transmission outdoor environments. Sadly, this solstitial resurgence indicates that the pattern of repeated variant-driven waves is one we might expect to live with for the foreseeable future. While huge swathes of the world’s population remain unvaccinated, high levels of Covid transmission present the opportunity for new immunity-evading variants to emerge. That fact makes the UK’s international Covid strategy seem perverse. Embarrassingly, the UK was one of the last hold-outs to the World Trade Organization’s belated partial agreement to waive vaccine patents. And despite promising last year to donate 100m vaccines to low-income countries, by May of this year fewer than 36.5m had been dispatched. The word pandemic derives from the Greek pandemos meaning “pertaining to all the people”. To solve this global problem, we need truly global solutions that make all the people of the world safe. We cannot, despite Matt Hancock’s claim, unilaterally declare ourselves “past the pandemic”. It doesn’t work like that. Kit Yates is director of the Centre for Mathematical Biology at the University of Bath and author of The Maths of Life and Death