The role of misinformation in the spread of the anti-vaccine movement: A descriptive study

INTRODUCTION

Misinformation represents a growing phenomenon that directly threatens the progress made in public health regarding immunization. Over the past decade, various studies have identified how the circulation of false or misleading information in digital media has contributed to the rise of the anti-vaccine movement, undermining trust in vaccines and health systems [1, 2]. This phenomenon has intensified particularly since the COVID-19 pandemic, generating a crisis of confidence that affects both vaccination coverage and the population’s perception of risk [3].

Although there is literature analyzing the anti-vaccine movement from various perspectives, there is still a lack of a systematic review that specifically explores how misinformation has influenced its global spread. Therefore, this study is based on the hypothesis that misinformation is a determining factor in the spread of the anti-vaccine movement, and its primary objective is to assess the attitudes, practices, and levels of exposure to vaccine misinformation among parents in Latin America.

Associated Factors

The expansion of the anti-vaccine movement stems from a series of complex and multifactorial factors. First, low health literacy is a major facilitator of misinformation. People with limited knowledge of science, immunology, or epidemiology have greater difficulty evaluating the validity of information sources, making them susceptible to pseudoscientific or misleading narratives [1].

Furthermore, confirmation bias—a cognitive phenomenon whereby individuals tend to seek out, interpret, and remember information that confirms their prior beliefs—reinforces anti-vaccine stances. This bias is amplified in digital environments, where algorithms tailor content to users’ interests, creating information bubbles that block access to diverse or evidence-based viewpoints [2].

Institutional mistrust also represents a critical factor. Many people distrust the recommendations of health agencies, governments, and pharmaceutical companies, whether because of a history of corruption or negligence, or because of perceived hidden economic interests. This lack of trust becomes fertile ground for vaccine-related conspiracy theories, which resonate particularly in contexts of uncertainty or crisis [3, 4]. We must also consider the influence of public figures or influencers without medical training, who use their reach on social media to promote anti-vaccine narratives. These messages, often based on personal experiences or notions of individual freedom, gain significant traction—even when lacking a scientific basis—and reinforce misconceptions among their followers [5].

At-Risk Populations

Vaccine-related misinformation does not affect all groups equally. There are particularly vulnerable populations at greater risk of adopting anti-vaccine beliefs and rejecting immunizations. These include people with low levels of education, who tend to have less access to reliable sources of scientific information and may rely more on personal experiences or informal content shared on social media [6].

Likewise, historically marginalized communities or those with a history of institutional mistreatment exhibit higher levels of skepticism toward health authorities. In these groups, mistrust may stem not only from current misinformation but also from a legacy of exclusion and neglect, leading them to reject interventions perceived as external or imposed.

Another significant at-risk group consists of parents of young children, who often face decisions about childhood vaccination in an environment saturated with conflicting information. Uncertainty, fear of adverse effects, and the desire to protect their children can make them easy targets for misinformation that appeals to emotion rather than science [7].

Also noteworthy is the youth and adult population with high exposure to social media, where viral content predominates over educational content. In these environments, the constant repetition of false or biased information, combined with social validation (likes, comments, shares), reinforces belief in anti-vaccine narratives and fosters distrust of immunization campaigns [8].

Impact of Social Media

Social media has established itself as one of the primary channels for the spread of vaccine misinformation. Platforms such as Facebook, Instagram, TikTok, YouTube, and X (formerly Twitter) use algorithms that prioritize viral content, often favoring the circulation of emotional or sensational messages that lack scientific backing. This type of content is typically more appealing to the average user than technical reports or institutional campaigns [9].

A key feature of these platforms is their ability to create closed communities, or echo chambers, where users interact exclusively with content that reinforces their beliefs while actively discrediting or blocking contrary information. In these spaces, the idea that vaccines are dangerous or unnecessary is reinforced, and a conspiratorial view of public health is promoted [10].

Furthermore, social media has facilitated the emergence of non-scientific opinion leaders, whose influence can surpass that of health experts. Through videos, posts, and live streams, these leaders share content that appeals to personal experience, suspicion toward the pharmaceutical industry, or rejection of health regulations, reaching millions of people with misinformation.

Although some platforms have attempted to implement control mechanisms, such as warnings or links to official information, these efforts have been partial and insufficient. In many cases, misinformation continues to spread without effective oversight, contributing to a loss of trust in vaccines, hindering the implementation of immunization campaigns, and creating an environment of growing polarization around public health [11,12].

