Anti-vaccine Sentiment Research Articles

Analysis of the Engagement with COVID-19 Vaccination-Related Posts in Sri Lankan Health-Oriented Social Media: A Social Listening Approach

With the introduction of the COVID-19 vaccination, there was a rise in anti-vaccine narratives leading to vaccine hesitancy. Social media platforms like Facebook have introduced policies to control the spread of these narratives. However, the comments section is frequently ignored. A preliminary anti-vaccination codebook was created using criteria identified in international literature and completed using the comments on the Health Promotion Bureau (HPB)’s Facebook page, which is the centre for health education and publicity of health information in Sri Lanka. Next, the most commented vaccine-related posts for each quarter were extracted from the HPB Facebook page and the comments were coded according to the finalised codebook and were analysed. The finalised codebook contained a total of 24 codes that were organised into six primary categories. A total of 7,316 comments were extracted. The comments that were against vaccination constituted 47.3% of all vaccine-related comments. The most commonly occurring code was ‘health hazards’. It was evident that the number of comments against vaccination has increased with time. This may indicate that anti-vaccination movements are becoming more prevalent in. It is essential to engage in extensive social listening in order to forestall the propagation of anti-vaccine sentiments and conspiracy theories.

Examining the Prevailing Negative Sentiments Surrounding Measles Vaccination: Unsupervised Deep Learning of Twitter Posts from 2017 to 2022.

Despite the proven safety and clinical efficacy of the Measles vaccine, many countries are seeing new heights of vaccine hesitancy or refusal, and are experiencing a resurgence of measles infections as a consequence. With the use of novel machine learning tools, we investigated the prevailing negative sentiments related to Measles vaccination through an analysis of public Twitter posts over a 5-year period. We extracted original tweets using the search terms related to "measles" and "vaccine," and posted in English from January 1, 2017, to December 15, 2022. Of these, 155,363 tweets were identified to be negative sentiment tweets from unique individuals, through the use of Bidirectional Encoder Representations from Transformers (BERT) Named Entity Recognition and SieBERT, a pretrained sentiment in English analysis model. This was followed by topic modeling and qualitative thematic analysis performed inductively by the study investigators. A total of 11 topics were generated after applying BERTopic. To facilitate a global discussion of results, the topics were grouped into four different themes through iterative thematic analysis. These include (a) the rejection of "anti-vaxxers" or antivaccine sentiments, (b) misbeliefs and misinformation regarding Measles vaccination, (c) negative transference due to COVID-19 related policies, and (d) public reactions to contemporary Measles outbreaks. Theme 1 highlights that the current public discourse may further alienate those who are vaccine hesitant because of the disparaging language often used, while Themes 2 and 3 highlight the typology of misperceptions and misinformation underlying the negative sentiments related to Measles vaccination and the psychological tendency of disconfirmation bias. Nonetheless, the analysis was based solely on Twitter and only tweets in English were included; hence, the findings may not necessarily generalize to non-Western communities. It is important to further understand the thinking and feeling of those who are vaccine hesitant to address the issues at hand.

Detecting Anti-vaccine Users on Twitter

Vaccine hesitancy, which has recently been driven by online narratives, significantly degrades the efficacy of vaccination strategies, such as those for COVID-19. Despite broad agreement in the medical community about the safety and efficacy of available vaccines, a large number of social media users continue to be inundated with false information about vaccines and are indecisive or unwilling to be vaccinated. The goal of this study is to better understand anti-vaccine sentiment by developing a system capable of automatically identifying the users responsible for spreading anti-vaccine narratives. We introduce a publicly available Python package capable of analyzing Twitter profiles to assess how likely that profile is to share anti-vaccine sentiment in the future. The software package is built using text embedding methods, neural networks, and automated dataset generation and is trained on several million tweets. We find this model can accurately detect anti-vaccine users up to a year before they tweet anti-vaccine hashtags or keywords. We also show examples of how text analysis helps us understand anti-vaccine discussions by detecting moral and emotional differences between anti-vaccine spreaders on Twitter and regular users. Our results will help researchers and policy-makers understand how users become anti-vaccine and what they discuss on Twitter. Policy-makers can utilize this information for better targeted campaigns that debunk harmful anti-vaccination myths.

