Mass Immunization Programs Research Articles

Molecular evolutionary and epidemiological dynamics of genotypes 1G and 2B of rubella virus.

Rubella Virus (RV), which causes measles-like rashes in children, puts millions of infants at risk of congenital defects across the globe. Employing phylogenetic approaches to the whole genome sequence data and E1 glycoprotein sequence data, the present study reports the substitution rates and dates of emergence of all thirteen previously described rubella genotypes, and gains important insights into the epidemiological dynamics of two geographically widely distributed genotypes 1G and 2B. The overall nucleotide substitution rate of this non-vector-borne RV is in the order of 10−3 substitutions/site/year, which is considerably higher than the substitution rates previously reported for the vector-borne alphaviruses within the same family. Currently circulating strains of RV share a common ancestor that existed within the last 150 years, with 95% Highest Posterior Density values ranging from 1868 to 1926 AD. Viral strains within the respective genotypes began diverging between the year 1930 s and 1980 s. Both genotype 1G and 2B have shown a decline in effective number of infections since 1990 s, a period during which mass immunization programs against RV were adapted across the globe. Although both genotypes showed some extent of spatial genetic structuring, the analyses also depicted an inter-continental viral dispersal. Such a viral dispersal pattern could be related to the migration of infected individuals across the regions coupled with a low coverage of MMR vaccination.

Flu vaccine experiences and beliefs influence vaccination decision making more than knowledge

Mass immunization programs have proven to be a primary preventive measure to limit the spread of many infectious diseases worldwide. Nurses are trained to be leaders in preventing potential global health problems, but they are one of the groups with the lowest rates of compliancy in receiving influenza vaccination. Since nursing faculty are important role models in molding attitudes and behaviors of future nurses (their students), we set out to explore the knowledge, attitudes and beliefs of the nursing faculty and their students regarding influenza vaccine decision making. Our study included an assessment of the knowledge, attitudes and beliefs (KABs) of the nursing faculty and students related to influenza vaccination and whether their KABs influence the decision to receive or decline the vaccination.  A cross-sectional survey was conducted using an anonymous questionnaire and our study indicated that personal experiences—either positive or negative—had a direct effect on influenza vaccine decision-making.  Additionally, personal experiences influenced beliefs, and beliefs were shown to influence decision-making regarding vaccination.  While beliefs and personal experiences had a direct effect on vaccine decision-making, knowledge had only an indirect effect through beliefs. Our study demonstrated that even though nursing practice is supposed to be driven by evidence-based medical practices, personal practices by nurses may be more influenced by personal beliefs than medical knowledge.

Pandemic influenza A H1N1 vaccines and narcolepsy: vaccine safety surveillance in action

The 2009 influenza A H1N1 pandemic placed unprecedented demand on public health authorities and the vaccine industry. Efforts were coordinated internationally to maximise the speed of vaccine development, distribution, and delivery, and the European Union's novel fast-track authorisation procedures mandated increased postmarketing surveillance to monitor vaccine safety. Clinicians in Finland and Sweden later identified an apparent increase in the incidence of narcolepsy associated with a specific adjuvanted pandemic influenza vaccine. After extensive review, the European Medicines Agency confirmed the existence of this association, which has since been detected in England, Ireland, France, and Norway. Assessments of the causal mechanisms continue. In this Review, we discuss how the narcolepsy association was detected, and we present the evidence according to the causality assessment criteria for adverse events following immunisation. The lessons learnt emphasise the central role of alert clinicians in reporting of suspected adverse reactions, and the importance of internationally robust postmarketing surveillance strategies as crucial components in future mass immunisation programmes.

Nurses must be more confident in assessing Gillick competence

The recent measles outbreak in south west Wales saw mass immunisation of children who had not received both doses of the measles, mumps and rubella (MMR) vaccine. The most difficult target group to immunise proved to be children in the 14-17 year age group, due in primarily to the reliance on parental consent for the immunisation instead of the child's consent under the rule in Gillick. For future mass immunisation programmes with this age group to be successful, nurses must be more confident in assessing Gillick competence and allow the child to consent to the vaccination. In this article the author considers the requirements for Gillick competence and highlights the factors nurses must consider when determining whether a child is competent to give consent to treatment.