MATERIALS AND METHODS

This study was an observational, cross-sectional, and descriptive study with an analytical component aimed at identifying possible associations between exposure to vaccine misinformation and the degree of acceptance or rejection of vaccines. The cross-sectional nature of the study involved data collection at a single point in time, yielding a “snapshot” of the participating population's opinions and attitudes without directly intervening in their behavior. The use of a descriptive design allowed us to characterize the sociodemographic profile of the respondents and the main sources of information they use. At the same time, the analytical approach enabled us to statistically test relationships among key variables, such as educational level, age, and vaccination predisposition.

The primary data collection tool was a structured survey, developed specifically for this study. Its design was based on a review of current scientific literature on perceptions and attitudes toward vaccines, as well as on questionnaires previously used in similar studies published in indexed journals. The questionnaire was designed in digital format to facilitate its dissemination and access by a larger number of participants, given the online format's advantages for reaching different locations and reducing logistical costs.

Population and Sample

The target population consisted of individuals over the age of 18, of any gender, educational level, or socioeconomic status, residing in Latin American countries, who were parents with active responsibility for decision-making regarding their children’s health and vaccination, both during childhood and adulthood.

Given the impossibility of accessing a comprehensive registry of the target population, a non-probabilistic, purposive sampling method was used. This technique involved selecting participants who met the inclusion criteria and were accessible through digital channels.

The structured survey was disseminated via social media (Facebook, Instagram, Twitter), instant messaging apps (WhatsApp, Telegram), and email, enabling us to reach people from various Latin American countries. To be included in this study, participants had to meet the following criteria:

Be a parent, that is, a person with at least one child.

Reside in any country in Latin America.

Have responsibility for or actively participate in decisions related to their children’s health and vaccination, both during childhood and adulthood.

Be at least 18 years of age, with the capacity to understand and answer the questionnaire.

Agree to voluntarily participate in the survey by signing the informed consent form or providing digital consent.

The following were excluded from the study:

Parents who are not involved in decisions regarding health or vaccinations.

People temporarily residing in Latin America.

People with cognitive or comprehension difficulties who are unable to answer the questionnaire adequately.

Incomplete surveys or those with inconsistent data that prevent a valid analysis of the collected information.

The final sample size was determined based on the total number of valid surveys received during the data collection period. Although a formal probabilistic calculation was not performed due to the sampling method, a sample of 117 participants was obtained to ensure variability in responses and provide sufficient statistical power.

Setting

The study was conducted entirely online. The questionnaire was hosted on the Google Forms platform, accessible from any device with an internet connection (mobile phone, tablet, or personal computer).

The data collection period lasted 6 weeks, during which time the link to the survey was distributed digitally. This approach allowed for:

Achieve broad geographic coverage without physical limitations.

Minimizing logistical costs.

Facilitate the participation of people from different countries and socioeconomic backgrounds.

RESULTS

Figure 1. Distribution of respondents by country of residence.

The results show that the majority of participants reside in Argentina (42%), followed by a significant proportion from Venezuela (31%).

Together, these two countries account for 73% of the total sample, reflecting a clear predominance of participants from the Southern Cone and Latin America—regions that share similar socioeconomic and health contexts regarding public vaccination policies.

The remainder of the sample (27%) is distributed among Brazil (8%), Ecuador (8%), Costa Rica (7%), Panama (2%), and the United States (2%), indicating a smaller but representative presence of diverse national and cultural contexts.

This geographic diversity adds value to the study by allowing for a comparison of perceptions and attitudes toward vaccination in countries with different levels of healthcare development and media exposure to misinformation.

Figure 1 shows the age distribution of the 117 survey participants. This allows subsequent analyses to be conducted with age as a moderating variable and enables an exploration of whether attitudes toward vaccination or perceptions of misinformation differ significantly across different age groups. Ages were grouped into 11-year intervals, and the distribution of each group is as follows:

The majority of respondents (31.6%) are in the 22–33 age range, indicating a predominance of young adults. This group tends to be more active on social media and is therefore considered more exposed to online misinformation.

They are followed by the 33–44 age group (17.1%) and the 44–55 age group (17.9%), which also suggests a significant representation of middle-aged adults.

The age extremes (under 11 and over 66) are underrepresented, which is to be expected if the survey was completed online and targeted at the adult population.

