Knowing less but presuming more: Dunning-Kruger effects and the endorsement of anti-vaccine policy attitudes

10.1016/j.vaccine.2019.04.063

BackgroundConspiracies about vaccination are prevalent. We assessed how the health information sources people rely upon and their political ideologies are associated with acceptance of vaccine conspiracies.MethodsOnline survey (N = 599) on Amazon’s Mechanical Turk crowdsource platform. Hypotheses were tested via structural equation modeling.ResultsAcceptance of vaccine conspiracy beliefs was associated positively with greater reliance on social media for health information (coef. = 0.42, p < .001), inversely related to use of medical websites (coef. = −0.21, p < .001), and not significantly related to use of providers for health information (coef. = −0.13, p = .061). In addition, liberal political orientation was negatively associated with acceptance of vaccine conspiracies (coef. = −0.29, p < .001).ConclusionsAn understanding of vaccine conspiracy acceptance requires a consideration of people’s health information sources. The greater susceptibility of political conservatives to conspiracy beliefs extends to the topic of vaccination.

Relationship of people’s sources of health information and political ideology with acceptance of conspiratorial beliefs about vaccines

BackgroundAn invisible threat has visibly altered the world. Governments and key institutions have had to implement decisive responses to the danger posed by the coronavirus pandemic. Imposed change will increase the likelihood that alternative explanations take hold. In a proportion of the general population there may be strong scepticism, fear of being misled, and false conspiracy theories. Our objectives were to estimate the prevalence of conspiracy thinking about the pandemic and test associations with reduced adherence to government guidelines.MethodsA non-probability online survey with 2501 adults in England, quota sampled to match the population for age, gender, income, and region.ResultsApproximately 50% of this population showed little evidence of conspiracy thinking, 25% showed a degree of endorsement, 15% showed a consistent pattern of endorsement, and 10% had very high levels of endorsement. Higher levels of coronavirus conspiracy thinking were associated with less adherence to all government guidelines and less willingness to take diagnostic or antibody tests or to be vaccinated. Such ideas were also associated with paranoia, general vaccination conspiracy beliefs, climate change conspiracy belief, a conspiracy mentality, and distrust in institutions and professions. Holding coronavirus conspiracy beliefs was also associated with being more likely to share opinions.ConclusionsIn England there is appreciable endorsement of conspiracy beliefs about coronavirus. Such ideas do not appear confined to the fringes. The conspiracy beliefs connect to other forms of mistrust and are associated with less compliance with government guidelines and greater unwillingness to take up future tests and treatment.

Coronavirus conspiracy beliefs, mistrust, and compliance with government guidelines in England

10.1017/S0033291720001890

Background:In 2018, Facebook introduced Ad Archive as a platform to improve transparency in advertisements related to politics and “issues of national importance.” Vaccine-related Facebook advertising is publicly available for the first time. After measles outbreaks in the US brought renewed attention to the possible role of Facebook advertising in the spread of vaccine-related misinformation, Facebook announced steps to limit vaccine-related misinformation. This study serves as a baseline of advertising before new policies went into effect.Methods:Using the keyword ‘vaccine’, we searched Ad Archive on December 13, 2018 and again on February 22, 2019. We exported data for 505 advertisements. A team of annotators sorted advertisements by content: pro-vaccine, anti-vaccine, not relevant. We also conducted a thematic analysis of major advertising themes. We ran Mann-Whitney U tests to compare ad performance metrics.Results:309 advertisements were included in analysis with 163 (53%) pro-vaccine advertisements and 145 (47%) anti-vaccine advertisements. Despite a similar number of advertisements, the median number of ads per buyer was significantly higher for anti-vaccine ads. First time buyers are less likely to complete disclosure information and risk ad removal. Thematically, anti-vaccine advertising messages are relatively uniform and emphasize vaccine harms (55%). In contrast, pro-vaccine advertisements come from a diverse set of buyers (83 unique) with varied goals including promoting vaccination (49%), vaccine related philanthropy (15%), and vaccine related policy (14%).Conclusions:A small set of anti-vaccine advertisement buyers have leveraged Facebook advertisements to reach targeted audiences. By deeming all vaccine-related content an issue of “national importance,” Facebook has further the politicized vaccines. The implementation of a blanket disclosure policy also limits which ads can successfully run on Facebook. Under current policies, improving transparency and limiting misinformation are not separate goals. Public health communication efforts should consider the impact on Facebook users’ vaccine attitudes and behaviors.

