Predictors of the Uptake of A (H1N1) Influenza Vaccine: Findings from a Population-Based Longitudinal Study in Tokyo

BACKGROUND: Overall pandemic A (H1N1) influenza vaccination rates remain low across all nations, including Japan. To increase the rates, it is important to understand the motives and barriers for the acceptance of the vaccine. We conducted this study to determine potential predictors of the uptake of A (H1N1) influenza vaccine in a cohort of Japanese general population. METHODOLOGY/PRINCIPAL FINDINGS: By using self-administered questionnaires, this population-based longitudinal study was conducted from October 2009 to April 2010 among 428 adults aged 18-65 years randomly selected from each household residing in four wards and one city in Tokyo. Multiple logistic regression analyses were performed. Of total, 38.1% of participants received seasonal influenza vaccine during the preceding season, 57.0% had willingness to accept A (H1N1) influenza vaccine at baseline, and 12.1% had received A (H1N1) influenza vaccine by the time of follow-up. After adjustment for potential confounding variables, people who had been vaccinated were significantly more likely to be living with an underlying disease (p = 0.001), to perceive high susceptibility to influenza (p = 0.03), to have willingness to pay even if the vaccine costs ≥ US$44 (p = 0.04), to have received seasonal influenza vaccine during the preceding season (p<0.001), and to have willingness to accept A (H1N1) influenza vaccine at baseline (p<0.001) compared to those who had not been vaccinated. CONCLUSIONS/SIGNIFICANCE: While studies have reported high rates of willingness to receive A (H1N1) influenza vaccine, these rates may not transpire in the actual practices. The uptake of the vaccine may be determined by several potential factors such as perceived susceptibility to influenza and sensitivity to vaccination cost in general population

Attitudes toward and Uptake of H1N1 Vaccine among Health Care Workers during the 2009 H1N1 Pandemic

BACKGROUND: Though recommended by many and mandated by some, influenza vaccination rates among health care workers, even in pandemics, remain below optimal levels. The objective of this study was to assess vaccination uptake, attitudes, and distinguishing characteristics (including doctor-nurse differences) of health care workers who did and did not receive the pandemic H1N1 influenza vaccine in late 2009. METHODOLOGY/PRINCIPAL FINDINGS: In early 2010 we mailed a self-administered survey to 800 physicians and 800 nurses currently licensed and practicing in Minnesota. 1,073 individuals responded (cooperation rate: 69%). 85% and 62% of Minnesota physicians and nurses, respectively, reported being vaccinated. Accurately estimating the risk of vaccine side effects (OR 2.0; 95% CI 1.5-2.7), agreeing with a professional obligation to be vaccinated (OR 10.1; 95% CI 7.1-14.2), an ethical obligation to follow public health authorities' recommendations (OR 9.9; 95% CI 6.6-14.9), and laws mandating pandemic vaccination (OR 3.1; 95% CI 2.3-4.1) were all independently associated with receiving the H1N1 influenza vaccine. CONCLUSIONS/SIGNIFICANCE: While a majority of health care workers in one midwestern state reported receiving the pandemic H1N1 vaccine, physicians and nurses differed significantly in vaccination uptake. Several key attitudes and perceptions may influence health care workers' decisions regarding vaccination. These data inform how states might optimally enlist health care workers' support in achieving vaccination goals during a pandemic