Figure 3. Proportion of participants by self-reported gender

Most respondents identified as women (64%), while 35% were men and 1% preferred not to state their gender. This distribution is moderately skewed toward females, which could be due to greater participation by women in responding to this type of public health survey, a phenomenon frequently observed in similar studies. This does not mean that male participation is insignificant, as it allows for comparisons by sex across variables.

The higher proportion of women may influence attitudes toward vaccination, as various studies show that women tend to be more concerned about preventive health and childhood vaccination.

In this regard, men tend to visit the doctor less frequently and may have different levels of trust in health information sources.

Figure 4. Distribution of respondents’ educational levels.

Sixty-four percent of respondents have completed tertiary or university education, while 22% are currently enrolled in or have interrupted higher education studies. Together, these two groups represent 86% of the total sample, indicating a highly educated population.

In contrast, only 14% of participants reported having completed or not completed secondary or primary education.

This distribution reveals a trend toward participation by individuals with a medium or high level of education, a common feature in studies conducted via digital platforms, where internet access and technological skills are often associated with higher levels of education. From the perspective of the central hypothesis—which posits that misinformation is a determining factor in the spread of the anti-vaccine movement—this finding is particularly significant.

Various studies have shown that a higher level of education is often correlated with:

Greater scientific and health literacy,

Greater critical thinking skills regarding information on social media

Greater trust in official sources and scientific evidence.

However, the fact that the sample consists predominantly of people with higher education does not guarantee immunity to misinformation. In recent years, it has been observed that even individuals with advanced education can be susceptible to anti-vaccine narratives when these are presented in an emotional manner, appealing to personal values or institutional distrust.

Therefore, this result suggests that public health communication strategies should be designed with consideration not only for educational level but also for the information channels and the type of persuasive discourse to which different audiences are exposed.

Figure 5. Respondents’ access to health services.

Most respondents (36%) report having access to the public health system, suggesting a high reliance on state-provided services. Twenty-one percent use private health insurance, while 12% have “obra social,” a form of coverage characteristic of the Argentine social security system. Twelve percent access both public and private services simultaneously, reflecting mixed health coverage strategies. 10% report having exclusively private access, and 9% state they have no health coverage whatsoever, constituting a potentially vulnerable group in terms of access to medical care.

Access to the healthcare system is a key determinant of vaccine perception and acceptance.

Individuals who use the public system typically receive information directly from healthcare institutions and official campaigns, which could foster trust in immunization policies. In contrast, those lacking coverage or relying on informal information networks may be more susceptible to misinformation and anti-vaccine messages spread on social media.

Furthermore, the coexistence of multiple coverage models (public, private, and social welfare) is characteristic of the Argentine system, leading to variability in the quality and frequency of contact with healthcare professionals. This heterogeneity could influence the level of information available and the perception of vaccine risk.

Overall, the results show that most participants have some form of formal access to health services, which facilitates the implementation of institutional communication strategies to counter misinformation within healthcare settings.

Figure 6. Distribution of respondents by presence of children.

More than half of the participants (57%) reported having children, while 43% reported not having children. This distribution reveals a balanced sample, although with a slight majority of parents.

The presence of children is a relevant factor in this study, given that the decision to vaccinate children is often one of the areas where beliefs, levels of information, and the influence of misinformation carry the most weight.

Adults with children are more directly exposed to childhood vaccination campaigns and to messages—both accurate and misleading—circulated in the media and on social media regarding the safety and effectiveness of vaccines.

The fact that more than half of the respondents are parents provides valuable insights into how misinformation impacts parental decision-making regarding vaccination.

This group can offer particularly useful insights into:

the level of trust in healthcare systems and pediatricians,

the most frequently consulted sources of information on vaccines, and

the emotions or fears associated with childhood vaccination.

On the other hand, the 43% who do not have children provide an interesting contrast, as they represent a group of adults who form opinions about vaccination based on individual or preventive perspectives rather than direct experience.

Comparing these two subgroups may reveal significant differences in risk perception, source credibility, and the influence of misinformation.

Figure 7. Compliance with the official childhood vaccination schedule.

Most participants with children (60%) stated that they had vaccinated their children in full accordance with their country’s official schedule. However, 29% acknowledged not having completed all vaccinations, while 11% reported partial vaccination, representing a total of 40% non-compliance (either full or partial).

This finding is significant because, although childhood vaccinations are free and mandatory in most Latin American countries, a considerable proportion of parents do not complete the recommended vaccination schedule.