Knowledge and attitudes about vaccinations among medical students during the COVID-19 pandemic

In Hungary, regarding the age-related mandatory vaccinations, the population is almost 100% vaccinated. In the case of recommended vaccinations, however, the situation is less favourable, and during the COVID-19 pandemic, anti-vaccination sentiment has also appeared in some groups to a greater extent than before. Reducing this is the task of all health professionals. The exploration of knowledge and attitudes about vaccinations, and the analysis of the characteristics of these factors according to gender, year and vaccine willingness/hesitancy among medical students at the University of Szeged. The cross-sectional study was conducted among first and fourth year medical students of the University, using an online questionnaire, which examined, in addition to sociodemographic characteristics, the administration of influenza and COVID-19 vaccinations, the self-assessment of knowledge about vaccinations, the importance of vaccinations, and student opinions about recommended vaccinations. Based on the definition of the WHO Strategic Advisory Group, 88.6% of the students belonged to the "vaccine willingness" group, who administered the vaccine against COVID-19 as soon as it became available, while the "vaccine hesitancy" group (11.4%) only asked for the vaccine when vaccination was made mandatory or not even then. According to the model adjusted to gender and year, those who showed willingness to vaccinate were more likely to consider the use of vaccinations, counselling, etc. important than those who were hesitant, while there was no correlation with the self-rating of knowledge. On the basis of the odds ratio of the statements related to the recommended vaccinations, it was possible to identify the opinions associated with vaccine willingness or hesitancy. Overall, student knowledge and attitudes showed a positive picture. On the other hand, it should be emphasized that the misconceptions identified among students showing vaccine hesitancy are the same as the anti-vaccination sentiments found among the general population. During university training, more emphasis should be placed on monitoring the willingness of students to be vaccinated, and on developing knowledge and communication. Orv Hetil. 2023; 164(21): 803-810.

COVID-19 Anti-Vaccine Sentiments in Malaysia: Narratives of Comments from Facebook Post.

The anti-vaccination movement was an ongoing issue in Malaysia, a Muslim-majority country, even before the COVID-19 pandemic. It is unclear whether the introduction of new COVID-19 vaccines would similarly provoke anti-vaccine sentiments. This study analyzed COVID-19 anti-vaccine sentiments in the Malaysian community. Anti-vaccine comments from Facebook page posts were extracted. The qualitative software QSR-NVivo 10 was used to manage, code and analyze the data. The fast-track COVID-19 vaccine evoked the fear of unknown long-term effects, safety, effectiveness and the duration of protection. The halal status of the COVID-19 vaccines is important. Although it is permissible to use vaccines that are not certified halal under the state of darurah (emergency), there was doubt that the current state has reached the stage of darurah that warrants the use of vaccines. COVID-19 vaccine microchip conspiracy theories were raised. COVID-19 is viewed as only severe for vulnerable populations, and hence vaccination is not needed for the healthy. There were opinions that coronavirus treatments would be more beneficial than vaccination. The anti-COVID-19 vaccine sentiments uncovered in this study provide important insights for the formulation of public health messages to instill confidence in new COVID-19 vaccines. Despite the pandemic being nearly over and many people worldwide having received COVID-19 vaccines, the findings provide important insight into potential issues regarding the introduction of new vaccines in the event of future pandemics.

Malaysian Newspapers’ Coverage of Anti-vaxxers: Implication on Vaccine Intakes

Introduction: The World Health Organization (WHO) named anti-vaxxers as one of the top ten public health hazards in 2019. Anti-vaxxers are a health danger since they are mostly responsible for the re-emergence of deadly contagious diseases such as measles, which has increased in recent years. The media such as newspapers, are responsible for disseminating messages and public knowledge about health issues, particularly health hazards. To particularly combat anti-vaccine views online, newspaper must provide critical information, such as scientific and verifiable facts. Newspapers need to also take a clear stand against anti-vaccine sentiments. Method: A quantitative content analysis was conducted on four newspapers (Harian Metro, Berita Harian, New Straits Times, and The Star) over a three-year period beginning 1 January 2019 and ending 30 September 2021. The 43-month period offered adequate data for analysing reporting trends. Result: The findings suggested that newspapers do significantly report about the antivaxxers with 247 news were focused on them. Conclusion: However, the newspapers tend to only publish generic information about the antivaxxers and rarely make compelling arguments against them.

Public Figure Vaccination Rhetoric and Vaccine Hesitancy: Retrospective Twitter Analysis.

