As UK nears zero Covid deaths, there’s good reason for optimism

The handling of the coronavirus crisis in the UK has provided few moments to celebrate, but the day we reach zero deaths from the disease will clearly be one to toast. That day may not be far off. On Tuesday, the UK reported four Covid deaths within 28 days of a positive test. On Monday it was only one. Months of painful lockdown, in the face of more transmissible variants, and the rapid rollout of effective vaccines, have proven their worth. We have good reason to feel optimistic for the months ahead.

No one will have forgotten the brutal winter. In January alone, the UK reported nearly 32,000 Covid deaths, an appalling tally directly linked to locking down too late. In April, the death toll fell to 753. This month, scientists advising the government expect deaths to fall further. It is worth remembering that it’s been more than nine months since the UK last reported zero Covid deaths. We may see more in May, though people will continue to die of Covid, and the numbers might well rise again when restrictions are lifted on indoor mixing.

One day doesn’t make for a meaningful milestone. More important is reaching consistently low daily death rates, a goal achieved through a combination of factors. At the start of the year, the lockdown broke chains of transmission and reduced R – the number of people an infected person passes the disease on to, on average. Once R fell below one, the epidemic started to shrink. For example, when R reached 0.8, every 100 cases passed the virus on to only 80 more people, and so the numbers fell. Fewer infections inevitably led to fewer deaths.

But as the vaccination programme swung into action, it took on an increasing share of the heavy lifting. First and foremost, these early shots gave the most vulnerable, and so those most likely to die from Covid, the immune defences to fend off the virus. Second, the shots hampered the spread of the disease, pushing R down even further. Even if vaccinated people become infected, and some can, the amount of virus in the respiratory system is lower, so they are less likely to pass it on.

The NHS vaccination programme was designed to protect those most at risk as fast as possible. This decision was key, not least for its simplicity. Jabs went first to those in the top nine priority groups drawn up by the Joint Committee on Vaccination and Immunisation. These included the clinically extremely vulnerable – people on drugs to suppress their immune systems, or those with underlying health conditions, for example – plus everyone aged 50 and over. Together, these 32 million people account for 99% of Covid deaths.

Before the vaccine rollout, public health authorities had only clinical trial data in their hands. They were unsure how effective the shots would be in the real world. The answer has now become clear thanks to a flurry of recent data. The first good news arrived in the form of vaccine uptake rates. At least 95% of those aged 50 and over have received at least one shot, far better than many scientists hope for.

Next came findings on the impressive impact of the vaccines. The ONS found that only a fraction of people in hospital with Covid were admitted more than three weeks after having the shot. It takes two to three weeks for the body to muster a good immune response. The findings came after work from Public Health Scotland showed that hospital admission rates fell sharply a month after a single dose. Further positive news came from Public Health England on the vaccine’s ability to curb the spread of the disease. While unvaccinated people infect about 10% of people in their households, the agency estimates the risk is nearly halved when the original case is vaccinated.

Outbreak modelling submitted to the Scientific Advisory Group for Emergencies (Sage) in March shows that daily Covid deaths could be close to zero in much of May and June, but then rise again in July and August. By how much is up for grabs. The art is to suppress the rise in infections as restrictions ease, by vaccinating more of the population. So far, this balancing act appears to have worked: steps one and two of the roadmap appear to have caused cases to plateau rather than take off again.

The pressing question now is what happens after steps three and four of the roadmap, scheduled for 17 May and 21 June respectively. The mass vaccination of older and more vulnerable people will keep deaths down, but not all will be protected because vaccines are never 100% effective. Many young people won’t be fully vaccinated until later in the year, but it is crucial to get high coverage in these age groups, not only to reduce the chances of infections reaching more vulnerable people, but to spare the younger people themselves from the risk of severe disease or the debilitating impact of long Covid.