Measuring vaccine confidence

The Lancet Infectious Diseases
Jul 2013  Volume 13  Number 7   p559 – 638

Inoculating communities against vaccine scare stories
Natasha Sarah Crowcroft, Kwame Julius McKenzie
Preview |
The biggest threat facing the success of immunisation might be public lack of confidence in vaccines, repeatedly undermined by safety concerns promulgated in social and news media.1 In The Lancet Infectious Diseases, Heidi Larson and colleagues’ study examines how a typology of concerns can be applied within an established global surveillance system, HealthMap, to track and characterise vaccine news stories.2,3 The usefulness of systematically tracking online media stories was first established for disease surveillance through a Canadian project, the Global Public Health Information Network,4 followed by several other systems including HealthMap.

Measuring vaccine confidence: analysis of data obtained by a media surveillance system used to analyse public concerns about vaccines
Heidi J Larson, David MD Smith, Pauline Paterson, Melissa Cumming, Elisabeth Eckersberger, Clark C Freifeld, Isaac Ghinai, Caitlin Jarrett, Louisa Paushter, John S Brownstein, Lawrence C Madoff

The intensity, spread, and effects of public opinion about vaccines are growing as new modes of communication speed up information sharing, contributing to vaccine hesitancy, refusals, and disease outbreaks. We aimed to develop a new application of existing surveillance systems to detect and characterise early signs of vaccine issues. We also aimed to develop a typology of concerns and a way to assess the priority of each concern.

Following preliminary research by The Vaccine Confidence Project, media reports (eg, online articles, blogs, government reports) were obtained using the HealthMap automated data collection system, adapted to monitor online reports about vaccines, vaccination programmes, and vaccine-preventable diseases. Any reports that did not meet the inclusion criteria—any reference to a human vaccine or vaccination campaign or programme that was accessible online—were removed from analysis. Reports were manually analysed for content and categorised by concerns, vaccine, disease, location, and source of report, and overall positive or negative sentiment towards vaccines. They were then given a priority level depending on the seriousness of the reported event and time of event occurrence. We used descriptive statistics to analyse the data collected during a period of 1 year, after refinements to the search terms and processes had been made.

We analysed data from 10 380 reports (from 144 countries) obtained between May 1, 2011, and April 30, 2012. 7171 (69%) contained positive or neutral content and 3209 (31%) contained negative content. Of the negative reports, 1977 (24%) were associated with impacts on vaccine programmes and disease outbreaks; 1726 (21%) with beliefs, awareness, and perceptions; 1371 (16%) with vaccine safety; and 1336 (16%) with vaccine delivery programmes. We were able to disaggregate the data by country and vaccine type, and monitor evolution of events over time and location in specific regions where vaccine concerns were high.

Real-time monitoring and analysis of vaccine concerns over time and location could help immunisation programmes to tailor more effective and timely strategies to address specific public concerns.

Bill & Melinda Gates Foundation.

Family Cluster of Middle East Respiratory Syndrome Coronavirus Infection

New England Journal of Medicine
June 27, 2013  Vol. 368 No. 26

Brief Report: Family Cluster of Middle East Respiratory Syndrome Coronavirus Infections
Z.A. Memish, A.I. Zumla, R.F. Al-Hakeem, A.A. Al-Rabeeah, and G.M. Stephens

A human coronavirus, called the Middle East respiratory syndrome coronavirus (MERS-CoV), was first identified in September 2012 in samples obtained from a Saudi Arabian businessman who died from acute respiratory failure. Since then, 49 cases of infections caused by MERS-CoV (previously called a novel coronavirus) with 26 deaths have been reported to date. In this report, we describe a family case cluster of MERS-CoV infection, including the clinical presentation, treatment outcomes, and household relationships of three young men who became ill with MERS-CoV infection after the hospitalization of an elderly male relative, who died of the disease. Twenty-four other family members living in the same household and 124 attending staff members at the hospitals did not become ill. MERS-CoV infection may cause a spectrum of clinical illness. Although an animal reservoir is suspected, none has been discovered. Meanwhile, global concern rests on the ability of MERS-CoV to cause major illness in close contacts of patients.

Trends in National Rotavirus Activity Before and After Introduction of Rotavirus Vaccine into the National Immunization Program in the United States, 2000 to 2012

The Pediatric Infectious Disease Journal
July 2013 – Volume 32 – Issue 7  pp: A15-A16,709-804,e265-e313

Trends in National Rotavirus Activity Before and After Introduction of Rotavirus Vaccine into the National Immunization Program in the United States, 2000 to 2012
Tate, Jacqueline E.; Haynes, Amber; Payne, Daniel C.; Cortese, Margaret M.; Lopman, Benjamin A.; Patel, Manish M.; Parashar, Umesh D.
Pediatric Infectious Disease Journal. 32(7):741-744, July 2013.
doi: 10.1097/INF.0b013e31828d639c

Background: Rotavirus vaccine introduction in the United States in 2006 led to substantial declines in rotavirus detections during 2007 to 2010. To further evaluate the long-term impact of the vaccine program, we assessed trends in rotavirus testing and detection in the 2010 to 2011 and 2011 to 2012 seasons compared with prevaccine seasons from 2000 to 2006.

