A fifth of people in the UK say they are unlikely to get a coronavirus vaccine if one is approved, a study highlighting “concerning” levels of misinformation has found.

Three-quarters (78%) of 17,500 adults surveyed by University College London (UCL) researchers said they would be “likely” to get vaccinated, with 49% saying they were “very likely” to do so.

But 22% said this was unlikely, and one in 10 said this was “very unlikely”, with factors including worries about unforeseen effects, preferences for natural immunity, concerns about commercial profiteering, and mistrust of vaccine benefits.

Almost one in three (30%) showed substantial beliefs that vaccines can cause unknown future problems, while 15% said they believed to varying degrees that vaccines do not work.

It is critical the Government and public health bodies publicise the importance of getting a vaccination

Twice as many people (21%) said they would be “very unlikely” to get the flu vaccine compared with those who said the same for the Covid-19 vaccine, with 64% saying it was likely they would do so.

The study authors said their findings suggest there is a substantial and worrying level of misinformation among the public and highlight fears that “lack any basis in fact”.

UCL’s Covid-19 Social Study, funded by the Nuffield Foundation, is the UK’s largest study into how adults are feeling during lockdown.

More than 70,000 people have been questioned weekly over the past 26 weeks.

Lead author Dr Daisy Fancourt, from UCL’s Institute of Epidemiology and Health Care, said: “Our study highlights a concerning level of misinformation around vaccines, which could significantly affect uptake once a Covid-19 vaccine is approved.

“Whilst the majority of people have said they are likely to get a Covid-19 vaccine once one is available, a worrying amount of respondents have said that not only will they not get the vaccine, but that they don’t believe vaccines work or worry about potential side-effects, concerns that lack any basis in fact.

“It is critical the Government and public health bodies publicise the importance of getting a vaccination, and explain why it will be critical in fighting the virus and protecting society.”

More than a third (38%) of respondents reported believing to varying degrees that natural immunity is better than immunity from vaccines.

Given people’s reasons for distrust of vaccines, transparency about the scientific evidence and the role of commercial providers is likely to be a key factor in gaining public trust

Over half (53%) said they believe vaccines can cause unforeseen effects, while a quarter reported believing that vaccines are used for commercial profiteering.

And 4% said they strongly believe that vaccine programmes are a con from pharmaceutical companies, and public authorities promote vaccination for financial gain.

Cheryl Lloyd, education programme head at the Nuffield Foundation, said: “These findings reveal valuable insights into public concerns about vaccinations and highlight the importance of building public trust in the safety and efficacy of a Covid-19 vaccine, particularly at a time when there is a significant lack of confidence in the Government response to the pandemic.

“Given people’s reasons for distrust of vaccines, transparency about the scientific evidence and the role of commercial providers is likely to be a key factor in gaining public trust, as is involving the public in the decision-making process.”