COVID-19 Vaccination Campaign Research Articles

Impact of SARS-CoV-2 infection in pregnant women and their babies: clinical and epidemiological features

ObjectiveAssess the risk associated with COVID-19 in pregnant women on maternal and neonatal outcomes in Catalonia (Spain) in 2020, before the beginning of COVID-19 vaccination campaign. MethodCross-sectional descriptive study with all pregnant women (41,560) and their live newborns (42,097) (1st March to 31st December 2020). Women were classified: positive and negative COVID-19 diagnosis during pregnancy. The outcomes analysed were complications during pregnancy, gestational age, admission of newborns to neonatal intensive care unit (NICU) and birth weight. Associations among positive COVID-19 and maternal and infant variables were measured with logistic regression models. Results were expressed as odds ratios and 95% confidence intervals. Models were adjusted for nationality, maternal age, socioeconomic status, type of pregnancy and type of centre where the delivery occurred (public or private management hospital). ResultsA total of 696 women (1.7%) were diagnosed with COVID-19 during pregnancy. Women with COVID-19 were 4.37 times more likely to have complications during pregnancy (4.37; 3.52-5.40). A total of 713 newborns (1.7%) were from mothers with COVID-19. A positive diagnosis of COVID-19 increased the risk of preterm birth (1.41; 1.03-1.89), admission to NICU (1.40; 1.06-1.82) and low birth weight (1.35; 0.99-1.80) in babies. ConclusionsPregnant women with COVID-19 had higher risk of developing complications during pregnancy and their newborns were more likely to be admitted to NICU and had prematurity.

Understanding Bangladesh’s Vaccine Diplomacy during COVID-19 Crisis

COVID-19 pandemic resulted in millions of deaths globally. Whether powerful or weak, every country was affected by this pandemic. The pandemic also resulted in the rise of vaccine nationalism and vaccine divide. Thus, it was difficult for the countries of the global South to have access to COVID-19 vaccines. When India failed to deliver the required number of vaccines, it became challenging for Bangladesh to manage COVID-19 vaccines for its millions of people. Against this backdrop, Bangladesh actively employed vaccine diplomacy both bilaterally and multilaterally to manage COVID-19 vaccines. Bangladesh’s vaccine diplomacy at bilateral and multilateral scale was instrumental in securing tens of thousands of lives from the COVID-19 global pandemic. In fact, Bangladesh has been one of the most successful cases of COVID-19 vaccination campaign as vaccine issue was prioritized among foreign policy priorities of Bangladesh. And vaccine diplomacy was the number one diplomatic choice of Bangladesh during the COVID-19 global pandemic. In this context, this study investigates one central question: How did Bangladesh employ vaccine diplomacy at bilateral and multilateral scale?

World Health Organization is losing online credibility towards health-sensitive topics: Infodemiological analysis of Facebook users' reactions.

Background: The scientific infodemic constitutes one of the greatest threats to public health and safety today. The credibility of the main dissemination agencies is an essential tool for adhering to measures to preserve public health. Methods: The study is a longitudinal retrospective conducted on a web platform to investigate netizens' infodemic attitude towards World Health Organization. Reactions such as "like," "love," "affection," "surprise," "sadness," "anger," and "derision" were collected under World Health Organization (WHO) Facebook posts on climate change (from 2019 to 2022) and vaccines (from 2021 to 2022). Descriptive statistics, linear regression, and correlation methods were implemented to identify possible trends and relationships with the COVID-19 vaccination campaign. Results: These findings showed a worrying increase in derision reactions about climate change-related posts (up to 22% in November 2022, with a quadratically growing trend over time since December 2020). Furthermore, infodemic reactions such as anger and especially derision made up the majority of emotional reactions to vaccine-related posts since 2021 and up to 44% of total reactions in November 2022 (median since July 2021=9%, IQR: 4%-14%). Finally, there is evidence of a correlation between the start of the COVID-19 vaccination campaign and public distrust towards the WHO, even for issues unrelated to vaccines such as climate change. Conclusion: Based on what is known in the literature, these preliminary findings signal that the WHO is losing online public credibility towards extremely relevant issues for global health. Infodemiological interventions in accordance with the recent literature are urgently required.