Methods: We examined data from July 2000 to June 2012 from 50 to 70 laboratories reporting to the National Respiratory and Enteric Viruses Surveillance System to compare rotavirus season timing and peak activity in the pre- and postvaccine introduction eras. To assess trends in rotavirus testing and detection, we restricted the analyses to 25 laboratories that consistently reported for ≥26 weeks for each season from 2000 to 2012.

Results: The threshold for the start of the rotavirus season was never achieved nationally during the 2011 to 2012 season, and the 2010 to 2011 season was 8 weeks shorter in duration than the prevaccine baseline. During these seasons, nationally, the number of positive rotavirus tests declined 74%–90% compared with the prevaccine baseline and the total number of tests performed annually declined 28%–36%. The annual proportion positive at the 25 consistently reporting laboratories remained below 10% in both seasons compared with a prevaccine baseline median of 26%. A pattern of biennial increases in rotavirus activity emerged during the 5 postvaccine seasons from 2007 to 2012, but activity remained substantially below prevaccine levels.

Conclusions: A substantial and sustained decline in rotavirus activity below the prevaccine baseline was observed in all 5 postvaccine introduction years, affirming the long-term health benefits of the US rotavirus vaccination program.

Productivity Costs in Economic Evaluations: Past, Present, Futur

Volume 31, Issue 7, July 2013

Productivity Costs in Economic Evaluations: Past, Present, Future
Marieke Krol, Werner Brouwer, Frans Rutten

Productivity costs occur when the productivity of individuals is affected by illness, treatment, disability or premature death. The objective of this paper was to review past and current developments related to the inclusion, identification, measurement and valuation of productivity costs in economic evaluations. The main debates in the theory and practice of economic evaluations of health technologies described in this review have centred on the questions of whether and how to include productivity costs, especially productivity costs related to paid work. The past few decades have seen important progress in this area. There are important sources of productivity costs other than absenteeism (e.g. presenteeism and multiplier effects in co-workers), but their exact influence on costs remains unclear. Different measurement instruments have been developed over the years, but which instrument provides the most accurate estimates has not been established. Several valuation approaches have been proposed. While empirical research suggests that productivity costs are best included in the cost side of the cost-effectiveness ratio, the jury is still out regarding whether the human capital approach or the friction cost approach is the most appropriate valuation method to do so. Despite the progress and the substantial amount of scientific research, a consensus has not been reached on either the inclusion of productivity costs in economic evaluations or the methods used to produce productivity cost estimates. Such a lack of consensus has likely contributed to ignoring productivity costs in actual economic evaluations and is reflected in variations in national health economic guidelines. Further research is needed to lessen the controversy regarding the estimation of health-related productivity costs. More standardization would increase the comparability and credibility of economic evaluations taking a societal perspective.

The Cost and Public Health Burden of Invasive Meningococcal Disease Outbreaks: A Systematic Review

Volume 31, Issue 7, July 2013

Review Article
The Cost and Public Health Burden of Invasive Meningococcal Disease Outbreaks: A Systematic Review
Andrea Anonychuk, Gloria Woo, Andrew Vyse, Nadia Demarteau

Invasive meningococcal disease (IMD) is a serious disease with a rapid onset, high mortality rate, and risk of long-term complications. Numerous reports in the literature conclude that IMD outbreaks are associated with substantial costs to society and significant burden on communities due to the cost associated with the prevention of secondary cases.

To systematically review the literature on the costs and public health burden associated with IMD outbreaks.

Studies were primarily identified through searching MEDLINE and EMBASE. Reports were included if they provided cost data related to the containment of an IMD outbreak after 1990 and were written in English, French, or Spanish. Costs were converted to 2010 United States dollars. Outbreaks were categorized by low-income countries (LIC) and high-income countries (HIC) based on gross domestic product per capita. Outbreak containment strategies were classified as small (e.g., targeting members of the school/institution where the outbreak occurred) or large (e.g., targeting everyone in the community).

Sixteen articles reporting data on 93 IMD outbreaks fulfilled the eligibility criteria and were included. The majority of outbreaks occurred in HIC. Five studies reported the use of small containment strategies including targeted vaccination and chemoprophylaxis, all occurring in HIC. The average cost per small containment strategy was 99,641 and the average cost per IMD case was 41,857. Eight studies reported large containment strategies involving widespread vaccination targeting a specific age group or community. For HIC, the average cost per large containment strategy was 579,851 and the average cost per IMD case was 55,755. In LIC, the average cost per large containment strategy was 3,407,590.

