Pandemic modelling for regions implementing an elimination strategy

Northern shortfin squid (Illex illecebrosus) and longfin inshore squid (Doryteuthis pealeii) are fished commercially and recreationally off Atlantic Canada, but limited reporting, particularly from recreational fisheries, has left major gaps in our understanding of their ecology and fishery dynamics. Our research used three years of data collected through citizen science initiatives, field visits, and commercial index harvesters to provide much-needed descriptions of squid fisheries and basic ecological characteristics, with a particular focus on Newfoundland and Labrador (NL). We documented active recreational squid fisheries landing both species, including the first confirmed observations of longfin inshore squid in the NL fishery. Distinct regional patterns emerged. North Coast Region fishers tended to use different gear and practices, achieved higher catch-per-unit effort (CPUE), and caught larger squid compared to other NL regions. South Coast Region fishers more frequently caught longfin inshore squid, and although relatively low CPUE was reported, this region tended to have a more active recreational fishery. Our findings reveal previously unrecognized regional variation in squid fisheries and highlight the need for improved understanding of squid ecology and the impacts of the recreational and commercial fisheries on the resource off Atlantic Canada.

Although New York State (NYS) recently adopted legislation eliminating nonmedical vaccination exemption options from school-entry requirements, the implications of the law for school vaccine coverage and medical vaccine exemption uptake have not been examined. To evaluate the implications of the repeal of school-entry nonmedical vaccination exemptions for vaccine coverage and medical exemption uptake at NYS schools outside of New York City (NYC). This cohort study had an interrupted time-series design and used generalized estimating equation models to examine longitudinal school immunization compliance data from the 2012 to 2013 through 2021 to 2022 school years. The cohort comprised NYS public and nonpublic schools, excluding NYC schools, with any students enrolled in kindergarten to 12th grade. Eligible schools had enrollment and immunization data before and after the implementation of the Senate Bill 2994A legislation. Data analyses were conducted in July 2023. Senate Bill 2994A was passed in June 2019, eliminating school-entry nonmedical vaccination exemptions. Since compliance with the law was evaluated for most students during the next school year, the 2019 to 2020 school year was considered to be the law's effective date. The primary outcomes were school vaccine coverage (defined as the percentage of students at each school who completed grade-appropriate requirements for all required vaccines) and medical exemption uptake (defined as the percentage of students at each school who received a medical exemption). Among the 3821 eligible schools, 3632 (95.1%) were included in the analysis, representing 2794 (96.9% of eligible) public schools and 838 (89.2% of eligible) nonpublic schools. The implementation of Senate Bill 2994A was associated with absolute increases in mean vaccine coverage of 5.5% (95% CI, 4.5%-6.6%) among nonpublic schools and 0.9% (95% CI, 0.7%-1.1%) among public schools, with additional annual increases in vaccine coverage observed through the 2021 to 2022 school year. The law's implementation was also associated with a 0.1% (95% CI, 0.0%-0.1%) mean absolute decrease in medical vaccination exemption uptake at both public and nonpublic schools, and small but significant mean annual decreases in medical vaccination exemptions (0.02%; 95% CI, 0.01%-0.03%) through the end of the study period. Results of this cohort study suggested that repeal of school-entry nonmedical vaccination exemptions was associated with increased vaccine coverage at NYS schools outside of NYC. Coverage gains were not replaced by increases in medical vaccination exemptions.

