Corrigendum: Modeling the future of tobacco control: Using SimSmoke to explore the feasibility of the tobacco endgame in Korea

[This corrects the article DOI: 10.18332/tid/174127.].

Modeling the future of tobacco control: Using SimSmoke to explore the feasibility of the tobacco endgame in Korea

INTRODUCTION

We used a simulation model to assess the feasibility of reaching the tobacco endgame target (reducing the smoking prevalence to below 5% by 2050) and explored potential implementation strategies.

METHODS

The impact of strengthened tobacco-control policies on smoking prevalence was analyzed using Korea SimSmoke, a discrete-time Markov process. We considered the effects of various scenarios from 2023 and predictions were conducted until 2050. To confirm the stability of the results, deterministic and probabilistic sensitivity analyses were carried out by increasing and decreasing parameter estimates.

RESULTS

The implementation of tobacco-control policies in accordance with the WHO MPOWER (Μonitor tobacco use and prevention policies; Protect people from tobacco smoke; Offer help to quit tobacco smoking; Warn of the dangers of tobacco; Enforce bans on tobacco advertising, promotion, and sponsorship; Raise taxes on tobacco) measures were insufficient to achieve the tobacco endgame objective of 5% by 2050. The overall predicted smoking prevalence in 2050 is 4.7% if all policies are fully implemented in accordance with the FCTC guidelines together with a complete ban on the sale of cigarettes to people born after 2003 and annual 10% increases in price. Sensitivity analyses using the varying policy effect assumptions demonstrated the robustness of the simulation results.

CONCLUSIONS

For a substantive reduction in smoking prevalence, it is essential to strongly implement the MPOWER strategy. Beyond this foundational step, the eradication of smoking requires a paradigm shift in the perception of conventional tobacco-control policies, including a tobacco-free generation strategy and radical increases in the price of tobacco products.

Switching people who smoke to unfiltered cigarettes: perceptions, addiction and behavioural effects in a cross-over randomised controlled trial

BACKGROUND

Behavioural research is needed to inform a ban on sales of filtered cigarettes that could reduce plastic waste due to discarded filters. This study reports on differences in perceptions, nicotine dependence and behaviour among participants in a cross-over randomised trial of filtered compared with unfiltered cigarettes.

METHOD

This proof-of-concept study involved 43 people who smoke filtered cigarettes (41.9% women, mean age 36.7 years). Participants were provided 2 weeks' supply of filtered cigarettes, 2 weeks of the same brand of unfiltered cigarettes and randomly assigned to starting conditions. Measures included the Modified Cigarette Evaluation Questionnaire; single-item cigarette perception questions; Fagerström Test of Nicotine Dependence; 7-day cigarette consumption, urinary cotinine and intention to quit. Analyses included linear and ordinal repeated measures mixed-effects models and paired t-tests.

RESULTS

Filtered cigarettes were perceived as better tasting, more satisfying, more enjoyable, less aversive, less harsh, less potent and less negatively reinforcing than unfiltered cigarettes. Filtered cigarettes were smoked at a higher rate during the trial than unfiltered cigarettes (p<0.05). There was no difference in cotinine, dependence or intention to quit between filtered versus unfiltered cigarette conditions (p>0.05).

CONCLUSION

People who smoke perceived unfiltered cigarettes as having greater nicotine effects and less desirable sensory effects than filtered cigarettes, and they smoked fewer of these during the trial. Although cotinine, dependence and intention to quit were similar for smoking unfiltered and filtered cigarettes in this small trial, results suggest that banning the sale of filtered cigarettes might make smoking less attractive overall to people who smoke.

TRIAL REGISTRATION NUMBER

NCT03749876.