Social media has emerged as a critical mass communication tool, with both health information and misinformation now spread widely on the web. Prior to the COVID-19 pandemic, some public figures promulgated anti-vaccine attitudes, which spread widely on social media platforms. Although anti-vaccine sentiment has pervaded social media throughout the COVID-19 pandemic, it is unclear to what extent interest in public figures is generating anti-vaccine discourse. We examined Twitter messages that included anti-vaccination hashtags and mentions of public figures to assess the connection between interest in these individuals and the possible spread of anti-vaccine messages. We used a data set of COVID-19-related Twitter posts collected from the public streaming application programming interface from March to October 2020 and filtered it for anti-vaccination hashtags "antivaxxing," "antivaxx," "antivaxxers," "antivax," "anti-vaxxer," "discredit," "undermine," "confidence," and "immune." Next, we applied the Biterm Topic model (BTM) to output topic clusters associated with the entire corpus. Topic clusters were manually screened by examining the top 10 posts most highly correlated in each of the 20 clusters, from which we identified 5 clusters most relevant to public figures and vaccination attitudes. We extracted all messages from these clusters and conducted inductive content analysis to characterize the discourse. Our keyword search yielded 118,971 Twitter posts after duplicates were removed, and subsequently, we applied BTM to parse these data into 20 clusters. After removing retweets, we manually screened the top 10 tweets associated with each cluster (200 messages) to identify clusters associated with public figures. Extraction of these clusters yielded 768 posts for inductive analysis. Most messages were either pro-vaccination (n=329, 43%) or neutral about vaccination (n=425, 55%), with only 2% (14/768) including anti-vaccination messages. Three main themes emerged: (1) anti-vaccination accusation, in which the message accused the public figure of holding anti-vaccination beliefs; (2) using "anti-vax" as an epithet; and (3) stating or implying the negative public health impact of anti-vaccination discourse. Most discussions surrounding public figures in common hashtags labelled as "anti-vax" did not reflect anti-vaccination beliefs. We observed that public figures with known anti-vaccination beliefs face scorn and ridicule on Twitter. Accusing public figures of anti-vaccination attitudes is a means of insulting and discrediting the public figure rather than discrediting vaccines. The majority of posts in our sample condemned public figures expressing anti-vax beliefs by undermining their influence, insulting them, or expressing concerns over public health ramifications. This points to a complex information ecosystem, where anti-vax sentiment may not reside in common anti-vax-related keywords or hashtags, necessitating further assessment of the influence that public figures have on this discourse.

Vaccine Decision-making in a Time of Conflicting Recommendations: A Call to Go Beyond Politics.

Vaccine Decision-making in a Time of Conflicting Recommendations: A Call to Go Beyond Politics.

Identifying Host Cell Gene Expression Modulation as Potential Markers for SARS-CoV2 Infection

Background The SARSCoV2 emergence in 2019 has caused health, safety, and socioeconomic issues around the world. Current testing prioritizes viral RNA detection, requiring specialized techniques, training, and time periods, resulting in significant testing limitations. Viral infection can cause changes in host cell gene expression, which vary from virus to virus. Recent research suggests SARSCoV2-induced gene expression modulations in infected human cells may be differentiated from expressions elicited by other acute respiratory illnesses. Data in this study highlight specific genes that are differentially expressed during SARSCoV2 infection. This novel application of individual sample analysis in connection with global databases, provides robust data for genes that are specifically modulated during SARSCoV2 infection. This expression profile would be valuable for SARSCoV2 testing, prevention, treatment, and basic virology research. Methods Previously collected COVID-19 surveillance-testing samples from cadets at the United States Air Force Academy were used to quantify the expression of 19 target genes using direct primer-mediated qRTPCR. Additionally, samples were analyzed with RNA-seq to assess the different transcriptomes between uninfected and SARSCoV2-infected samples. Results were compared with national databases to confirm agreement with the results. Results 19 genes were identified to be altered during SARSCoV2 infection using in-lab experimental results. This expression profile matches previous research and may uniquely describe SARSCoV2 infection. The genes expected to be upregulated according to previous research, IL1B, IFI44L, ACE2 & DUX3, were all upregulated. RNA-seq data confirms these results and identified 122 other genes that are significantly different between uninfected and SARSCoV2 infected samples. The results have a 93% agreement rate with national databases. Conclusion Despite the availability of vaccines for SARSCoV2, the continual mutation and evolution of the virus, the emergence of novel and increasingly infectious strains, and the anti-vaccine sentiment increase the need for safe and rapid testing alternative options. The expression profile of altered host genes during SARSCoV2 infection could be extremely advantageous to detect and prevent infection, as well as further research efforts for treatment and understanding SARSCoV2 infection.

