Partisanship predicts COVID-19 vaccine brand preference: the case of Argentina

Vaccine adoption has always been a problem that behavioral scientists deemed important to study. However, the Coronavirus pandemic highlighted the need to study not only the factors promoting adoption in general but also those that could speed up vaccination campaigns that are time-sensitive. Despite efforts to discourage consumers from seeking specific COVID-19 vaccine brands, reports indicated people were still actively seeking brands and canceling appointments when offered a non-preferred brand. Public health authorities recognize that vaccine controversies and resistance undermine collective wellbeing, highlighting the need for research on factors that can increase vaccine adoption and speed. Brewer et al. (2017) proposed the Increasing Vaccination Model, where thoughts and feelings (e.g., confidence in effectiveness) and social processes (e.g., norms) drive motivation, but practical barriers (e.g., availability) can still prevent vaccination. In this research, the authors propose that in a future pandemic, foreseeing consumers' vaccine brand preferences based on measurable traits like political affiliation could help diminish resistance and promote fast adoption. They test whether political party affiliation influences perceptions of vaccines' safety and effectiveness and alters perceptions of practical barriers (e.g., management of the campaign).

Theoretical framework integrates marketing and political identity research. Brand preference is influenced by more than rational evaluation; intuition, sensation, emotion, and self-concept congruence drive choices, with consumers preferring brands that represent desired identities and avoiding those linked to undesired selves. During COVID-19, multiple vaccine brands were available, implying that uptake was shaped by brand characteristics and equity, not only clinical effectiveness. Media, political discourse, and promotional campaigns can shift beliefs and intentions about vaccines. Reports from the US and Canada indicated brand choosiness (e.g., preference for Pfizer/Moderna over J&J/AstraZeneca), with public officials’ statements potentially amplifying choosiness. Political identity affects consumer choices and brand evaluation, with partisanship linked to belief bias, motivated reasoning, and acceptance of congenial information. Political ideology predicted vaccine hesitancy and uptake across contexts, moderated by which party was in power and trust in government. Politicization also extended to vaccine country of origin, with preferences for domestically produced or trusted-country vaccines and denigration of vaccines from rival countries. The Argentine context is well-suited: a bi-partisan structure (Frente de Todos, FT, ruling; Juntos por el Cambio, JxC, opposition) and availability of both Eastern (Sputnik V, Sinopharm) and Western (Pfizer, Moderna, AstraZeneca) vaccines, with political ties influencing early access (e.g., Sputnik V). Hypotheses: H1: FT supporters perceive Eastern vaccines as more effective and safer; JxC supporters perceive Western vaccines as more effective and safer. H2: FT supporters show lower willingness to switch brands than JxC supporters. H3a: FT supporters more willing to switch to Eastern vaccines (from Western), JxC to Western (from Eastern). H3b: JxC supporters more willing to refuse a non-preferred brand than FT supporters. H4a–H4e: FT supporters report higher satisfaction with received vaccine, greater ease of scheduling, higher perceived availability, greater eagerness to vaccinate, and higher perceived importance/helpfulness of vaccination.

Design: Quantitative cross-sectional online survey conducted in Argentina from July 27 to August 4, 2021. Data collected via Wonder, a national online panel with incentives. Sampling quotas: not vaccinated, partially vaccinated, and fully vaccinated participants. Ethics approval by CEMIC (Protocol 435, v.5). Analyses conducted in RStudio. Sample: N=450 recruited; final N=432 after exclusions (49.5% female; mean age 44.6 years, SD 15.9; vaccination status: 30.6% not vaccinated, 34.7% partially, 34.7% fully; political affiliation: 19.0% FT, 30.8% JxC, 32.6% independent, 17.6% prefer not to say). Among vaccinated (N=300), administered brands included AstraZeneca (25.7%), Sputnik V (32.7%), Sinopharm (32.0%), Covishield (6.7%), Pfizer (1.0%), J&J (0.3%). Measures: Participants rated perceived effectiveness and safety for each vaccine brand available in Argentina on 1–7 scales. Campaign-related perceptions: ease of scheduling an appointment, perceived availability in area, satisfaction with received vaccine, eagerness to be vaccinated, and perceived importance and helpfulness of vaccination. Political affiliation measured on a 1 (Strongly FT) to 7 (Strongly JxC) scale; recoded into FT (1–3), JxC (5–7), independent (4), and prefer not to say. Vaccine brands grouped by origin: Western (Pfizer, Moderna, Johnson & Johnson, AstraZeneca) vs Eastern (Covishield, Sinopharm, Sputnik V). For brand preference, vaccinated participants reported hypothetical willingness to switch brands if they could go back; unvaccinated reported willingness to refuse a non-preferred brand if offered. Analytic approach: Two-way mixed ANOVAs tested effects of vaccine origin (within-subjects: Western vs Eastern) and partisanship (between-subjects: FT vs JxC) on perceived effectiveness and safety. Chi-square tests assessed differences in proportions for (a) willingness to switch brands among vaccinated overall and by origin of switch (Eastern↔Western) and (b) willingness to refuse a non-preferred brand among unvaccinated. One-way ANOVAs tested partisanship effects on campaign support measures (satisfaction, appointment ease, availability, eagerness, importance, helpfulness).

