Mass Vaccination Campaign Research Articles

The Ambivalence of Post COVID-19 Vaccination Responses in Humans.

The Coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has prompted a massive global vaccination campaign, leading to the rapid development and deployment of several vaccines. Various COVID-19 vaccines are under different phases of clinical trials and include the whole virus or its parts like DNA, mRNA, or protein subunits administered directly or through vectors. Beginning in 2020, a few mRNA (Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273) and adenovirus-based (AstraZeneca ChAdOx1-S and the Janssen Ad26.COV2.S) vaccines were recommended by WHO for emergency use before the completion of the phase 3 and 4 trials. These vaccines were mostly administered in two or three doses at a defined frequency between the two doses. While these vaccines, mainly based on viral nucleic acids or protein conferred protection against the progression of SARS-CoV-2 infection into severe COVID-19, and prevented death due to the disease, their use has also been accompanied by a plethora of side effects. Common side effects include localized reactions such as pain at the injection site, as well as systemic reactions like fever, fatigue, and headache. These symptoms are generally mild to moderate and resolve within a few days. However, rare but more serious side effects have been reported, including allergic reactions such as anaphylaxis and, in some cases, myocarditis or pericarditis, particularly in younger males. Ongoing surveillance and research efforts continue to refine the understanding of these adverse effects, providing critical insights into the risk-benefit profile of COVID-19 vaccines. Nonetheless, the overall safety profile supports the continued use of these vaccines in combating the pandemic, with regulatory agencies and health organizations emphasizing the importance of vaccination in preventing COVID-19's severe outcomes. In this review, we describe different types of COVID-19 vaccines and summarize various adverse effects due to autoimmune and inflammatory response(s) manifesting predominantly as cardiac, hematological, neurological, and psychological dysfunctions. The incidence, clinical presentation, risk factors, diagnosis, and management of different adverse effects and possible mechanisms contributing to these effects are discussed. The review highlights the potential ambivalence of human response post-COVID-19 vaccination and necessitates the need to mitigate the adverse side effects.

Cost of COVID-19 vaccine delivery in nine States in Nigeria via the U.S. Government Initiative for Global Vaccine Access

BackgroundIn 2022, the U.S. Centers for Disease Control and Prevention collaborated with implementing partners, African Field Epidemiology Network and Sydani Group, to support COVID-19 vaccination efforts in Nigeria. To characterize the costs of COVID-19 vaccination, this study evaluated financial costs per dose for activities implemented to support the intensification campaign for COVID-19 vaccination.MethodsThis retrospective evaluation collected secondary data from existing expenditure and programmatic records on resource utilization to roll out COVID-19 vaccination during 2022. The study included incremental financial costs of the activities implemented to support an intensification campaign for COVID-19 vaccination across nine states and six administrative levels in Nigeria from the perspective of the external donor (U.S. Government). Costs for vaccines and injection supplies, transport of vaccines, and any economic costs, including government in-kind contributions, were not included. All costs were converted from Nigerian Naira to 2022 U.S. Dollars (US$).ResultsThe estimated financial delivery cost of the COVID-19 vaccination intensification campaign was US$0.84 per dose (total expenditure of US$6.29 million to administer 7,461,971 doses). Most of the financial resources were used for fieldwork activities (86%), followed by monitoring and supervision activities (8%), coordination activities (5%), and training-related activities (1%). Labor (58%) and travel (37%) were the resource inputs that accounted for the majority of the cost, while shares of other resource inputs were marginal (1% for each). Most labor costs (79%) were spent on payments for mass vaccination campaign teams, including pay-for-performance incentives. By administrative level, the largest share of costs (46%) was for pay-for-performance incentives at the community, health facility, or campus levels combined, followed by local government area level (24%), community level only (15%), state level (9%), national level (3%), campus level only (1%), and health facility level only (< 1%).ConclusionsFindings from the evaluation can help to inform resources needed for vaccination activities to respond to future outbreaks and pandemics in resource-limited settings, particularly to reach new target populations not regularly included in routine childhood immunization delivery.

Raising the case of hepatitis E: Report from the 2nd international HEV symposium

The 2nd International Hepatitis E Virus Symposium was held on April 28 and 29, 2023, in London, UK. The conference was hosted by the International Vaccine Institute and brought together key clinicians, researchers, and private and public stakeholders for a dedicated forum on hepatitis E virus (HEV). The scientific program spanned multiple facets of HEV, from updates on clinical research and diagnostic advances to vaccine development. The conference highlighted presentations on several critical HEV vaccine studies that will greatly impact the field, including the largest effectiveness study of Hecolin vaccine outside of China and the first reactive mass-vaccination campaign in South Sudan. This report summarizes information shared at the convening and offers perspectives on the steps forward for hepatitis E.