Structure of Adverse Events Following Immunisation against Coronavirus Infection (COVID-19) in the Kyrgyz Republic

There is considerable interest worldwide in developing safe and effective vaccines against COVID-19. Pharma-covigilance of adverse events following immunisation (AEFIs) is a key to making informed decisions regarding the global COVID-19 vaccination campaign. In the Kyrgyz Republic, there have been developed a national immunisation information system (IIS) for automated recording of vaccines, vaccinated persons, and AEFIs and a mobile application for AEFI reporting, called Den Sooluk.The aim of the study was to analyse the pattern of AEFIs against COVID-19 in the Kyrgyz Republic.Materials and methods: the study analysed the spontaneous safety reports submitted to the national IIS database through the Den Sooluk mobile application from 29.03.2021 to 25.09.2022.Results: according to the data available by 25.09.2022, the total number of vaccinated people in the country amounted to 2,940,082. At the time, the IIS database included 2111 AEFIs: 1 fatal (and coincidental), 3 severe and 2108 minor ones. AEFIs were more frequent in the young and middle-aged population (81.5%), than in the elderly (18.5%). The following AEFIs were reported: injection site pain (21.25%), fatigue (20.7%), headache (19.8%), body temperature above 38 °C (10.10%), miscellaneous symptoms (5.12%), chills (4.41%), dizziness (4.32%), sore throat (3.36%), myalgia (2.9%), and nausea (2.2%).Conclusions: all COVID-19 vaccines used in the Kyrgyz Republic can be considered adequately safe. Pharmacovigilance of AEFIs is an integral part of the requirements to ensure the safe use of vaccines, and collecting of spontaneous reports on AEFIs supports adequate functioning of the post-marketing surveillance system. It is essential to provide access to electronic information platforms to health professionals and patients in order to ensure vaccination transparency and coordination and enable quick and safe reporting of AEFIs associated with the use of COVID-19 vaccines.

Comparative analysis of risk factors for COVID-19 mortality before, during and after the vaccination programme in Mexico

ObjectivesThe purpose of this study was to compare case fatality rates (CFRs) and odds for mortality by risk factors of patients with COVID-19 in Mexico, before, during and after the implementation of the national COVID-19 vaccination programme. Study designA large database including COVID-19 monitoring cases was used to perform an observational retrospective study. MethodsThe Chi-squared test and multivariate logistic regression analyses were applied to data from COVID-19-positive patients in Mexico. Data were analysed over 3 years, 2020, 2021 and 2022, corresponding with pre-, during and post-vaccination periods. The unadjusted odds ratios and 95% confidence interval were used to estimate the risk factors for COVID-19 mortality in each of the years. ResultsStatistically significant differences in CFR and odds ratio were found in the studied years, favouring postvaccination period. Significant changes in CFR by age, sex and main comorbidities indicated changes in the epidemic dynamics after the implementation of the COVID-19 vaccination campaign. The likelihood of death increased for hospitalised cases and for patients who were middle-aged or older in 2021 and 2022, whereas the odds of death associated with sex and comorbidities remained similar or reduced over the 3 years. ConclusionsImplementation of the COVID-19 vaccination programme during 2021 showed positive consequences on CFR. The increased odds of dying in hospitalised patients are likely to be due to the unvaccinated proportion of patients.

Vaccination against SARS-CoV-2 and its relationship with public interest in mental health: a study between 2020-2022 in Spain

ABSTRACT The possible relationship between vaccination against SARS-CoV-2 (COVID-19) and mental health has been largely unexplored. We investigated variations in public interest in mental health issues between the different periods of the vaccination campaign against SARS-CoV-2 in Spain and before the initiation of the campaign. Using Google Trends, we explored the relative search volume (RSV) for the terms ‘anxiety’, ‘depression’, ‘stress’, ‘insomnia’, and ‘suicide’ between 03/01/2020 and 01/15/2022. The RSV was compared for these terms with respect to four periods: the pre-vaccination pandemic period; the period running from initiation of vaccination until 50% of the population was fully vaccinated (FV); the period running from 50% FV to 70% FV; and the period after 70% FV. Differences in the RSV indices were observed between the studied periods for ‘anxiety’(F = 6.07; p = 0.001; ƞ2 = 0.16), ‘stress’ (F = 7.77; p < 0.001; ƞ2 = 0.19), and ‘insomnia’ (F = 3.80; p = 0.013; ƞ2 = 0.11). A lower RSV was found for ‘anxiety’, ‘stress’, and ‘insomnia’ after 70% FV compared to the two previous vaccination periods. A lower RSV was also found for ‘stress’ after achieving the milestone of 70% FV in relation to the period prior to initiation of the campaign. In conclusion, there is less need for information on specific mental health topics in the period after 70% FV. In Spain, reaching this vaccination milestone may have had a positive impact on anxiety, stress, and insomnia levels in the population, as reflected in fewer web searches for information on these psychopathological processes. The promotion of the COVID-19 vaccination campaign could take into account the changes observed in this preliminary study with respect to public interest in stress, anxiety, and insomnia once a large percentage of the population has been vaccinated.

