Science

The UK is about to hit its Covid vaccine ceiling

The nation’s Covid-19 vaccine uptake rate is slowing. The question now is how long until it flatlines altogether?
The UK is about to hit its Covid vaccine ceiling
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Nearly 90 per cent of UK adults have had their first vaccine dose, and 75 per cent have had both doses, but the number of people getting their jabs is slowing every day. Just under 40,000 people received their first jab on Saturday, August 7 – down from more than 137,000 at the start of July and a meagre figure compared to March’s peak of 500,000 a day. For second doses, the average is about 160,000 a day. Unlike other countries, this slowdown isn’t down to lack of supply – it’s about lack of demand. 

In most older age groups, vaccination numbers have started to flatline. On July 1, 85.5 per cent of people aged 50-54 in England had had a first dose, but by August 1 that had crept up to just 86 per cent. Uptake remains high across all age groups – and making the vaccine available to all 16 and 17-year olds will further boost coverage – but it remains likely that millions of people in the UK will not receive a Covid vaccine – either because they are too young to be eligible, for health reasons or because they haven’t come forward.

This slowdown isn’t a surprise: vaccine uptake rates were always going to fall – that’s the whole point of a mass vaccination campaign. The people who were most likely to come forward for a vaccine have done so already. The government recently opened up vaccines to people aged 16 and 17 years old, which will temporarily boost the number of daily jabs, but it will likely settle back down again. According to Colin Angus, a senior researcher at the University of Sheffield, vaccine uptake rate is close to levelling off. “I’d be fairly surprised if the population level total increased by more than a few percentage points from where it sits at the moment,” he says. 

Uptake numbers get noticeably lower as you descend the age groups; the data suggest the younger you are, the less likely you are to get vaccinated. In England, more than 30 per cent of adults under the age of 30 still have yet to get their first dose, although they have had less time to do so. Younger people might be less motivated to get vaccinated, says Alexandre De Figueiredo, statistics lead at the London School of Hygiene and Tropical Medicine’s Vaccine Confidence Project, because the risk of severe illness and death is much lower for them than older people.

Some countries are taking harsher measures to increase coverage. Only​ half of the French population has received a first dose, with only a third having had both doses. In late July, the French government passed a bill that requires a health pass (which shows whether a person has been vaccinated, had a recent negative test, or has recovered from Covid-19) in order to gain access to restaurants, bars, trains and planes. Within 48 hours of the announcement, more than 2.2 million people made appointments to get vaccinated.

The UK recently took a leaf out of France’s book. The government has ​​announced that at the end of September, people in England will need to be fully vaccinated to gain entry to nightclubs, plus other events with large crowds. In October, it will be mandatory for all care home workers to be vaccinated. Mandating vaccines might have counterproductive effects, says De Figueiredo. “Pushing young people further away or coercing them or making them do something they don’t want to, you might dent trust in people in the vaccines.”

The government is taking other measures to bump up numbers in younger people.  On August 1, it announced that companies such as Uber and Deliveroo would offer discounts and incentives to customers who get vaccinated. Other efforts include getting celebrities, including Thandiwe Newton and Harry Redknapp, to encourage people to go get the jab. “We’re providing information at every opportunity on how to get a vaccine and its benefits – including through partnerships with celebrities and influencers, social media platforms and dating apps to encourage uptake amongst younger age groups,” says a spokesperson from the Department of Health and Social Care. 

Even if the government does shoot for 100 per cent coverage, it doesn’t mean it will hit it. There will always be people unwilling or unable to get the vaccine. Many of the remaining stragglers yet to be vaccinated simply don’t want to have the jab. And this plays out in the data too. Black or Black British adults and those living in poorer, deprived areas display a higher degree of hesitancy towards getting vaccinated, according to a survey conducted by the Office for National Statistics (ONS). And amongst these groups, vaccination rates remain the lowest. 

An analysis of NHS records found that Black people were the least likely to have been vaccinated, and take up was also lower in poorer areas – only 87 per cent of people over 50 in the most deprived areas had been vaccinated, compared with 95 per cent in the least deprived. Amongst 18 to 21 year olds, vaccine hesitancy was about five per cent and nine per cent amongst 22 to 25 year olds. But, again, according to recent data from the ONS, only four per cent of the adult population reported being hesitant to get the vaccine. That means that vaccine hesitancy can’t be the only reason for this gap – the barrier could be practicality, as opposed to ideology. Opening more prominent vaccine centres, offering paid time-off to get vaccinated – and to allow recovery from any side effects afterwards – are all ways to overcome practical barriers. 

De Figueiredo reiterates that vaccine mandates aren’t the way to go – in fact, he says they could lead to indirect discrimination, since uptake is lower in ethnic minorities, and forcing them to get vaccinated against their will could amount to a form of segregation. A study led by De Figueiredo suggested that those sitting on the fence would be less likely to get vaccinated if vaccine passports were brought in. “Those kinds of coercive strategies aren’t going to help them address their fears.” 

Exactly how many people need to have immunity remains one of the biggest questions of the pandemic, but the answer still isn’t clear, says Samir Bhatt, an infectious disease modeller at Imperial College London. And the pipe dream of herd immunity appears to be dead. The original estimate for the herd immunity threshold was about 70 per cent coverage, either through vaccination or previous exposure to the virus. But herd immunity is dependent on how infectious the disease is, and the spread of the Delta variant has bumped up the required threshold; it could even be as much as 98 per cent. Taking into account that vaccines aren’t 100 per cent protective and that immunity may wane over time, achieving herd immunity might well be impossible. The ultimate goal, Bhatt says, is to just reach as many people as possible. “Shooting for potential herd immunity is pointless,” he says. “What we should be shooting for is keeping infections as low as possible.”

And part of that will be vaccinating children, he says. Currently, only children between 12 and 15 deemed vulnerable or those living with vulnerable adults are being offered the vaccine, as well as all 16 and 17-year olds. The next pressing question is whether otherwise healthy 12 to 15-year olds will be offered a vaccine. The Joint Committee on Vaccination and Immunisation is still investigating the harm-benefit balance of vaccinating this age group. 

As for the remaining unvaccinated adults, De Figueiredo isn’t clear on whether reaching the last few extra per cent is worth the extra effort. “You’re getting down to the people who are just quite reluctant or fearful about vaccination,“ he says. “We’ve done such a good job, I think that we only now stand to risk possibly doing public health harm.”  

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