Key stakeholder perspectives on delivery of vaccination services in Quebec community pharmacies.

Undervaccination is a public health issue that disproportionately affects underserved populations. Pharmacists are accessible health care professionals who have the potential to better reach communities. The aim of this study is to understand how organizational obstacles influence the pharmacist's ability to meet underserved clients' vaccination needs in community pharmacy. We conducted semi-structured interviews with key stakeholders in Quebec. Results were codified according to domains of the Consolidated Framework for Implementation Research. Fourteen interviews were carried out with representatives from pharmacy associations, pharmacy chains and banners, integrated health and social service centres, and local Quebec Public Health departments. Barriers to promoting vaccination were identified in four areas: 1) vaccine service logistics, 2) the pharmacy setting, 3) external influences and 4) pharmacist's knowledge and beliefs. Technological tools accessible to pharmacists are sufficient but not user-friendly due to the lack of integration between the pharmacy software, the vaccine registry and the provincial appointment system. Technology limits access to vaccination for certain underserved populations. Moreover, the incentives linked to vaccination do not favour the vaccination of difficult-to-reach clients and they limit pharmacists' ability to be proactive with vaccine recommendations. Pharmacists are more inclined to participate in mass vaccination campaigns, and delegating vaccine administration to nurses and technicians allows pharmacies to financially break even. Certain services such as travel health vaccination require an extended set of knowledge, which creates resistance for some pharmacists to integrate the role. Pharmacists are well-placed to improve vaccination uptake, but several technological and organizational barriers limit their ability to provide vaccination services and reach underserved communities. A better alignment between incentives and proactive promotion should be put forward to encourage pharmacists to actively identify and reach underserved populations.

Wastewater-Based Surveillance Reveals the Effectiveness of the First COVID-19 Vaccination Campaigns in Assisted Living Facilities.

The COVID-19 pandemic has disproportionately affected vulnerable populations, including residents of assisted living facilities (ALFs). This study investigates the impact of non-pharmaceutical interventions (NPIs) and mass vaccination campaigns on SARS-CoV-2 transmission dynamics within four ALFs in Maricopa County, Arizona, United States from January to April 2021. Initial observations reveal a significant SARS-CoV-2 prevalence in Maricopa County, with 7452 new COVID-19 cases reported on 4 January 2021. Wastewater surveillance indicates elevated viral loads within ALFs with peak concentrations reaching 1.35 × 107 genome copies/L at Facility 1 and 4.68 × 105 copies/L at Facility 2. The implementation of NPIs, including isolation protocols, resulted in a rapid decline in viral loads in wastewater. Following mass vaccination campaigns, viral loads reduced across all facilities, except Facility 4. Facility 1 demonstrated a mean viral load decrease from 1.65 × 106 copies/L to 1.04 × 103 copies/L post-vaccination, with a statistically significant U-statistic of 28.0 (p-value = 0.0027). Similar trends are observed in Facilities 2 and 3, albeit with varying degrees of statistical significance. In conclusion, this study provides evidence supporting the role of NPIs and vaccination campaigns in controlling SARS-CoV-2 transmission within ALFs.

Monkeypox: A Growing Global Health Challenge and the Need for Vigilant Preparedness