Lessons learned from the Global Polio Eradication Initiative: A roadmap for the international COVID-19 vaccination campaign.

The COVID-19 vaccine is lauded by many as one of the greatest accomplishments in modern medicine, with the potential to definitively contain the deadliest pandemic of the last century. With the vaccine rollout now underway in the developing world, a robust, methodical, and swift global distribution effort is required to ensure that it will be done in an equitable manner. Taking into account the vast geographic, socioeconomic, cultural, and political diversity of countries around the world, global vaccination efforts have historically required multifaceted, time consuming, and labor-intensive approaches to be effective. However, with over 33 years of experience from the Global Polio Eradication Initiative - an international health initiative aimed at eradicating poliomyelitis - the COVID-19 vaccination campaign does not have to be approached blindly. Using lessons learned from the Global Polio Eradication Initiative, this paper aims to identify the supply- and demand-side barriers to the success of the international COVID-19 vaccination effort, and ways each can be overcome. Most notably, health systems shortcomings, political and cultural messaging, and civil unrest and violent conflict serve as daunting obstacles to the success of the COVID-19 vaccination campaign. The Global Polio Eradication Initiative has been able to overcome many of these same obstacles with innovative strategies such as context-specific microplanning, robust health surveillance systems, and community-centered education and advocacy programs. Ultimately, while the Global Polio Eradication Initiative is still fighting the battle of polio eradication, it has provided a roadmap for the COVID-19 vaccination campaign to be executed in a more swift and equitable manner.

Vaximap: route optimisation for housebound vaccination

During the United Kingdom’s Covid-19 vaccination campaign, general practitioners (GPs) have held responsibility for vaccinating housebound patients. This presented them with a large, complex and unfamiliar logistical challenge, namely determining the most time-efficient route to visit multiple patients at their home address. In response to a lack of existing solutions tailored specifically to vaccination, and in light of overwhelming demand, Vaximap (https://www.vaximap.org) was created in January 2021 to automate the process of route planning. It is free of charge for all users and has been used to-date to plan vaccinations for over 470,000 patients. This article analyses usage data to estimate the time savings (3 work years) and financial savings (£110,000) the service has yielded for GP surgeries, thus demonstrating that it helped to accelerate the UK’s Covid-19 vaccination campaign at critical moments.

Modeling a COVID-19 Vaccination Campaign in the State of Madhya Pradesh, India

COVID-19 vaccination campaigns have been launched across the globe to mitigate the impact of the COVID-19 disease. However, COVID-19 vaccination campaigns (Vaccination campaigns are the complete process of COVID-19 vaccination campaigns beyond just administrating vaccines.) are a complex multi-stakeholder process, and therefore, it is important to understand the key components and drivers of vaccination campaigns to help devise strategies to increase vaccination coverage for existing and future vaccination efforts. A system dynamics modeling approach was used to trace the vaccination campaign for the Indian state of Madhya Pradesh. The results identified the key stakeholders of the vaccination campaign and their inter-linkages, and the diverse perspectives of stakeholders of vaccination campaigns in Madhya Pradesh were collated in a structured format. Further, system dynamics models were developed to capture all aspects of the vaccination campaign in Madhya Pradesh, including the challenges and innovations. The outcomes of the study can assist academicians, practitioners, and policymakers develop vaccination programs at sub-national, national, and global levels. They will guide decision-makers to take preemptive measures to mitigate possible risks and challenges and provide improved services as part of vaccination campaigns.

Conceptual Semantics and Public Messaging

This study explores the conceptual semantics of risk–benefit discourse about COVID-19 vaccination and the implications for public health messaging. The underlying methodology is the natural semantic metalanguage (NSM) approach. The study proposes a semantic explication of the English word risk in one of its most frequently used frames in COVID-19 vaccine discourse (i.e. the risk of ...), as well as an “advice script” for the complex task of “weighing the risks and benefits” of a vaccination decision. Drawing on COVID-19 vaccination campaigns in Australia and Denmark, the study stresses the difficulties of communicating public health messages using conceptually complex and culture-specific words such as risk. Though the issues are complex, it is argued that adopting a minimal languages approach may provide a way forward, by enabling the creation of texts that are both easier to understand and more easily translated.

