The Stability of Influenza Vaccination Behavior Over Time: A Longitudinal Analysis of Individuals Across 8 Years

Using a computational cognitive model to simulate the effects of personal and social network experiences on seasonal influenza vaccination decisions

Introduction

Seasonal influenza poses significant societal costs, including illness, mortality, and reduced work productivity. Vaccination remains the most effective strategy for preventing the disease, yet vaccination rates in the United States fall below 50% for adults. Understanding the factors influencing vaccination decisions is crucial for designing interventions to improve uptake. This study investigates how personal experiences and the experiences of social contacts affect individual decisions to get vaccinated against influenza.

Methods

A multi-year longitudinal survey study was conducted to examine the impact of personal and social network experiences on vaccination decisions. Participants' vaccination behaviors and experiences with influenza were tracked over time. To model these influences, we developed a memory-based vaccination decision model using the Adaptive Control of Thought - Rational (ACT-R) integrated cognitive architecture, which incorporates cognitive processes associated with memory and decision-making.

Results

The survey results demonstrated that both personal experiences with influenza and the experiences of close social contacts significantly influenced vaccination decisions. The memory-based model, built within the ACT-R framework, effectively captured these effects, providing a computational representation of how personal and social factors contribute to vaccination behaviors.

Discussion

The findings suggest that personal and social experiences play a critical role in shaping vaccination decisions, which can inform the development of targeted interventions to increase vaccination uptake. By incorporating cognitive processes into the model, we identified potential strategies to enhance vaccine promotion efforts, such as recalling past experiences with illness to motivate individuals to get vaccinated.

Factors Associated With Repeat Pediatric Influenza Vaccination Among Inconsistent Vaccinators

Promoting consistent vaccination practices may help improve suboptimal influenza vaccination rates. This study evaluated the prevalence and correlates of repeat influenza (flu) vaccination among children who had previously received the vaccine inconsistently. An online survey study was conducted in 2022 among parents of commercially insured children ages 3 to 19 years who were previously inconsistently vaccinated. Of 317 respondents, 85% reported that their child received a flu vaccine in the 2021 to 2022 flu season. Among these parents, 61% reported concern that their child would get sick from flu as the most important reason for vaccinating. Repeat vaccination was less likely among parents who reported that school/daycare requirements were a reason for vaccinating in the prior season (odd ratio [OR] = 0.17, 95% confidence interval [CI] = 0.05-0.55). Our findings suggest that school policies may improve vaccination rates among inconsistent vaccinators.

Effectiveness of financial incentives on influenza vaccination among older adults in China: a randomized clinical trial

OBJECTIVES

To investigate the short-term and long-term effectiveness of different levels of financial incentives on increasing the willingness to vaccinate and vaccine uptake.

METHODS

A randomized controlled trial was conducted to investigate the effectiveness of financial incentives of three groups with monetary incentives (CNY 20, CNY 40, and CNY 60; 1 CNY = 0.13 EUR) vs. a control group-CNY 0-on influenza vaccine uptake among 720 older adults (≥60 years) in Beijing, China. The primary outcome was vaccine uptake, and the secondary outcomes were intention to vaccinate and length of time to immunization.

RESULTS

Financial incentive significantly promoted higher intention to influenza vaccination (120/178 [67.42%] vs. 442/542 [81.55%]; Relative Risk [RR], 1.21; 95% CI, 1.02-1.42) and higher vaccination participation (74/178 [41.57%] vs. 316/542 [58.30%]; RR, 1.39; 95% CI, 1.10-1.75). CNY 60 had the largest impact on the intention to vaccinate (15.00% vs. 13.48% and 13.90%) and vaccination uptake (19.42% vs. 14.05% and 16.67%) compared with CNY 20 and CNY 40. Time to vaccination was significantly lower among participants receiving incentives than those without ([37.21 days; 95% CI, 34.33-39.99] vs. [48.27 days; 95% CI, 43.47-53.07]; Hazard Ratio [HR] 1.57, 95% CI 1.22-2.03). We found no long-term influence of financial incentives on vaccination decisions in the following year (217/542, 40.04% vs. 65/178, 36.52%; RR 1.08, 95% CI 0.82-1.42).