European Tobacco Products Directive (TPD): current impact and future steps

Efforts to reduce the toll of tobacco-related morbidity and mortality in the European Union are spearheaded by the Tobacco Products Directive (TPD), a legal act implemented during 2016-2021, with the overall aim to reduce tobacco consumption by 2% in Europe. Within this time frame, several core tobacco control measures were implemented, the impact of which is outlined within this manuscript. Key successful legislative actions implemented in this time frame led to greater availability of information and further regulation of additives, the banning of mentholated cigarettes, enhanced pictorial package warnings and a regulatory framework for e-cigarettes. While repeated cross-sectional data indicated a 12.5% relative reduction in smoking prevalence after implementation of the TPD, the differential regulation of cigarettes and roll-your-own tobacco compared with other products, such as cigarillos, e-cigarettes and heated tobacco products, may have also led to product displacement. Moreover, as the TPD could not keep up with the ever-changing nicotine product landscape, further adaptations may be needed.

Closing the gaps in tobacco endgame evidence: a scoping review

OBJECTIVE

Tobacco endgame policies aim to rapidly and permanently reduce smoking to minimal levels. We reviewed evidence syntheses for: (1) endgame policies, (2) evidence gaps, and (3) future research priorities.

DATA SOURCES

Guided by JBI scoping review methodology, we searched five databases (PubMed, CINAHL, Scopus, Embase and Web of Science) for evidence syntheses published in English since 1990 on 12 policies, and Google for publications from key national and international organisations. Reference lists of included publications were hand searched.

STUDY SELECTION

Two reviewers independently screened titles and abstracts. Inclusion criteria were broad to capture policy impacts (including unintended), feasibility, public and stakeholder acceptability and other aspects of policy implementation.

DATA EXTRACTION

We report the results according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews checklist.

DATA SYNTHESIS

Eight policies have progressed to evidence synthesis stage (49 publications): mandatory very low nicotine content (VLNC) standard (n=26); product standards to substantially reduce consumer appeal or remove the most toxic products from the market (n=1); moving consumers to reduced risk products (n=8); tobacco-free generation (n=4); ending sales (n=2); sinking lid (n=2); tax increases (n=7); and restrictions on tobacco retailers (n=10). Based on published evidence syntheses, the evidence base was most developed for a VLNC standard, with a wide range of evidence synthesised.

CONCLUSIONS

VLNC cigarettes have attracted the most attention, in terms of synthesised evidence. Additional focus on policies that reduce the availability of tobacco is warranted given these measures are being implemented in some jurisdictions.

Getting there together: highlights, challenges and opportunities for tobacco control in the Oceania region

BACKGROUND

The paper focuses on the geographical region of Oceania. We highlight the tobacco control leadership demonstrated in this region and describe the challenges and opportunities to achieving country-specific smoke-free goals.

RESULTS

Significant achievements include smoke-free nation goals, world-leading initiatives such as plain packaging, and a bold plan by New Zealand to reduce the retail availability of smoked tobacco products and remove virtually all the nicotine from cigarettes and rolling tobacco. There are significant challenges and opportunities before reaching smoke-free status including implementation pathways requiring strong governance and leadership and compliance monitoring and enforcement.

CONCLUSIONS

We conclude that achieving a smoke-free Oceania is possible through already existing bold country and regional smoke-free goals, excellent tobacco control leadership, experience and resources, and an understanding of how to work collectively. However, a commitment to focus tobacco control efforts regionally is required to achieve a smoke-free Oceania together.

Support for New Zealand's Smokefree 2025 goal and key measures to achieve it: findings from the ITC New Zealand Survey

OBJECTIVES

To assess support among smokers and recent quitters for the Smokefree New Zealand (NZ) 2025 goal and measures to facilitate its achievement.

METHODS

Data from CATI interviews with 1,155 (386 Māori) smokers and recent quitters in Wave 1 (August 2016-April 2017) and 1,020 (394 Māori) in Wave 2 (June-December 2018) of the International Tobacco Control (ITC) NZ Survey.