• Perceived effectiveness and safety by origin and partisanship (H1): Significant interaction between vaccine origin and partisanship on perceptions (F(108,15408)=4.47, p<0.001, η2=0.007). FT supporters rated Eastern vaccines higher on effectiveness (M=5.37, SD=1.50) and safety (M=5.44, SD=1.49) than JxC supporters (effectiveness M=4.45, SD=1.35; safety M=4.38, SD=1.33). Conversely, JxC supporters rated Western vaccines higher on effectiveness (M=5.31, SD=1.26) and safety (M=5.16, SD=1.31) than FT supporters (effectiveness M=4.90, SD=1.49; safety M=4.95, SD=1.56).
• Willingness to switch vaccine brand (H2): Among vaccinated, a greater proportion of JxC supporters wanted to switch brands compared to FT supporters (χ2(3,300)=38.52, p<0.001); all four conditions differed in post-hoc tests (p<0.001).
• Direction of hypothetical switches by origin (H3a): FT supporters tended to switch from Western to Eastern, whereas JxC supporters tended to switch from Eastern to Western (χ2(18,182)=48.34, p<0.001).
• Willingness to refuse a non-preferred brand among unvaccinated (H3b): JxC supporters more likely to refuse a non-preferred brand than FT supporters (χ2(6,128)=29.77, p<0.001); fewer FT supporters than expected reported refusal (p<0.001).
• Campaign support and perceptions (H4a–H4e): • Satisfaction with received vaccine (vaccinated): F(3,296)=12.76, p<0.001; FT > JxC. • Ease of scheduling appointment: F(3,428)=7.72, p<0.001; FT > JxC. • Perceived local availability: F(3,428)=11.42, p<0.001; FT > JxC. • Eagerness to vaccinate: vaccinated F(3,296)=3.86, p<0.01; unvaccinated F(3,128)=5.43, p<0.01; FT > JxC. • Perceived importance of vaccination: F(3,428)=8.64, p<0.001; FT > JxC. • Perceived helpfulness of vaccination: F(3,428)=11.2, p<0.001; FT > JxC.

Findings show that partisanship systematically shapes perceptions of COVID-19 vaccine brands and support for vaccination campaigns. In Argentina’s bi-partisan context with both Eastern and Western vaccines available, FT (ruling party) supporters favored and rated Eastern-origin vaccines as safer and more effective, while JxC (opposition) supporters favored Western-origin vaccines. These results align with theories that political identity influences consumer evaluations and that individuals prefer brands congruent with their self-concept and in-group identity. The politicized discourse and country-of-origin cues appear to drive motivated perceptions that can override epistemic information about safety and effectiveness. Behaviorally, JxC supporters expressed greater desire to switch to Western vaccines and higher willingness to refuse non-preferred brands, whereas FT supporters showed the opposite pattern and higher compliance. FT supporters also viewed the campaign more positively (appointment ease, availability, satisfaction, eagerness, perceived importance/helpfulness), consistent with links between government trust, political alignment, and health behaviors. These partisan asymmetries have policy implications: messaging and supply allocation strategies should consider predictable partisan brand preferences to reduce friction, delays, and hesitancy in future vaccination campaigns. The results suggest that traditional call-to-action messages may be insufficient when identity-congruent brand preferences are salient; instead, interventions leveraging branding, trusted messengers, and tailored communication could mitigate partisan bias in vaccine uptake.

The study demonstrates that political party affiliation predicts COVID-19 vaccine brand perceptions and preferences in Argentina: FT supporters favor Eastern vaccines, while JxC supporters favor Western ones, affecting perceived safety/effectiveness, hypothetical switching, refusal of non-preferred brands, and evaluations of the vaccination campaign. These findings extend consumer psychology and social identity perspectives into the public health domain, highlighting that brand identity and partisan alignment can shape health-related decisions. Policy implications include anticipating partisan brand preferences in supply allocation and communication strategies to minimize delays and hesitancy in future pandemics. Future research should examine causal pathways, broaden to additional political groups, assess effects in other countries with varied party structures and vaccine availability, and study long-term impacts of pandemic dynamics on vaccination attitudes and general vaccine perceptions.

• Unequal group sizes: More JxC than FT supporters were recruited; robustness checks using both parametric and non-parametric tests yielded consistent results, but imbalance remains a limitation.
• Scope of political groups: Analyses focused on the two major parties (FT and JxC); findings may not generalize to supporters of smaller political platforms.
• Vaccine availability context: At data collection, AstraZeneca (a Western vaccine) was more available than Pfizer/Moderna in Argentina; administered brand distributions could influence some results (particularly relevant to H3a).
• Temporal and contextual factors: The COVID-19 crisis and rollout may have altered general vaccination perceptions; long-term consequences and shifts in decision priorities warrant future study.
• Cross-sectional design: Limits causal inference regarding the directionality between partisanship and vaccine brand preference.