Follow-up shots could have prevented thousands of severe Covid-19 cases in the U.K in the summer of 2022, research has shown.
Of more than 40,000 infections that resulted in hospitalisation or death between June and September, scientists linked more than 7,100 to undervaccination, in a paper published in The Lancet.
The study could help policymakers run better vaccination campaigns and even improve their understanding of other kinds of health issues, scientists say.
Falling vaccine uptake
The U.K. gave the world’s first Covid-19 vaccine outside of clinical trials back in December 2020.
Uptake of that first dose was high, with around 90% of the eligible population having had the shot as of January 2022.
The vast majority also recieved a second dose, in line with manufacturers’ recommendations.
In 2022, adults were encouraged to get further doses to maintain protection against Covid-19. Regular booster campaigns continue to take place.
But vaccine uptake has fallen over time, with almost 50% of the population in some areas having missed at least one recommended dose at the time of the study.
People in England and Northern Ireland were less likely to have had all their doses, compared to those in Scotland and Wales.
Young people, men, people of color, people on lower incomes and those with fewer existing health problems were all less likely to have had every recommended dose.
Age remained a crucial factor in outcomes, however, with around 5,400 of those severe cases that might have been prevented in people aged 75 and older.
Study co-lead Prof Sir Aziz Sheikh said the research could help make sure the groups who missed shots are better served in future.
“As new variants emerge, this study will help to pinpoint groups of our society and areas of the country where public health campaigns should be focused and tailored for those communities,” he said, according to the BBC.
Infectious disease expert Dr Andrew Freedman from the Cardiff University School of Medicine agreed. The scientist, who was not involved in the study itself, told the U.K.’s Science Media Centre the research could help policymakers deliver more effective vaccination campaigns.
“As the authors point out, these findings will help identify which groups should in future be specifically targeted to maximise uptake of vaccines for Covid-19 and other infections. This will be particularly crucial in the event of another pandemic,” he said.
‘A remarkable achievement’
“One of the strengths of this study is the inclusion of data on the whole U.K. population — a remarkable achievement and one which will have applications in many other areas of health policy.”
The population-wide analysis included data on everyone over the age of 5 in the U.K — a country with a population of 67 million people.
Prof Cathie Sudlow, chief scientist at research consortium Health Data Research UK who performed the study, said this kind of analysis could be applied to other areas of health.
“We believe that we could and should extend these approaches to many other areas of medicine, such as cancer, heart disease and diabetes, to search for better understanding, prevention and treatment of disease,” she said in a statement.