10.1016/j.vaccine.2019.10.066

Vaccine-Related Advertising in the Facebook Ad Archive

10.1503/cmaj.109-3179

Twelve years after publishing a landmark study that turned tens of thousands of parents around the world against the measles, mumps and rubella (MMR) vaccine because of an implied link between vaccinations and autism, The Lancet has retracted the paper.

Lancet retracts 12-year-old article linking autism to MMR vaccines

Since its very inception, the practice of mass vaccination has frequently met with ambivalence and occasionally encountered open resistance. For many health professionals, this opposition was and remains a mystery. How can parents deny their children a preventive treatment of such obvious individual and public benefit?

10.2471/BLT.07.050369

Vaccine anxieties: global science, child health and society

WHO's newly launched platform aims to combat misinformation around COVID-19. John Zarocostas reports from Geneva.WHO is leading the effort to slow the spread of the 2019 coronavirus disease (COVID-19) outbreak. But a global epidemic of misinformation—spreading rapidly through social media platforms and other outlets—poses a serious problem for public health. “We’re not just fighting an epidemic; we’re fighting an infodemic”, said WHO Director-General Tedros Adhanom Ghebreyesus at the Munich Security Conference on Feb 15.

10.1016/S0140-6736(20)30461-X

How to fight an infodemic

In the second part of a special BMJ series, Brian Deer reveals a secret scheme to raise huge sums from a campaign, launched at a London medical school, that claimed links between MMR, autism, and bowel disease

10.1136/bmj.c5258

How the vaccine crisis was meant to make money

10.1136/bmj.d22

This week we begin a special series of articles by the journalist Brian Deer. It focuses on what may seem a familiar story—the scare linking the MMR vaccine with autism, launched at a press conference in 1998 after the Lancet published a paper by Andrew Wakefield and colleagues describing 12 children with brain and bowel disease.

The fraud behind the MMR scare

10.1136/bmj.285.6338.357

A national assessment of the efficacy of pertussis vaccination was made in 21 area health authorities in England. Notification rates for children given either three doses of diphtheria/tetanus/pertussis vaccine or diphtheria/tetanus vaccine were studied during the two and a half-year period January 1978-June 1980. A survey of home circumstances showed that the two vaccine groups could be validly compared. Home visits were made to assess the severity of the illness, the attack rates in home contacts, and to take pernasal swabs. Pertussis vaccination was found to be of outstanding value in preventing serious disease. Nevertheless, its effect in controlling whooping cough is limited by the fact that protection for home contacts is less satisfactory, and by the occurrence of mild cases in vaccinated children which may contribute to the spread of the disease.

Efficacy of pertussis vaccination in England. Report from the PHLS Epidemiological Research Laboratory and 21 area health authorities.

Vaccines do not cause autism.You wouldn't know that if you'd ever used an Amazon Prime account to watch the 2016 documentary "Vaxxed: From Cover-Up to Catastrophe."Following criticism from Rep. Adam Schiff (D-CA), Amazon took down the documentary from its streaming video subscription service on March 1st.

Amazon Has Removed a Misleading Documentary on Vaccines, And It's About Time

Coronavirus disease (COVID-19) advice for the public: Mythbusters

To assess the impact of anti-vaccine movements that targeted pertussis whole-cell vaccines, we compared pertussis incidence in countries where high coverage with diphtheria-tetanus-pertussis vaccines (DTP) was maintained (Hungary, the former East Germany, Poland, and the USA) with countries where immunisation was disrupted by antivaccine movements (Sweden, Japan, UK, The Russian Federation, Ireland, Italy, the former West Germany, and Australia). Pertussis incidence was 10 to 100 times lower in countries where high vaccine coverage was maintained than in countries where immunisation programs were compromised by anti-vaccine movements. Comparisons of neighbouring countries with high and low vaccine coverage further underscore the efficacy of these vaccines. Given the safety and cost-effectiveness of whole-cell pertussis vaccines, our study shows that, far from being obsolete, these vaccines continue to have an important role in global immunisation.

10.1016/S0140-6736(97)04334-1

Impact of anti-vaccine movements on pertussis control: the untold story

THE AMERICAN ANTI-VACCINATIONISTS AND THEIR ARGUMENTS

In 1873—4 Sweden suffered its last smallpox epidemic. The disease broke out in epidemic proportions in Stockholm late in the autumn of 1873. The medical corps in the capital city had long been concerned about what they regarded as the failure of the vaccination programme and warned the authorities about the prospects of an epidemic if the disease, which was raging Europe, reached the city. Stockholm was less well protected than the rest of the country, partially because the vaccination system had broken down there. However, there was also resistance to vaccination in various social classes. While some resistance may have been on religious grounds, some reflected the uncertainty that had arisen about the effectiveness of vaccination when the protection proved to be less than lifelong. Publicists also distributed literature emphasizing the right of individuals to make their own decisions rather than being coerced by society. The liberal social policy of the day was reflected in more restrictive policies that shifted responsibility from the collective to the private spheres. Not until faced by a crisis in the form of an epidemic did the municipal government act.

10.1093/shm/5.3.369

The Right to Die? Anti-vaccination Activity and the 1874 Smallpox Epidemic in Stockholm

10.1017/s0025727300048225

The politics of prevention: anti-vaccinationism and public health in nineteenth-century England.

The British Vaccination Act of 1840 was the first incursion of the state, in the name of public health, into traditional civil liberties. The activities of today's propagandists against immunisations are directly descended from, indeed little changed from, those of the anti-vaccinationists of the late nineteenth century, say Robert Wolfe and Lisa Sharp Much attention has been given on the internet to the “anti-vaccination” movement—using vaccination in its wider sense of “any immunisation”—and its possible harmful effects on uptake rates of immunisations. Many observers believe that the movement is something new and a consequence of concerns arising from the large number of immunisations now given, but concern over vaccination began shortly after the introduction of smallpox vaccination and has continued unabated ever since. Methods of disseminating information have changed since the 19th century, but the concerns and activities of anti-vaccination movements in the United Kingdom and their counterparts in the United States have changed little since then. The historian Martin Kaufman, writing about anti-vaccination movements in 19th and early 20th century America, concluded his paper with this comment, “With the improvements in medical practice and the popular acceptance of the state and federal governments' role in public health, the anti-vaccinationists slowly faded from view, and the movement collapsed.”1 We hope that a brief historical examination of anti-vaccination sentiments will give medical professionals a better sense of perspective about the groups opposing immunisations and their arguments.

10.1136/bmj.325.7361.430

Anti-vaccinationists past and present

In spring 2010, the Institute of Medicine’s Preparedness Forum organized three workshops to discuss and examine the vaccination campaign. The workshops were held in Raleigh, North Carolina (April 15); Austin, Texas (April 27); and Seattle, Washington (May 11). They were organized by a planning committee that included representatives from relevant federal agencies and state and local public health authorities and associations. The workshops were designed to facilitate a series of conversations focused on the following objectives: Examine innovative efforts used to distribute and administer vaccine and discuss how they may inform future efforts; Examine how jurisdictions and providers interpreted and applied the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (CDC/ACIP) recommendations for use of 2009 H1N1 vaccine; Highlight successful approaches used by jurisdictions to develop and use innovative partnerships with traditional and non-traditional partners, such as community groups and the private sector; and Discuss strategies used to collect, monitor, evaluate, and use data during the 2009 H1N1 vaccination campaigns.For each area, participants discussed lessons learned and challenges that arose during the vaccination campaigns and identified strategies to address these challenges for future emergency vaccination programs and other medical countermeasures dispensing campaigns.

The 2009 H1N1 Influenza Vaccination Campaign

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Report on the uptake of seasonal influenza vaccine in frontline health care workers (HCWs) during the 2019 to 2020 influenza vaccination programme in England.

Seasonal flu vaccine uptake in healthcare workers: winter 2019 to 2020

Report on the uptake of influenza vaccine in eligible GP patient groups during the 2019 to 2020 influenza vaccination programme in England.

Seasonal flu vaccine uptake in GP patients: winter 2019 to 2020

A targeted immunisation programme may offer some protection, but it will not deliver ‘life as normal’

If you're pinning your hopes on a Covid vaccine, here's a dose of realism

BackgroundBecause of the risk of complication, pregnant women were a priority target for vaccination during the A (H1N1) pandemic influenza. In Quebec, 63% of pregnant women were vaccinated, which is a higher rate than vaccination against seasonal influenza. However, the behaviour of pregnant women relative to the vaccination during the H1N1 pandemic is unknown. The present study was aimed at identifying factors influencing the decision-making of pregnant women regarding H1N1 vaccination.MethodsA cross-sectional survey was conducted in February 2010 in pregnant women or in early postpartum at the Sherbrooke University Hospital Centre using a self-administered questionnaire based on the Health Belief Model (HBM). Data items collected were: socio-demographic data, vaccination status, information sources consulted, knowledge on vaccination, and the HBM dimensions: effectiveness and risks of vaccination, severity and vulnerability towards the influenza. The associations between questionnaire variables and vaccination status were assessed by univariate and multivariate analysis.ResultsOf the 250 women interviewed, 95% knew that the vaccination was recommended, but only 76% received the vaccine. Variables positively associated with vaccination were late vaccination during pregnancy (OR = 7.3, 95% CI 2.1–25.3), belief in the efficacy of the vaccine (OR = 7, 95% CI 2–23.4), and consultation of the Pandémie-Québec website (OR = 4.5, 95% CI 1.5–13.4). However, the belief that the vaccine had not been adequately tested (OR = 0.08, 95% CI 0.02–0.35) and consultation of mainstream websites (OR = 0.22, 95% CI 0.06–0.81) were associated with lower vaccination rates.ConclusionsThe vast majority of pregnant women were aware of the recommendations relative to A (H1N1) vaccination. Internet media played an important role in their decision to get vaccinated. Better information on the safety of the vaccine must be prepared for future pandemics.

10.1016/j.vaccine.2010.12.109

Determinants of A (H1N1) vaccination: Cross-sectional study in a population of pregnant women in Quebec

The study aimed to determine factors influencing the uptake of 2009 H1N1 influenza vaccine in a multiethnic Asian population. Population-based, cross-sectional survey was conducted between October and December 2009. Approximately 70% of overall participants indicated willingness to be vaccinated against the 2009 H1N1 influenza. Participants who indicated positive intention to vaccinate against 2009 H1N1 influenza were more likely to have favorable attitudes toward the 2009 H1N1 vaccine. A halal (acceptable to Muslims) vaccine was the main factor that determined Malay participants’ decision to accept vaccination, whereas safety of the vaccine was the main factor that influenced vaccination decision for Chinese and Indian participants. The study highlights the challenges in promoting the 2009 H1N1 vaccine. Ethnic-sensitive efforts are needed to maximize acceptance of H1N1 vaccines in countries with diverse ethnic communities and religious practices.

10.1016/j.vaccine.2010.04.043

Factors influencing the uptake of 2009 H1N1 influenza vaccine in a multiethnic Asian populationAuthor links open overlay panel

This article aims at exploring a case of information crisis in Italy through the lens of vaccination-related topics. Such a controversial issue, dividing public opinion and political agendas, has received diverse information coverage and public policies over time in the Italian context, whose situation appears quite unique compared with other countries because of a strong media spectacularization and politicization of the topic. In particular, approval of the “Lorenzin Decree,” increasing the number of mandatory vaccinations from 4 to 10, generated a nationwide debate that divided public opinion and political parties, triggering a complex informative crisis and fostering the perception of a social emergency on social media. This resulted in negative stress on lay publics and on the public health system. The study adopted an interdisciplinary framework, including political science, public relations, and health communication studies, as well as a mixed-method approach, combining data mining techniques related to news media coverage and social media engagement, with in-depth interviews to key experts, selected among researchers, journalists, and communication managers. The article investigates reasons for the information crisis and identifies possible solutions and interventions to improve the effectiveness of public health communication and mitigate the social consequences of misinformation around vaccination.

10.1177/0002764220910245

Blurred Shots: Investigating the Information Crisis Around Vaccination in Italy

10.2105/AJPH.2011.300133

To learn more about racial and ethnic disparities in influenza vaccination during the 2009-H1N1 pandemic, we examined nationally representative survey data of US adults. We found disparities in 2009-H1N1 vaccine uptake between Blacks and Whites (13.8% vs 20.4%); Whites and Hispanics had similar 2009-H1N1 vaccination rates. Physician offices were the dominant location for 2009-H1N1 and seasonal influenza vaccinations, especially among minorities. Our results highlight the need for a better understanding of how communication methods and vaccine distribution strategies affect vaccine uptake within minority communities.

Racial and Ethnic Disparities in Uptake and Location of Vaccination for 2009-H1N1 and Seasonal Influenza

Since Wakefield et al. (1998), the public was exposed to mixed information surrounding the claim that measles–mumps–rubella vaccine causes autism. A persistent trend to delay the vaccination during 1998–2011 in the US was driven by children of college-educated mothers, suggesting that these mothers held biases against the vaccine influenced by the early unfounded claim. Consistent with confirmatory bias, exposures to negative information about the vaccine strengthened their biases more than exposures to positive information attenuated them. Positive online information, however, had strong impacts on vaccination decisions, suggesting that online dissemination of vaccine-safety information may help tackle the sticky misinformation.

10.1016/j.jhealeco.2019.102284

Confirmatory bias in health decisions: Evidence from the MMR-autism controversy

10.1371/journal.pone.0089177

The current studies investigated the potential impact of anti-vaccine conspiracy beliefs, and exposure to anti-vaccine conspiracy theories, on vaccination intentions. In Study 1, British parents completed a questionnaire measuring beliefs in anti-vaccine conspiracy theories and the likelihood that they would have a fictitious child vaccinated. Results revealed a significant negative relationship between anti-vaccine conspiracy beliefs and vaccination intentions. This effect was mediated by the perceived dangers of vaccines, and feelings of powerlessness, disillusionment and mistrust in authorities. In Study 2, participants were exposed to information that either supported or refuted anti-vaccine conspiracy theories, or a control condition. Results revealed that participants who had been exposed to material supporting anti-vaccine conspiracy theories showed less intention to vaccinate than those in the anti-conspiracy condition or controls. This effect was mediated by the same variables as in Study 1. These findings point to the potentially detrimental consequences of anti-vaccine conspiracy theories, and highlight their potential role in shaping health-related behaviors.

The Effects of Anti-Vaccine Conspiracy Theories on Vaccination Intentions

Although social media provides a way for people to congregate with like-minded others, it can also play a role in spreading misinformation about public health interventions. Previous research demonstrates that parents who use the Internet to gather information on vaccination are more likely to hold anti-vaccination beliefs. There has been little examination of vaccination decision-making discussions on parenting blogs. This study seeks to fill that gap. Posts and comments on the top 25 top parenting blogs were analyzed using a mixed-method approach. Comments were analyzed using deductive coding scheme that examined whether content areas of interest were present or absent in vaccination discussions. Posts were coded inductively using a thematic analysis. Posts and comments were further coded as strongly vaccine-discouraging, vaccine-ambivalent, or strongly vaccine-encouraging. Finally, posts were grouped by year of publication and comments were analyzed within each group to examine the evolution of vaccination decision-making discussions in the parenting blogosphere over the past decade. Fifty-two percent of posts were categorized as strongly vaccine-discouraging and were most commonly associated with expressions of individual liberty. Comments were nearly 3 times as likely to strongly discourage vaccination than to strongly encourage it. Comments on the oldest posts (2006–2009), were more likely to strongly discourage vaccination (p = 0.008), whereas comments on newer posts (2013–2015), were more likely to strongly encourage vaccination (p = 0.003). These findings suggest there is a need for public health professionals to understand the concerns being expressed in these forums, and develop innovative ways to dispel anti-vaccination myths, as these views may create obstacles in the meeting the goals of the public health agenda.

10.1080/21645515.2017.1321182

“To each his own”: Discussions of vaccine decision-making in top parenting blogs

A questionnaire survey on the attitude of healthcare workers towards pandemic influenza vaccination showed low acceptance (17%) of the pandemic vaccine. Factors associated with vaccine uptake were acceptance of seasonal influenza vaccination, medical profession and age. The main reason for refusal of vaccination was fear of side effects, which was stronger in those who received information on the safety of the vaccine mainly from mass media.

Low acceptance of vaccination against the 2009 pandemic influenza A(H1N1) among healthcare workers in Greece

During the H1N1 pandemic in 2009–10, the vaccination behavior of parents played a critical role in preventing and containing the spread of the disease and the subsequent health outcomes among children. Several studies have examined the relationship between parents’ health communication behaviors and vaccinations for children in general. Little is known, however, about the link between parents’ health communication behaviors and the vaccination of their children against the H1N1 virus, and their level of vaccine-related knowledge. We drew on a national survey among parents with at least one child less than 18 years of age (n = 639) to investigate Parents’ H1N1-related health communication behaviors including sources of information, media exposure, information-seeking behaviors, H1N1-related knowledge, and neighborhood social capital, as well as the H1N1 vaccination rates of their children. Findings showed that there is a significant association between the degree at which parents obtained H1N1 vaccination for their children and health communication variables: watching the national television news and actively seeking H1N1 information. And this association was moderated by the extent of the parents’ H1N1-related knowledge. In addition, the parents’ degree of neighborhood social capital mediated the association between H1N1 knowledge of the parents and H1N1 vaccination acceptance for their children. We found, compared to those with a low-level of neighborhood social capital, parents who have a high-level of neighborhood social capital are more likely to vaccinate their children. These findings suggest that it is necessary to design a strategic health communication campaign segmented by parent health communication behaviors.

10.1016/j.vaccine.2013.07.068

Associations between health communication behaviors, neighborhood social capital, vaccine knowledge, and parents’ H1N1 vaccination of their children

10.1056/NEJMp2021971

here are sufficient data demonstrating that coexisting conditions in patients with Covid-19 influence clinical outcomes and that older age and male sex are associated with a greater risk of death. But despite disproportionately higher rates of Covid-19 infection, hospitalization, and death in racial and ethnic minority groups, the direct effects of genetic or biologic host factors remain unknown.1

Racial Disproportionality in Covid Clinical Trials

Objective To evaluate the risk of narcolepsy in children and adolescents in England targeted for vaccination with ASO3 adjuvanted pandemic A/H1N1 2009 vaccine (Pandemrix) from October 2009.Design Retrospective analysis. Clinical information and results of sleep tests were extracted from hospital notes between August 2011 and February 2012 and reviewed by an expert panel to confirm the diagnosis. Vaccination and clinical histories were obtained from general practitioners.Setting Sleep centres and paediatric neurology centres in England.Participants Children and young people aged 4-18 with onset of narcolepsy from January 2008.Main outcome measures The odds of vaccination in those with narcolepsy compared with the age matched English population after adjustment for clinical conditions that were indications for vaccination. The incidence of narcolepsy within six months of vaccination compared with the incidence outside this period measured with the self controlled cases series method.Results Case notes for 245 children and young people were reviewed; 75 had narcolepsy (56 with cataplexy) and onset after 1 January 2008. Eleven had been vaccinated before onset; seven within six months. In those with a diagnosis by July 2011 the odds ratio was 14.4 (95% confidence interval 4.3 to 48.5) for vaccination at any time before onset and 16.2 (3.1 to 84.5) for vaccination within six months before onset. The relative incidence from the self controlled cases series analysis in those with a diagnosis by July 2011 with onset from October 2008 to December 2010 was 9.9 (2.1 to 47.9). The attributable risk was estimated as between 1 in 57 500 and 1 in 52 000 doses.Conclusion The increased risk of narcolepsy after vaccination with ASO3 adjuvanted pandemic A/H1N1 2009 vaccine indicates a causal association, consistent with findings from Finland. Because of variable delay in diagnosis, however, the risk might be overestimated by more rapid referral of vaccinated children.

10.1136/bmj.f794

Risk of narcolepsy in children and young people receiving AS03 adjuvanted pandemic A/H1N1 2009 influenza vaccine: retrospective analysis

Because the novel influenza A (H1N1) virus [2009 influenza A (H1N1)] was identified in April 2009, two separate influenza vaccines were distributed in the United States in 2009–10 season: a seasonal vaccine and an influenza A (H1N1) 2009 monovalent vaccine (2009 H1N1 vaccine) [1, 2]. To estimate national and state level influenza vaccination coverage from August 2009 through May 2010, CDC used combined data from the Behavioral Risk Factor Surveillance System (BRFSS) and the National 2009 H1N1 Flu Survey (NHFS). This report describes national findings from these surveys and updates previously published interim 2009–10 seasonal [3] and 2009 H1N1 [4] influenza vaccination coverage estimates. The interim estimates were based on vaccinations reported through the end of January 2010 using interviews conducted through February 2010. The final estimates in this report include vaccinations reported through May 2010 based on interviews through June 2010.

Final estimates for 2009–10 Seasonal Influenza and Influenza A (H1N1) 2009 Monovalent Vaccination Coverage – United States, August 2009 through May, 2010.