The Ongoing Public Health Challenge of Monkeypox Monkeypox is relatively a new threat to the global community as it has brought into focus the issue of improved surveillance and response to infectious diseases[1]. Initially, a rather exotic zoonotic pathogen limited to certain regions of Central and West Africa, monkeypox is being detected in the countries that previously did not report its occurrence, which creates new challenges for the health care systems of the world[2]. Understanding the Disease Monkeypox is an infectious disease that results from the attack of monkeypox virus which is in the Ortho poxvirus group of the virus family Poxviridae though the smallpox virus has been eradicated. The disease has some symptoms are similar to smallpox and includes fever, body aches, and rash that goes through different stages. Despite the fact that monkeypox is less severe when compared with smallpox, significant morbidity and potentially mortality cannot be ruled out[3]. Direct human-to-human transmission is by contact with infected body fluids, aerosols, or fomites such as used clothing, beddings among others. Recent epidemics have been experienced in the urban areas as this makes it easier for the virus to spread due to high population densities. This has transformed the disease from one which affected isolated African communities to a problem in developed, globally connected cities[4]. Why Should We Be Concerned? The stoppage of smallpox vaccination has exposed the people to Ortho poxviruses such as monkeypox. The constant risk of getting zoonotic diseases due to factors such as deforestation, urbanization and close interaction with animals means that diseases, which are mainly associated with animals, can easily infect human beings. Furthermore, the flexibility in the global interconnectivity of today’s world through travel and business has facilitated the spread of the virus across the borders. In 2022, 34 monkeypox cases were reported in European countries, the Americas, and other areas of the world, where the disease had not been identified[5, 6]. The Public Health Response To this recent outbreak of the disease, the WHO and the CDC have scaled up awareness campaigns and encouraged surveillance as well as put in place measures to contain the spread of the disease. Mass vaccination campaigns using smallpox vaccines that work against monkeypox have been intensified in the affected countries, however, there are several problems with implementing this approach: the difficulties of delivering vaccines in time and the scarcity of the vaccines themselves[7]. These are important in educating communities on how to avoid the disease and this include avoiding contact with sick persons, washing hands regularly and consulting a doctor when experiencing early symptoms of the disease. It also means that health systems need to be ready and able to identify such patients and isolate them to avoid spreading of the virus[8, 9]. Looking Forward The spread of monkeypox in the non-endemic countries is a cause of concern and questions the efficiency of our societies’ prevention, detection, and controlling of infectious diseases. Even as the current outbreaks have informed the world of the virus, it is important to note that this is not a one-off case[10]. Zoonotic diseases, which can be transmitted from animals to people, will remain a threat into the future as people increase in numbers and expand their living space into the domain of wildlife. The fight against monkeypox is the fight against all other infectious diseases that can be most effectively fought for with a proper approach and mutual cooperation of all countries[11]. Monkeypox is not as dangerous as some other infectious diseases but looking at the example of how this disease affected people one can conclude that public health cannot be unguarded. Prevention of such diseases in the future would require increased investment in the global health care system, outcome of research on new diseases and vaccination exercises. We cannot afford to wait for another pandemic to happen in order to start acting[12, 13].

The impact of coronavirus pandemic shutdowns on immunization completion in Hadeetha, Anbar, Iraq: A case-study of vaccine completion in a recovering healthcare system

The SARS-COV2 pandemic caused significant disruptions in immunization delivery. Baseline deficit gaps in immunization completion exacerbated ongoing disparities in immunization coverage in low- and middle-income. Emerging reports focused on global strategies for return to routine immunization schedules. Currently, there are no studies that examined the dual challenge of returning to normal immunization in a conflict-recovery setting, such as the ISIS (Islamic State of Iraq and Syria) occupation of Iraq post-COVID-19 pandemic.The objective of this study was to estimate the number of children in Hadeetha, Iraq from 12 to 24 months of age who continued to be lost to the routine immunization schedule due to the COVID-19 pandemic shutdowns. Random sampling occurred from a compiled district health facility registrar of all children in the target birth cohort who had a 12-month immunization scheduled during the 2020 lockdown and were lost to the immunization schedule. A total of 171 households from the sampling frame were included in the final sample. In this cross-sectional study, survey data was collected on the head of the household, the caregiver and the child. Additional questions assessed vaccine hesitancy, vaccine information trusted sources and COVID-19 impact on healthcare access. A risk factor analysis was applied to assess using Chi-square (Χ2) for predictors of lack of DTP3 (Diphtheria, Tetanus and Polio) third dose completion. Of children in the study, 67.3 % did not complete the 6-antigen series at 12-months of age and 46.2 % were missing DTP3 for vaccines to be completed during the pandemic shutdown. Specific risk factors for lack of immunization for the DTP3 vaccine included area of residence, age and caregiver knowledge of vaccines. Respondents indicated a dependence on mass vaccination campaigns but also indicated a willingness to receive phone reminders and television campaigns about vaccination schedules.