Hope-Simpson's Progressive Immunity Hypothesis as a Possible Explanation for Herpes Zoster Incidence Data

Varicella-zoster virus (VZV) is the causative agent of both varicella (chickenpox) and herpes zoster (HZ) (shingles). After varicella infection, the virus remains dormant in the host's dorsal ganglia and can reactivate due to waning cell-mediated immunity, causing HZ. Exposure of varicella-immune persons to VZV may boost the host's immune response, resulting in a protective effect against HZ. In this study, we used mathematical models of VZV transmission and HZ development to test the biological hypothesis of "progressive immunity," originally proposed by Hope-Simpson (Proc R Soc Med. 1965;58:9-20), that cell-mediated protection against HZ increases after each episode of exposure to VZV. Predictions from a model incorporating such a hypothesis were compared with those of other concurrent models proposed for explaining HZ epidemiology. The progressive immunity model fits significantly better the age profile of HZ incidence for Finland (years 2000-2006), Italy (2003-2005), Spain (1997-2004), and the United Kingdom (1991-1992), suggesting that this mechanism may be critical in shaping HZ patterns. The model thus validated is an alternative to VZV models currently used to evaluate the impact of mass immunization programs for varicella and therefore extends the range of tools available to assist policy-makers with the present decision paralysis on the introduction of vaccination.

Prevalence of HBV infection in suspected population of conflict-affected area of war against terrorism in North Waziristan FATA Pakistan

BackgroundHepatitis B virus (HBV) infection is a major cause of severe liver diseases including fibrosis, hepatocellular carcinoma (HCC) and cirrhosis related end stage liver diseases (ESLD) in mankind. It is a common belief that infectious diseases have historically been responsible for the massiveness of war-related deaths, so the aim of this study was to estimate the prevalence of HBV infection and to demonstrate the various socio-economic, demographic and possible risk factors related to HBV infection among the conflict-affected peoples due to war against terrorism in North Waziristan. MethodsBlood samples were collected from total 790 suspected individuals from the conflict-affected population of North Waziristan and were analyzed initially tested for the presence of HBsAg, HBeAg antigens, Anti-HBc and Anti-HBs antibodies using ELISA methods. All the positive samples were tested by real time PCR to confirm the presence of HBV DNA in ELISA positive specimens. ResultsTotal of 126 (15.94%) samples were found positive for HBV DNA by real-time PCR. Among these positive subjects, 95 (75.5%) were males while 31 (24.5%) were females in a ratio of approximately 3:1. High HBV prevalence (41.26%) was observed among the subjects of subdivision Miran Shah relating to the high frequency of military activities against terrorism as compared to Mir Ali subdivision (35.7%) and Razmak subdivision (19.8%). Among the age groups, high prevalence (38.88%) was observed in age group 21–30 as compared to children and in older age groups. The modes of HBV transmission in this area was associated with re-uses of contaminated needles/syringes in medical care, barbers shops, sexual exposure and tattooing are the principal causal risks factors. Furthermore HBV infection was significantly higher in people with low socioeconomic status, in illiterate persons and in drivers. ConclusionOur results indicate high prevalence rate of HBV infection in young subjects obviously confirms the entire absence of any program to fight HBV. Mass Immunization programs, awareness campaigns and education efforts should be practiced immediately to reduce HBV transmission among young peoples of this conflict zone.

Occult Hepatitis B (OBH) in Clinical Settings

Context: Occult hepatitis B (OHB), or persistent HBV DNA in patients who are hepatitis B surface antigen (HBsAg) negative, is a recently recognized entity. In an attempt to summarize the issues, this review presents an overview of the current proposed hypothesis on the clinical relevance and also updates the knowledge on the classification of OHB in different clinical settings. Evidence Acquisition: OHB could be found in different population and clinical backgrounds including: viral co-infections (with either human immunodeficiency or hepatitis C viruses), HBV chronic carriers, dialysis patients, transplantation settings and certain clinical situations (named in here: special clinical settings) with no apparent distinguishable clinical parameters. Results: The exact magnitude, pathogenesis, and clinical relevance of OHB are unclear. Even the possible role exerted by this cryptic infection on liver disease outcome, and hepatocellular carcinoma development remains unknown. Conclusions: monitoring of Individuals with positive anti-HBc, mass immunization programs and improvement in diagnostic tools seem to be important to control the probability of transmission of HBV through cryptic HBV infection.