IntroductionTo assess potential benefits and direct healthcare cost savings with expansion of an existing childhood influenza immunisation program, we developed a dynamic transmission model for the state of Western Australia, evaluating increasing coverage in children < 5 years and routinely immunising school-aged children. MethodsA deterministic compartmental Susceptible-Exposed-Infectious-Recovered age-stratified transmission model was developed and calibrated using laboratory-notification and hospitalisation data. Base case vaccine coverage estimates were derived from 2019 data and tested under moderate, low and high vaccine effectiveness settings. The impact of increased coverage on the burden of influenza, influenza-associated presentations and net costs were assessed using the transmission model and estimated health utilisation costs. ResultsUnder base case vaccine coverage and moderate vaccine effectiveness settings, 225,460 influenza cases are expected annually across all ages. Direct healthcare costs of influenza were estimated to be A$27,608,286 per annum, dominated by hospital costs. Net cost savings of >$A1.5 million dollars were observed for every 10 % increase in vaccine coverage in children < 5 years. Additional benefits were observed by including primary school age children (5–11 years) in the funded influenza vaccination program - a reduction in cases, presentations, hospitalisations and approximately $A4 million net costs savings were observed for every 10 % increase in coverage. The further addition of older children (12–17 years) resulted in only moderate additional net cost savings figures, compared with a 5–11year-old program alone. Net costs savings were predominantly derived by a reduction in influenza-associated hospitalisation in adults. ConclusionsAny increase in influenza vaccine coverage in children < 5 years, above a base case of 50 % coverage resulted in a substantive reduction in influenza cases, presentations, hospitalisations and net costs when applied to the West Australian population. However, the most impactful pediatric program, from both a disease prevention and costs perspective, would be one that increased vaccination coverage among primary-school aged children.

Vaccine hesitancy, the reluctance or refusal to receive vaccination, is a growing public health problem in the United States and globally. State policies that eliminate nonmedical ("personal belief") exemptions to childhood vaccination requirements are controversial, and their effectiveness to improve vaccination coverage remains unclear given limited rigorous policy analysis. In 2016, a California policy (Senate Bill 277) eliminated nonmedical exemptions from school entry requirements. The objective of this study was to estimate the association between California's 2016 policy and changes in vaccine coverage. We used a quasi-experimental state-level synthetic control analysis and a county-level difference-in-differences analysis to estimate the impact of the 2016 California policy on vaccination coverage and prevalence of exemptions to vaccine requirements (nonmedical and medical). We used publicly available state-level data from the US Centers for Disease Control and Prevention on coverage of measles, mumps, and rubella (MMR) vaccination, nonmedical exemption, and medical exemption in children entering kindergarten. We used county-level data individually requested from state departments of public health on overall vaccine coverage and exemptions. Based on data availability, we included state-level data for 45 states, including California, from 2011 to 2017 and county-level data for 17 states from 2010 to 2017. The prespecified primary study outcome was MMR vaccination in the state analysis and overall vaccine coverage in the county analysis. In the state-level synthetic control analysis, MMR coverage in California increased by 3.3% relative to its synthetic control in the postpolicy period (top 2 of 43 states evaluated in the placebo tests, top 5%), nonmedical exemptions decreased by 2.4% (top 2 of 43 states evaluated in the placebo tests, top 5%), and medical exemptions increased by 0.4% (top 1 of 44 states evaluated in the placebo tests, top 2%). In the county-level analysis, overall vaccination coverage increased by 4.3% (95% confidence interval [CI] 2.9%-5.8%, p < 0.001), nonmedical exemptions decreased by 3.9% (95% CI 2.4%-5.4%, p < 0.001), and medical exemptions increased by 2.4% (95% CI 2.0%-2.9%, p < 0.001). Changes in vaccination coverage across counties after the policy implementation from 2015 to 2017 ranged from -6% to 26%, with larger increases in coverage in counties with lower prepolicy vaccine coverage. Results were robust to alternative model specifications. The limitations of the study were the exclusion of a subset of US states from the analysis and the use of only 2 years of postpolicy data based on data availability. In this study, implementation of the California policy that eliminated nonmedical childhood vaccine exemptions was associated with an estimated increase in vaccination coverage and a reduction in nonmedical exemptions at state and county levels. The observed increase in medical exemptions was offset by the larger reduction in nonmedical exemptions. The largest increases in vaccine coverage were observed in the most "high-risk" counties, meaning those with the lowest prepolicy vaccine coverage. Our findings suggest that government policies removing nonmedical exemptions can be effective at increasing vaccination coverage.