IMD outbreaks were associated with substantial costs. We found that although there were numerous reports on IMD outbreaks, data on containment costs were very limited. More research in this area is warranted.

Evolution of Type 2 Vaccine Derived Poliovirus Lineages

PLoS One
[Accessed 29 June 2013]

Evolution of Type 2 Vaccine Derived Poliovirus Lineages. Evidence for Codon-Specific Positive Selection at Three Distinct Locations on Capsid Wall
Tapani Hovi, Carita Savolainen-Kopra, Teemu Smura, Soile Blomqvist, Haider Al-Hello, Merja Roivainen
Research Article | published 28 Jun 2013 | PLOS ONE 10.1371/journal.pone.0066836

Partial sequences of 110 type 2 poliovirus strains isolated from sewage in Slovakia in 2003–2005, and most probably originating from a single dose of oral poliovirus vaccine, were subjected to a detailed genetic analysis. Evolutionary patterns of these vaccine derived poliovirus strains (SVK-aVDPV2) were compared to those of type 1 and type 3 wild poliovirus (WPV) lineages considered to have a single seed strain origin, respectively. The 102 unique SVK-aVDPV VP1 sequences were monophyletic differing from that of the most likely parental poliovirus type 2/Sabin (PV2 Sabin) by 12.5–15.6%. Judging from this difference and from the rate of accumulation of synonymous transversions during the 22 month observation period, the relevant oral poliovirus vaccine dose had been administered to an unknown recipient more than 12 years earlier. The patterns of nucleotide substitution during the observation period differed from those found in the studied lineages of WPV1 or 3, including a lower transition/transversion (Ts/Tv) bias and strikingly lower Ts/Tv rate ratios at the 2nd codon position for both purines and pyrimidines. A relatively low preference of transitions at the 2nd codon position was also found in the large set of VP1 sequences of Nigerian circulating (c)VDPV2, as well as in the smaller sets from the Hispaniola cVDPV1 and Egypt cVDPV2 outbreaks, and among aVDPV1and aVDPV2 strains recently isolated from sewage in Finland. Codon-wise analysis of synonymous versus non-synonymous substitution rates in the VP1 sequences suggested that in five codons, those coding for amino acids at sites 24, 144, 147, 221 and 222, there may have been positive selection during the observation period. We conclude that pattern of poliovirus VP1 evolution in prolonged infection may differ from that found in WPV epidemics. Further studies on sufficiently large independent datasets are needed to confirm this suggestion and to reveal its potential significance.

Vaccinating Girls and Boys with Different Human Papillomavirus Vaccines: Can It Optimise Population-Level Effectiveness?

PLoS One
[Accessed 29 June 2013]
Vaccinating Girls and Boys with Different Human Papillomavirus Vaccines: Can It Optimise Population-Level Effectiveness?
Mélanie Drolet, Marie-Claude Boily, Nicolas Van de Velde, Eduardo L. Franco, Marc Brisson Research Article | published 26 Jun 2013 | PLOS ONE 10.1371/journal.pone.0067072

Decision-makers may consider vaccinating girls and boys with different HPV vaccines to benefit from their respective strengths; the quadrivalent (HPV4) prevents anogenital warts (AGW) whilst the bivalent (HPV2) may confer greater cross-protection. We compared, to a girls-only vaccination program with HPV4, the impact of vaccinating: 1) both genders with HPV4, and 2) boys with HPV4 and girls with HPV2.

We used an individual-based transmission-dynamic model of heterosexual HPV infection and diseases. Our base-case scenario assumed lifelong efficacy of 100% against vaccine types, and 46,29, 8, 18,6% and 77, 43, 79, 8, 0% efficacy against HPV-31,-33,-45,-52,-58 for HPV4 and HPV2, respectively.

Assuming 70% vaccination coverage and lifelong cross-protection, vaccinating boys has little additional benefit on AGW prevention, irrespective of the vaccine used for girls. Furthermore, using HPV4 for boys and HPV2 for girls produces greater incremental reductions in SCC incidence than using HPV4 for both genders (12 vs 7 percentage points). At 50% vaccination coverage, vaccinating boys produces incremental reductions in AGW of 17 percentage points if both genders are vaccinated with HPV4, but increases female incidence by 16 percentage points if girls are switched to HPV2 (heterosexual male incidence is incrementally reduced by 24 percentage points in both scenarios). Higher incremental reductions in SCC incidence are predicted when vaccinating boys with HPV4 and girls with HPV2 versus vaccinating both genders with HPV4 (16 vs 12 percentage points). Results are sensitive to vaccination coverage and the relative duration of protection of the vaccines.

Vaccinating girls with HPV2 and boys with HPV4 can optimize SCC prevention if HPV2 has higher/longer cross-protection, but can increase AGW incidence if vaccination coverage is low among boys.