Fear, mistrust, and vaccine hesitancy: Narratives of the dengue vaccine controversy in the Philippines

Vaccine Hesitancy among Immigrants: A Narrative Review of Challenges, Opportunities, and Lessons Learned

(1) Background: Vaccination reluctance is a major worldwide public health concern as it poses threats of disease outbreaks and strains on healthcare systems. While some studies have examined vaccine uptake within specific countries, few provide an overview of the barriers and trends among migrant groups. To fill this knowledge gap, this narrative review analyzes immunization patterns and vaccine hesitancy among immigrant populations. (2) Methods: Four researchers independently evaluated the quality and bias risk of the 18 identified articles using validated critical appraisal tools. (3) Results: Most studies focused on vaccine hesitancy among migrants in the United States and Canada, with a higher COVID-19 vaccine reluctance than native-born residents. Contributing factors to this hesitancy include demographics, cultural views, obstacles to healthcare access, financial hardship, and distrust in health policies. Additionally, immigrants in North America and Europe face unfair vaccine challenges due to misinformation, safety concerns, personal perspectives, language barriers, immigration status, and restricted healthcare access. (4) Conclusions: Tailored vaccine education programs and outreach campaigns sensitive to immigrants' diversity should be developed to address this issue. It is also important to investigate community-specific obstacles and assess the long-term sustainability of current efforts to promote vaccination among marginalized migrant groups. Further research into global immunization disparities among immigrant populations is crucial.

Economic optimization of Wolbachia-infected Aedes aegypti release to prevent dengue

BACKGROUND

Dengue virus, primarily transmitted by the Aedes aegypti mosquito, is a major public health concern affecting ≈3.83 billion people worldwide. Recent releases of Wolbachia-transinfected Ae. aegypti in several cities worldwide have shown that it can reduce dengue transmission. However, these releases are costly, and, to date, no framework has been proposed for determining economically optimal release strategies that account for both costs associated with disease risk and releases.

RESULTS

We present a flexible stochastic dynamic programming framework for determining optimal release schedules for Wolbachia-transinfected mosquitoes that balances the cost of dengue infection with the costs of rearing and releasing transinfected mosquitoes. Using an ordinary differential equation model of Wolbachia and dengue in a hypothetical city loosely describing areas at risk of new dengue epidemics, we determined that an all-or-nothing release strategy that quickly brings Wolbachia to fixation is often the optimal solution. Based on this, we examined the optimal facility size, finding that it was inelastic with respect to the mosquito population size, with a 100% increase in population size resulting in a 50-67% increase in optimal facility size. Furthermore, we found that these results are robust to mosquito life-history parameters and are mostly determined by the mosquito population size and the fitness costs associated with Wolbachia.

CONCLUSIONS

These results reinforce that Wolbachia-transinfected mosquitoes can reduce the cost of dengue epidemics. Furthermore, they emphasize the importance of determining the size of the target population and fitness costs associated with Wolbachia before releases occur. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Knowledge, attitudes, and practices related to dengue among public school teachers in a Central Luzon Province in the Philippines: an analytic cross-sectional study

BACKGROUND

Dengue has become a major health issue in tropical regions as the numbers of reported cases and estimated infections continuously increase. In the Philippines, many challenges remain in preventing and controlling the disease amidst all the mitigation efforts of the government. This study sought to measure the health literacy of Filipino teachers and determine the associations among teachers' knowledge, attitudes, and selected practices (KAP) against dengue.

METHODS

Elementary and secondary school teachers from the consistently declared dengue hotspots in the City of San Fernando, Pampanga, Philippines, from the years 2017 to 2019 were selected as target participants in this cross-sectional study. A self-administered online survey tool was used in this study for both screening of participants and the KAP survey proper. STATA, descriptive statistics, and multiple logistic regression were used for the data analysis. Odds Ratios (ORs) and 95% confidence intervals (CIs) were reported.