Occult Hepatitis B (OBH) in Clinical Settings

ContextOccult hepatitis B (OHB), or persistent HBV DNA in patients who are hepatitis B surface antigen (HBsAg) negative, is a recently recognized entity. In an attempt to summarize the issues, this review presents an overview of the current proposed hypothesis on the clinical relevance and also updates the knowledge on the classification of OHB in different clinical settings.Evidence AcquisitionOHB could be found in different population and clinical backgrounds including: viral co-infections (with either human immunodeficiency or hepatitis C viruses), HBV chronic carriers, dialysis patients, transplantation settings and certain clinical situations (named in here: special clinical settings) with no apparent distinguishable clinical parameters.ResultsThe exact magnitude, pathogenesis, and clinical relevance of OHB are unclear. Even the possible role exerted by this cryptic infection on liver disease outcome, and hepatocellular carcinoma development remains unknown.ConclusionsMonitoring of Individuals with positive anti-HBc, mass immunization programs and improvement in diagnostic tools seem to be important to control the probability of transmission of HBV through cryptic HBV infection.

Tort law and mass immunization programs: lessons from the polio and flu episodes.

Tort law and mass immunization programs: lessons from the polio and flu episodes.

Emergence and reemergence of vaccinia-like viruses: global scenario and perspectives.

Among the members of the genus Orthopoxvirus (OPXV), vaccinia virus (VACV), the type species of the genus is a double-stranded DNA virus, belongs to the subfamily Chordopoxvirinae of the family Poxviridae. The causative agents of smallpox, VACV and Variola virus are mutually immunogenic and the type species of Orthopoxvirus, cause only mild complications in humans. Therefore, the VACV was used as a smallpox vaccine world over under mass immunization program promoted by World Health Organization, which lead to the variola eradication globally in 1979. Since then, no vaccination of human population has been carried out; however, vaccination has been continued for at-risk laboratory workers, military personnel and others working with recombinant VACV or other non-variola orthopoxviruses (OPXVs). There has now been a surge in the development of safer smallpox vaccines and understanding of the biology of VACV necessitating re-use of this vaccine in most vulnerable population, because of rise in bioterrorist threats globally. Also, globally there has been the emergence and re-emergence of vaccinia-like viruses (VLVs) in Brazil, buffalopox viruses in Egypt, Indonesia, India and its neighbouring countries like Nepal, Pakistan. Bioterrorism as well as emergence and re-emergence of the VLVs constitute a concern as 50% of the population globally (40% in USA)<30years are unvaccinated and most vulnerable for smallpox reemergence. Thus, the search for new generation safer smallpox vaccine entails review of biology of VLVs in the smallpox-free world. In this review, we present occurrence of VLVs in the world with exhaustive discussion particularly on the emergence and re-emergence of these viruses in India and Brazil where VLVs are sufficiently studied.

The changing and dynamic epidemiology of meningococcal disease

The epidemiology of invasive meningococcal disease continues to change rapidly, even in the three years since the first Meningococcal Exchange Meeting in 2008. Control of disease caused by serogroup C has been achieved in countries that have implemented meningococcal C or quadrivalent meningococcal ACWY conjugate vaccines. Initiation of mass immunization programs with meningococcal A conjugate vaccines across the meningitis belt of Africa may lead to the interruption of cyclical meningococcal epidemics. A meningococcal B vaccination program in New Zealand has led to a decreased incidence of high rates of endemic serogroup B disease. Increases in serogroup Y disease have been observed in certain Nordic countries which, if they persist, may require consideration of use of a multiple serogroup vaccine. The imminent availability of recombinant broadly protective serogroup B vaccines may provide the tools for further control of invasive meningococcal disease in areas where serogroup B disease predominates. Continued surveillance of meningococcal disease is essential; ongoing global efforts to improve the completeness of reporting are required.

Health

The World Health Organisation defines good health as ‘a state of complete physical, mental and social well-being and not merely the absence of disease and infirmity’. People in the UK are healthier and living longer than ever before, with the major advances in life expectancy over the last century due mainly to public health innovations such as improvements in water quality and sewerage, and mass immunisation programmes which have reduced infectious diseases (DH,2010). This chapter looks not only at these improvements in life expectancy and lifestyles in the population, but changes in the prevalence of chronic sickness and disability and the impact on health services. There is also analysis of mental well-being and the effects of environmental factors such as winter temperature and infections on health.

