Vaccination coverage rates of military personnel worldwide: a systematic review of the literature

Objectives

Due to the professionally specific risk of infection in the armed forces, recommendations for vaccination are usually adapted for soldiers and are subject to special regulations. Little data is available on scientifically measured vaccination coverage of soldiers.

Methods

A systematic literature research was carried out in the PubMed database using the search terms “army” or “military” or “Bundeswehr” and “vaccination” or “vaccine”. Studies covering the period from 1990 to 2018 that contain statements on vaccination coverage rates of soldiers were identified. Twenty-two out of the initially found 1801 results were used.

Results

The studies found were conducted in nine different countries with eight out of the 22 studies originating from the USA. The size of study was between 180 and 32,502 subjects. On average, the vaccination rates determined in the studies were between 26.8 and 94.7%. Hepatitis A coverage was lowest (a minimum of 11.3%) and tetanus vaccination coverage was highest (with a maximum of 94.7%). Vaccination rates decreased with increasing age and coverage tended to be lower for men than for women. The term of service did not have a significant effect on vaccination rates.

Conclusions

On the whole, most studies referred to recruits. They showed high vaccination rates for standard vaccinations and lower vaccination rates for indication and seasonal vaccinations. However, there were also vaccination gaps of temporary-career volunteers. This leads to a considerable effort at the armed forces to complete vaccine protection in case of a short-term operational commitment.

Global trends in measles publications

INTRODUCTION

Beginning with the 1960s, this review analyzes trends in publications on measles indexed by the National Library of Medicine from January 1960 to mid-2018. It notes both the growth in numbers of published papers, and the increasing number and proportion of publications, in the current century, of articles on such items as costing, measles elimination, and determinants of coverage.

METHODS

A two-person team extracted from the National Library of Medicine (NLM) homepage all citations on measles beginning in 1960 and continuing through mid-2018. These were then classified both by overall number and by subject matter, with tabular summaries of both by decade and by subject matter. The tabular presentation forms the basis for a discussion of the ten most frequently cited subjects, and publication trends, with a special emphasis on the current century.

RESULTS

As in the past, the most often currently published items have been on coverage and its determinants, measles elimination, outbreak reports, SSPE, and SIAs. The putative relationship between vaccination and autism saw a spurt of articles in the 1990s, rapidly declining after the IOM report rejecting the causative hypothesis.

CONCLUSION

There is a discussion on the sequencing of polio and measles eradication, the former unlikely before 2022, and an examination of likely research priorities as the world moves from measles control to measles eradication. There is a key role for social science in combatting vaccination reticence. The role of technical innovations, such as micropatch vaccination, is discussed.

Measles control in Australia - threats, opportunities and future needs

Control of measles was the focus of a national workshop held in 2015 in Sydney, Australia, bringing together stakeholders in disease control and immunisation to discuss maintaining Australia's measles elimination status in the context of regional and global measles control. The global epidemiology of measles was reviewed, including outbreaks in countries that have achieved elimination, such as the Disneyland outbreak in the United States and large outbreaks in Sydney, Australia. Transmission of measles between Australia and New Zealand occurs, but has not been a focus of control measures. Risk groups, the genetic and seroepidemiology of measles as well as surveillance, modelling and waning vaccine-induced immunity were reviewed. Gaps in policy, research and practice for maintaining measles elimination status in Australia were identified and recommendations were developed. Elimination of measles globally is challenging because of the infectiousness of measles and the need for 2-dose vaccine coverage rates in excess of 95% in all countries to achieve it. Until this occurs, international travel will continue to permit measles importation from endemic countries to countries that have achieved elimination. When measles cases are imported, failure to diagnose and isolate cases places the health system at risk of measles outbreaks. Vaccine funding models can result in gaps in vaccine coverage for adults and migrants. Australia introduced a whole-of-life immunisation register in 2016 and catch-up vaccination for at-risk communities, which will improve measles control. Research on diagnosis, immunology, case management and modelling of vaccination strategies are important to ensure continued control of measles.

Systematic Review of Health Economic Analyses of Measles and Rubella Immunization Interventions

Economic analyses for vaccine-preventable diseases provide important insights about the value of prevention. We reviewed the literature to identify all of the peer-reviewed, published economic analyses of interventions related to measles and rubella immunization options to assess the different types of analyses performed and characterize key insights. We searched PubMed, the Science Citation Index, and references from relevant articles for studies in English and found 67 analyses that reported primary data and quantitative estimates of benefit-cost or cost-effectiveness analyses for measles and/or rubella immunization interventions. We removed studies that we characterized as cost-minimization analyses from this sample because they generally provide insights that focused on more optimal strategies to achieve the same health outcome. The 67 analyses we included demonstrate the large economic benefits associated with preventing measles and rubella infections using vaccines and the benefit of combining measles and rubella antigens into a formulation that saves the costs associated with injecting the vaccines separately. Despite the importance of population immunity and dynamic viral transmission, most of the analyses used static models to estimate cases prevented and characterize benefits, although the use of dynamic models continues to increase. Many of the analyses focused on characterizing the most significant adverse outcomes (e.g., mortality for measles, congenital rubella syndrome for rubella) and/or only direct costs, and the most complete analyses present data from high-income countries.