DISCUSSION

Our study suggests that modest financial incentives will boost short-term influenza vaccination rates and shorten the length of time to immunization in China. No one single-time financial incentive had a long-term effect on future vaccination behaviours or helped establish regular vaccination behaviours.

Predicting future vaccination habits: The link between influenza vaccination patterns and future vaccination decisions among old aged adults in China

BACKGROUND

Annual influenza vaccination is crucially recommended for the elderly to maintain humoral immunity. Insufficient coverage requires us to understand the determinants of their influenza behaviors and how these patterns impact vaccination choices.

METHODS

Data from 540 Beijing residents aged over 65 were collected through interviews, capturing vaccination history and sociodemographic details. Individual influenza vaccination records from 2016 to 2020 were obtained from China's Immunization Information Systems. A latent class model identified three vaccination patterns. Multinomial logistic regression assessed relative risk ratios (RRRs) for vaccination based on sociodemographic factors. Vaccination patterns were used to predict future vaccination likelihood.

RESULTS

The analysis revealed three groups: sporadically vaccinated (63.33%), occasionally vaccinated (18.71%), and frequently vaccinated (17.96%). Factors associated with frequent vaccination included age over 70 (RRR = 2.81), lower income (RRR = 0.39), higher vaccine hesitancy (RRR = 3.10), multiple chronic conditions (RRR = 2.72), and rural residence (RRR = 2.48). The frequently vaccinated group was more likely to sustain regular vaccination habits in subsequent years compared to the occasionally vaccinated group.

CONCLUSIONS

Only 17.96% of Beijing's older population exhibited a consistent influenza vaccination pattern. Older age, rural residency, and chronic diseases correlated with repeated influenza vaccination. Segmenting the population based on past vaccination behavior can aid in designing targeted interventions to improve vaccination rates.

Leisure-time physical activity and mortality from influenza and pneumonia: a cohort study of 577 909 US adults

OBJECTIVE

To examine the association of leisure-time physical activity with mortality from influenza and pneumonia.

METHODS

A nationally representative sample of US adults (aged ≥18 years) who participated in the National Health Interview Survey from 1998 to 2018 were followed for mortality through 2019. Participants were classified as meeting both physical activity guidelines if they reported ≥150 min/week of moderate-intensity equivalent aerobic physical activity and ≥2 episodes/week of muscle-strengthening activity. Participants were also classified into five volume-based categories of self-reported aerobic and muscle-strengthening activity. Influenza and pneumonia mortality was defined as having an underlying cause of death with an International Classification of Diseases, 10th Revision code of J09-J18 recorded in the National Death Index. Mortality risk was assessed using Cox proportional hazards, adjusting for sociodemographic and lifestyle factors, health conditions and influenza and pneumococcal vaccination status. Data were analysed in 2022.

RESULTS

Among 577 909 participants followed for a median of 9.23 years, 1516 influenza and pneumonia deaths were recorded. Compared with participants meeting neither guideline, those meeting both guidelines had 48% lower adjusted risk of influenza and pneumonia mortality. Relative to no aerobic activity, 10-149, 150-300, 301-600 and >600 min/week were associated with lower risk (by 21%, 41%, 50% and 41%). Relative to <2 episodes/week of muscle-strengthening activity, 2 episodes/week was associated with 47% lower risk and ≥7 episodes/week with 41% higher risk.

CONCLUSIONS

Aerobic physical activity, even at quantities below the recommended level, may be associated with lower influenza and pneumonia mortality while muscle-strengthening activity demonstrated a J-shaped relationship.