RESULTS

(Wave 2 unless stated): Almost all (95%) participants were aware of and more than half (56%) supported the smokefree goal. Support was highest (69-92%) for measures to reduce smoking uptake and protect children from exposure to secondhand smoke. Support was also high for other smokefree policies including mandated denicotinisation of smoked tobacco products (73%) and tobacco retailer licensing (70%, Wave 1). Support was lowest (<30%) for increasing the tobacco tax, but higher (59%) if additional revenue raised was used to help smokers to quit. Support for Smokefree 2025 and key measures to achieve it was generally higher among ex-smokers than smokers but mostly similar among Māori and non-Māori participants.

CONCLUSIONS

There is substantial support among smokers and ex-smokers for the Smokefree 2025 goal and many measures that could help achieve it. Implications for public health: Implementing a comprehensive strategy to achieve Smokefree 2025 is likely to be acceptable among New Zealand's smokers and ex-smokers.

Optimizing spatial and seasonal deployment of vaccination campaigns to eliminate wildlife rabies

Understanding how the spatial deployment of interventions affects elimination time horizons and potential for disease re-emergence has broad application to control programmes targeting human, animal and plant pathogens. We previously developed an epidemiological model that captures the main features of rabies spread and the impacts of vaccination based on detailed records of fox rabies in eastern Germany during the implementation of an oral rabies vaccination (ORV) programme. Here, we use simulations from this fitted model to determine the best vaccination strategy, in terms of spatial placement and timing of ORV efforts, for three epidemiological scenarios representative of current situations in Europe. We found that consecutive and comprehensive twice-yearly vaccinations across all regions rapidly controlled and eliminated rabies and that the autumn campaigns had the greater impact on increasing the probability of elimination. This appears to result from the need to maintain sufficient herd immunity in the face of large birth pulses, as autumn vaccinations reach susceptible juveniles and therefore a larger proportion of the population than spring vaccinations. Incomplete vaccination compromised time to elimination requiring the same or more vaccination effort to meet similar timelines. Our results have important practical implications that could inform policies for rabies containment and elimination in Europe and elsewhere. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'. This theme issue is linked with the earlier issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'.

Impact of tax and tobacco-free generation on health-adjusted life years in the Solomon Islands: a multistate life table simulation

OBJECTIVE

To estimate health-adjusted life years (HALY) gained in the Solomon Islands for the 2016 population over the remainder of their lives, for three interventions: hypothetical eradication of cigarettes; 25% annual tax increases to 2025 such that tax represents 70% of sales price of tobacco; and a tobacco-free generation (TFG).

DESIGN

We adapted an existing multistate life table model, using Global Burden of Disease (GBD) and other data inputs, including diseases contributing >5% of the GBD estimated disability-adjusted life years lost in the Solomon Islands in 2016. Tax effects used price increases and price elasticities to change cigarette smoking prevalence. The TFG was modelled by no uptake of smoking among those 20 years and under after 2016.

RESULTS

Under business as usual (BAU) smoking prevalence decreased over time, and decreased faster under the tax intervention (especially for younger ages). For example, for 20-year-old males the best estimated prevalence in 2036 was 22.9% under BAU, reducing to 14.2% under increased tax. Eradicating tobacco in 2016 would achieve 1510 undiscounted HALYs per 1000 people alive in 2016, over the remainder of their lives. The tax intervention would achieve 370 HALYs per 1000 (24.5% of potential health gain), and the TFG 798 HALYs per 1000 people (52.5%). By time horizon, 10.5% of the HALY gains from tax and 8.0% from TFG occur from 2016 to 2036, and the remainder at least 20 years into the future.

CONCLUSION

This study quantified the potential of two tobacco control policies over maximum health gains achievable through tobacco eradication in the Solomon Islands.

Tobacco control within and beyond WHO MPOWER: outcomes from Taiwan SimSmoke

Introduction

Adult smoking prevalence in Taiwan rapidly declined from 26.5% in 2005 to 20.0% in 2015. Nevertheless, future projections on smoking-attributable deaths and current per capita consumption do not paint an equally bright picture.

Methods

We used SimSmoke, a tobacco control simulation model to assess the impact of tax increases and other policies by predicting past and projecting over future decades smoking rates and smoking-attributable mortality.

