skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Measuring vaccination coverage and concerns of vaccine holdouts from web search logs
Abstract To design effective vaccine policies, policymakers need detailed data about who has been vaccinated, who is holding out, and why. However, existing data in the US are insufficient: reported vaccination rates are often delayed or not granular enough, and surveys of vaccine hesitancy are limited by high-level questions and self-report biases. Here we show how search engine logs and machine learning can help to fill these gaps, using anonymized Bing data from February to August 2021. First, we develop avaccine intent classifierthat accurately detects when a user is seeking the COVID-19 vaccine on Bing. Our classifier demonstrates strong agreement with CDC vaccination rates, while preceding CDC reporting by 1–2 weeks, and estimates more granular ZIP-level rates, revealing local heterogeneity in vaccine seeking. To study vaccine hesitancy, we use our classifier to identify two groups,vaccine early adoptersandvaccine holdouts. We find that holdouts, compared to early adopters matched on covariates, are 67% likelier to click on untrusted news sites, and are much more concerned about vaccine requirements, development, and vaccine myths. Even within holdouts, clusters emerge with different concerns and openness to the vaccine. Finally, we explore the temporal dynamics of vaccine concerns and vaccine seeking, and find that key indicators predict when individuals convert from holding out to seeking the vaccine.  more » « less
Award ID(s):
2327709
PAR ID:
10543020
Author(s) / Creator(s):
; ;
Publisher / Repository:
https://www.nature.com/
Date Published:
Journal Name:
Nature Communications
Volume:
15
Issue:
1
ISSN:
2041-1723
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Wallqvist, Anders (Ed.)
    The SARS-CoV-2 pandemic has generated a considerable number of infections and associated morbidity and mortality across the world. Recovery from these infections, combined with the onset of large-scale vaccination, have led to rapidly-changing population-level immunological landscapes. In turn, these complexities have highlighted a number of important unknowns related to the breadth and strength of immunity following recovery or vaccination. Using simple mathematical models, we investigate the medium-term impacts of waning immunity against severe disease on immuno-epidemiological dynamics. We find that uncertainties in the duration of severity-blocking immunity (imparted by either infection or vaccination) can lead to a large range of medium-term population-level outcomes (i.e. infection characteristics and immune landscapes). Furthermore, we show that epidemiological dynamics are sensitive to the strength and duration of underlying host immune responses; this implies that determining infection levels from hospitalizations requires accurate estimates of these immune parameters. More durable vaccines both reduce these uncertainties and alleviate the burden of SARS-CoV-2 in pessimistic outcomes. However, heterogeneity in vaccine uptake drastically changes immune landscapes toward larger fractions of individuals with waned severity-blocking immunity. In particular, if hesitancy is substantial, more robust vaccines have almost no effects on population-level immuno-epidemiology, even if vaccination rates are compensatorily high among vaccine-adopters. This pessimistic scenario for vaccination heterogeneity arises because those few individuals that are vaccine-adopters are so readily re-vaccinated that the duration of vaccinal immunity has no appreciable consequences on their immune status. Furthermore, we find that this effect is heightened if vaccine-hesitants have increased transmissibility (e.g. due to riskier behavior). Overall, our results illustrate the necessity to characterize both transmission-blocking and severity-blocking immune time scales. Our findings also underline the importance of developing robust next-generation vaccines with equitable mass vaccine deployment. 
    more » « less
  2. Achieving sufficient COVID-19 vaccination coverage has been hindered in many areas by vaccine hesitancy. Many studies based on large survey samples have characterized vaccine refusal, but there are fewer in-depth qualitative studies that explore hesitant adoption: the middle-ground between vaccine acceptance and refusal, and how individuals may move across this continuum depending on their lived experience. For this paper, we use the narratives of 25 adults living in off-road, predominately Alaska Native communities to describe the complex decision-making processes undertaken by ‘hesitant adopters’, defined in our study as those who completed their initial COVID-19 series despite reporting hesitancy. Interviewees' stories help illustrate how hesitant adopters' decision-making processes involved making sense of information through interactions with trusted individuals, lived experiences, observations, emotions, and personal motivations. For the majority of these hesitant adopters' (n = 20, 80%) interpersonal interactions were key in helping to make the decision to get vaccinated. Over half of the interviewees (n = 14, 56%) described how conversations with individuals they trusted, including healthcare providers, family, friends, and interactions through their professional network made them feel safe. One third of the hesitant adopters (n = 7, 28%) attributed their decision to get vaccinated based on the influence of Alaska Native Elders including their knowledge, personal experiences, as well as being motivated by the desire to protect them. Independent research was also important to about a quarter of hesitant adopters (n = 6, 24%), and for these interviewees it was the process of gathering information on their own and learning from others, especially healthcare providers who could answer their questions and alleviate their concerns. This paper illustrates the temporality of vaccine decision-making: vaccine acceptance for those who are hesitant may be an ongoing process that is influenced by personal experience, relationships, and context. 
    more » « less
  3. null (Ed.)