Monitoring the VDPV2 outbreak in Egypt during 2020–2021 highlights the crucial role of environmental surveillance and boosting immunization in combating Poliovirus

BackgroundPoliovirus is a highly infectious enterovirus (EV) that primarily affects children and can lead to lifelong paralysis or even death. Vaccine-derived polioviruses (VDPVs) are a great threat since they are derived from the attenuated virus in the Oral Poliovirus Vaccine (OPV) and can mutate to a more virulent form. The purpose of this study was to identify VDPV serotype 2 through the year 2020–2021 via surveillance of sewage samples collected from different localities and governorates in Egypt and stool specimens from Acute Flaccid Paralysis (AFP) cases. Both were collected through the national poliovirus surveillance system and according to the guidelines recommended by the WHO.MethodsA total of 1266 sewage samples and 3241 stool samples from January 2020 to December 2021 were investigated in the lab according to World Health Organization (WHO) protocol for the presence of Polioviruses by cell culture, molecular identification of positive isolates on L20B cell line was carried out using real-time polymerase chain reactions (RT-PCR). Any positive isolates for Poliovirus type 2 and isolates suspected of Vaccine Derived Poliovirus Type 1 and type 3 screened by (VDPV1) or Vaccine Poliovirus Type 3 (VDPV3) assay in RT-PCR were referred for VP1 genetic sequencing.ResultsThe outbreak was caused by circulating VDPV2 (cVDPV2) strains started in January 2021. By the end of February 2021, a total of 11 cVDPV2s were detected in sewage samples from six governorates confirming the outbreak situation. One additional cVDPV2 was detected later in the sewage sample from Qena (June 2021). The first and only re-emergence of VDPV2 in stool samples during the outbreak was in contact with Luxor in June 2021. By November 2021, a total of 80 VDPVs were detected. The Egyptian Ministry of Health and Population (MOHP), in collaboration with the WHO, responded quickly by launching two massive vaccination campaigns targeting children under the age of five. Additionally, surveillance systems were strengthened to detect new cases and prevent further spread of the virus.ConclusionThe continued threat of poliovirus and VDPVs requires ongoing efforts to prevent their emergence and spread. Strategies such as improving immunization coverage, using genetically stable vaccines, and establishing surveillance systems are critical to achieving global eradication of poliovirus and efficient monitoring of VDPVs outbreaks.

Tracking Measles and Rubella Elimination Progress-World Health Organization African Region, 2022-2023.

Measles or rubella elimination is verified when endemic transmission of the corresponding virus has been absent for over 36 months in a defined area, in the presence of a well-performing surveillance system. This report updates the progress by 47 countries in the WHO African Region towards the goal of attaining verification of measles and rubella elimination in at least 80% of the countries of the region by 2030. We reviewed the WHO-UNICEF vaccination coverage estimates for the first and second doses of measles- and measles-rubella-containing vaccines, as well as the available coverage data for measles supplementary immunization activities, during 2022-2023. We also reviewed the measles-surveillance performance and analyzed the epidemiological trends of measles and rubella as reported in the case-based surveillance database. The WHO-UNICEF estimates of first measles vaccine dose (MCV1) and second measles vaccine dose (MCV2) coverage for the African Region for 2022 were 69% and 45%, respectively. Rubella-containing vaccines have been introduced in the routine immunization program in 32 of 47 (68%) countries as of the end of 2022, with no introductions during 2023. In 2022 and 2023, a total of 144,767,764 children were vaccinated in the region with measles or MR vaccines in 24 countries through 32 mass vaccination campaigns. The administrative coverage target of 95% was reached in only 15 (49%) of the 32 vaccination campaigns. In 2023, a total of 125,957 suspected cases of measles were reported through the case-based surveillance system, and 73,625 cases (58%) were confirmed to be measles, either by laboratory testing, by epidemiological linkage, or based on clinical compatibility. A total of 4805 confirmed rubella cases were reported, though this total represents substantial under-ascertainment. The regional incidence of measles was 60.3 cases per million population. Twenty-six countries (55%) met the targets for the two principal surveillance system performance-monitoring indicators. No country in the region has attained the verification of measles or rubella elimination as of the end of 2023. Addressing systemic problems with routine immunization and using tailored approaches to reach unvaccinated children can contribute to progress towards measles and rubella elimination. In addition, periodic and timely high-quality preventive SIAs remain a critical programmatic strategy to reach unvaccinated children.

Factors associated with the rabies vaccination status of dogs in households in Beni City, D.R. Congo.