RESULTS

The study comprised 604 participants whose mean age was 38.4 years. Television was determined as the top media source of information, and various health staff were the most trusted and common source of information. Good knowledge on dengue treatment (OR = 1.81; 95% CI 1.18-2.78) and dengue prevention (OR = 1.85; 95% CI 1.26-2.71) were positively associated with having good practices on protection against mosquito bites. Good knowledge on dengue signs and symptoms (OR = 1.56; 95% CI 1.02-2.37) and dengue prevention (OR = 2.38; 95% CI 1.59-3.58) were positively associated with having good practices on preventing breeding sites. Those with positive perceived susceptibility to dengue had lower odds of having good practices on protection against mosquito bites (OR = 0.64; 95% CI 0.41-0.99) and of having good practices on preventing breeding sites (OR = 0.46; 95% CI 0.26-0.81).

CONCLUSION

Even with the existing dengue policies, programs, and strategies, and the high disease literacy rate of Filipinos, dengue remains a struggle with an increasing case rate. Therefore, specific concepts should be emphasized, and interventions should be fine-tuned to better reach and influence the target population to attain a dengue-free Philippines.

Value of information dynamics in Disease X vaccine clinical trials

BACKGROUND

Solutions have been proposed to accelerate the development and rollout of vaccines against a hypothetical disease with epidemic or pandemic potential called Disease X. This may involve resolving uncertainties regarding the disease and the new vaccine. However the value for public health of collecting this information will depend on the time needed to perform research, but also on the time needed to produce vaccine doses. We explore this interplay, and its effect on the decision on whether or not to perform research.

METHOD

We simulate numerically the emergence and transmission of a disease in a population using a susceptible-infected-recovered (SIR) compartmental model with vaccination. Uncertainties regarding the disease and the vaccine are represented by parameter prior distributions. We vary the date at which vaccine doses are available, and the date at which information about parameters becomes available. We use the expected value of perfect information (EVPI) and the expected value of partially perfect information (EVPPI) to measure the value of information.

RESULTS

As expected, information has less or no value if it comes too late, or (equivalently) if it can only be used too late. However we also find non trivial dynamics for shorter durations of vaccine development. In this parameter area, it can be optimal to implement vaccination without waiting for information depending on the respective durations of dose production and of clinical research.

CONCLUSION

We illustrate the value of information dynamics in a Disease X outbreak scenario, and present a general approach to properly take into account uncertainties and transmission dynamics when planning clinical research in this scenario. Our method is based on numerical simulation and allows us to highlight non trivial effects that cannot otherwise be investigated.

'I was terrified for my child': understanding the link between the Dengvaxia® controversy and the measles vaccine hesitancy in Pasay City, Philippines

BACKGROUND

The Dengvaxia® (dengue vaccine) controversy has been identified as one of the main reasons for the measles vaccine hesitancy in the Philippines. Our study aimed to identify various issues related to the Dengvaxia® controversy and to link these issues with the social perspective of measles vaccine refusal.

METHODS

Semi-structured interviews and a focus group discussion using ethnography research were conducted with 41 parents and healthcare workers in Pasay City. Using Victor Turner's Social Drama Theory, our study identified existing social issues relating to the different angles of the Dengvaxia® controversy and the measles vaccine hesitancy.

RESULTS

Misinformation on the failed Dengvaxia® rollout implementation has challenged the fundamental understanding of the importance of immunization programs. Our findings on vaccine hesitancy in the community showed a complex problem with compounded factors, including medical populism, moral panics and other social views. We described how Pasay City's clinic waiting room became a significantly important scenario where individuals often discuss information, concerns and experiences on vaccines and vaccine hesitancy.

CONCLUSION

Our study suggests that the Dengvaxia® controversy may reduce the measles vaccination confidence in the Philippines. Lack of transparency played a crucial role in this dilemma, producing a cascading effect on the other vaccines' safety.

Dengue vaccine acceptance and willingness to pay: a systematic review and meta-analysis

OBJECTIVE

Dengue is the most important human vector-borne disease in terms of disease burden. A first dengue vaccine has recently been licenced, and others are in advanced stages of development. However, to date, none of these vaccines has achieved balanced efficacy and safety for all dengue serotypes. The aim of this systematic review and meta-analysis was to assess the global acceptance and willingness to pay for unspecified dengue vaccines.