Results

The model accurately depicts the decline in smoking prevalence observed in Taiwan from 2000 to 2015. Nonetheless, under the ‘status quo’ scenario, smoking-attributable mortality is projected to continue growing, peaking at 26 602 annual deaths in 2039 and cumulative deaths >1 million by 2044. By comparing projections with current policies with a counterfactual scenario based on the 2000 policy levels, SimSmoke estimates that tobacco control in Taiwan has been able to reduce smoking prevalence by 30% in 2015 with 450 000 fewer smoking-attributable deaths by 2060. Modified scenarios show that doubling the retail price of cigarettes and fully implementing the remaining MPOWER measures would avert approximately 45 000 lives by 2040 and 130 000 by 2060.

Conclusions

Tobacco will be a leading cause of death in Taiwan for the coming decades, showing yet again the long-term consequences of smoking on public health. The MPOWER package, even if adopted at the highest level with a large tax increase, is unlikely to reduce smoking prevalence to the endgame goal of 5% in the next five decades.

Determinants of electronic cigarette use among Finnish adults: Results from a population-based survey

Background

Electronic cigarette (e-cigarette) use is rising in the Western world, but studies from the Nordic countries are lacking. Many countries are implementing policy changes, brought about for example by the 2014 European Tobacco Products Directive, and monitoring e-cigarette use is considered important. The aim of this article is to account for the prevalence of e-cigarette use among the Finnish adult population and to examine correlates of ever use and current use of e-cigarettes prior to some changes in the Finnish regulatory scheme.

Methods

A population-based survey was conducted in 2014. A representative random sample (N = 7000) of Finnish people aged 15-69 years was drawn from the Finnish Population Information System. Data were collected by self-administered anonymous online/postal questionnaire. The response rate was 50% (n = 3485). A multinomial logistic regression model was used to estimate the association between e-cigarette use and different explanatory variables.

Results

Of all participants, 2% were current and 12% were ever users of e-cigarettes. Younger age and current or previous tobacco use increased the odds for both current and ever use of e-cigarettes when compared with never users. Unemployment and lower education were associated with current e-cigarette use and being a student was associated with ever use of e-cigarettes.

Conclusions

The current use of e-cigarettes in the adult population is low in Finland, having at least tried is more common. Both types of e-cigarette use are concentrated to groups considered to be more vulnerable, such as younger people and those with a lower socioeconomic position. Further monitoring of e-cigarette use is needed in view of Finland's aim to become nicotine and tobacco free by 2030.

Addressing the Challenges and Opportunities of the Polio Endgame: Lessons for the Future

The Global Commission for the Certification of the Eradication of Poliomyelitis certified the eradication of type 2 poliovirus in September 2015, making type 2 poliovirus the first human pathogen to be eradicated since smallpox. The eradication of type 2 poliovirus, the absence of detection of type 3 poliovirus worldwide since November 2012, and cornering type 1 poliovirus to only a few geographic areas of 3 countries has enabled implementation of the endgame of polio eradication which calls for a phased withdrawal of oral polio vaccine beginning with the type 2 component, introduction of inactivated poliovirus vaccine, strengthening of routine immunization in countries with extensive polio resources, and initiating activities to transition polio resources, program experience, and lessons learned to other global health initiatives. This supplement focuses on efforts by global partners to successfully launch polio endgame activities to permanently secure and sustain the enormous gains of polio eradication forever.

Polio Endgame: Lessons Learned From the Immunization Systems Management Group

The Immunization Systems Management Group (IMG) was established to coordinate and oversee objective 2 of the Polio Eradication and Endgame Strategic Plan 2013–2018, namely, (1) introduction of ≥1 dose of inactivated poliovirus vaccine in all 126 countries using oral poliovirus vaccine (OPV) only as of 2012, (2) full withdrawal of OPV, starting with the withdrawal of its type 2 component, and (3) using polio assets to strengthen immunization systems in 10 priority countries. The IMG’s inclusive, transparent, and partnership-focused approach proved an effective means of leveraging the comparative and complementary strengths of each IMG member agency. This article outlines 10 key factors behind the IMG’s success, providing a potential set of guiding principles for the establishment and implementation of other interagency collaborations and initiatives beyond the polio sphere.

