The more people who get a COVID-19 vaccine, the safer we're all going to be.

But not everyone wants the jab. In the UK, for example, 12 percent of people are "strongly hesitant" about getting vaccinated, and experts are now looking at better understanding this hesitancy in order to change minds and save lives.

According to new research, focusing on the personal benefits of the vaccine rather than the collective good is more likely to move the needle. In a survey of 18,855 people in the UK, highlighting the personal over the collective was most effective at altering the opinions of strongly hesitant participants, although the difference was a small one.

That means emphasizing how vaccinations can protect against serious illness or even long COVID on an individual level, rather than how they enable the reopening of economies and ensure less transmission of the coronavirus around communities, speeding up a return to normality for society as a whole.

"It was clear that highlighting personal benefit was more effective than emphasizing collective benefit for those who were strongly hesitant," write the researchers in their paper.

"For this subgroup, it might be harder to shift perspective now to the collective benefits, but highlighting the personal perspective could have a greater attraction."

The volunteers were split up into 10 groups before being given a statement about COVID-19 vaccines: some statements mentioned collective benefits, others mentioned personal benefits, and one was simply a statement from the National Health Service (NHS) in the UK about the safety and efficacy of the jab.

These groups were then asked again about getting the vaccine. Among the participants who were originally strongly hesitant, those who read the control message scored 28.53 on a 35-point scale of vaccine hesitancy (with 35 being the most hesitant), while those who read about the personal benefits averaged 27.04 on the same scale.

Amongst other messages that led to a decrease in hesitancy for the most doubtful participants were messages addressing concerns over vaccine safety in relation to the speed of their development.

The team behind the study says that the message of collective benefit has worked well and still has a part to play – but for the people who haven't been moved by that message, a different approach might be needed.

"This shows the potential of the personal benefit messaging, but of course that still needs to be amplified, and embedded and repeated," psychologist Daniel Freeman, from the University of Oxford in the UK, told The Guardian.

While COVID-19 vaccine uptake has been strong in the UK – two-thirds of the population there have now received at least one dose – the picture varies from country to country. With the SARS-CoV-2 virus still rife in nations like India and Brazil, much more work is required to bring the pandemic under control.

Experts are still working to understand how the vaccines we've got so far might respond to emerging variants of coronavirus, but it's clear that for us all to be as safe as possible, we need everyone who can to get vaccinated. Now we might have a better idea of how to convince the people who still aren't sure.

"The effectiveness of the COVID-19 vaccination program depends on mass participation: the greater the number of people vaccinated, the less risk to the population," write the researchers in their paper. "Concise, persuasive messaging is crucial."

The research has been published in Lancet Public Health.