Modelling the Interplay between Responsive Individual Vaccination Decisions and the Spread of SARS-CoV-2

The uptake of COVID-19 vaccines remains low despite their high effectiveness. Epidemic models that represent decision-making psychology can provide insight into the potential impact of vaccine promotion interventions in the context of the COVID-19 pandemic. We coupled a network-based mathematical model of SARS-CoV-2 transmission in Georgia, USA with a social-psychological vaccination decision-making model in which vaccine side effects, post-vaccination infections, and other unidentified community-level factors could "nudge" individuals towards vaccine resistance while hospitalization spikes could nudge them towards willingness. Combining an increased probability of hospitalization-prompted resistant-to-willing switches with a decreased probability of willing-to-resistant switches prompted by unidentified community-level factors increased vaccine uptake and decreased SARS-CoV-2 incidence by as much as 30.7% and 24.0%, respectively. The latter probability had a greater impact than the former. This illustrates the disease prevention potential of vaccine promotion interventions that address community-level factors influencing decision-making and anticipate the case curve instead of reacting to it.

Association of COVID-19 Vaccination With Influenza Vaccine History and Changes in Influenza Vaccination

This survey study assesses how COVID-19 vaccination differs across historical influenza vaccination patterns and whether influenza vaccination changed during the COVID-19 pandemic.

Reciprocal relationships among influenza experiences, perceptions, and behavior: Results from a national, longitudinal survey of United States adults

OBJECTIVE

Our objective was to model the reciprocal relationships of perceived risk of contracting influenza with and without influenza vaccination, vaccination behavior, and reported influenza illness.

METHODS

We fit structural equation models to data from a longitudinal survey of adults in the United States collected through the RAND American Life Panel. Data come from fall and spring surveys fielded before and after each of 3 influenza seasons, 2016/2017, 2017/2018, and 2018/2019, for a total of 6 waves.

RESULTS

As expected, reported influenza experience was associated with increased perceived influenza risk in subsequent survey waves. Furthermore, perceived risk was associated with subsequent vaccination behavior, such that vaccination was more common for those with higher perceived unvaccinated influenza risk and lower perceived vaccinated influenza risk. Perhaps surprisingly, both elements of perceived risk were also associated with a greater likelihood of subsequent reported influenza illness. This malleability in illness reports may reflect uncertainty, as more respondents reported being sick but being unsure about whether they had influenza than reported certainty that they had influenza.

CONCLUSIONS

Interventions that influence perceptions about past experience with influenza, including increased testing and informational campaigns about influenza symptoms, could have unanticipated impacts on perceptions of influenza vaccination and vaccination behavior.

Vaccination Against COVID-19: A Longitudinal Trans-Theoretical Study to Determine Factors that Predict Intentions and Behavior

BACKGROUND

Despite the clear benefits of vaccination, their uptake against common infectious diseases is suboptimal. In December 2020, vaccines against COVID-19 became available.

PURPOSE

To determine factors that predict who will take the COVID-19 vaccine based on a conceptual model.

METHODS

An online survey was administered twice: prior to public vaccination, and after vaccinations were available. Participants were 309 Israelis with initial data and 240 at follow-up. Baseline questionnaires measured intentions to be vaccinated and hypothesized predictors clustered in four categories: background, COVID-19, vaccination, and social factors. Self-reported vaccination uptake was measured at follow-up.

RESULTS

Sixty-two percent of the sample reported having been vaccinated. Intentions were strongly associated with vaccination uptake and mediated the effects of other predictors on behavior. Eighty-six percent of the variance in vaccination intentions was explained by attitudes toward COVID-19 vaccination, regret for having declined vaccination, trust in vaccination, vaccination barriers, past flu vaccination, perceived social norms, and COVID-19 representations.

CONCLUSIONS

Beliefs related directly to the COVID-19 vaccine explained most of the variance in intentions to vaccinate, which in turn predicted vaccination uptake.