Choosing COVID-19 treatment over prevention through vaccination: A U.S. social media case study

Background: This study examined anti-vaccination social media posts that favored COVID-19 treatment (monoclonal antibodies (mAbs)) rather than prevention through vaccination, both of which were under Emergency Use Authorization rather than full approval from the U.S. Food and Drug Administration at the time of this study. Our research stemmed from participation in a U.S. public health education campaign led by a coalition of government agencies to expand provider and health system use of mAbs with high-risk COVID-19 positive patients. Aim: Inform real world communication strategies for treatment over prevention therapies. Methods: We analyzed the most-engaged tweets that mentioned mAbs and vaccines from March 1 to August 31, 2021. Results: Our qualitative analysis identified the following themes: distrust in science, individualism, and politically oriented or partisan sentiment. Discussion: Countering anti-vaccine messages and reducing the susceptibility of vaccine-hesitant individuals to these messages must involve message design that considers the individualism and distrust revealed in this study. We recommend two approaches: (1) unmasking anti-vaccine messaging techniques; (2) using colloquial and values-driven language. Conclusions: Our findings reinforce the need for public health practitioners to monitor public and social media discourse, adopt messaging that navigates anti-vaccine sentiment, and engage with the preference for treatment over prevention.

Lessons From a House on Fire-From Smallpox to Polio.

Global burden of disease morbidity and mortality has shifted dramatically in the last 30 years from infectious to non-communicable diseases, leading to major improvements in global child survival and enhanced life expectancy for all age groups. Vaccination efforts worldwide have been key to this achievement, but with a reduction in vaccine preventable diseases, anti-vaccine sentiments have concurrently increased. Eradication of smallpox in 1977 is a testament to vaccination impacts on human health. Despite this historic success, recent increases in infectious disease outbreaks, such as polio and measles, especially among poorly vaccinated populations, have underscored the risks of resurgence of diseases once thought eliminated in the United States and elsewhere. Engaging governments, community leaders, and the public will be critical to continuing the advancement of global health through elimination of vaccine preventable diseases.

Association between acceptance of routine pregnancy vaccinations and COVID-19 vaccine uptake

COVID-19 vaccination is a key approach to reduce morbidity and mortality in pregnant patients and their newborns. Anti-vaccine sentiment has recently increased, with unclear impact on pregnant patients. We examined the association between acceptance of Tdap and influenza (flu) vaccines, considered to be routine pregnancy vaccines, and COVID-19 vaccine acceptance. A retrospective cohort study of all patients who delivered at a single site from December 2020 - March 2022. Demographic, pregnancy, neonatal, and vaccination data were abstracted from the electronic medical record, which imports vaccine history from the California Immunization Registry. COVID-19 vaccine acceptance was defined by receiving at least 1 vaccine dose. The relationship between flu and Tdap vaccine acceptance, baseline characteristics, and COVID-19 vaccine uptake was described by univariable analysis. We identified independent predictors of vaccine uptake with multivariable logistic regression. Of the 8,070 patients, 4,483 (55.5%) accepted the COVID-19 vaccine. Of those who received the COVID-19 vaccine, 3,432 (76.6%) and 3,109 (69.4%) received flu and Tdap vaccines. Patients were more likely to receive the COVID-19 vaccine if they had received the flu vaccine (OR 3.8, 95% CI 3.5 - 4.2) and if they had received the Tdap vaccine (OR 2.9, 95% CI 2.7 - 3.2). Tdap vaccine acceptance, flu vaccine acceptance, advanced maternal age, obesity, Asian race, and private insurance were independent predictors of vaccine uptake after adjusting for potential confounders (Figure). There were no differences in preterm birth, low birthweight and NICU admission between patients who received and did not receive the COVID-19 vaccine (Table). Patients were more likely to accept COVID-19 vaccination if they received Tdap or flu vaccinations. Older age and obesity, known risk factors for severe COVID-19 infections, were independent predictors of vaccine uptake. Disparities in COVID-19 vaccination uptake bear further exploration to guide efforts in equitable and widespread vaccine distribution.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

COVID vaccine stigma: detecting stigma across social media platforms with computational model based on deep learning