Impact of healthcare capacity disparities on the COVID-19 vaccination coverage in the United States: a cross-sectional study

The impact of the COVID-19 vaccination campaign in the US has been hampered by a substantial geographical heterogeneity of the vaccination coverage. Several studies have proposed vaccination hesitancy as a key driver of the vaccination uptake disparities. However, the impact of other important structural determinants such as local disparities in healthcare capacity is virtually unknown. In this cross-sectional study, we conducted causal inference and geospatial analyses to assess the impact of healthcare capacity on the vaccination coverage disparity in the US. We evaluated the causal relationship between the healthcare system capacity of 2417 US counties and their COVID-19 vaccination rate. We also conducted geospatial analyses using spatial scan statistics to identify areas with low vaccination rates. We found a causal effect of the constraints in the healthcare capacity of a county and its low-vaccination uptake. Counties with higher constraints in their healthcare capacity were more probable to have COVID-19 vaccination rates ≤50, with 35% higher constraints in low-vaccinated areas (vaccination rates ≤ 50) compared to high-vaccinated areas (vaccination rates > 50). We also found that COVID-19 vaccination in the US exhibits a distinct spatial structure with defined "vaccination coldspots". We found that the healthcare capacity of a county is an important determinant of low vaccine uptake. Our study highlights that even in high-income nations, internal disparities in healthcare capacity play an important role in the health outcomes of the nation. Therefore, strengthening the funding and infrastructure of the healthcare system, particularly in rural underserved areas, should be intensified to help vulnerable communities. None.

Are We Prepared for the Next Pandemic? Management, Systematic Evaluation and Lessons Learned from an In-Hospital COVID-19 Vaccination Centre for Healthcare Workers

the organisation of a COVID-19 vaccination campaign for healthcare workers (HCWs) within a university hospital presents a challenge of a particularly large scale and urgency. Here, we evaluate the in-hospital vaccination process and centre for HCWs at LMU University Hospital in Munich, Germany. We executed a mixed-method process evaluation of the vaccination centre at LMU University Hospital during the first COVID-19 vaccination campaign. In a programme monitoring, we continuously assessed the implementation of the centre's operational management including personnel resources. In evaluating the outreach to and satisfaction of the target group with the centre and process, we executed two anonymous surveys aimed at the HCWs vaccinated at the in-hospital centre (1) as well as centre staff members (2). staff numbers and process time per person were reduced several times during the first vaccination campaign. Lessons concerning appointment scheduling were learned. HCWs vaccinated at the in-hospital centre were satisfied with the process. A longer waiting time between admission and inoculation, perceived dissatisfying accessibility as well as an increased frequency of observed adverse events were linked to a reduced satisfaction. Comparatively subpar willingness to adhere to non-pharmaceutical measures was observed. Centre staff reported high satisfaction and a workload relatively equal to that of their regular jobs. Our outcomes provide references for the implementation of an in-hospital vaccination centre in similar settings.

Rehabilitation outcomes in patients with post-COVID-19 vaccine-associated Guillain-Barre syndrome.

With COVID-19 vaccination campaign worldwide, associated Guillain-Barre syndrome (GBS) is being increasingly reported from different countries. The objectives of the study were to observe the clinical profile and rehabilitation outcomes in patients with post-COVID-19 vaccine-associated GBS. This prospective study was conducted in neurological rehabilitation unit with in-patients. A detailed customized rehabilitation program was formulated based on the clinical status and associated complications. Outcome measures were documented on the day of admission and at discharge and compared. The study included 16 patients (eight males) of which 15 (93.75%) received the CoviShield (AstraZeneca) and 1 Covaxin (Bharat Biotech) vaccine. The median (IQR) duration of first symptom was 9 (18.25) days and for motor symptoms 18 (12.75) days. Functional improvement was observed in patients using Barthel index scores and Hughes disability scores and overall neuropathy limitation scale. All rehabilitation outcomes showed a statistically significant improvement (P < 0.05) from the time of admission to discharge. At discharge, complete independence in activities of daily living was achieved in 4 (25%) patients and 5 (31.25%) were minimally dependent. Three (18.75%) patients were walking independently, seven (43.75%) with minimal support, and four with walker (25%). Nine (56.25%) patients needed bilateral ankle-foot orthosis and two bilateral knee gaiters for locomotion. Comprehensive inpatient rehabilitation interventions in patients with post-COVID-19 vaccine-associated GBS result in significant functional recovery.

