Who is motivated to accept a booster and annual dose? A dimensional and person‐centered approach

Abstract

The transmissibility of new COVID‐19 variants and decreasing efficacy of vaccines led authorities to recommend a booster and even an annual dose. However, people's willingness to accept new doses varied considerably. Using two independent longitudinal samples of 4596 (Mean age = 53.6) and 514 (Mean age = 55.9) vaccinated participants, we examined how people's (lack of) vaccination motivation for their first dose was associated with their intention to get a booster (Sample 1) and an annual dose (Sample 2) several months later (Aim 1). We also aimed to capture the impact of the motivational heterogeneity on these intentions by capitalizing on participants' different motivational profiles collected at baseline (Aim 2). Across both samples, autonomous motivation, controlled motivation, and distrust‐based amotivation were uniquely related to, respectively, higher, lower, and even lower booster and annual dose intentions. Further, a two‐step clustering procedure revealed five profiles, with the profiles characterized by higher autonomous motivation (i.e. Good Quality and High Quantity profiles) reporting the highest vaccination intentions and the profile characterized by the highest number of obstacles (i.e. Global Amotivated profile) yielding the lowest vaccination intentions. These results stress the critical need to support citizens' volitional endorsement of vaccination to harvest long‐term benefits with respect to COVID‐19.

Psychological science and its societal mission during the SARS‐CoV‐2 pandemic: The Motivation Barometer as an evidence‐informed policy instrument in Belgium

“…Further, in terms of methodology , the Motivation Barometer relied on a variety of research designs and statistical methods to collect and analyze findings. We used both cross‐sectional cohorts (e.g., Van Oost et al., 2022) and longitudinal follow‐up surveys (e.g., Waterschoot, Van Oost, Vansteenkiste et al., 2023), but also administered experimental designs in both a vignette format (e.g., Morbée, Waterschoot, et al., 2022) and in real‐life intervention studies (e.g., Laporte et al., 2022).…”

“…Autonomous regulation for vaccination predicted concurrent vaccination intentions as well as future self‐reported behavior, including the subscription to a waiting list, effective vaccine uptake (Schmitz et al., 2022), and the intention to take a booster and annual vaccine after 8 and 13 months (Waterschoot, Van Oost, Vansteenkiste, et al., 2023). Interestingly, although external regulation was slightly positively related to vaccine uptake (Schmitz et al., 2022), the effect became slightly negative when predicting the intention to accept a booster or annual dose, suggesting that the encountered pressure around vaccination backfired over time (Waterschoot, Van Oost, Vansteenkiste, et al., 2023). The differential role of autonomous and external regulation for vaccination also manifested when predicting people's shifts in vaccination intentions across the first year of the vaccination roll‐out (Waterschoot, Van Oost, Schmitz, et al., 2023).…”

“…Effort‐based amotivation is at stake when citizens may not have sufficient resources available (e.g., physical or mental energy) to engage in behaviors required for vaccination. Distrust‐based amotivation was negatively related to the intention to accept a vaccine, both concurrently (Schmitz et al., 2022) and several months later when people were probed for their intention to accept a booster or annual dose (Waterschoot, Van Oost, Vansteenkiste, et al., 2023). Also, an increase in distrust‐based amotivation over time prevented citizens from moving toward greater vaccination.…”

“…Further, effort‐based amotivation appeared unrelated to people's vaccination intentions (Schmitz et al, 2022; Waterschoot, Van Oost, Vansteenkiste, et al., 2023), presumably because it was relatively effortless for citizens to get a vaccine in Belgium, as vaccination centers were within close distance and the logistic process ran rather smoothly (see also Morbée, Waterschoot, et al., 2022). The low prevalence of effort‐based amotivation may not be observed in other nations, with effort‐based amotivation then potentially yielding a different effect.…”

“…Profiling analyses that aim to identify different groups of individuals, each characterized by a particular combination of reasons for (not) getting vaccinated, slightly nuance these findings. Citizens who score high on effort‐based amotivation only express lower intentions to accept a booster or annual dose compared to motivated groups, yet, their intentions are higher than those of groups characterized by the presence of distrust‐based amotivation (Waterschoot, Van Oost, Vansteenkiste, et al., 2023). Overall, such profile analyses indicate that unvaccinated individuals are rather heterogeneous.…”