A global perspective of vaccination of healthcare personnel against measles: systematic review

Measles transmission has been well documented in healthcare facilities. Healthcare personnel who are unvaccinated and who lack other evidence of measles immunity put themselves and their patients at risk for measles. We conducted a systematic literature review of measles vaccination policies and their implementation in healthcare personnel, measles seroprevalence among healthcare personnel, measles transmission and disease burden in healthcare settings, and impact/costs incurred by healthcare facilities for healthcare-associated measles transmission. Five database searches yielded 135 relevant articles; 47 additional articles were found through cross-referencing. The risk of acquiring measles is estimated to be 2 to 19 times higher for susceptible healthcare personnel than for the general population. Fifty-three articles published worldwide during 1989-2013 reported measles transmission from patients to healthcare personnel; many of the healthcare personnel were unvaccinated or had unknown vaccination status. Eighteen articles published worldwide during 1982-2013 described examples of transmission from healthcare personnel to patients or to other healthcare personnel. Half of European countries have no measles vaccine policies for healthcare personnel. There is no global policy recommendation for the vaccination of healthcare personnel against measles. Even in countries such as the United States or Finland that have national policies, the recommendations are not uniformly implemented in healthcare facilities. Measles serosusceptibility in healthcare personnel varied widely across studies (median 6.5%, range 0-46%) but was consistently higher among younger healthcare personnel. Deficiencies in documentation of two doses of measles vaccination or other evidence of immunity among healthcare personnel presents challenges in responding to measles exposures in healthcare settings. Evaluating and containing exposures and outbreaks in healthcare settings can be disruptive and costly. Establishing policies for measles vaccination for healthcare personnel is an important strategy towards achieving measles elimination and should be a high priority for global policy setting groups, governments, and hospitals.

Susceptibility to measles, rubella, mumps, and varicella-zoster viruses among healthcare workers

BACKGROUND

It is important to identify and immunize susceptible healthcare workers to prevent and control hospital infections. Our aim was to evaluate the specific antibodies against the measles, mumps, and rubella viruses and the varicella zoster virus among healthcare workers in a tertiary-care hospital.

PATIENTS AND METHODS

A total of 284 healthcare workers (89 men and 195 women; mean age, 33.5 ± 11 years), including 111 nurses, 87 physicians, 34 laboratory technicians, and 52 members of the housekeeping staff, of Van Training and Research Hospital were enrolled in this study. Antibodies were detected with an enzyme-linked immunosorbent assay.

RESULTS

The numbers of workers with serological susceptibility to mumps, measles, rubella, or chicken pox were 26 (9.2%), 18 (6.3%), 7 (2.5%), and 5 (1.8%), respectively. Although the difference was not statistical significant, the rate of seroprevalence of antibodies was lowest for measles (90.8%; p>0.05). Susceptibility to measles, mumps, and rubella, and chicken pox was more prevalent among young healthcare workers (p<0.001). Not all healthcare workers born before 1957 were immune to these vaccine-preventable diseases.

CONCLUSION

These data confirm that screening and vaccination of susceptible healthcare workers is essential regardless of age.

Health economics of rubella: a systematic review to assess the value of rubella vaccination

Background

Most cases of rubella and congenital rubella syndrome (CRS) occur in low- and middle-income countries. The World Health Organization (WHO) has recently recommended that countries accelerate the uptake of rubella vaccination and the GAVI Alliance is now supporting large scale measles-rubella vaccination campaigns. We performed a review of health economic evaluations of rubella and CRS to identify gaps in the evidence base and suggest possible areas of future research to support the planned global expansion of rubella vaccination and efforts towards potential rubella elimination and eradication.

Methods

We performed a systematic search of on-line databases and identified articles published between 1970 and 2012 on costs of rubella and CRS treatment and the costs, cost-effectiveness or cost-benefit of rubella vaccination. We reviewed the studies and categorized them by the income level of the countries in which they were performed, study design, and research question answered. We analyzed their methodology, data sources, and other details. We used these data to identify gaps in the evidence and to suggest possible future areas of scientific study.

Results

We identified 27 studies: 11 cost analyses, 11 cost-benefit analyses, 4 cost-effectiveness analyses, and 1 cost-utility analysis. Of these, 20 studies were conducted in high-income countries, 5 in upper-middle income countries and two in lower-middle income countries. We did not find any studies conducted in low-income countries. CRS was estimated to cost (in 2012 US$) between $4,200 and $57,000 per case annually in middle-income countries and up to $140,000 over a lifetime in high-income countries. Rubella vaccination programs, including the vaccination of health workers, children, and women had favorable cost-effectiveness, cost-utility, or cost-benefit ratios in high- and middle-income countries.