Evaluation of vaccination strategies for the metropolitan area of Madrid via agent-based simulation

ObjectiveWe analyse the impact of different vaccination strategies on the propagation of COVID-19 within the Madrid metropolitan area, starting on 27 December 2020 and ending in Summer of 2021.Materials and...

“We Write to Dismantle Prejudices, Myths and Lies”: The Role of Journalists in the COVID-19 Vaccination Campaign in Romania

ABSTRACT In Romania, an important role in the dissemination of scientific information, decisive for increasing confidence in the vaccination against COVID-19, was played not only by official communication,, but also by media professionals who covered this subject extensively. The present research analyses the opinions of 33 Romanian journalists, from the national and local press, aiming to find out their professional attitude regarding the vaccination campaign. The opinions were collected through the structured interview, applied through electronic communication channels, between February 20, 2021 and March 1, 2021. Several research questions were the basis of this article: how professional journalists understand the role of the press in a pandemic crisis, in which disinformation, fake news, and deceptive information, decreased trust in vaccination; how journalists relate to the state of balance and what they consider to be the role of the journalistic act, also in relation to the authorities. The most important result of this study is that many of the interviewed journalists believe that, in the context of the national and global health crisis, the correct information is based on scientific evidence and the coverage of official communication, with the role of professional journalism being to combat misinformation, pseudoscience, conspiracies, and fake news.

Prevalence of SARS-CoV-2 antibodies among Belgian nursing home residents and staff during the primary COVID-19 vaccination campaign

Background Nursing home residents (NHR) and staff have been disproportionally affected by the COVID-19 pandemic and were therefore prioritised in the COVID-19 vaccination strategy. However, frail older adults, like NHR, are known to have decreased antibody responses upon vaccination targeting other viral antigens. Objectives As real-world data on vaccine responsiveness, we assessed the prevalence of SARS-CoV-2 antibodies among Belgian NHR and staff during the primary COVID-19 vaccination campaign. Methods In total, we tested 1629 NHR and 1356 staff across 69 Belgian NHs for the presence of SARS-CoV-2 IgM/IgG antibodies using rapid tests. We collected socio-demographic and COVID-19-related medical data through questionnaires. Sampling occurred between 1 February and 24 March 2021, in a randomly sampled population that received none, one or two BNT162b2 vaccine doses. Results We found that during the primary vaccination campaign with 59% of the study population fully vaccinated, 74% had SARS-CoV-2 antibodies. Among fully vaccinated individuals only, fewer residents tested positive for SARS-CoV-2 antibodies (77%) than staff (98%), suggesting an impaired vaccine-induced antibody response in the elderly, with lowest seroprevalences observed among infection naïve residents. COVID-19 vaccination status and previous SARS-CoV-2 infection were predictors for SARS-CoV-2 seropositivity. Alternatively, age ≥ 80 years old, the presence of comorbidities and high care dependency predicted SARS-CoV-2 seronegativity in NHR. Conclusion These findings highlight the need for further monitoring of SARS-CoV-2 immunity upon vaccination in the elderly population, as their impaired humoral responses could imply insufficient protection against COVID-19. Trial registration This study was retrospectively registered on ClinicalTrials.gov (NCT04738695).

Implementation of the COVID-19 vaccination campaign: experiences and perspectives from the point of view of the Association of Statutory Health Insurance Physicians Westfalen-Lippe (KVWL)

The main task of the Association of Statutory Health Insurance Physicians Westfalen-Lippe (KVWL) is to provide comprehensive outpatient medical and psychotherapeutic care in the region of Westfalen-Lippe (WL). It represents approximately 15,000 physicians and psychotherapists. Since the beginning of the COVID-19 pandemic, the range of tasks has expanded to include dealing with the pandemic and its containment.This article describes the implementation of the COVID-19 vaccination campaign in WL, the northeastern part of North Rhine-Westphalia (NRW) with apopulation of 8.3million, as well as the experience gained in setting up vaccination centers and conducting mass vaccinations. Akey problem throughout the time of mass vaccination was the unsteady availability of vaccines. This negatively impacted the operation of the vaccination centers, particularly their utilization and performance. Another burden in the implementation of the vaccination targets was the frequent lack of transparency and comprehensible communication in the dedicated guidelines for the vaccination order (prioritization). Nevertheless, the policy targets were entirely implemented.

