Who should receive a covid-19 booster vaccine? As countries in the northern hemisphere prepare for winter, it is a question that governments must tackle 鈥� and some are reaching very different answers.
The latest covid-19 vaccines are expected to bolster protection by targeting more recent variants of the coronavirus. In the US, the government has recommended that everyone 6 months and older should get a booster, whereas agencies in the UK and many other are only permitting the most vulnerable to do so.
In the UK, that adults 65 years and older, people with certain underlying health conditions and those in close contact with immunocompromised individuals, such as caregivers and healthcare workers. and France have adopted similar policies.
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This approach, recommended by the UK鈥檚 Joint Committee on Vaccination and Immunisation, aims to prevent the most severe cases of covid-19. The committee estimates that in people under 65 would require vaccinating far more individuals in this age group, with the disparity even greater when comparing people with and without underlying health conditions. 鈥淪o, it makes sense to focus efforts on protecting those most likely to benefit,鈥� says committee member at the University of Bristol, UK.
The exact costs of these two approaches are unclear, though vaccinating more people will obviously raise the price tag. The UK Department of Health and Social Care plans to publish details about the cost-effectiveness of the booster programme, while the US Centers for Disease Control and Prevention (CDC) estimates that it will cost more than $33,000 per year of full health saved for adults. The same figures for children aren鈥檛 available.
Costs aside, the logistics involved in providing universal boosters would also strain the UK鈥檚 healthcare systems, delaying care for other conditions, says at University College London. Plus, models posit that of the country鈥檚 population has antibodies against the coronavirus, suggesting that most people already have some protection. Booster shots would then offer minimal benefit to those least vulnerable.
The trouble is, we can鈥檛 predict whether previous immunity will protect against new variants. Immunity also starts waning six months to a year after vaccination, says Banerjee. That is why the US decided to recommend universal use of the updated booster despite most estimates indicating that doing so isn鈥檛 cost-effective. In fact, the CDC found that such vaccination will only save money across all age groups in scenarios where covid-19 cases significantly ramp up, to the point that hospitalisation rates quadruple. Similar figures aren鈥檛 available for the UK.
鈥淐hildren and adults with no underlying conditions still experience severe covid-19 illness,鈥� says a CDC spokesperson. For example, in the US, half of those aged 17 and younger who died in hospital due to covid-19 between January 2022 and June 2023 . Meanwhile, the same was true for 13 per cent of 18 to 49-year-olds admitted to a hospital intensive care unit for covid-19. 鈥淭he CDC is making the recommendation to protect the greatest number of people possible,鈥� says the spokesperson.
Universal vaccination also continues to safeguard against long covid, which often affects people without a severe initial infection, says Banerjee. Research suggests vaccination may lower the odds of developing long covid . 鈥淭hat鈥檚 another rationale for having vaccination for people who aren鈥檛 necessarily going to be admitted [to hospital],鈥� he says.
The divergent approaches to covid-19 vaccination in the US and UK come down to differing views on costs, risks and benefits. In the UK, health services are already stretched, facing everything from to . In those conditions, it is perhaps no surprise the country is taking a more limited approach. Meanwhile, in the US, an abundance of caution prevails. 鈥淚t is kind of a better-safe-than-sorry argument,鈥� says Banerjee.
Ultimately, existing immunity rates and the relatively low prevalence of covid-19 mean that the difference between the two approaches will probably be marginal at the population level. For individuals though, there are still risks to not getting vaccinated, regardless of health status. That is why some people have called for the UK government to allow the private purchase of the updated boosters.
鈥淰accines are ultimately subject to individual choice,鈥� says Finn. 鈥淚f a vaccine is offered by the state, individuals can refuse them. Conversely, if it is not offered, individuals who nevertheless want them should be able to obtain them.鈥�
