Vaccine-preventable outbreaks: still with us after all these years

Perceived Effects of COVID-19 on Vaccine Hesitancy and Clinician Discussion: A Qualitative Study

BACKGROUND AND OBJECTIVES

Studies note a high prevalence of pediatric coronavirus disease 2019 (COVID-19)-specific vaccine hesitancy in the United States. Our objective was to assess whether clinicians perceive a spillover effect of COVID-19 vaccine hesitancy onto other vaccines, and the impact of this spillover on their general recommendation behavior.

METHODS

We conducted semistructured interviews with pediatricians in California and Colorado pediatric practices (January-March 2023). We transcribed, coded, and analyzed interviews using content analysis.

RESULTS

We interviewed 21 pediatricians (10 in California, 11 in Colorado). Clinicians observed some spillover effect of vaccine-favorable changes among some parents and greater hesitancy among others regarding the risks and benefits of childhood vaccination in general. This spillover was informed by 2 divergent patterns of parental trust in health systems and individual clinicians caused by the COVID-19 pandemic. Factors driving perceived changes included media coverage, greater knowledge about vaccination, and misinformation. Some clinicians felt that their approach to vaccine recommendations became more patient-centered, whereas others reported declining engagement in persuading hesitant parents about vaccination.

CONCLUSIONS

Clinicians described a hardening of parental views toward vaccines in both directions, which impacted their recommendation behavior. There is a need for vaccine hesitancy monitoring and better training and support for clinicians facing vaccine hesitant parents.

From Cotton Mather to Dr Fauci: Historical Markers of Vaccine Hesitancy

Vaccine hesitancy became an important topic in the public discourse and academic research during the COVID-19 pandemic, but its history is as long as the history of immunization. One can find the same determinants of vaccine hesitancy, though in variable proportions, since the 1721 Boston smallpox epidemic. We aim to describe several historical immunization moments and analyze them using the vaccine hesitancy framework of the "5Cs" (ie, confidence, complacency, constraints, risk calculation, and collective responsibility).

From Cotton Mather to Dr Fauci: Historical Markers of Vaccine Hesitancy

Vaccine hesitancy became an important topic in the public discourse and academic research during the COVID-19 pandemic, but its history is as long as the history of immunization. One can find the same determinants of vaccine hesitancy, though in variable proportions, since the 1721 Boston smallpox epidemic. We aim to describe several historical immunization moments and analyze them using the vaccine hesitancy framework of the "5Cs" (ie, confidence, complacency, constraints, risk calculation, and collective responsibility).

MA, Tovar-Rosero YY, Oñate AA, O'Ryan M. Two centuries of vaccination: historical and conceptual approach and future perspectives

Over the past two centuries, vaccines have been critical for the prevention of infectious diseases and are considered milestones in the medical and public health history. The World Health Organization estimates that vaccination currently prevents approximately 3.5-5 million deaths annually, attributed to diseases such as diphtheria, tetanus, pertussis, influenza, and measles. Vaccination has been instrumental in eradicating important pathogens, including the smallpox virus and wild poliovirus types 2 and 3. This narrative review offers a detailed journey through the history and advancements in vaccinology, tailored for healthcare workers. It traces pivotal milestones, beginning with the variolation practices in the early 17th century, the development of the first smallpox vaccine, and the continuous evolution and innovation in vaccine development up to the present day. We also briefly review immunological principles underlying vaccination, as well as the main vaccine types, with a special mention of the recently introduced mRNA vaccine technology. Additionally, we discuss the broad benefits of vaccines, including their role in reducing morbidity and mortality, and in fostering socioeconomic development in communities. Finally, we address the issue of vaccine hesitancy and discuss effective strategies to promote vaccine acceptance. Research, collaboration, and the widespread acceptance and use of vaccines are imperative for the continued success of vaccination programs in controlling and ultimately eradicating infectious diseases.

Pilot study to determine effect of an altruism intervention focusing on herd immunity to enhance influenza vaccination rates

OBJECTIVE

A prospective, single-arm clinical trial was conducted to evaluate an altruism-tailored educational intervention to improve parental attitudes and vaccine uptake in vaccine-hesitant parents.

METHODS

Vaccine-hesitant parents at two primary care sites, spanning two influenza seasons from 2020 to 2021 were provided an intervention (spoken and written communication) which highlighted altruistic benefits of accepting the seasonal influenza vaccine to optimize herd immunity to help protect pediatric cancer patients. Eligible parents included those with children eligible for the seasonal influenza vaccine, those who were proficient in English, and those with scores on the adjusted Vaccine Hesitancy Scale (aVHS) suggesting vaccine hesitancy (score ≥ 3). Enrollees completed a demographic questionnaire, underwent the educational intervention, and repeated the aVHS. Vaccination status at that visit was assessed. The primary outcome was change in aVHS scores obtained pre- and post-intervention. Influenza vaccine acceptance, along with demographic information, were also analyzed.

RESULTS

We enrolled 510 parents of influenza vaccine eligible children and identified 73 vaccine-hesitant parents. There was an overall trend toward lower aVHS score, with a mean change in hesitancy score of -0.4 (P < 0.01). 43/73 (58.9 %) of the cohort experienced a positive effect toward a lower aVHS score, and 27/73 (37.0 %) of vaccine hesitant subjects became non-hesitant on the aVHS. Several demographic characteristics were associated with vaccine hesitancy in the screening population: educational level lower than bachelor's degree (p = 0.03), household income < 400 % of federal poverty level (p < 0.01), unmarried (p = 0.02), and identifying with a political affiliation other than Democrat (p < 0.01). However, no demographic characteristics were significantly associated with an individual becoming non-hesitant. Our altruism-tailored communication approach carried the largest positive impact on the altruism-specific question on the aVHS, decreasing the post-intervention response value by nearly 25 % (P < 0.01).

CONCLUSIONS

Our altruism-tailored communication approach significantly improved attitudes regarding childhood influenza vaccine among vaccine-hesitant parents.

CLINICALTRIALS

gov Identifier: NCT04568590.

Faster than warp speed: early attention to COVD-19 by anti-vaccine groups on Facebook

Background

The unprecedented rapid development of COVID-19 vaccines has faced SARS-CoV- (COVID-19) vaccine hesitancy, which is partially fueled by the misinformation and conspiracy theories propagated by anti-vaccine groups on social media. Research is needed to better understand the early COVID-19 anti-vaccine activities on social media.

Methods

This study chronicles the social media posts concerning COVID-19 and COVID-19 vaccines by leading anti-vaccine groups (Dr Tenpenny on Vaccines, the National Vaccine Information Center [NVIC] the Vaccination Information Network [VINE]) and Vaccine Machine in the early months of the COVID-19 pandemic (February–May 2020).

Results

Analysis of 2060 Facebook posts showed that anti-vaccine groups were discussing COVID-19 in the first week of February 2020 and were specifically discussing COVID-19 vaccines by mid-February 2020. COVID-19 posts by NVIC were more widely disseminated and showed greater influence than non-COVID-19 posts. Early COVID-19 posts concerned mistrust of vaccine safety and conspiracy theories.

Conclusion

Major anti-vaccine groups were sowing seeds of doubt on Facebook weeks before the US government launched its vaccine development program ‘Operation Warp Speed’. Early anti-vaccine misinformation campaigns outpaced public health messaging and hampered the rollout of COVID-19 vaccines.

A validated modification of the vaccine hesitancy scale for childhood, influenza and HPV vaccines

INTRODUCTION

Vaccine hesitancy contributes to outbreaks of preventable disease worldwide. The Vaccine Hesitancy Scale (VHS), developed by the international WHO SAGE Working Group, has been validated previously for measuring hesitancy towards childhood vaccines; some psychometric properties were suboptimal.

METHODS

We collected data using large, nationally-representative samples of parents in the U.S. We adapted the VHS items, and additional hesitancy items, to assess hesitancy towards influenza and HPV vaccines in addition to routine childhood vaccines. We then used exploratory and confirmatory factor analysis to identify latent constructs and create modified scales for childhood (VHS-child), influenza (VHS-flu) and HPV (VHS-HPV) vaccines with improved psychometric properties. Finally, we compared hesitancy scores on the VHS-child, VHS-flu, and VHS-HPV, to self-reported receipt of each vaccine category, and compared subscale scores to assess whether drivers of hesitancy differed by vaccine category.

RESULTS

2052 parents of children <18 years old completed the VHS-child and VHS-flu while 2020 parents of adolescents completed the VHS-HPV. A two-factor structure of 'risks' and a 'lack of confidence' was found for each vaccine category. Slight modifications to the VHS improved psychometric properties. Hesitancy was strongly associated with vaccine receipt: e.g., 76% of parents not hesitant towards influenza vaccine had vaccinated their child the past season, versus 9% of hesitant parents (p < 0.0001). Subscale scores also differed significantly between vaccines: lack of confidence was greater towards influenza (Median (IQR): 2.0 (1.2, 3.3)) and HPV (2.0 (1.3, 3.0)) vaccines than childhood (1.2 (1.0, 1.8), p < 0.0001 for both) vaccines; perceived risks of HPV vaccines (2.7 (1.7, 3.7)) were greater than for childhood vaccines (2.0 (1.3, 3.0), p < 0.0001).

CONCLUSIONS

Our modified VHS scales perform well psychometrically and allow for consistent measurement of the extent and reasons for hesitancy between vaccine categories. We suggest that future work use these scales to examine hesitancy towards other vaccines and to monitor hesitancy over time.

The role of epidemiology in informing United States childhood immunization policy and practice

One of the ten greatest public health achievements is childhood vaccination because of its impact on controlling and eliminating vaccine-preventable diseases (VPDs). Evidence-based immunization policies and practices are responsible for this success and are supported by epidemiology that has generated scientific evidence for informing policy and practice. The purpose of this report is to highlight the role of epidemiology in the development of immunization policy and successful intervention in public health practice that has resulted in a measurable public health impact: the control and elimination of VPDs in the United States. Examples in which epidemiology informed immunization policy were collected from a literature review and consultation with experts who have been working in this field for the past 30 years. Epidemiologic examples (e.g., thimerosal-containing vaccines and the alleged association between the measles, mumps, and rubella (MMR) vaccine and autism) are presented to describe challenges that epidemiologists have addressed. Finally, we describe ongoing challenges to the nation's ability to sustain high vaccination coverage, particularly with concerns about vaccine safety and effectiveness, increasing use of religious and philosophical belief exemptions to vaccination, and vaccine hesitancy. Learning from past and current experiences may help epidemiologists anticipate and address current and future challenges to respond to emerging infectious diseases, such as COVID-19, with new vaccines and enhance the public health impact of immunization programs for years to come.

Parental Hesitancy About Routine Childhood and Influenza Vaccinations: A National Survey

BACKGROUND AND OBJECTIVES

The World Health Organization has designated vaccine hesitancy as 1 of the 10 leading threats to global health, yet there is limited current national data on prevalence of hesitancy among US parents. Among a nationally representative sample of US parents, we aimed to (1) assess and compare prevalence of hesitancy and factors driving hesitancy for routine childhood and influenza vaccination and (2) examine associations between sociodemographic characteristics and hesitancy for routine childhood or influenza vaccination.

METHODS

In February 2019, we surveyed families with children using the largest online panel generating representative US samples. After weighting, we assessed hesitancy using a modified 5-point Vaccine Hesitancy Scale and labeled parents as hesitant if they scored >3.

RESULTS

A total of 2176 of 4445 parents sampled completed the survey (response rate 49%). Hesitancy prevalence was 6.1% for routine childhood and 25.8% for influenza vaccines; 12% strongly and 27% somewhat agreed they had concerns about serious side effects of both routine childhood and influenza vaccines. A total of 70% strongly agreed that routine childhood vaccines are effective versus 26% for influenza vaccine (P < .001). In multivariable models, an educational level lower than a bachelor's degree and household income <400% of the federal poverty level predicted hesitancy about both routine childhood and influenza vaccines.

CONCLUSIONS

Almost 1 in 15 US parents are hesitant about routine childhood vaccines, whereas >1 in 4 are hesitant about influenza vaccine. Furthermore, 1 in 8 parents are concerned about vaccine safety for both routine childhood and influenza vaccines, and only 1 in 4 believe influenza vaccine is effective. Vaccine hesitancy, particularly for influenza vaccine, is prevalent in the United States.

Cost Analysis of 3 Concurrent Public Health Response Events: Financial Impact of Measles Outbreak, Super Bowl Surveillance, and Ebola Surveillance in Maricopa County

OBJECTIVE

To generate estimates of the direct costs of mounting simultaneous emergency preparedness and response activities to respond to 3 major public health events.

DESIGN

A cost analysis was performed from the perspective of the public health department using real-time activity diaries and retrospective time and activity self-reporting, wage and fringe benefit data, and financial records to track costs.

SETTING

Maricopa County Department of Public Health (MCDPH) in Arizona. The nation's third largest local public health jurisdiction, MCDPH is the only local health agency serving Maricopa's more than 4 000 000 residents. Responses analyzed included activities related to a measles outbreak with 2 confirmed cases, enhanced surveillance activities surrounding Super Bowl XLIX, and ongoing Ebola monitoring, all between January 22, 2015, and March 4, 2015.

PARTICIPANTS

Time data were sought from all MCDPH staff who participated in activities related to any of the 3 relevant responses. In addition, time data were sought from partners at the state health department and a community hospital involved in response activities. Time estimates were received from 128 individuals (response rate 88%).

MAIN OUTCOME MEASURE

Time and cost to MCDPH for each response and overall.

RESULTS

Total MCDPH costs for measles-, Super Bowl-, and Ebola-related activities from January 22, 2015, through March 4, 2015, were $224 484 (>5800 hours). The majority was for personnel ($203 743) and the costliest response was measles ($122 626 in personnel costs). In addition, partners reported working more than 700 hours for these 3 responses during this period.

CONCLUSIONS

Funding for public health departments remains limited, yet public health responses can be cost- and time-intensive. To effectively plan for future public health responses, it may be necessary to share experiences and financial lessons learned from similar public health responses. External partnerships represent a key contribution for responses such as those examined. It can be expensive for local public health departments to mount effective responses, especially when multiple responses occur simultaneously.

Studying Public Perception about Vaccination: A Sentiment Analysis of Tweets

Text analysis has been used by scholars to research attitudes toward vaccination and is particularly timely due to the rise of medical misinformation via social media. This study uses a sample of 9581 vaccine-related tweets in the period January 1, 2019 to April 5, 2019. The time period is of the essence because during this time, a measles outbreak was prevalent throughout the United States and a public debate was raging. Sentiment analysis is applied to the sample, clustering the data into topics using the term frequency-inverse document frequency (TF-IDF) technique. The analyses suggest that most (about 77%) of the tweets focused on the search for new/better vaccines for diseases such as the Ebola virus, human papillomavirus (HPV), and the flu. Of the remainder, about half concerned the recent measles outbreak in the United States, and about half were part of ongoing debates between supporters and opponents of vaccination against measles in particular. While these numbers currently suggest a relatively small role for vaccine misinformation, the concept of herd immunity puts that role in context. Nevertheless, going forward, health experts should consider the potential for the increasing spread of falsehoods that may get firmly entrenched in the public mind.

Legal approaches to promoting parental compliance with childhood immunization recommendations

Rates of vaccine-preventable diseases have increased in the United States in recent years, largely due to parental refusals of recommended childhood immunizations. Empirical studies have demonstrated a relationship between nonvaccination rates and permissive state vaccine exemption policies, indicating that legal reforms may promote higher immunization rates. This article reviews relevant data and considers the legal landscape. It analyzes federal and state Constitutional law, concluding that religious and personal belief exemptions to school-entry vaccine mandates are not constitutionally required. It identifies public health, bioethical, and policy considerations relevant to the choice among legal approaches employed by states to promote parental compliance. The article describes a range of legal tools that may help promote parental cooperation with immunization recommendations.

Vaccination Perceptions of College Students: With and without Vaccination Waiver

Introduction

The resurgence of vaccine preventable diseases occurs more often among intentionally unvaccinated individuals, placing at direct risk young adults not caught up on vaccinations. The objectives of this study were to characterize the sociodemographic characteristics of young adults with and without vaccination waivers and identify their perceived benefits, barriers, and influencers of vaccination.

Methods

Young adults (n = 964) from a Midwestern rural university responded to a survey (fall 2015-spring 2016) designed to identify their perception toward vaccination. Instrument consistency was measured using the Cronbach α-scores. The Chi-square test was used to test any sociodemographic differences and Mann-Whitney U-tests results for differences between exempt and non-exempt students. Analysis occurred in spring 2017.

Results

A little over one-third of young adults with a vaccination waiver were not up to date on their vaccinations, and think that vaccinations can cause autism. The biggest identifiable benefit was effective control against disease. The surveyed young adults ranked the out of pocket cost associated with vaccination as the most important barrier and safe and easy to use vaccines as the most important influencer of vaccination.

Conclusion

Young adults who have had a vaccination waiver appear to not be up to date on their vaccinations. Vaccine administration programs, such as university campus clinics, would benefit from addressing perceptions unique to young adults with and without a vaccine waiver. This would subsequently better provide young adults a second shot for getting appropriately caught up on vaccinations.

How well do ICD-9 physician claim diagnostic codes identify confirmed pertussis cases in Alberta, Canada? A Canadian Immunization Research Network (CIRN) Study

Background

Rates of Bordetella pertussis have been increasing in Alberta, Canada despite vaccination programs. Waning immunity from existing acellular component vaccines may be contributing to this. Vaccine effectiveness can be estimated using a variety of data sources including diagnostic codes from physician billing claims, public health records, reportable disease and laboratory databases. We sought to determine if diagnostic codes from billing claims (administrative data) are adequately sensitive and specific to identify pertussis cases among patients who had undergone disease-specific laboratory testing.

Methods

Data were extracted for 2004–2014 from a public health communicable disease database that contained data on patients under investigation for B. pertussis (both those who had laboratory tests and those who were epidemiologically linked to laboratory-confirmed cases) in Alberta, Canada. These were deterministically linked using a unique lifetime person identifier to the provincial billing claims database, which contains International Classification of Disease version 9 (ICD-9) diagnostic codes for physician visits. We examined visits within 90 days of laboratory testing. ICD-9 codes 033 (whooping cough), 033.0 (Bordetella pertussis), 033.1 (B. parapertussis), 033.8 (whooping cough, other specified organism), and 033.9 (whooping cough, other unspecified organism) in any of the three diagnostic fields for a claim were classified as being pertussis-specific codes. We calculated sensitivity, specificity, positive (PPV) and negative (NPV) predictive values.

Results

We identified 22,883 unique patients under investigation for B. pertussis. Of these, 22,095 underwent laboratory testing. Among those who had a laboratory test, 2360 tested positive for pertussis. The sensitivity of a pertussis-specific ICD-9 code for identifying a laboratory-confirmed case was 38.6%, specificity was 76.9%, PPV was 16.0%, and NPV was 91.6%.

Conclusion

ICD-9 codes from physician billing claims data have low sensitivity and moderate specificity to identify laboratory-confirmed pertussis among persons tested for pertussis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2321-1) contains supplementary material, which is available to authorized users.

Perspectives on benefit-risk decision-making in vaccinology: Conference report

Benefit/risk (B/R) assessment methods are increasingly being used by regulators and companies as an important decision-making tool and their outputs as the basis of communication. B/R appraisal of vaccines, as compared with drugs, is different due to their attributes and their use. For example, vaccines are typically given to healthy people, and, for some vaccines, benefits exist both at the population and individual level. For vaccines in particular, factors such as the benefit afforded through herd effects as a function of vaccine coverage and consequently impact the B/R ratio, should also be taken into consideration and parameterized in B/R assessment models. Currently, there is no single agreed methodology for vaccine B/R assessment that can fully capture all these aspects. The conference "Perspectives on Benefit-Risk Decision-making in Vaccinology," held in Annecy (France), addressed these issues and provided recommendations on how to advance the science and practice of B/R assessment of vaccines and vaccination programs.