The reasons behind this phenomenon may include a lack of information, mistrust of the healthcare system, the influence of anti-vaccine rhetoric, or logistical difficulties (scheduling, appointments, availability of doses).

This result is fundamental to the study’s central hypothesis, which posits that misinformation is a determining factor in the spread of the anti-vaccine movement.

The fact that nearly half of parents have not properly completed or initiated the vaccination schedule could reflect:

Exposure to misinformation on social media or within family circles,

Doubts about the safety or necessity of certain vaccines, or

Lack of awareness of the official schedule and the recommendations of health authorities.

These data suggest the need to strengthen public communication strategies and to reinforce health education, particularly targeting parents and caregivers, through accessible campaigns grounded in scientific evidence.

Figure 8. Compliance with the official vaccination schedule among the adult population.

The results show that the vast majority of participants (94%) reported having received vaccines in their adult lives, suggesting a high degree of compliance with and acceptance of vaccination in this population group.

In contrast, 6% indicated they had not been vaccinated, a minority percentage but a relevant one when analyzing individual perceptions of risk and levels of health information.

The high proportion of vaccinated adults could be associated with the existence of effective national campaigns (such as those for influenza, COVID-19, or hepatitis B), as well as with greater collective awareness of the importance of preventive immunization in recent years.

However, the small group that did not get vaccinated could reflect disinterest, forgetfulness, or mistrust—all factors potentially linked to misinformation or a lack of institutional reminders. This finding partially supports the study’s central hypothesis.

While the majority of adults exhibit appropriate vaccination behaviors, the existence of a minority who do not get vaccinated or do not retain a clear memory of their immunization status may highlight the effects of misinformation and the lack of sustained health education. In particular, these results suggest that even in contexts where access to vaccines is widespread and free, the persistence of erroneous or contradictory messages can create gaps in vaccine adherence.

Therefore, this reinforces the need for ongoing communication strategies that also target the adult population—not just parents or caregivers—promoting the updating of vaccination schedules and reinforcing trust in health institutions.

Figure 9. Perception of the importance of childhood vaccination.

The results show that the vast majority of respondents (83%) consider childhood vaccination to be “very important,” and another 11% rate it as “important.”

Overall, 94% of participants demonstrate a clearly favorable attitude toward childhood immunization. Only 4%

% maintain a neutral stance, and barely 4% express a negative perception or disinterest in vaccination.

This distribution indicates a high social value placed on vaccination, which could be linked to widespread recognition of the historical impact of vaccines on the prevention of communicable diseases.

It also reflects that a culture of prevention and trust in medical science predominates within the surveyed sample. These findings are relevant to the study’s central hypothesis, since,

despite the growing circulation of misinformation on social media, the data indicate that the majority of the population maintains a positive and rational view of childhood vaccination. This suggests that, although misinformation exists, its impact on general attitudes may be more related to confusion or doubt than to outright rejection of vaccination.

However, the presence of a small group that downplays the importance of vaccines—even though it is a minority—deserves attention, as it may represent the segment most susceptible to anti-vaccine rhetoric or misleading messages about vaccine safety and efficacy.

This group should be a priority in future public health communication strategies aimed at building trust through clear, empathetic, and scientifically grounded information.

Figure 10. Level of agreement with the statement “Vaccination protects not only the individual but also the community.”

The vast majority of respondents (87%) agreed or strongly agreed with the statement that vaccination protects both the individual and the community, demonstrating a broad understanding of collective responsibility in public health. 9% remained neutral, and only 4% (3% disagreed and 1% strongly disagreed) expressed disagreement or lack of agreement with the statement.

These results indicate widespread acceptance of the social value of vaccination, beyond personal protection, and reflect a high level of health awareness and a sense of collective solidarity.

The small group that does not share this view may represent a minority influenced by more individualistic beliefs or by misinformation that questions the collective efficacy of vaccines.

The majority consensus regarding the community role of vaccination reinforces the hypothesis that accurate information and health education are protective factors against misinformation.

Recognizing vaccination as an act of social protection rather than merely individual protection reflects a higher level of health literacy, which reduces vulnerability to anti-vaccine messages.

On the other hand, the existence of a small percentage of disagreement suggests that misinformation continues to have some, albeit limited, reach within the population. This justifies the need for sustained educational campaigns that strengthen understanding of the concept of herd immunity, especially in sectors with less access to scientific information or in communities where conspiracy theories circulate.

