Impact of the coronavirus disease 2019 epidemic and a free influenza vaccine strategy on the willingness of residents to receive influenza vaccines in Shanghai, China

The influenza vaccine is not included in China's national immunization program. Here, we assessed influenza vaccine coverage among Shanghai residents and estimated the impacts of the coronavirus disease 2019 (COVID-19) epidemic and a hypothetical free vaccine strategy on the willingness of participants to receive influenza vaccines. The coverage of influenza vaccines among Shanghai residents from 2015 to 2019 was 1.4% (range: 1%-2.4%). A total of 792 adult participants (aged 19-59 years) along with 821 children and 445 older individuals were included in the analysis. The willingness of participants to receive influenza vaccines reached 68.4% following the COVID-19 epidemic. Furthermore, if the vaccine was made available at no cost, 85.9% of participants were willing to be vaccinated. Our data indicated that influenza vaccine coverage is extremely low in Shanghai but that more than two-thirds of participants were willing to receive influenza vaccines following the COVID-19 epidemic. Making influenza vaccines available for free could further increase coverage.