Research Aims to Boost Pertussis Control

Before the availability of the pertussis vaccine, more than 270 000 cases and 10 000 deaths were reported annually in the United States. Mass immunization programs begun around the world in the 1940s almost eradicated childhood cases of the disease by the 1970s.

Acceptance of a vaccine against pandemic influenza A (H1N1) virus amongst healthcare workers in Beijing, China

Due to the advent of the new influenza A (H1N1) strain in 2009, many countries introduced mass immunization programs. Healthcare workers (HCWs) were amongst the key groups targeted for the vaccine in these programs. However, experience with the seasonal influenza vaccine has shown that there are multiple barriers related to the attitudes and perceptions of the population which influence uptake. The aim of this study was to determine pandemic influenza A (H1N1) vaccination rate amongst a group of Chinese HCWs and the associated factors around acceptance.A cross-sectional investigation of HCWs (doctors, nurses and technicians) from 19 hospitals in Beijing, China was conducted in January 2010. The main outcome measures were awareness, risk perception of H1N1, preventive measures and uptake of H1N1 vaccination during the pandemic. A total of 1657 HCWs completed the survey. A quarter of the participants reported receiving the pandemic influenza A (H1N1) vaccine. Occupation (being a doctor), receiving seasonal flu vaccine and believing in the effectiveness of the vaccine were all strongly associated with accepting the pandemic influenza A (H1N1) vaccine. Over a thousand participants (61%, 1008/1657) agreed that they were ‘concerned about the side effects of the swine flu vaccine’, while 758 (46%) were ‘concerned that the vaccine had not been tested adequately’.While studies reported high rates of willingness to receive the vaccine, in reality these did not transpire. Aside from promoting seasonal flu vaccination, authorities need to start educational campaigns much earlier in a pandemic. Programs that are simultaneously launched with the introduction of the vaccine will not be as successful, as those which have built momentum alongside the pandemic.

A Survey for Changed Control Policies of Hepatitis B in Republic of Korea

목 적:우리나라의 B형 간염 조절을 위한 초창기 예방접종 정책과 1회용 주사기를 포함한 혈액매개질환의 감염원이 될 수 있는 기구 사용 정책에 관한 자료를 수집, 정리하여 향후 정책 수립 및 평가에 활용할 수 있도록 하였다. 방 법:국내 학회지 또는 논문, 정부 웹사이트, 전산화된 주요 일간신문 등을 검색하여 수집된 자료들의 내용을 확인하였다. 자료의 내용에 따라 정부의 B형 간염 조절 정책, 학교에서의 B형 간염 단체 예방접종 사업, B형 간염 백신 사용 상황, 1회용 주사기를 포함 혈액매개질환의 전파 가능성이 있는 기구 사용에 관한 정책 등 네 가지 주제로 나누어 각각에 대해 시기별 정책 변화를 정리하였다. 결 과: 1980년대 초 B형 간염에 대한 사회적 관심이 컸기 때문에 B형 간염 백신이 신속히 도입, 개발되었으며, 1983년 말에 'B형 간염 퇴치를 위한 5개년 계획'이 수립되어 1984-5년 2년간에만 B형 간염 백신을 접종한 사람은 약 600만명이었다. 그러나 접종 대상이 신생아가 아닌 성인에 초점을 맞추었기에 전문가들의 반론에 따라 2년만에 계획은 백지화되었다. 이후 학교 단체 예방접종 사업이 진행되고, 1995년에는 국가 필수예방접종에 포함되는 등 신생아 중심의 예방접종 정책이 유지되었다. 1회용 주사기의 사용은 1980년대 초부터 권고 되었으나 1985년이 돼서야 법제화되었다. 결 론:우리나라에서의 B형 간염 감염 관리에 대한 성공 요인은 B형 간염 백신의 조기 도입 및 대량 접종, 높은 접종률, 1회용 주사기 사용 등이 종합적으로 작용하여 이루어진 것이라 생각된다. 그러나 이를 뒷받침할만한 공식적 자료가 너무 부족하다. 따라서 정부가 보유하고 있는 모든 감염 관련 자료들의 정리와 전산화 작업이 매우 시급하다고 여겨진다. 【Purpose : We have tried to search all concerning data on the policies of hepatitis vaccination or surveillance of medical equipments that can transmit blood mediated diseases, including disposable syringe, in Republic of Korea, to propose references to other medical professionals. Methods : Data from domestic journals, government websites, computerized newspapers, etc. were reviewed. The data were arranged into four categories (governmental policies on hepatitis control, hepatitis mass immunization program in school, using process of hepatitis vaccine, and policies on medical equipments surveillance, including disposable syringes, which is considered as source of blood mediated infection), and the periodic changes on each subjects in policies were reviewed. Results : Due to growing social concerns on hepatitis in early 1980s, swift introduction and production of hepatitis vaccine was made. After establishment of 5 year project for eradication of hepatitis B in late 1983, number of vaccinated population jumped up to 6 million within 2 years (1984-85). However, since the immunization targets were mainly adult, not infant, this project was annulled in late 1985. Following this project, hepatitis mass immunization program in school was carried out. In year 1995, hepatitis vaccine was included in national immunization program. The use of disposable syringe was recommended from year 1980 but legislated in year 1985, finally. Conclusion : The mainstay in controlling hepatitis in Republic of Korea was coordination of prompt introduction of vaccine, mass immunization, high vaccination coverage rate, or use of disposable syringes. However, since there is lack of official data available, it is urgent to arrange and computerize all government data related to infectious diseases.】