Figure 11. Trust in vaccines offered in the country.

Most participants (61%) expressed confidence in the vaccines offered in their country, while 32% expressed doubt or uncertainty, and 7% stated outright that they did not trust them. These results show a predominance of positive attitudes toward vaccines, although they also reveal a considerable portion of the population (42%) that exhibits indecision or total or partial distrust. This finding is key, as the World Health Organization (WHO) recognizes vaccine hesitancy as one of the main current threats to global public health.

The observed uncertainty may stem from exposure to contradictory or false information, a lack of clear communication from health authorities, prior negative experiences with the healthcare system, or generalized institutional distrust.

This result directly supports the study’s central hypothesis, which posits that misinformation is a determining factor in the spread of the anti-vaccine movement. The percentage of people expressing doubt or a lack of trust (42%) can be interpreted as evidence of the impact of misinformation on the public perception of vaccines. Although the majority maintains a favorable stance, the existence of a significant segment of undecided individuals demonstrates the fragility of trust in contexts where erroneous or alarmist information circulates.

This underscores the need to reinforce communication grounded in scientific evidence, strengthening the credibility of official sources and the population’s media literacy so that people can distinguish between verified information and disinformation.

Figure 12. Hesitancy regarding childhood vaccination.

The results show that the majority of parents (74%) have had no doubts about vaccinating their children, while 26% did report having experienced some degree of indecision at some point. This proportion, although a minority, is significant from a public health perspective, as it highlights the presence of a group susceptible to the influence of misinformation or anti-vaccine rhetoric.

In contexts where the circulation of misinformation is high, even a small percentage of indecision can negatively impact childhood vaccination coverage rates, affecting herd immunity.

The most common causes of doubt are typically associated with:

Confusing or false messages spread on social media,

Fears about adverse effects,

Mistrust of health or pharmaceutical institutions, and

A lack of dialogue with healthcare professionals who provide accessible and reliable information

This finding is directly linked to the study’s central hypothesis, which posits that misinformation is a key factor in the spread of the anti-vaccine movement. The 26% of parents who reported having hesitated to vaccinate their children represent a segment vulnerable to the influence of misinformation—a group that does not necessarily reject vaccination but requires greater informational support and effective communication strategies.

The existence of this group reinforces the need for public health policies to include sustained educational campaigns capable of addressing doubts through empathy and scientific evidence.

In this way, health communication can become a key tool for rebuilding trust and preventing indecision from turning into active vaccine refusal.

Figure 13. Main sources of information on vaccines.

The vast majority of respondents (72%) identified their doctor or pediatrician as their primary source of information on vaccines, demonstrating a high level of trust in healthcare professionals as intermediaries of scientific knowledge. Second, 14% stated they turn to the Internet in general, followed by 6% who consult family or friends, while 4% obtain their information through social media and 3% through traditional media such as television, radio, or print media. Finally, only 1% stated that they directly seek out scientific answers that inspire confidence.

This distribution indicates that, while consulting professionals predominates, a significant portion (around 24%) obtains information from non-specialized or digital sources, where the accuracy of the content is not always guaranteed.

The use of social media and the Internet, although a minority in this case, is a high-risk channel for exposure to misinformation, given that anti-vaccine messages with wide reach and no editorial oversight circulate in these spaces.

This finding reinforces the central hypothesis of the research: misinformation influences the perception and acceptance of vaccines, and its spread is facilitated by the use of unreliable or unscientific sources.

While the predominance of doctors or pediatricians as the primary source is a positive aspect, the fact that a quarter of respondents obtain information outside the healthcare sector demonstrates that scientific communication has not yet managed to dominate the public narrative on vaccination.

This result highlights the need to:

Strengthen doctor-patient communication, leveraging the high level of trust that healthcare professionals inspire.

Train healthcare teams to detect and counter misinformation during consultations.

Launch official digital campaigns that occupy the same information spaces where misinformation circulates, especially on social media and search engines.

Figure 14. Reasons for hesitation or refusal regarding childhood vaccination.

The results show that fear of adverse effects (33%) is the most common reason for hesitation or refusal regarding childhood vaccination. This is followed by distrust of the pharmaceutical industry (29%), a common argument in contemporary anti-vaccine discourse. To a lesser extent, respondents cited lack of access to vaccination services (21%) and religious or personal beliefs (17%) as factors influencing their decision. These data show that most of the reported reasons are perceptual or informational in nature, rather than structural. In other words, doubts and beliefs stemming from misinformation or a lack of trust predominate over logistical or material barriers.