Human rabies transmitted by dogs still kills thousands of people each year worldwide. Dog bites are common in the city of Beni (Democratic Republic of Congo), which shows low rabies vaccination coverage. This study aimed to determine the factors associated with the rabies vaccination status of dogs. A cross-sectional analytical study was conducted in the town of Beni among dog owners, during a household survey selected using a multistage sampling. The information sought concerned the knowledge and characteristics of the dog owners as well as the vaccination status of these dogs. Logistic regression was used to investigate associations between the vaccination status of the dogs and the main independent factors. Rabies vaccination coverage in Beni was 26% (95% confidence interval [CI]: 22% - 30%). The main factors associated with the rabies vaccination status of the dog were primary education level of household head (adjusted odds ratio [aOR]:4.8; 95% CI: 1.2- 19.8); university education level of household head (aOR: 5.9; 95% CI: 1.6-22); perceived rabies severity (aOR: 44. 4; 95% CI: 10.4-188), having more than one dog in the household (aOR: 2.6; 95% CI: 1.6-4.3); age range 7-12 months (aOR: 0.2; 95% CI: 0.1-0.6) and confined dog breeding (aOR: 3.9; 95% CI: 1.1-14.9). The low vaccination coverage in Beni requires mass vaccination campaigns against canine rabies targeting the dog owners with low education levels, those raising more than one dog, with stray dogs or dogs less than 12 months old.

All-cause mortality according to COVID-19 vaccination status: An analysis of the UK office for National statistics public data

Background The mass vaccination campaign against COVID-19 has been commonly considered the best response to the global COVID-19 pandemic crisis. However, to assess its real-world overall effects, the best way can be the analysis of all-cause mortality by vaccination status. The UK is perhaps the only country which has made publicly available all-cause mortality data by vaccination status. Methods Data from April 2021 to May 2023 published by the UK Office for National Statistics (ONS) were retrospectively analyzed by age groups and vaccination status; the standardized mortality ratio (SMR) for all-cause and non-COVID-19 mortality was calculated against the corresponding unvaccinated groups. Results We found that across all age groups, all-cause mortality SMRs increased from a certain date, dependent on the age group. Across all age groups, all-cause mortality SMRs were initially much lower than 1. However, due to their increase, by a certain date for the 18-39, 80-89 and 90+ age groups they exceeded the reference value. For the other age groups, the date at which the SMR would reach 1 can be predicted, provided the trend is maintained. Non-COVID-19 SMRs’ trends were very similar. Their initial values much lower than 1 are suggestive of significant biases in the ONS dataset, leading to underestimate the risks for the vaccinated people, as it is implausible that COVID-19 vaccines protect against non-COVID-19 deaths. Conclusions The increase over time in all-cause death SMRs in vaccinated people compared to unvaccinated, and their excess from the reference values for certain age groups, should be carefully considered to understand the underlying factors. It would be desirable for other major countries to systematically collect all-cause mortality by vaccination status and, in the meantime, a moratorium on promoting mass vaccination campaigns should be implemented.

Optimal Allocation of Multi-Type Vaccines in a Two-Dose Vaccination Campaign for Epidemic Control: A Case Study of COVID-19

As a typical case of the optimal planning for the provision of restricted medical resources, widespread vaccination is considered an effective and sustainable way to prevent and control large-scale novel coronavirus disease 2019 (COVID-19) outbreaks. However, an initial supply shortage of vaccines is inevitable because of the narrow production and logistical capacity. This work focuses on the multi-type vaccine resource allocation problem in a two-dose vaccination campaign under limited supply. To address this issue, we extended an age-stratified susceptible, exposed, infectious, and recovered (SEIR) epidemiological model to incorporate a two-dose vaccination campaign involving multiple vaccine types to fully characterize the various stages of infection and vaccination. Afterward, we integrated the proposed epidemiological model into a nonlinear programming (NLP) model to determine the optimal allocation strategy under supply capacity and vaccine hesitancy constraints with the goal of minimizing the cumulative number of deaths due to the pandemic over the entire planning horizon. A case study based on real-world data from the initial mass vaccination campaign against COVID-19 in the Midlands, England, was taken to validate the applicability of our model. Then, we performed a comparative study to demonstrate the performance of the proposed method and conducted an extensive sensitivity analysis on critical model parameters. Our results indicate that prioritizing the allocation of vaccines to elderly persons is an effective strategy for reducing COVID-19-related fatalities. Furthermore, we found that vaccination alone will not be sufficient for epidemic control in the short term, and appropriate non-pharmacological interventions are still important for effective viral containment during the initial vaccine rollout. The results also showed that the relative efficacy of the first dose is a vital factor affecting the optimal interval between doses. It is always best to complete the two-dose vaccination schedule as soon as possible when the relative efficacy of the first dose is low. Conversely, delaying the second dose of a vaccine as long as possible to increase the proportion of the population vaccinated with a single dose tends to be more favorable when the relative efficacy of the first dose is high. Finally, our proposed model is general and easily extendable to the study of other infectious disease outbreaks and provides important implications for public health authorities seeking to develop effective vaccine allocation strategies for tackling possible future pandemics.