Update on Chronic Hepatitis B

Chronic hepatitis B virus (HBV) infection affects over 350 million people worldwide and over 1 million die annually of HBV-related chronic liver disease. The prolonged immunologic response to HBV infection leads to the development of cirrhosis, liver failure, or hepatocellular carcinoma (HCC) in up to 40% of patients. The implementation of mass immunization programs has dramatically decreased the incidence of HBV infection among infants, children, and adolescents in many countries, but there remains a large number who were infected with HBV before such programs. A variety of host, viral, and external factors influence HBV disease progression and the risk of chronic infection. Six drugs are currently FDA-approved for the treatment of chronic HBV infection. While novel antiviral drugs have improved the management of cirrhosis, strategies to prevent and treat HCC remain inadequate.

Acceptability of Internet adverse event self-reporting for pandemic and seasonal influenza immunization among health care workers

This study assessed the acceptability and feasibility of Internet self-reporting for adverse events following pandemic and seasonal influenza immunization among 270 health care workers at a tertiary care children's and women's hospital in fall 2009. Participants responded to an online questionnaire 72 h after vaccine receipt. Non-responders were sent a reminder email 8–10 days after vaccine receipt, followed by a telephone call for those who did not respond online. The overall online response rate was high (88%). Participants rated the online self-report easy to use and would be willing to use it again. The high response rate and acceptability of the online report method suggest that web-based self-reporting for adverse event following immunization (AEFI) has the potential for rapid assessments of AEFI in mass or new immunization programs.

Is a mass immunization program for pandemic (H1N1) 2009 good value for money? Evidence from the Canadian Experience

In response to the pandemic H1N1 influenza 2009 outbreak, many jurisdictions undertook mass immunization programs that were among the largest in recent history. The objective of this study was to determine the cost-effectiveness of the mass H1N1 immunization program in Ontario, Canada's most populous province (population 13,000,000). This analysis suggests that a mass immunization program as carried out in Ontario and many other high-income health care systems in response to H1N1 2009 was effective in preventing influenza cases and health care resource use and was also highly cost-effective despite the substantial program cost.

Is a mass immunization program for pandemic (H1N1) 2009 good value for money? Early evidence from the Canadian experience

Is a mass immunization program for pandemic (H1N1) 2009 good value for money? Early evidence from the Canadian experience

Is a Mass Immunization Program for Pandemic (H1N1) 2009 Good Value for Money? Early Evidence from the Canadian Experience.

This work contributes informed estimates to the current debate about the pandemic (H1N1) 2009 mass immunization program’s economic merits. We performed a cost-utility analysis of the (H1N1) 2009 mass immunization program in Ontario, Canada’s most populous province. The analysis is based on a simulation model of a pandemic (H1N1) 2009 outbreak, surveillance data, and administrative data. We consider no immunization versus mass immunization reaching 30% of the population. Immunization program costs are expected to be $118 million in Ontario. Our analysis indicates this program will reduce influenza cases by 50%, preventing 35 deaths, and cutting treatment costs in half. A pandemic (H1N1) 2009 immunization program is likely to be highly cost-effective.