Conclusions

Treatment of CRS is costly and rubella vaccination programs are highly cost-effective. However, in order for research to support the global expansion of rubella vaccination and the drive towards rubella elimination and eradication, additional studies are required in low-income countries, to tackle methodological limitations, and to determine the most cost-effective programmatic strategies for increased rubella vaccine coverage.

Serological survey of mumps immunity among health care workers in the Catalonia region of Spain

Susceptible health care workers are at risk of acquiring and transmitting mumps to or from patients. A survey was carried out in 639 health care workers from tertiary public hospitals and primary care centers in the Catalonia region of Spain during 2009 to determine the prevalence of immunity to mumps among this group. The prevalence of immune health care workers was 87.5% (95% confidence interval, 84.7-89.9). Vaccination with 2 doses of vaccine should be reinforced in health care workers to minimize the risk of mumps transmission in health care settings.

Consequences of an unrecognized measles exposure in an emergency department

A recent measles case in a paediatric hospital ED resulted in 111 individuals (patients, family members and health-care workers) potentially being exposed to measles. This report documents the efforts taken to contact trace and provide best practice care for all those exposed to the index case. It also provides a snapshot of community prevalence information on immunity to measles. One hundred per cent of contacted children (n = 24) eligible for vaccination were immunized, whereas 96% of adults surveyed or tested (n = 44) had assumed or proven immunity. However, six infants aged between 6 and 9 months were exposed and might have been a sufficiently large reservoir to facilitate the ongoing spread of measles in the community, if contact tracing and preventative measures had not occurred. This scenario also highlights the need to consider measles in the ED, particularly among travellers, with urgent isolation of suspected cases in the ED according to guidelines discussed.

Healthcare workers and immunity to infectious diseases

OBJECTIVE

In 2002, New South Wales (NSW) Health introduced an updated policy for occupational screening and vaccination against infectious diseases. This study describes healthcare worker (HCW) immunity to hepatitis B, measles, mumps, rubella (MMR) and varicella based on serological screening, following introduction of this policy.

METHODS

HCW screening serology performed at two healthcare facilities in south western Sydney (Bankstown and Fairfield) was extracted for the period September 2003 to September 2005. Immunity to hepatitis B, MMR and varicella was quantitated and cross-tabulated against age, sex and staff risk category.

RESULTS

A total of 1,320 HCWs were screened. Almost two thirds were immune to hepatitis B while immunity to MMR and varicella ranged from 88% to 94%. Age stratification showed lower levels of measles immunity in those born after 1965.

CONCLUSIONS

Despite availability of vaccination for over two decades, a significant proportion of HCWs at these two facilities were non-immune to hepatitis B. This is of concern for those non-immune staff involved in direct clinical care, who are at risk of blood and body fluid exposures. The small group of HCWs non-immune to MMR and varicella pose a risk to themselves and others in the event of an outbreak.

IMPLICATIONS

There is a need for improved implementation of the occupational screening and vaccination policy, including better education of HCWs about the risks of non-immunity to vaccine preventable diseases. The revised 2007 NSW Health policy may assist this process and will need evaluation to determine whether HCW immunity improves in the coming years.

Reliability of medical students' vaccination histories for immunisable diseases

BACKGROUND

Medical students come into contact with infectious diseases early on their career. Immunity against vaccine-preventable diseases is therefore vital for both medical students and the patients with whom they come into contact.

METHODS

The purpose of this study was to compare the medical history and serological status of selected vaccine-preventable diseases of medical students in Germany.

RESULTS

The overall correlation between self-reported medical history statements and serological findings among the 150 students studied was 86.7 %, 66.7 %, 78 % and 93.3 % for measles, mumps, rubella and varicella, conditional on sufficient immunity being achieved after one vaccination. Although 81.2 % of the students' medical history data correlated with serological findings, significant gaps in immunity were found.

CONCLUSION

Our findings indicate that medical history alone is not a reliable screening tool for immunity against the vaccine-preventable diseases studied.

Exposure of Ugandan health personnel to measles and rubella: Evidence of the need for health worker vaccination

With rubella and, until recently, measles highly endemic in Uganda, health personnel are at risk of these vaccine-preventable diseases and a source of transmission to patients. Measles and rubella serology (IgG) and history of exposure and vaccination were determined among 311 health care workers in a nationwide study. All tested positive for measles IgG, whereas 49.2% reported having been vaccinated. Rubella antibodies were present in 98.1% of personnel; 3.2% of women of child-bearing age were still susceptible. Increasing age and longer duration of service increased the risk of rubella infection. A national policy on health worker protection should include immunisation against vaccine-preventable diseases upon entry to training.