The study presents the first computational model of COVID vaccine stigma that can identify stigmatised sentiment with a high level of accuracy and generalises well across a number of social media platforms. The aim of the study is to understand the lexical features that are prevalent in COVID vaccine discourse and disputes between anti-vaccine and pro-vaccine groups. This should provide better insight for healthcare authorities, enabling them to better navigate those discussions. The study collected posts and their comments related to COVID vaccine sentiment in English, from Reddit, Twitter, and YouTube, for the period from April 2020 to March 2021. The labels used in the model, “stigma”, “not stigma”, and “undefined”, were collected from a smaller Facebook (Meta) dataset and successfully propagated into a larger dataset from Reddit, Twitter, and YouTube. The success of the propagation task and consequent classification is a result of state-of-the-art annotation scheme and annotated dataset. Deep learning and pre-trained word vector embedding significantly outperformed traditional algorithms, according to two-tailed P(T≤t) test and achieved F1 score of 0.794 on the classification task with three classes. Stigmatised text in COVID anti-vaccine discourse is characterised by high levels of subjectivity, negative sentiment, anxiety, anger, risk, and healthcare references. After the first half of 2020, anti-vaccination stigma sentiment appears often in comments to posts attempting to disprove COVID vaccine conspiracy theories. This is inconsonant with previous research findings, where anti-vaccine people stayed primarily within their own in-group discussions. This shift in the behaviour of the anti-vaccine movement from affirming climates to ones with opposing opinions will be discussed and elaborated further in the study.

When They "Come From Away" Every Day.

When They "Come From Away" Every Day.

A comparative analysis of anti-vax discourse on twitter before and after COVID-19 onset.

This study aimed to identify and assess the prevalence of vaccine-hesitancy-related topics on Twitter in the periods before and after the Coronavirus Disease 2019 (COVID-19) outbreak. Using a search query, 272,780 tweets associated with anti-vaccine topics and posted between 1 January 2011, and 15 January 2021, were collected. The tweets were classified into a list of 11 topics and analyzed for trends during the periods before and after the onset of COVID-19. Since the beginning of COVID-19, the percentage of anti-vaccine tweets has increased for two topics, "government and politics" and "conspiracy theories," and decreased for "developmental disabilities." Compared to tweets regarding flu and measles, mumps, and rubella vaccines, those concerning COVID-19 vaccines showed larger percentages for the topics of conspiracy theories and alternative treatments, and a lower percentage for developmental disabilities. The results support existing anti-vaccine literature and the assertion that anti-vaccine sentiments are an important public-health issue.

Canine and feline core vaccinations: US veterinarians' concerns and perceived impact of COVID-19 antivaccination views on veterinary medicine.

Assess US veterinarians' perceptions regarding vaccine concerns (their own and owners') and the association between owners' vaccine concerns and COVID-19 antivaccination sentiments. Members of the Veterinary Information Network. An electronic survey distributed via the Veterinary Information Network data collection portal. 1,341 US veterinarians completed the survey. Top veterinarian concerns for vaccinating a healthy adult dog were anaphylaxis, soreness at injection site, and lethargy; for cats, these concerns included vaccine-associated sarcoma, lethargy, and soreness at injection site. Veterinarians reported that the most common concerns mentioned by owners included that the pet does not go outside, that vaccinations are unnecessary, that vaccinations can lead to chronic or severe illness, and cost. Veterinarians reported an increased number of dog and cat owners reluctant about or resistant to the idea of rabies vaccines and core vaccines since the time that COVID-19 vaccines became widely available. There was an association between veterinarians' perceptions of local COVID-19 antivaccination sentiments and the increase in the number of vaccine-resistant or -concerned clients. There appears to be little overlap between veterinarians' primary concerns related to vaccinations and their perception of dog and cat owners' primary concerns. The fact that the number of resistant clients is positively associated with the presence of veterinarians' perceptions of a local COVID-19 antivaccination sentiment suggests that human antivaccination sentiments impact pet owners' views of companion animal vaccinations. A better understanding of the cognitive biases that impact owners' vaccine decisions can help veterinarians better communicate with vaccine-reluctant clients and increase vaccination compliance rates.

Covid 19 vaccines and the misinterpretation of perceived side effects clarity on the safety of vaccines.