Fear of adverse effects is one of the most common manifestations of vaccine hesitancy, driven largely by the circulation of false or exaggerated news about post-vaccination reactions on social media. Likewise, mistrust of the pharmaceutical industry reflects the influence of conspiracy narratives that link vaccines to economic interests, undermining the perception of safety and altruism within the healthcare system.

This finding is directly related to the study’s central hypothesis, which posits that misinformation is a determining factor in the spread of the anti-vaccine movement.

The predominant motives—fear, mistrust, and personal beliefs—are observable effects of exposure to false or distorted information, rather than indicators of a lack of resources or inaccessibility to the healthcare system.

This suggests that, to reverse attitudes of doubt or rejection, public health strategies should focus on:

Improving risk communication by addressing fears with empathy and transparency.

Strengthening institutional trust by presenting clear scientific evidence on the safety and efficacy of vaccines.

Training health professionals to identify the most common concerns and provide responses tailored to the public’s level of understanding.

In summary, the results reinforce the need to design evidence-based communication interventions that combat misinformation and restore trust in the healthcare system and in science.

Figure 15. Willingness to vaccinate children with new vaccines.

Most respondents (56%) stated they were willing to vaccinate their children with new vaccines, reflecting a predominantly positive attitude toward scientific innovation and preventive healthcare. However, 42% responded that their decision would depend on the type of vaccine, indicating a stance of caution or indecision, and 2% expressed total rejection of that possibility.

These data suggest that, although acceptance is widespread, a significant percentage of parents still have reservations, possibly related to the novelty of the vaccine, the rapid pace of its development, or the conflicting information that often accompanies the introduction of new vaccines (as was evident during the COVID-19 pandemic).

The “depends on the vaccine” category represents a key group from a public health perspective, as it comprises the undecided population—that is, people who do not reject vaccines but require additional information or institutional validation to make a decision.

This finding is directly related to the study’s central hypothesis, which posits that misinformation significantly influences the perception and acceptance of vaccines. The presence of a 42% undecided population indicates that public trust is not absolute and that the decision-making process is mediated by the degree of credibility of information sources and the clarity of the scientific message.

Indecision regarding new vaccines reflects the need for:

Strengthened communication by health authorities, with clear and accessible information on safety and efficacy.

Institutional transparency regarding approval processes, clinical trials, and adverse effects.

Educational strategies that reduce uncertainty and strengthen trust in medical science.

Overall, the results reveal a favorable trend toward vaccination, but also a warning about the persistent influence of misinformation, which may affect parents’ future willingness to accept immunological innovations.

DISCUSSION

The Role of Misinformation: Doubt vs. Total Rejection

The results confirm that misinformation is not intended to provoke outright rejection among the majority of the studied population, but rather to sow doubt about vaccination. Although the majority of respondents value vaccination, and 92% of adults have been vaccinated, 42% express a lack of trust or uncertainty about the vaccines available in their country. This finding is consistent with the hesitancy continuum model proposed by Larson et al. [1] in their global systematic review, which defined hesitancy as a state between total acceptance and rejection. Subsequent studies by Dubé et al. [5] reinforced this idea by classifying intervention strategies, concluding that the undecided population—which is not firmly opposed to vaccines—is the segment most susceptible to the influence of the anti-vaccine movement and, therefore, the highest priority for public health. The finding that doubt outweighs total rejection is also consistent with recent studies on hesitancy in Latin America, such as those documented by Barrera-Cruz et al. [14] and Wilson et al. [17]. These studies confirm that, unlike in other regions, the problem in Latin America manifests most frequently as delays in following the vaccination schedule and selective hesitancy rather than outright refusal, which aligns with the high vaccination intent (92%) and the partial non-compliance observed in their sample (41%).

Analysis of the reasons for hesitancy or non-vaccination validates the link to misinformation. The main reasons cited by parents are fear of adverse effects (33%) and distrust of the pharmaceutical industry (29%). These perceptions are the central narratives promoted by anti-vaccine discourse, as described by Kata and other authors [10], who point to the proliferation of conspiracy theories and alarmist messages regarding post-vaccination safety. The persistence of these fears, even in a highly educated sample, suggests that the discourse of misinformation appeals to emotion and institutional distrust, penetrating beyond the level of formal education.