Assessing the resilience of child immunisation programmes using geospatial modelling and interrupted time series analysis in Ethiopia and Kenya amidst the COVID-19 pandemic: tracking coverage and identifying key challenges

IntroductionThe COVID-19 pandemic disrupted healthcare provision and access in sub-Saharan Africa. Lockdowns and travel restrictions, coupled with fear of contracting the virus, disrupted services, especially for women’s and children’s health,...

Rabies Realities: Navigating Barriers to Rabies Control in Rural Zambia-A Case Study of Manyinga and Mwansabombwe Districts.

Rabies persists as a longstanding issue in Zambia, despite being preventable. The current control measures, including dog vaccination, population control, and movement restriction, guided by 'The Control of Dogs Act Chapter 247 of the Laws of Zambia', have not yielded the desired impact in many areas of the country including Manyinga and Mwansabombwe districts. These two districts continue to report low dog vaccination rates, unrestricted dog movements, and escalating cases of animal and human rabies, along with dog bites. Aligned with global aspirations to achieve zero human rabies cases by 2030, this study scrutinizes the determinants and obstacles hampering the execution of rabies control initiatives in Manyinga and Mwansabombwe. Spanning approximately 11 months, this cross-sectional study gathered pre- and post-vaccination data from 301 households in Manyinga and 100 households in Mwansabombwe. Questionnaires probed knowledge, attitudes, and practices related to rabies prevention and control. A transect survey, key informant interviews, and assessment of rabies vaccination and dog bite records complemented the data collection. Findings revealed that 88.0% of respondents from both districts possessed knowledge about rabies, confirming affected species and transmission. Moreover, 76.8% in Manyinga and 88.6% in Mwansabombwe were acquainted with rabies prevention and control methods. Concerning dog owners, 89.0% were aware of rabies, 66.0% understood its prevention and control, and the majority identified bites as the primary mode of transmission. Despite the high level of knowledge recorded during the survey, the implementation of preventive measures was low, which was attributed to low levels of law enforcement by the local government authority, inadequate staffing in the veterinary department, unwillingness to pay for dog vaccinations, and unavailability of rabies vaccine at the veterinary office in both districts. Vaccination coverage stood at 64.0% in Manyinga and 21.0% in Mwansabombwe. Notably, education and occupation exhibited a positive significant association with rabies knowledge. In terms of dog bite cases, Manyinga recorded 538 dog bite cases from 2017 to June 2022, while Mwansabombwe recorded 81 dog bite and 23 jackal bite cases from 2021 to June 2022. The study underscores critical knowledge gaps in rural areas and emphasizes the imperative for enhanced public education and awareness programs, improved rabies surveillance, free mass vaccination campaigns, and community engagement to augment vaccination coverage and knowledge about rabies.

Assessing seropositivity of MMR antibodies in individuals aged 2–22: evaluating routine vaccination effectiveness after the 2003 mass campaign-a study from Iran’s National Measles Laboratory

Background and purposeThe seroprevalence of antibodies against measles, mumps, and rubella (MMR) was evaluated 17 years following a mass vaccination campaign in individuals aged 2 to 22 years who had received routine immunization but were not eligible for an extended immunization program.MethodsSamples were acquired from Iran’s National Measles Laboratory (NML), with individuals showing positive IgM results excluded. Out of the samples collected in 2020, a random selection of 290 serum samples was chosen, representing individuals between the ages of 2 and 22 years from diverse regions in the country. These samples were subjected to analysis using an enzyme-linked immunosorbent assay (ELISA) to quantify specific IgG antibodies against MMR.ResultsThe seroprevalence rates of antibodies for measles, mumps, and rubella were determined to be 76.2%, 89.3%, and 76.9%, respectively. Younger age groups exhibited higher seropositivity rates for measles and mumps, whereas the 7- to 11-year-old group demonstrated the highest seropositivity rate for rubella. A reduction in antibody status was observed from younger to older age groups, particularly those aged 17–22.ConclusionThe study unveiled suboptimal antibody levels for measles and rubella, highlighting the necessity for further investigation and potential adjustments to future vaccination strategies. Moreover, the decline in antibody status post-vaccination can accumulate in seronegative individuals over time, elevating the risk of outbreaks.