Contribution of Global Polio Eradication Initiative-Funded Personnel to the Strengthening of Routine Immunization Programs in the 10 Focus Countries of the Polio Eradication and Endgame Strategic Plan

Background.

The Polio Eradication and Endgame Strategic Plan (PEESP) established a target that at least 50% of the time of personnel receiving funding from the Global Polio Eradication Initiative (GPEI) for polio eradication activities (hereafter, “GPEI-funded personnel”) should be dedicated to the strengthening of immunization systems. This article describes the self-reported profile of how GPEI-funded personnel allocate their time toward immunization goals and activities beyond those associated with polio, the training they have received to conduct tasks to strengthen routine immunization systems, and the type of tasks they have conducted.

Methods.

A survey of approximately 1000 field managers of frontline GPEI-funded personnel was conducted by Boston Consulting Group in the 10 focus countries of the PEESP during 2 phases, in 2013 and 2014, to determine time allocation among frontline staff. Country-specific reports on the training of GPEI-funded personnel were reviewed, and an analysis of the types of tasks that were reported was conducted.

Results.

A total of 467 managers responded to the survey. Forty-seven percent of the time (range, 23%–61%) of GPEI-funded personnel was dedicated to tasks related to strengthening immunization programs, other than polio eradication. Less time was spent on polio-associated activities in countries that had already interrupted wild poliovirus (WPV) transmission, compared with findings for WPV-endemic countries. All countries conducted periodic trainings of the GPEI-funded personnel. The types of non–polio-related tasks performed by GPEI-funded personnel varied among countries and included surveillance, microplanning, newborn registration and defaulter tracing, monitoring of routine immunization activities, and support of district immunization task teams, as well as promotion of health behaviors, such as clean-water use and good hygiene and sanitation practices.

Conclusion.

In all countries, GPEI-funded personnel perform critical tasks in the strengthening of routine immunization programs and the control of measles and rubella. In certain countries with very weak immunization systems, GPEI-funded personnel provide critical support for the immunization programs, and sudden discontinuation of their employment would potentially disrupt the immunization programs in their countries and create a setback in capacity and effectiveness that would put children at higher risk for vaccine-preventable diseases.

Implementing the Synchronized Global Switch from Trivalent to Bivalent Oral Polio Vaccines-Lessons Learned From the Global Perspective

In 2015, the Global Commission for the Certification of Polio Eradication certified the eradication of type 2 wild poliovirus, 1 of 3 wild poliovirus serotypes causing paralytic polio since the beginning of recorded history. This milestone was one of the key criteria prompting the Global Polio Eradication Initiative to begin withdrawal of oral polio vaccines (OPV), beginning with the type 2 component (OPV2), through a globally synchronized initiative in April and May 2016 that called for all OPV using countries and territories to simultaneously switch from use of trivalent OPV (tOPV; containing types 1, 2, and 3 poliovirus) to bivalent OPV (bOPV; containing types 1 and 3 poliovirus), thus withdrawing OPV2. Before the switch, immunization programs globally had been using approximately 2 billion tOPV doses per year to immunize hundreds of millions of children. Thus, the globally synchronized withdrawal of tOPV was an unprecedented achievement in immunization and was part of a crucial strategy for containment of polioviruses. Successful implementation of the switch called for intense global coordination during 2015-2016 on an unprecedented scale among global public health technical agencies and donors, vaccine manufacturers, regulatory agencies, World Health Organization (WHO) and United Nations Children's Fund (UNICEF) regional offices, and national governments. Priority activities included cessation of tOPV production and shipment, national inventories of tOPV, detailed forecasting of tOPV needs, bOPV licensing, scaling up of bOPV production and procurement, developing national operational switch plans, securing funding, establishing oversight and implementation committees and teams, training logisticians and health workers, fostering advocacy and communications, establishing monitoring and validation structures, and implementing waste management strategies. The WHO received confirmation that, by mid May 2016, all 155 countries and territories that had used OPV in 2015 had successfully withdrawn OPV2 by ceasing use of tOPV in their national immunization programs. This article provides an overview of the global efforts and challenges in successfully implementing this unprecedented global initiative, including (1) coordination and tracking of key global planning milestones, (2) guidance facilitating development of country specific plans, (3) challenges for planning and implementing the switch at the global level, and (4) best practices and lessons learned in meeting aggressive switch timelines. Lessons from this monumental public health achievement by countries and partners will likely be drawn upon when bOPV is withdrawn after polio eradication but also could be relevant for other global health initiatives with similarly complex mandates and accelerated timelines.