METHODS

This systematic review and meta-analysis included cross-sectional and cohort studies that reported values for vaccine acceptance (percentage) and willingness to pay for currently available or hypothetical vaccines. These values were pooled using random-effects models for the acceptance, while weighted linear regression was chosen for willingness to pay. Heterogeneity between studies was assessed using prediction intervals (PIs), and a domain-based tool was used to assess the risk of bias. Subgroup and sensitivity analyses were performed where appropriate. This study was registered with PROSPERO (CRD42021255784).

RESULTS

We included 19 studies from the Americas and Asia in the quantitative meta-analysis. The risk of bias was mainly related to the selection of participants and to the assumptions about the safety and efficacy of the vaccines. The percentage of vaccine acceptance was 88.3% (95% CI: 81.0%-93.0%), with some heterogeneity between studies (80% PI: 52.9%-98.1%). Willingness to pay was US$ 46.7 (95% CI: 25.9-67.5) per vaccine recipient. There were differences between continents, with higher acceptance in the Americas.

CONCLUSIONS

We were able to obtain global estimates of vaccine acceptance and willingness to pay and identify the associated factors that influence these values. This knowledge is relevant for the planning of future vaccination strategies.

Dengue Vaccination: Towards a New Dawn of Curbing Dengue Infection

Dengue is an infectious disease caused by dengue virus (DENV) and is a serious global burden. Antibody-dependent enhancement and the ability of DENV to infect immune cells, along with other factors, lead to fatal Dengue Haemorrhagic Fever and Dengue Shock Syndrome. This necessitates the development of a robust and efficient vaccine but vaccine development faces a number of hurdles. In this review, we look at the epidemiology, genome structure and cellular targets of DENV and elaborate upon the immune responses generated by human immune system against DENV infection. The review further sheds light on various challenges in development of a potent vaccine against DENV which is followed by presenting a current account of different vaccines which are being developed or have been licensed.

Misinformation, infighting, backlash, and an 'endless' recovery; policymakers recount challenges and mitigating measures after a vaccine scare in the Philippines

Background

Vaccine scares undermine longstanding global health achievements. Remarkably little data has documented the lived experiences of policymakers working amidst vaccine scares and navigating their fallout. As a result, chances and challenges of large-scale national recuperation efforts are poorly understood.

Objective

This study aims to explore the perspectives of policymakers involved in ongoing efforts to boost vaccine confidence in the Philippines following a 2017 Dengvaxia scare and the current COVID-19 pandemic.

Methods

Between August and November 2020, we conducted 19 semi-structured narrative interviews with purposively selected policymakers from governmental agencies and non-governmental organizations in the Philippines. Interviews were conducted online, transcribed, and analyzed following the tenets of reflexive thematic analysis.

Results

We present results as an emerging model that draws on a chronology conveyed by policymakers in their own words. The Dengvaxia scare proved ‘a decisive wedge’ that splintered Filipino society and pitted governmental agencies against one another. The scare stoked distorted vaccination narratives, which were ‘accelerated rapidly’ via social media, and ignited feelings of uncertainty among policymakers of how to convey clear, accurate health messaging and how to prevent drops in care-seeking more broadly.

Conclusions

Efforts to regain trust placed exceptional burdens on an already-strained health system. Respondent-driven recommendations on how to reinforce vaccine confidence and improve vaccination rollout include: developing clear vaccine messages, fostering healthcare providers’ and policymakers’ communication skills, and rebuilding trust within, toward and across governmental agencies. Further research on how to build enabling environments and rebuild trust in and across institutions remains paramount.

Applying Cultural Intelligence to Improve Vaccine Hesitancy Among Black, Indigenous, and People of Color

Despite the overwhelming evidence to support the benefits of vaccines for preventable diseases and improving health outcomes throughout the world, vaccine hesitancy and resistance continues to be a concern during the COVID-19 pandemic. Although Black, Indigenous, and People of Color (BIPOC) experience the highest rates of morbidity and mortality from COVID-19, mistrust and historical unethical research and medical practices continue to preclude this population from getting the vaccine. This article urges clinicians to subscribe to development and application of cultural intelligence to understand the impact of structural racism and cultural considerations of BIPOC to partner in strategy development.