In the era of Covid 19 and mass vaccination programs, the anti-vaccination movement across the world is currently at an all-time high. Much of this anti-vaccination sentiment could be attributed to the alleged side effects that are perpetuated across social media from anti-vaccination groups. Fear mongering and misinformation being peddled by people with no scientific training to terrorise people into staying unvaccinated is not just causing people to remain susceptible to viral outbreaks, but could also be causing more side effects seen in the vaccination process. This brief review will offer data that may demonstrate that misinformation perpetuated by the anti-vaccination movement may be causing more deaths and side effects from any vaccine. A mini review of published literature has been conducted and found that mental stress clearly causes vasoconstriction and arterial constriction of the blood vessels. Therefore, if subjects are panicked, concerned, stressed or scared of the vaccination, their arteries will constrict and become smaller in and around the time of receiving the vaccine. This biological mechanism (the constriction of veins, arteries and vessels under mental stress) is the most likely cause for where there has been blood clots, strokes, heart attacks, dizziness, fainting, blurred vision, loss of smell and taste that may have been experienced shortly after vaccine administration. The extreme mental stress of the patient could most likely be attributed to the fear mongering and scare tactics used by various anti-vaccination groups. This paper does not aim to rule in or out every side effect seen, but it is highly likely that many apparent side effects seen shortly after a subject has received a vaccine could be the result of restricted or congested blood flow from blood vessel or arterial constriction caused by emotional distress or placebo based on fear around vaccines.

Awareness of Vaccination against Respiratory Tract Diseases, Including Pneumonia, Influenza, and COVID-19 in Patients with Diabetes Mellitus

Patients with diabetes have an increased risk of severe acute respiratory infections, and vaccination is their life-saving option. This study aimed to investigate the interest and knowledge of patients about influenza, pneumonia, and COVID-19(coronavirus disease 2019) vaccines. Materials. We handed out a questionnaire to patients with diabetes who were admitted to the endocrinology clinic between April and August 2021. The questionnaire collected information on demographic data, knowledge about respiratory tract disease vaccines, and hesitancy about vaccines. Results. Four hundred twenty-four patients (female = 256, male = 168) enrolled in the study. In this study, 148 (34.9%) participants were vaccinated against pneumonia, 155 (36.6%) against flu, and 312 (73.6%) against COVID-19. In addition, antivaccination sentiment was recorded in 8.7% of patients with diabetes. We found that participants in the study primarily rely on doctors as the source of information about vaccines (doctor (46.7%), nurse (1.2%), television (8.7%), friend/neighbour (8.7%), and others (2.6%)). The rate of vaccination was statistically higher than the presence of comorbid diseases. Conclusions. We examined the vaccine awareness of patients with diabetes and investigated factors affecting it. İt was determined that vaccination awareness is affected by many factors, especially comorbid diseases and educational status. The study showed that patients primarily relied on doctors as their source of information for vaccination. Doctor-centered vaccination promotion programmes can increase the rate of vaccination.

In ongoing efforts to vaccinate communities against COVID-19, pharmacists must address fear and misinformation

In ongoing efforts to vaccinate communities against COVID-19, pharmacists must address fear and misinformation

The Role of Influential Actors in Fostering the Polarized COVID-19 Vaccine Discourse on Twitter: Mixed Methods of Machine Learning and Inductive Coding.

BackgroundSince COVID-19 vaccines became broadly available to the adult population, sharp divergences in uptake have emerged along partisan lines. Researchers have indicated a polarized social media presence contributing to the spread of mis- or disinformation as being responsible for these growing partisan gaps in uptake.ObjectiveThe major aim of this study was to investigate the role of influential actors in the context of the community structures and discourse related to COVID-19 vaccine conversations on Twitter that emerged prior to the vaccine rollout to the general population and discuss implications for vaccine promotion and policy.MethodsWe collected tweets on COVID-19 between July 1, 2020, and July 31, 2020, a time when attitudes toward the vaccines were forming but before the vaccines were widely available to the public. Using network analysis, we identified different naturally emerging Twitter communities based on their internal information sharing. A PageRank algorithm was used to quantitively measure the level of “influentialness” of Twitter accounts and identifying the “influencers,” followed by coding them into different actor categories. Inductive coding was conducted to describe discourses shared in each of the 7 communities.ResultsTwitter vaccine conversations were highly polarized, with different actors occupying separate “clusters.” The antivaccine cluster was the most densely connected group. Among the 100 most influential actors, medical experts were outnumbered both by partisan actors and by activist vaccine skeptics or conspiracy theorists. Scientists and medical actors were largely absent from the conservative network, and antivaccine sentiment was especially salient among actors on the political right. Conversations related to COVID-19 vaccines were highly polarized along partisan lines, with “trust” in vaccines being manipulated to the political advantage of partisan actors.ConclusionsThese findings are informative for designing improved vaccine information communication strategies to be delivered on social media especially by incorporating influential actors. Although polarization and echo chamber effect are not new in political conversations in social media, it was concerning to observe these in health conversations on COVID-19 vaccines during the vaccine development process.