A new survey from United Kingdom researchers on attitudes toward COVID-19 vaccination across 15 nations has found that just four in 10 people would be willing to receive treatment, well below the estimated threshold needed to reach herd immunity.

Out of 13,500 respondents surveyed by Imperial College London, just 41 percent of people said they would accept vaccination at the time of the survey, which was conducted between Nov. 11 and Nov. 24, with 51 percent saying they would be willing to get vaccinated next year.

There is concern among health experts that growing vaccine skepticism could jeopardize efforts to achieve herd immunity. Multiple health departments are working on the assumption that a threshold of between 65 and 70 percent vaccine coverage will be necessary to control the spread of the novel coronavirus.

"There is a lot of evidence that vaccines are safe, but unfortunately there is also a lot of misinformation out there," said Sarah Jones, project colead and doctoral researcher at the Institute of Global Health Innovation, or IGHI, at Imperial College London.

The survey, which was conducted before the UK approved the Pfizer vaccine, covered 10 nations in Europe, as well as Canada, Australia, South Korea, Japan and Singapore.

Among the countries surveyed, France had the highest vaccine hesitancy, with just a quarter of respondents saying they would receive treatment at the time of the survey, rising to 35 percent next year. The UK had the lowest vaccine hesitancy, with 65 percent saying they would agree to a shot in 2021, rising from 54 percent in November.

Fear over possible side effects was among the most common concerns. More than half of global respondents (54 percent) were worried about side effects, with people in France and Spain showing the greatest concern (66 percent and 67 percent respectively) while those in the UK and Denmark had the least concern (31 percent and 29 percent respectively).

Just over half of those surveyed said they were confident in their government's ability to provide them with an effective vaccine. In Singapore, 64 percent had faith in national authorities, the highest among surveyed countries, while France had the lowest at 36 percent.

Ara Darzi, co-director of the IGHI, said that the findings highlight the need for governments to devise vaccine information campaigns and rollout strategies that can help inform and reassure the public and increase their willingness to take part in vaccination programs.

"More needs to be done to build the public's trust around coronavirus vaccines so that immunization campaigns worldwide can make a meaningful impact on curbing the virus," said Darzi.

A separate survey from Londonbased consultancy Kantar found that levels of vaccine hesitancy had increased between June and November in the UK, the United States and France.