Coverage of Two-Dose Preemptive Cholera Mass Vaccination Campaign in High-Priority Hotspots in Shashemene, Oromia Region, Ethiopia.

Cholera is a public health priority in Ethiopia. The Ethiopian National Cholera Plan elaborates a multi-year scheme of oral cholera vaccine (OCV) use. Aligned with this, a preemptive OCV campaign was conducted under our Ethiopia Cholera Control and Prevention project. Here, we present the OCV vaccination outcomes. Cholera high-priority hotspots in the Oromia Region, Shashemene Town (ST) and Shashemene Woreda (SW), were selected. Four kebelles (Abosto, Alelu, Arada, and Awasho) in ST and 4 clusters (Faji Gole, Harabate, Toga, and Chabi) in SW were study sites with OCV areas nested within. A total of 40 000 and 60 000 people in ST and SW, respectively, were targeted for a 2-dose OCV (Euvichol-Plus) campaign in 11-15 May (first round [R1]) and 27-31 May (second round [R2]) 2022. Daily administrative OCV coverage and a coverage survey in 277 randomly selected households were conducted. The administrative OCV coverage was high: 102.0% for R1 and 100.5% for R2 in ST and 99.1% (R1) and 100.0% (R1) in SW. The coverage survey showed 78.0% (95% confidence interval [CI]: 73.1-82.9) of household members with 2-dose OCV and 16.8% (95% CI: 12.4-21.3) with no OCV in ST; and 83.1% (95% CI: 79.6-86.5) with 2-dose OCV and 11.8% (95% CI: 8.8-14.8) with no OCV in SW. The 2-dose coverages in 1-4-, 5-14-, and ≥15-year age groups were 88.3% (95% CI: 70.6-96.1), 88.9% (95% CI: 82.1-95.7), and 71.3% (95% CI: 64.2-78.3), respectively, in ST and 78.2% (95% CI: 68.8-87.7), 91.0% (95% CI: 86.6-95.3), and 78.7% (95% CI: 73.2-84.1) in SW. High 2-dose OCV coverage was achieved. Cholera surveillance is needed to assess the vaccine impact and effectiveness.

Enhancing Mass Vaccination Programs with Queueing Theory and Spatial Optimization.

Mass vaccination is a cornerstone of public health emergency preparedness and response. However, injudicious placement of vaccination sites can lead to the formation of long waiting lines or queues , which discourages individuals from waiting to be vaccinated and may thus jeopardize the achievement of public health targets. Queueing theory offers a framework for modeling queue formation at vaccination sites and its effect on vaccine uptake. We developed an algorithm that integrates queueing theory within a spatial optimization framework to optimize the placement of mass vaccination sites. The algorithm was built and tested using data from a mass canine rabies vaccination campaign in Arequipa, Peru. We compared expected vaccination coverage and losses from queueing (i.e., attrition) for sites optimized with our queue-conscious algorithm to those obtained from a queue-naive version of the same algorithm. Sites placed by the queue-conscious algorithm resulted in 9-19% less attrition and 1-2% higher vaccination coverage compared to sites placed by the queue-naïve algorithm. Compared to the queue-naïve algorithm, the queue-conscious algorithm favored placing more sites in densely populated areas to offset high arrival volumes, thereby reducing losses due to excessive queueing. These results were not sensitive to misspecification of queueing parameters or relaxation of the constant arrival rate assumption. One should consider losses from queueing to optimally place mass vaccination sites, even when empirically derived queueing parameters are not available. Due to the negative impacts of excessive wait times on participant satisfaction, reducing queueing attrition is also expected to yield downstream benefits and improve vaccination coverage in subsequent mass vaccination campaigns.