Retrospective study of the immunogenicity and safety of the CoronaVac SARS-CoV-2 vaccine in people with underlying medical conditions

BackgroundPeople living with chronic disease, particularly seniors (≥60 years old), made up of most severe symptom and death cases among SARS-CoV-2 infected patients. However, they are lagging behind in the national COVID-19 vaccination campaign in China due to the uncertainty of vaccine safety and effectiveness. Safety and immunogenicity data of COVID-19 vaccines in people with underlying medical conditions are needed to address the vaccine hesitation in this population.MethodsWe included participants (≥40 years old) who received two doses of CoronaVac inactivated vaccines (at a 3–5 week interval) and were healthy or had at least one of 6 common chronic diseases. The incidence of adverse events after vaccination was monitored. Vaccine immunogenicity was studied by determining neutralizing antibodies and SARS-CoV-2-specific T cell responses post vaccination.ResultsHere we show that chronic diseases are associated with a higher rate of mild fatigue following the first dose of CoronaVac. By day 14–28 post vaccination, the neutralizing antibody level shows no significant difference between disease groups and healthy controls, except for people with coronary artery disease (p = 0.0287) and chronic respiratory disease (p = 0.0416), who show moderate reductions. Such differences diminish by day 90 and 180. Most people show detectable SARS-CoV-2-specific T cell responses at day 90 and day 180 without significant differences between disease groups and healthy controls.ConclusionsOur results highlight the comparable safety, immunogenicity and cellular immunity memory of CoronaVac in seniors and people living with chronic diseases. This data should reduce vaccine hesitancy in this population.

Return on Investment of the COVID-19 Vaccination Campaign in New York City

New York City, an early epicenter of the pandemic, invested heavily in its COVID-19 vaccination campaign to mitigate the burden of disease outbreaks. Understanding the return on investment (ROI) of this campaign would provide insights into vaccination programs to curb future COVID-19 outbreaks. To estimate the ROI of the New York City COVID-19 vaccination campaign by estimating the tangible direct and indirect costs from a societal perspective. This decision analytical model of disease transmission was calibrated to confirmed and probable cases of COVID-19 in New York City between December 14, 2020, and January 31, 2022. This simulation model was validated with observed patterns of reported hospitalizations and deaths during the same period. An agent-based counterfactual scenario without vaccination was simulated using the calibrated model. Costs of health care and deaths were estimated in the actual pandemic trajectory with vaccination and in the counterfactual scenario without vaccination. The savings achieved by vaccination, which were associated with fewer outpatient visits, emergency department visits, emergency medical services, hospitalizations, and intensive care unit admissions, were also estimated. The value of a statistical life (VSL) lost due to COVID-19 death and the productivity loss from illness were accounted for in calculating the ROI. During the study period, the vaccination campaign averted an estimated $27.96 (95% credible interval [CrI], $26.19-$29.84) billion in health care expenditures and 315 724 (95% CrI, 292 143-340 420) potential years of life lost, averting VSL loss of $26.27 (95% CrI, $24.39-$28.21) billion. The estimated net savings attributable to vaccination were $51.77 (95% CrI, $48.50-$55.85) billion. Every $1 invested in vaccination yielded estimated savings of $10.19 (95% CrI, $9.39-$10.87) in direct and indirect costs of health outcomes that would have been incurred without vaccination. Results of this modeling study showed an association of the New York City COVID-19 vaccination campaign with reduction in severe outcomes and avoidance of substantial economic losses. This significant ROI supports continued investment in improving vaccine uptake during the ongoing pandemic.

Addressing vaccine hesitancy in developing countries: Survey and experimental evidence.

Vaccine hesitancy is proving to be a significant impediment to COVID-19 vaccination campaigns in some developing countries. This study focuses on vaccine hesitancy and means of reducing it. Data come from a large, representative phone survey and online randomized survey experiment, both run in Papua New Guinea, a developing country with low vaccination rates. Less than 20% of relevant respondents to the phone survey were willing to be vaccinated, primarily because of fear of side effects and low trust in the vaccine. Although vaccine hesitancy was high in the online experiment, participants who received a message emphasizing that the vaccine was safe and COVID-19 dangerous were 68% more likely to state they planned to be vaccinated than those in the control group. A message appealing to social norms was also effective in reducing vaccine hesitancy, although its efficacy was limited to certain types of people.