Population Attributable Fraction of Nonvaccination of COVID-19 Due to Vaccine Hesitancy, United States, 2021

Understanding the extent of coronavirus disease 2019 (COVID-19) nonvaccination attributable to vaccine hesitancy versus other barriers can help prioritize approaches for increasing vaccination uptake. Using data from the Centers for Disease Control and Prevention's Research and Development Survey, a nationally representative survey fielded from May 1 to June 30, 2021 (n = 5,458), we examined the adjusted population attribution fraction (PAF) of COVID-19 vaccine hesitancy attributed to nonvaccination according to sociodemographic characteristics and health-related variables. Overall, the adjusted PAF of nonvaccination attributed to vaccine hesitancy was 76.1%. The PAF was highest among adults who were ≥50 years of age (87.9%), were non-Hispanic White (83.7%), had a bachelor's degree or higher (82.7%), had an annual household income of at least $75,000 (85.5%), were insured (82.4%), and had a usual place for health care (80.7%). The PAF was lower for those who were current smokers (65.3%) compared with never smokers (77.9%), those who had anxiety or depression (65.2%) compared with those who did not (80.1%), and those who had a disability (64.5%) compared with those who did not (79.2%). Disparities in PAF suggest areas for prioritization of efforts for intervention and development of messaging campaigns that address all barriers to uptake, including hesitancy and access, to advance health equity and protect individuals from COVID-19.

Susceptibility to Hepatitis A Virus Infection in the United States, 2007-2016

BACKGROUND

Despite national immunization efforts, including universal childhood hepatitis A (HepA) vaccination recommendations in 2006, hepatitis A virus (HAV)-associated outbreaks have increased in the United States. Unvaccinated or previously uninfected persons are susceptible to HAV infection, yet the susceptibility in the US population is not well known.

METHODS

Using National Health and Nutrition Examination Survey 2007-2016 data, we estimated HAV susceptibility prevalence (total HAV antibody negative) among persons aged ≥2 years. Among US-born adults aged ≥20 years, we examined prevalence, predictors, and age-adjusted trends of HAV susceptibility by sociodemographic characteristics. We assessed HAV susceptibility and self-reported nonvaccination to HepA among risk groups and the "immunization cohort" (those born in or after 2004).

RESULTS

Among US-born adults aged ≥20 years, HAV susceptibility prevalence was 74.1% (95% confidence interval, 72.9-75.3%) during 2007-2016. Predictors of HAV susceptibility were age group 30-49 years, non-Hispanic white/black, 130% above the poverty level, and no health insurance. Prevalences of HAV susceptibility and nonvaccination to HepA, respectively, were 72.9% and 73.1% among persons who reported injection drug use, 67.5% and 65.2% among men who had sex with men, 55.2% and 75.1% among persons with hepatitis B or hepatitis C, and 22.6% and 25.9% among the immunization cohort. Susceptibility and nonvaccination decreased over time among the immunization cohort but remained stable among risk groups.

CONCLUSIONS

During 2007-2016, approximately three-fourths of US-born adults remained HAV susceptible. Enhanced vaccination efforts are critically needed, particularly targeting adults at highest risk for HAV infection, to mitigate the current outbreaks.