The Effectiveness of Technology-Aided Monitoring for Early Childhood Vaccination Coverage: Evidence from a Natural Experiment

We developed a spatially structured, fully stochastic, individual-based SARS-CoV-2 transmission model to evaluate the feasibility of sustaining SARS-CoV-2 local containment in mainland China considering currently dominant Omicron variants, China’s current immunization level, and non-pharmaceutical interventions (NPIs). We also built a statistical model to estimate the overall disease burden under various hypothetical mitigation scenarios. We found that due to high transmissibility, neither Omicron BA.1 or BA.2 could be contained by China’s pre-Omicron NPI strategies which were successful prior to the emergence of the Omicron variants. However, increased intervention intensity, such as enhanced population mobility restrictions and multi-round mass testing, could lead to containment success. We estimated that an acute Omicron epidemic wave in mainland China would result in significant number of deaths if China were to reopen under current vaccine coverage with no antiviral uptake, while increasing vaccination coverage and antiviral uptake could substantially reduce the disease burden. As China’s current vaccination has yet to reach high coverage in older populations, NPIs remain essential tools to maintain low levels of infection while building up protective population immunity, ensuring a smooth transition out of the pandemic phase while minimizing the overall disease burden.

The “Zero by 30” strategic plan aims to eliminate human deaths from dog-mediated rabies by 2030 and domestic dog vaccination is a vital component of this strategic plan. In areas where domestic dog vaccination has been implemented, it is important to assess the impact of this intervention. Additionally, understanding temporal and seasonal trends in the incidence of animal rabies cases may assist in optimizing such interventions. Data on the incidence of probable rabies cases in domestic and wild animals were collected between January 2011 and December 2018 in thirteen districts of south-east Tanzania where jackals comprise over 40% of reported rabies cases. Vaccination coverage was estimated over this period, as five domestic dog vaccination campaigns took place in all thirteen districts between 2011 and 2016. Negative binomial generalized linear models were used to explore the impact of domestic dog vaccination on the annual incidence of animal rabies cases, whilst generalized additive models were used to investigate the presence of temporal and/or seasonal trends. Increases in domestic dog vaccination coverage were significantly associated with a decreased incidence of rabies cases in both domestic dogs and jackals. A 35% increase in vaccination coverage was associated with a reduction in the incidence of probable dog rabies cases of between 78.0 and 85.5% (95% confidence intervals ranged from 61.2 to 92.2%) and a reduction in the incidence of probable jackal rabies cases of between 75.3 and 91.2% (95% confidence intervals ranged from 53.0 to 96.1%). A statistically significant common seasonality was identified in the monthly incidence of probable rabies cases in both domestic dogs and jackals with the highest incidence from February to August and lowest incidence from September to January. These results align with evidence supporting the use of domestic dog vaccination as part of control strategies aimed at reducing animal rabies cases in both domestic dogs and jackals in this region. The presence of a common seasonal trend requires further investigation but may have implications for the timing of future vaccination campaigns.

Universal hepatitis B vaccination in adults aged 19–59 years: Updated recommendations of the advisory committee on immunization practices—United States, 2022

BackgroundIn an influenza pandemic, the benefit of vaccines and antiviral medications will be constrained by limitations on supplies and effectiveness. Non-pharmaceutical public health interventions will therefore be vital in curtailing disease spread. However, the most comprehensive assessments of the literature to date recognize the generally poor quality of evidence on which to base non-pharmaceutical pandemic planning decisions. In light of the need to prepare for a possible pandemic despite concerns about the poor quality of the literature, combining available evidence with expert opinion about the relative merits of non-pharmaceutical interventions for pandemic influenza may lead to a more informed and widely accepted set of recommendations. We evaluated the evidence base for non-pharmaceutical public health interventions. Then, based on the collective evidence, we identified a set of recommendations for and against interventions that are specific to both the setting in which an intervention may be used and the pandemic phase, and which can be used by policymakers to prepare for a pandemic until scientific evidence can definitively respond to planners' needs.MethodsBuilding on reviews of past pandemics and recent historical inquiries, we evaluated the relative merits of non-pharmaceutical interventions by combining available evidence from the literature with qualitative and quantitative expert opinion. Specifically, we reviewed the recent scientific literature regarding the prevention of human-to-human transmission of pandemic influenza, convened a meeting of experts from multiple disciplines, and elicited expert recommendation about the use of non-pharmaceutical public health interventions in a variety of settings (healthcare facilities; community-based institutions; private households) and pandemic phases (no pandemic; no US pandemic; early localized US pandemic; advanced US pandemic).ResultsThe literature contained a dearth of evidence on the efficacy or effectiveness of most non-pharmaceutical interventions for influenza. In an effort to inform decision-making in the absence of strong scientific evidence, the experts ultimately endorsed hand hygiene and respiratory etiquette, surveillance and case reporting, and rapid viral diagnosis in all settings and during all pandemic phases. They also encouraged patient and provider use of masks and other personal protective equipment as well as voluntary self-isolation of patients during all pandemic phases. Other non-pharmaceutical interventions including mask-use and other personal protective equipment for the general public, school and workplace closures early in an epidemic, and mandatory travel restrictions were rejected as likely to be ineffective, infeasible, or unacceptable to the public.ConclusionThe demand for scientific evidence on non-pharmaceutical public health interventions for influenza is pervasive, and present policy recommendations must rely heavily on expert judgment. In the absence of a definitive science base, our assessment of the evidence identified areas for further investigation as well as non-pharmaceutical public health interventions that experts believe are likely to be beneficial, feasible and widely acceptable in an influenza pandemic.