Seroprevalence and immunization history of selected vaccine preventable diseases in medical students

To evaluate protection against vaccine-preventable diseases in medical students, we obtained data on immunization status and history of diphtheria, tetanus, pertussis, poliomyelitis, measles, mumps, rubella, varicella and hepatitis B from students with elective periods in our institution. Further, serum antibodies against measles, mumps, rubella and varicella-zoster virus (VZV) and hepatitis B surface (HBs) antigen were determined on a voluntary basis. For students with incomplete immunization status or lack of protective antibodies, vaccination was offered for free. Success of catch-up immunizations was serologically confirmed 4 weeks later. From May 1999 to April 2003, 170 students were enrolled; their mean age was 26 years with a median of 25 years (range 22-48 years). Immunization records were complete in 148 (87%), incomplete in 11 (6.5%) and missing in 11 (6.5%) students. Only 26% of the cohort had a complete and up-to-date immunization status. Seroprevalence of IgG antibodies against measles, mumps, rubella, VZV and HBs (> or = 10 IU/l) in 149 students were 85, 85, 92, 97 and 90%, respectively. Indications for > or = 1 catch-up immunization were found in 125 (74%) students and were accepted by 97 of them (78%). Sixty two (99%) of 63 immunized students available for follow-up demonstrated an adequate serological response. In conclusion, the great majority of medical students had immunization gaps. Systematic immunization programmes for medical students should be implemented.

Prevalence of measles, rubella, mumps, and varicella antibodies among healthcare workers in Japan

OBJECTIVES

To evaluate the immune status of healthcare workers (HCWs) against measles, rubella, mumps, and varicella in Japan, and to promote an adequate vaccination program among HCWs.

SETTING

University of Tokyo Hospital.

PARTICIPANTS

Eight hundred seventy-seven HCWs.

DESIGN

Serologic screening for measles, rubella, mumps, and varicella was performed on HCWs. Antibodies against measles, rubella, and mumps were detected using hemagglutination inhibition (HI) assay ($4.20 per test). If serum was negative by HI assay, enzyme-linked immunosorbent assay (EIA) was performed ($12.60 per test). Anti-varicella antibodies were detected by EIA only.

RESULTS

Among tested HCWs, 98.5%, 90.4%, 85.8%, and 97.2% had immunity to measles, rubella, mumps, and varicella, respectively. All those born before 1970 were seropositive for measles. However, individuals susceptible to rubella, mumps, and varicella were present in all age groups. The sensitivities and negative predictive values of HI assay compared with EIA were 86.6% and 11.3% for measles, 99.1% and 92.2% for rubella, and 47.8% and 24.1% for mumps, respectively. For measles and mumps, prevaccination screening by HI assay in combination with EIA led to significant savings compared with EIA only. In contrast, it was estimated that prevaccination screening using only HI assay would be more economical for rubella.

CONCLUSIONS

Aggressive screening and vaccination of susceptible HCWs was essential regardless of age. Prevaccination serologic screening using a combination of HI assay and EIA was more economical for measles and mumps.

Susceptibility of healthcare workers to measles, mumps rubella and varicella

Susceptible healthcare workers are at risk of acquiring and transmitting measles, mumps, rubella and varicella to or from patients. We tested 333 employees at Padova University Hospital, for specific IgG. Of the workers tested, 98.2% were positive for measles, 85.9% for mumps, 97.6% for rubella and 97.9% for varicella. Eventhough participants born before 1957 were not all positive, they had a higher prevalence of immunity. We suggest serological screening in high-risk areas (paediatrics, oncology, radiotherapy, infectious diseases, maternity and the laboratory) and vaccination of susceptible employees.

An outbreak of mumps among young adults in Vancouver, British Columbia, associated with 'rave' parties

In early 1997 an unexpectedly high number of cases of mumps was reported in Vancouver, British Columbia.

METHODS

A case control study was conducted to address four objectives: 1) Describe the outbreak and the population at risk, 2) examine the impact of mumps on this population, 3) identify personal risk factors for infection, and 4) test the hypothesis that social gatherings, 'rave' parties in particular, were a risk factor in this outbreak.

RESULTS

Mumps infection was associated with: attending a rave party [OR = 17; 95% CI: 2.7-710], residing in Vancouver [OR = 3.7; 95% CI: 1.4-10], and contact with a person with mumps [OR = 13; 95% CI: 2-552], during the 'exposure' period. Vaccine effectiveness, ascertained by self-reported immunization status, was 80% [95% CI: 29%-96%].

CONCLUSIONS

Attendance at rave parties was associated with mumps infection during this outbreak. Many persons aged 17-40 may remain susceptible to mumps; in BC these persons are eligible for one dose of MMR and should be encouraged to be vaccinated.