Covid boosters are a game changer – if they are free for everyone

Private Covid boosters are available for people who are not eligible for these vaccines from the NHS. But is it worth paying for a shot?

Because most people have now been exposed to Sars-CoV-2 through previous vaccination and/or infection, our immune systems are generally well equipped to recognize and kill the virus if we become infected.

Still, the number of antibodies circulating in our blood is likely low unless we have been recently infected or given a booster.

Antibodies help prevent us from contracting Covid by binding to the virus and preventing it from entering our cells. Although memory cells will quickly start producing new antibodies when they encounter Sars-CoV-2, there will be a slight delay before they reach a high enough level to block infection, potentially providing a period during which Covid can take hold.

Such infections will still generally be shorter and milder than if you had never had Covid, but they remain an unpleasant inconvenience.

Covid boosters are a fast and safe way to replenish these antibodies. Yet access to the free NHS booster Covid vaccine in Britain in spring 2024 will be limited to people aged 75 and over, residents of care homes for the elderly and people aged six months and over with weakened immune systems.

In the US, the Centers for Disease Control and Prevention (CDC) recommends that people aged 65 and over should receive an additional dose of the Covid-19 vaccine, while the Food and Drug Administration (FDA) has suggested that everyone receive an annual dose is offered. A single-dose booster – similar to the annual flu jab – with a second dose for people at higher risk of serious illness, including children under the age of two and adults aged 50 or over.

According to a modeling study published in Annals of Internal Medicine by March, this strategy could result in 123,869 fewer hospital admissions, 5,524 fewer deaths and a saving of $3.63 billion (£2.9 billion) in direct healthcare costs per year – assuming uptake was comparable to that of the annual flu jab – compared to a scenario in which only 20% of the population received a Covid booster annually.

Prof Stephen Griffin, a virologist at the University of Leeds, is not surprised by these results and is in favor of the FDA’s approach.

“It is based on a very good assessment of clinical benefits, recognizing the importance of protecting both young children and the over-50s,” he said. “Children under five years of age are at increased risk after a Sars-CoV-2 infection compared to children in primary school – especially children under five years of age – and there is no reason why they should be exposed to infection if there is a very good, safe vaccine is available.”

One problem is that Britain tends to focus on hospital admissions and deaths in its cost-benefit analysis, rather than considering other outcomes such as long Covid-19, Griffin added.

Still, he and other British experts have welcomed the expansion of access to Covid boosters – although they worry the cost is likely to limit their uptake.

Prof. Neil Mabbott, an immunopathologist at the University of Edinburgh, said: “If people have to prioritize other needs during a cost of living crisis, they don’t necessarily have to worry about whether I should pay for a vaccine or not.”

Mabbott believes that anyone over 50 would benefit from an additional booster, “as their immunity to previous boosters will wane”.

“There is also the issue of the long Covid-19 crisis to take into account,” he said. “There are still a large number of people who have it or could develop it, even if they have received a relatively mild dose of Covid-19.”

Professor Lawrence Young, a virologist at the University of Warwick, thinks having a booster makes sense for people aged 65 and over, those with clinical conditions such as diabetes, heart problems and autoimmune diseases, and those living with vulnerable individuals.

“This will not only provide personal protection against severe Covid and limit infection of more vulnerable individuals, but will also limit the spread of the virus, and hopefully any new variants, among the general population,” he said.