Lessons Learned From Managing the Planning and Implementation of Inactivated Polio Vaccine Introduction in Support of the Polio Endgame

The Immunization Systems Management Group (IMG) was established as a time-limited entity, responsible for the management and coordination of Objective 2 of the Polio Eradication and Endgame Strategic Plan. This objective called for the introduction of at least 1 dose of inactivated polio vaccine (IPV) into the routine immunization programs of all countries using oral polio vaccine (OPV) only. Despite global vaccine shortages, which limited countries' abilities to access IPV in a timely manner, 105 of 126 countries using OPV only introduced IPV within a 2.5-year period, making it the fastest rollout of a new vaccine in history. This achievement can be attributed to several factors, including the coordination work of the IMG; high-level engagement and advocacy across partners; the strong foundations of the Expanded Programme on Immunization at all levels; Gavi, the Vaccine Alliance's vaccine introduction experiences and mechanisms; innovative approaches; and proactive communications. In many ways, the IMG's work on IPV introduction can serve as a model for other vaccine introductions, especially in an accelerated context.

Communications, Immunization, and Polio Vaccines: Lessons From a Global Perspective on Generating Political Will, Informing Decision-Making and Planning, and Engaging Local Support

The requirements under objective 2 of the Polio Eradication and Endgame Strategic Plan 2013-2018-to introduce at least 1 dose of inactivated poliomyelitis vaccine (IPV); withdraw oral poliomyelitis vaccine (OPV), starting with the type 2 component; and strengthen routine immunization programs-set an ambitious series of targets for countries. Effective implementation of IPV introduction and the switch from trivalent OPV (containing types 1, 2, and 3 poliovirus) to bivalent OPV (containing types 1 and 3 poliovirus) called for intense global communications and coordination on an unprecedented scale from 2014 to 2016, involving global public health technical agencies and donors, vaccine manufacturers, World Health Organization and United Nations Children's Fund regional offices, and national governments. At the outset, the new program requirements were perceived as challenging to communicate, difficult to understand, unrealistic in terms of timelines, and potentially infeasible for logistical implementation. In this context, a number of core areas of work for communications were established: (1) generating awareness and political commitment via global communications and advocacy; (2) informing national decision-making, planning, and implementation; and (3) in-country program communications and capacity building, to ensure acceptance of IPV and continued uptake of OPV. Central to the communications function in driving progress for objective 2 was its ability to generate a meaningful policy dialogue about polio vaccines and routine immunization at multiple levels. This included efforts to facilitate stakeholder engagement and ownership, strengthen coordination at all levels, and ensure an iterative process of feedback and learning. This article provides an overview of the global efforts and challenges in successfully implementing the communications activities to support objective 2. Lessons from the achievements by countries and partners will likely be drawn upon when all OPVs are completely withdrawn after polio eradication, but also may offer a useful model for other global health initiatives.

