Hesitancy around COVID-19 vaccines could lead to thousands of extra deaths over a two-year period, Imperial epidemiologists show.

** UPDATE (24-03-2021): This research (Report 43) has now been peer reviewed and published in Nature Communications Medicine. **

High numbers of people refusing or delaying a vaccine could increase the mortality rate by up to eight times compared with ideal vaccination uptake.

Getting vaccinated is an individual choice with social consequences Daniela Olivera Mesa Imperial College London

The team estimate that this hesitancy would lead to an extra 236 deaths per million population over a two year period for a vaccine with high efficacy.

Vaccine hesitancy has the potential to threaten the successful roll-out of SARS-CoV-2 vaccines globally.

The findings are published in a new online report by the Imperial College COVID-19 Response Team.

This latest report evaluates the potential impact of vaccine hesitancy on the control of the pandemic and the relaxation of non-pharmaceutical interventions (NPIs).

The analysis combines an epidemiological model of SARS-CoV-2 transmission with data on vaccine hesitancy from population surveys.

The research finds that the mortality over a two-year period could be up to eight times higher in countries with high vaccine hesitancy compared to an ideal vaccination uptake if NPIs are relaxed.

Vaccine hesitancy could prolong lockdown measures

In addition, the authors say that high vaccine hesitancy could prolong the need for NPIs to remain in place.

The team emphasises that addressing vaccine hesitancy with behavioural interventions is an important priority in the control of the COVID-19 pandemic.

Daniela Olivera Mesa, said: "Getting vaccinated is an individual choice, however, this choice has social consequences. Our work demonstrated that vaccine hesitancy can have a substantial health impact that affects both the vaccinated and unvaccinated populations. Building trust in vaccines is an important public health priority to control COVID-19".

Professor Azra Ghani, said: "Our work demonstrates the importance of achieving high levels of vaccine coverage if we are to return to a normal way of life. Vaccine hesitancy has declined in the UK in recent months but uptake remains unequal. It is important to understand the reasons behind vaccine hesitancy so that those that remain uncertain about getting vaccinated can have their concerns addressed".

Dr Peter Winskill, said: "The global effort to develop effective and safe vaccines against SARS-CoV-2 has been unprecedented. To ensure that the full benefits of these vaccines are realised, high levels of vaccine coverage must be achieved. Vaccine hesitancy can jeopardise this goal, leading to adverse public health outcomes or the need to prolong non-pharmaceutical interventions".

The work is presented in the latest report from the WHO Collaborating Centre for Infectious Disease Modelling within the MRC Centre for Global Infectious Disease Analysis, Jameel Institute (J-IDEA), Imperial College London.

Since the emergence of the new coronavirus (COVID-19) in December 2019, the Imperial College COVID-19 Response Team has adopted a policy of immediately sharing research findings on the developing pandemic.