    Most research on vaccine hesitancy has focused on parental attitudes toward childhood vaccination, but it will be important to understand dimensions of vaccine hesitancy in the adult population as more adult vaccines are introduced in the future. We modified the Vaccine Hesitancy Scale to target adult vaccines and provide measures of its reliability and validity relative to influenza vaccine uptake and COVID-19 vaccination acceptance in cross-sectional internet surveys in the United States and in China. We assessed the impact of vaccine hesitancy on influenza and COVID-19 vaccination using multivariable regression modeling, which informed concurrent validity of the adult Vaccine Hesitancy Scale (aVHS). Among 1103 participants in the March 2020 China survey, 5.4% would not accept a COVID-19 vaccine, whereas this figure was 18.8% for the March 2020 US survey and 27.3% for the June 2020 US survey. The aVHS exhibits good internal consistency in all three surveys. Models adjusted for age, gender and income level show that prevalence of COVID-19 vaccine acceptance was a fraction as high in those who scored higher on the VHS than those who scored lower on all three surveys. Prevalence of past and future flu vaccine acceptance was a fraction as high in those with higher aVHS scores than those with lower scores. Prevalence of COVID-19 vaccine acceptance is lower in those with higher vaccine hesitancy scores, which supports the scale’s concurrent validity. The aVHS exhibits good internal consistency, making it a valid and reliable tool for measuring vaccination uptake. 
    more » « less
  4. Stimpson, Jim P (Ed.)
    Introduction The Latinx population has the second highest COVID-19 death rate among racial/ethnic groups in the United States and less than half of Latinx youth aged 5–17 years old completed their COVID-19 primary vaccination series as of September 2022. COVID-19 vaccine misinformation detrimentally impacts vaccination rates. In this study, we examined factors that predicted Latinx youth COVID-19 vaccine hesitancy and vaccination status. Methods A community-based sample of 290 Latinx parent and adolescent dyads from a Southwestern metropolitan area of the United States who were recruited to complete an online survey at baseline at T1 (August 2020 –March 2021) and one year later. We tested a longitudinal mediation model in which we examined individual and family factors that would predict youth COVID-19 vaccine hesitancy and vaccination status over time. Results Youth’s pandemic disbelief (i.e., the belief that the COVID-19 pandemic is a conspiracy or not real) predicted greater youth’s COVID-19 vaccine hesitancy, and in turn, a lower likelihood of youth’s COVID-19 vaccination. Youth’s pandemic disbelief also predicted greater parent’s vaccination hesitancy which, in turn, predicted greater youth’s vaccination hesitancy and a lower likelihood of COVID-19 vaccination. Parents’ pandemic disbelief predicted their own COVID-19 hesitancy, but not youth hesitancy Discussion Our study findings provide initial evidence that general pandemic disbelief was a significant driver of vaccine hesitancy and vaccination among Latinx families. The study contributes to the limited research investigating COVID-19 vaccination in the Latinx community and among Latinx youth, further aiding how COVID-19 vaccine disparities can be mitigated among racial/ethnic populations. 
    more » « less
  5. Context:Throughout the COVID-19 pandemic, state and local health departments served as risk communicators to the public; however, public health practitioners have limited resources at their disposal when trying to communicate information, especially when guidance is rapidly changing. Identifying how the population gathers information across channels and which subsets of the population utilize which channels can help practitioners make the best use of these limited resources. Objective:To identify how individuals utilized different information channels to get COVID-19–related information and determine its effect on one COVID-19–related action: vaccine intentions. Design:This study applies latent class analysis to utilization of information channels to characterize information consumption patterns during the COVID-19 infodemic and then explores the relationship between these patterns and vaccine hesitancy. Setting:The data were collected from theCOVID-19 Vaccine Hesitancy Survey, which is a nationally representative sample of US adults 18 years and older recruited from Social Science Research Solutions (SSRS)'s Opinion Panel. Participants:The online survey was conducted between April 7 and April 11, 2021, after the COVID-19 vaccine was available to all adults and enrolled more than 3000 respondents (n = 3014). Main Outcome Measure(s):Respondents were asked about their frequency of information seeking related to the COVID-19 vaccine, sociodemographics, and vaccine perceptions. Results:Based on fit statistics and prior research, we identified 6 latent classes that characterize information seeking: Nonseekers, Legacy, Legacy + Facebook/Instagram, Traditional Omnivore, Omnivore + Broad Social Media, and Twitter. Sociodemographics, political, economic, and COVID-19 exposure variables are associated with different patterns of seeking information about COVID-19. Membership in 3 of these classes was associated with higher rates of vaccine refusal and vaccine hesitancy. Discussion:The study has implications for public health officials and policymakers who use media channels to share news and health information with the public. Information should be tailored to the sociodemographic profiles of those users who are likely consuming information across multiple different channels. 
    more » « less