Monitoring the Path to the Elimination of Infectious Diseases

During the endgame of elimination programs, parasite populations may exhibit dynamical phenomena not typical of endemic disease. Particularly, monitoring programs for tracking infection prevalence may be hampered by overall rarity, the sporadic and unpredictable timing and location of outbreaks, and under-reporting. A particularly important problem for monitoring is determining the distance that must be covered to achieve the elimination threshold at an effective reproduction number less than one. In this perspective, we suggest that this problem may be overcome by measuring critical slowing down. Critical slowing down is a phenomenon exhibited by nonlinear dynamical systems in the vicinity of a critical threshold. In infectious disease dynamics, critical slowing down is expressed as an increase in the coefficient of variation and other properties of the fluctuations in the number of cases. In simulations, we show the coefficient of variation to be insensitive to under-reporting error and therefore a robust measurement of the approach to elimination. Additionally, we show that there is an inevitable delay between the time at which the effective reproduction number is reduced to below one and complete elimination is achieved. We urge that monitoring programs include dynamical properties such as critical slowing down in their metrics for measuring achievement and avoid withdrawing control activities prematurely.

The polio endgame: rationale behind the change in immunisation

The decades long effort to eradicate polio is nearing the final stages and oral polio vaccine (OPV) is much to thank for this success. As cases of wild poliovirus continue to dwindle, cases of paralysis associated with OPV itself have become a concern. As type-2 poliovirus (one of three) has been certified eradicated and a large proportion of OPV-related paralysis is caused by the type-2 component of OPV, the World Health Assembly endorsed the phased withdrawal of OPV and the introduction of inactivated polio vaccine (IPV) into routine immunisation schedules as a crucial step in the polio endgame plan. The rapid pace of IPV scale-up and uptake required adequate supply, planning, advocacy, training and operational readiness. Similarly, the synchronised switch from trivalent OPV (all three types) to bivalent OPV (types 1 and 3) involved an unprecedented level of global coordination and country commitment. The important shift in vaccination policy seen through global IPV introduction and OPV withdrawal represents an historical milestone reached in the polio eradication effort.

HIV-1 Transmission During Recent Infection and During Treatment Interruptions as Major Drivers of New Infections in the Swiss HIV Cohort Study

BACKGROUND

Reducing the fraction of transmissions during recent human immunodeficiency virus (HIV) infection is essential for the population-level success of "treatment as prevention".

METHODS

A phylogenetic tree was constructed with 19 604 Swiss sequences and 90 994 non-Swiss background sequences. Swiss transmission pairs were identified using 104 combinations of genetic distance (1%-2.5%) and bootstrap (50%-100%) thresholds, to examine the effect of those criteria. Monophyletic pairs were classified as recent or chronic transmission based on the time interval between estimated seroconversion dates. Logistic regression with adjustment for clinical and demographic characteristics was used to identify risk factors associated with transmission during recent or chronic infection.

FINDINGS

Seroconversion dates were estimated for 4079 patients on the phylogeny, and comprised between 71 (distance, 1%; bootstrap, 100%) to 378 transmission pairs (distance, 2.5%; bootstrap, 50%). We found that 43.7% (range, 41%-56%) of the transmissions occurred during the first year of infection. Stricter phylogenetic definition of transmission pairs was associated with higher recent-phase transmission fraction. Chronic-phase viral load area under the curve (adjusted odds ratio, 3; 95% confidence interval, 1.64-5.48) and time to antiretroviral therapy (ART) start (adjusted odds ratio 1.4/y; 1.11-1.77) were associated with chronic-phase transmission as opposed to recent transmission. Importantly, at least 14% of the chronic-phase transmission events occurred after the transmitter had interrupted ART.

CONCLUSIONS

We demonstrate a high fraction of transmission during recent HIV infection but also chronic transmissions after interruption of ART in Switzerland. Both represent key issues for treatment as prevention and underline the importance of early diagnosis and of early and continuous treatment.

Immunogenicity and effectiveness of routine immunization with 1 or 2 doses of inactivated poliovirus vaccine: systematic review and meta-analysis

Background. The World Health Organization has recommended that all 124 countries currently using only oral poliovirus vaccine (OPV) introduce at least 1 dose of inactivated poliovirus vaccine (IPV) before the global withdrawal of serotype 2 OPV in 2016. A 1- or 2-dose schedule, potentially administered intradermally with reduced antigen content, may make this affordable.