Despite the lifting of COVID-19 restrictions, the COVID-19 pandemic and its effects remain a global challenge including the sub-Saharan Africa (SSA) region. Knowledge of the COVID-19 dynamics and its potential trends amidst variations in COVID-19 vaccine coverage is therefore crucial for policy makers in the SSA region where vaccine uptake is generally lower than in high-income countries. Using a compartmental epidemiological model, this study aims to forecast the potential COVID-19 trends and determine how long a wave could be, taking into consideration the current vaccination rates. The model is calibrated using South African reported data for the first four waves of COVID-19, and the data for the fifth wave are used to test the validity of the model forecast. The model is qualitatively analysed by determining equilibria and their stability, calculating the basic reproduction number and investigating the local and global sensitivity analysis with respect to . The impact of vaccination and control interventions are investigated via a series of numerical simulations. Based on the fitted data and simulations, we observed that massive vaccination would only be beneficial (deaths averting) if a highly effective vaccine is used, particularly in combination with non-pharmaceutical interventions. Furthermore, our forecasts demonstrate that increased vaccination coverage in SSA increases population immunity leading to low daily infection numbers in potential future waves. Our findings could be helpful in guiding policy makers and governments in designing vaccination strategies and the implementation of other COVID-19 mitigation strategies.

Pertussis outbreaks continue to challenge public health efforts in the Deep South of Thailand. Low vaccination coverage is among many key contributory factors. The objective of this study is to explore policy alternatives aiming to expand vaccination coverage in Thailand’s Deep South. We applied a compartmental model alongside rapid cost-effectiveness analysis to examine how different vaccination strategies impact pertussis cases and associated costs. Four vaccination scenarios with varying coverage levels (ranging from 62% to 91% within a 120-day timeframe) were compared against a scenario with the baseline vaccine coverage (61%). With a reproduction number (R0) of five, the model predicted a remarkable decrease in pertussis cases and fatalities as the vaccination coverage increases. All scenarios yielded cost-saving outcomes, with the scenario of an increase of 10% coverage being the most cost-effective relative to the status quo. However, in high epidemic states (R0=6), the scenario of an increase of 30% coverage was the most optimal for cost-saving in deaths prevention. These results highlight the need for expedite vaccine roll-out and the integration of non-pharmaceutical interventions for pertussis control. Further studies that explore various aspects of the model while incorporating more intricate parameters are recommended.

PurposeIncreasing influenza vaccination coverage in healthcare workers is a challenge. Especially during the ongoing COVID-19 pandemic, high vaccination coverage should be attained. This review analyzed strategies to increase influenza vaccination coverage in healthcare workers.MethodsA literature search using PubMed was conducted and 32 publications on influenza vaccination campaigns for healthcare workers were reviewed for key interventions and resulting vaccination coverage.ResultsAmong key interventions analyzed, mandatory vaccination policies or multifaceted campaigns including a vaccinate-or-wear-a-mask policy as well as mandatory declination reached vaccination coverage in healthcare workers of over 90%. Although campaigns solely based on education and promotion or on-site-vaccination did not regularly exceed an absolute vaccination coverage of 40%, a substantial relative increase in vaccination coverage was reached by implementation of these strategies.ConclusionMandatory vaccination policies are effective measures to achieve high overall vaccination coverage. In clinics where policies are infeasible, multifaceted campaigns comprising on-site vaccination, vaccination stands and educational and promotional campaigns as well as incentives should be implemented. Lessons learned from influenza campaigns could be implemented in future SARS-CoV-2 vaccination campaigns.