Assessing the impacts of vaccination and viral evolution in contact networks

A key lesson learned with COVID-19 is that public health measures were very different from country to country. In this study, we provide an analysis of epidemic dynamics using three well-known stochastic network models—small-world networks (Watts–Strogatz), random networks (Erdös–Rényi), and scale-free networks (Barabási–Albert)—to assess the impact of different viral strains, lockdown strategies, and vaccination campaigns. We highlight the significant role of highly connected nodes in the spread of infections, particularly within Barabási–Albert networks. These networks experienced earlier and higher peaks in infection rates, but ultimately had the lowest total number of infections, indicating their rapid transmission dynamics. We also found that intermittent lockdown strategies, particularly those with 7-day intervals, effectively reduce the total number of infections, serving as viable alternatives to prolonged continuous lockdowns. When simulating vaccination campaigns, we observed a bimodal distribution leading to two distinct outcomes: pandemic contraction and pandemic expansion. For WS and ER networks, rapid mass vaccination campaigns significantly reduced infection rates compared to slower campaigns; however, for BA networks, differences between vaccination strategies were minimal. To account for the evolution of a virus into a more transmissible strain, we modeled vaccination scenarios that varied vaccine efficacy against the wild-type virus and noted a decline in this efficacy over time against a second variant. Our results showed that vaccination coverage above 40% significantly flattened infection peaks for the wild-type virus, while at least 80% coverage was required to similarly reduce peaks for variant 2. Furthermore, the effect of vaccine efficacy on reducing the peak of variant 2 infection was minimal. Although vaccination strategies targeting hub nodes in scale-free networks did not substantially reduce the total number of infections, they were effective in increasing the probability of preventing pandemic outbreaks. These findings underscore the need to consider the network structure for effective pandemic control.

Incidence of neurological complication symptoms post-mRNA vaccination among the urban population of Makkah Province of Kingdom of Saudi Arabia

ObjectiveThis research aimed to assess the incidence of neurological complication symptoms among residents of the Makkah province in Saudi Arabia following the rapid approval and administration of mRNA vaccines. Given the differences in demographic factors such as age, race, medical history, and lifestyle among individuals, close monitoring of vaccine-related side effects becomes crucial, especially in mass vaccination campaigns. MethodA cross-sectional online survey study was conducted in both English and Arabic languages, with a sample size determined using the Raosoft sample size calculator statistical analyzer. The study aimed for a 95% confidence level, a 5% margin of error, and a response distribution of 50%. Descriptive statistics were employed using Statistical Package for Social Sciences version 22.0. The Shapiro–Wilk test was utilized to assess data normality, and the statistical significance of the data was determined using Pearson's Chi-Squared test and the Kruskal–Wallis test. ResultThe study included 846 volunteers aged 18 and above, all of whom had received mRNA vaccine in the Makkah region. Data were systematically tabulated and categorized for descriptive analysis. The study found P-values less than .05, and the summarized P-values were presented. The majority of participants (73%) were from the Taif area (32%) within the Makkah region. ConclusionThis study sheds light on the challenges faced by the population of the Makkah region in Saudi Arabia following mRNA vaccinations. Although some complications were reported post-vaccination, it is noteworthy that these challenges were effectively managed by the medical authorities.

Systematic Review of the Epidemiology, disease severity and preventive measures of Mpox disease: A public health guideline for densely-populated countries

Background Research on Mpox is essential to protect public health, develop effective interventions, and enhance global preparedness for infectious disease outbreaks. Owing to the scarcity of any specific treatment for Mpox disease, public health guidelines are important for patient care and management. Therefore, this systematic review suggests a public health policy guidelines to control Mpox diseases, especially in densely populated countries. Methods In this systematic review study, the databases and search engines PubMed, Scopus, BanglaJol, WHO, and Google Scholar were searched, and related literature was retrieved for further investigation. Articles describing monkeypox epidemiology, clinical symptoms, and preventive strategies, and published in English language were the core inclusion criteria; articles published in other languages were excluded. All records in the literature were managed through Mendeley (version 1.19.4) reference manager and summarized for further investigation. Results Mpox severity is prevalent in America and Europe. Male (96.3%) and young adults aged 18-44 years (mean: 34 years) were the most vulnerable population due to the virus. Among the patients, rash and fever were the most frequent symptoms, with cough, vomiting, anogenital pain and/or bleeding, conjunctivitis, diarrhea, and genital edema being the least prevalent symptoms in less than 5% of the patients. As there is no specific treatment for the disease, infection control in densely populated countries require early detection, isolation of infected individuals, strict infection control measures, mass vaccination campaigns, education, public awareness campaigns, and continued investment in research. Conclusions This study underscores the urgent need for comprehensive infection control strategies, including early detection, strict isolation protocols, mass vaccination initiatives, and ongoing research investment given the absence of specific treatment options for the disease.