Methods. A systematic review and meta-analysis of studies documenting seroconversion after 1 or 2, full or fractional (1/5) doses of enhanced-potency IPV was performed. Studies reporting the clinical efficacy of IPV were also reviewed.

Results. Twenty study arms from 12 published articles were included in the analysis of seroconversion. One full dose of intramuscular IPV seroconverted 33%, 41%, and 47% of infants against serotypes 1, 2, and 3 on average, whereas 2 full doses seroconverted 79%, 80%, and 90%, respectively. Seroconversion increased with age at administration. Limited data from case-control studies indicate clinical efficacy equivalent to the proportion seroconverting. One fractional dose of intradermal IPV gave lower seroconversion (10%–40%), but after 2 doses seroconversion was comparable to that with full-dose IPV.

Conclusions. Routine immunization with 2 full or fractional doses of IPV given after 10 weeks of age is likely to protect >80% of recipients against poliomyelitis if poliovirus reemerges after withdrawal of OPV serotypes.

'The times are changing': New Zealand smokers' perceptions of the tobacco endgame

BACKGROUND

The New Zealand government's goal of achieving a smoke-free society by 2025 reflects growing interest in 'endgame' solutions to tobacco smoking. However, tobacco companies have framed 'endgame' strategies as contrary to individual freedoms and 'choice'; these claims heighten politicians' sensitivity to 'nanny state' allegations and may undermine tobacco control policies. Public support for stronger policies could strengthen political will; however, little is known about how smokers perceive endgame scenarios or the factors underlying their support or opposition to these.

METHODS

The authors conducted 47 in-depth interviews with four priority groups: Māori, Pacific, young adults and pregnant women; all were smokers or very recent quitters. The authors used thematic analysis to interpret the transcripts.

RESULTS

Most participants strongly supported the 2025 smoke-free goal, recognised the broader social good that would result and accepted the personal inconvenience of quitting. Yet they wanted to retain control over when and how they would quit and asserted their 'freedom' to smoke. Participants identified interventions that would extend current policy and maintain the autonomy they valued; the authors classified these into four themes: restricting supply, diminishing visibility, decreasing availability and affordability, and increasing quit support.

CONCLUSIONS

Politicians may have a stronger mandate to implement endgame policies than they appreciate. Participants' use of industry arguments when asserting their freedom to 'choose' to smoke and quit suggests a need for denormalisation strategies that challenge industry propaganda, demonstrate how endgame measures would empower smokers and re-iterate the community benefits a smoke-free society will deliver.

The elimination of fox rabies from Europe: determinants of success and lessons for the future

Despite perceived challenges to controlling an infectious disease in wildlife, oral rabies vaccination (ORV) of foxes has proved a remarkably successful tool and a prime example of a sophisticated strategy to eliminate disease from wildlife reservoirs. During the past three decades, the implementation of ORV programmes in 24 countries has led to the elimination of fox-mediated rabies from vast areas of Western and Central Europe. In this study, we evaluated the efficiency of 22 European ORV programmes between 1978 and 2010. During this period an area of almost 1.9 million km&sup2; was targeted at least once with vaccine baits, with control taking between 5 and 26 years depending upon the country. We examined factors influencing effort required both to control and eliminate fox rabies as well as cost-related issues of these programmes. The proportion of land area ever affected by rabies and an index capturing the size and overlap of successive ORV campaigns were identified as factors having statistically significant effects on the number of campaigns required to both control and eliminate rabies. Repeat comprehensive campaigns that are wholly overlapping much more rapidly eliminate infection and are less costly in the long term. Disproportionally greater effort is required in the final phase of an ORV programme, with a median of 11 additional campaigns required to eliminate disease once incidence has been reduced by 90 per cent. If successive ORV campaigns span the entire affected area, rabies will be eliminated more rapidly than if campaigns are implemented in a less comprehensive manner, therefore reducing ORV expenditure in the longer term. These findings should help improve the planning and implementation of ORV programmes, and facilitate future decision-making by veterinary authorities and policy-makers.