Background: Measles outbreaks are reported after insufficient vaccine coverage, especially in countries recovering from natural disaster or conflict. We compared seroprevalence to measles in blood donors in Rwanda and Sweden and explored distribution of active cases of measles and vaccine coverage in Rwanda.Methods: 516 Rwandan and 215 Swedish blood donors were assayed for measles-specific immunoglobulin G (IgG) by enzyme-linked immunosorbent assay (ELISA). Data on vaccine coverage and acute cases in Rwanda from 1980 to 2014 were collected, and IgM on serum samples and polymerase chain reaction (PCR) on nasopharyngeal (NPH) swabs from suspected measles cases during 2010–2011 were analysed.Results: The seroprevalence of measles IgG was significantly higher in Swedish blood donors (92.6%; 95% CI: 89.1–96.1%) compared to Rwandan subjects (71.5%; 95% CI: 67.6–75.4%) and more pronounced <35 years of age. The OD values were significantly lower in the Rwandan blood donors as compared to Swedish subjects (p < 0.00001). However, effective measles vaccine coverage was concomitant with decrease in measles cases in Rwanda, with the exception of an outbreak in 1995 following the 1994 genocide. 76/544 serum samples were IgM positive and 21/31 NPH swabs were PCR positive for measles, determined by sequencing to be of genotype B3.Conclusions: Measles seroprevalence was lower in Rwandan blood donors compared to Swedish subjects. Despite this, the number of reported measles cases in Rwanda rapidly decreased during the study period, concomitant with increased vaccine coverage. Taken together, the circulation of measles was limited in Rwanda and vaccine coverage was favourable, but seroprevalence and IgG levels were low especially in younger age groups.

Non-pharmaceutical interventions (NPIs) are central to mitigating COVID-19 and influenza, yet comparative economic evaluations remain scarce. This systematic review assessed the cost effectiveness and reporting quality of NPI evaluations across both diseases. The study was registered with PROSPERO (CRD42024552613). Following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, we searched five medical (PubMed, Scopus, EMBASE, CINAHL, and EconLit) and four health technology assessment databases (NHS HTA, CRD DARE, NHS EED, and INAHTA) up to December 2025, including only full economic evaluations. The search strategy incorporated four domains-'influenza,' 'COVID-19,' 'NPIs,' and 'economic evaluation'-and was guided by the WHO NPI framework, encompassing five domains: personal protective, environmental, physical distancing, travel-related, and educational measures. Reporting quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards 2022 (CHEERS 2022) checklist. Thirty-three studies (13 influenza, 20 COVID-19), predominantly from high-income countries, were included. School closures, the most frequently evaluated NPI, were generally not cost effective except during severe pandemics or bundled with other measures. Workforce and business closures were cost effective only in high-severity influenza, with inconsistent findings for COVID-19. Social distancing was cost effective for COVID-19 but not for H1N1 influenza. Isolation, lockdowns, and travel restrictions were cost effective only when implemented early. Face masks and hand hygiene, assessed solely for COVID-19, were generally cost effective when implemented alongside other measures. The median CHEERS score was 75.0%, with one study rated excellent. Our review highlights heterogeneity in cost effectiveness by pandemic severity, intervention type, bundling of measures, and timing. Strategies that combined low-cost NPIs like masks or hand hygiene demonstrated better value, while socially disruptive measures like school and business closure incurred high costs with inconsistent cost-effectiveness outcomes. Integration with vaccines or antivirals further enhanced cost effectiveness. Evidence gaps include the scarcity of evaluations from low-resource settings and variability in country-specific value thresholds. Addressing these gaps is essential for guiding efficient and cost-effective pandemic preparedness.

COVID-19 VACCINATION AND EPIDEMIOLOGICAL INDICATORS IN MARANHÃO BETWEEN 2021 AND 2025: A CORRELATIONAL ANALYSIS