Trust and Communication Channels

A key protective finding is that the physician or pediatrician is the primary source of vaccine information for 72% of participants. This high level of trust in healthcare professionals is an asset that public policies must leverage. However, the coexistence of this finding with a 41% rate of childhood non-compliance and a 42% rate of indecision indicates that the dialogue in the doctor’s office, while crucial, is not robust enough to counteract the misinformation circulating through other channels.

Twenty-four percent of participants use non-specialized sources (the Internet, social media, family/friends), channels that are recognized for their potential to amplify misinformation [6, 9, 15], creating an infodemic that can negatively influence health decisions [13]. This communication gap requires health authorities not only to strengthen health professionals' training to address indecision but also to actively engage in digital spaces to counter anti-vaccine messages, as suggested in the literature.

Implications and Findings of the Study

The main contribution of this study lies in the characterization of conditional hesitancy among Latin American parents: 42% of respondents state that their decision to administer new vaccines to their children “depends on the type of vaccine.” This demonstrates that the battle against the anti-vaccine movement is no longer against monolithic rejection, but against widespread and selective uncertainty. Parents in this group are not anti-vaccine; rather, they need transparency and solid evidence to make decisions, making them a priority segment for risk communication. This finding reinforces the need for targeted, segmented interventions to combat skepticism about specific vaccines, as noted by Viana et al. [16] in the regional context. These authors emphasize that the current challenge in the region is not only a lack of general knowledge but also indecision influenced by contextual factors and perceived risks of specific diseases, leading to delays or selective refusal of certain doses. Therefore, communication strategies must shift from generic messages (“get vaccinated”) to a personalized approach that clearly differentiates between mandatory high-impact vaccines (such as MMR or the basic schedule) and newly introduced vaccines (such as HPV or COVID-19), providing specific risk/benefit information for each.

Methodological Limitations

It is essential to note the limitations inherent in the design. As this is a cross-sectional observational study, the results reflect an association at a given point in time but do not allow for establishing causality (i.e., that misinformation is the direct cause of non-compliance).

The most significant limitation lies in the non-probabilistic, purposive sampling. The sample, obtained through digital platforms, is biased toward individuals with higher levels of education and internet access. Therefore, the results cannot be generalized to the entire population of parents in Latin America, especially those with limited access to technology or lower literacy levels. If mistrust stands at 42% in a highly educated population, this figure could be considerably higher in segments with less access to verified information.

Future Research

The persistence of vaccine hesitancy and partial non-compliance in the region calls for future research. It is necessary to complement this descriptive study with:

Qualitative studies that explore the personal narratives behind the fear of adverse effects and distrust of pharmaceutical companies.

Intervention studies evaluating the effectiveness of digital communication campaigns specifically designed to counter misinformation on the platforms most used by the young population (ages 22–33).

Longitudinal analyses to determine whether sustained exposure to anti-vaccine messages over time predicts a change in vaccination practices

CONCLUSION

The objective of this descriptive study was to evaluate the role of misinformation in parents' vaccination attitudes and practices in Latin America. The results confirm that, although there is a largely favorable attitude toward childhood immunization (92% consider it important or very important), the persistent circulation of misinformation is a determining factor in generating indecision regarding vaccines or conditional doubt among the population.

The findings reveal a significant behavioral contradiction: despite the high regard for vaccines, 41% of parents reported partial or total non-compliance with the official childhood vaccination schedule. This non-compliance is directly related to the fact that 42% of participants expressed doubt or uncertainty about the vaccines offered in their country.

The skepticism centers primarily on the core narratives promoted by anti-vaccine rhetoric, with the main reasons being fear of adverse effects (33%) and distrust of the pharmaceutical industry (29%). This underscores that misinformation successfully operates by appealing to emotions and institutional distrust, even penetrating the study sample, which was characterized by a high level of education (86% with higher education).

A fundamental strength in the fight against misinformation was identified: doctors and pediatricians are the primary sources of information (72%). This trust placed in healthcare professionals must be capitalized on and strengthened, as the doctor’s office is established as the primary space for countering erroneous messages.

In summary, this study concludes that the main challenge for public health in Latin America is not outright rejection but indecision. A strategic approach is needed to bring evidence-based communication to digital spaces—where misinformation circulates—and to train healthcare teams to establish a transparent and empathetic dialogue that robustly addresses the doubts of the undecided population, prioritizing clear information on risks and benefits to restore trust.

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40. 40 Appendix 1
41. 41 Structured survey