Vaccination greatly reduces disease, disability, death and inequity worldwide.

In low-income countries, infectious diseases still account for a large proportion of deaths, highlighting health inequities largely caused by economic differences. Vaccination can cut health-care costs and reduce these inequities. Disease control, elimination or eradication can save billions of US dollars for communities and countries. Vaccines have lowered the incidence of hepatocellular carcinoma and will control cervical cancer. Travellers can be protected against "exotic" diseases by appropriate vaccination. Vaccines are considered indispensable against bioterrorism. They can combat resistance to antibiotics in some pathogens. Noncommunicable diseases, such as ischaemic heart disease, could also be reduced by influenza vaccination. Immunization programmes have improved the primary care infrastructure in developing countries, lowered mortality in childhood and empowered women to better plan their families, with consequent health, social and economic benefits. Vaccination helps economic growth everywhere, because of lower morbidity and mortality. The annual return on investment in vaccination has been calculated to be between 12% and 18%. Vaccination leads to increased life expectancy. Long healthy lives are now recognized as a prerequisite for wealth, and wealth promotes health. Vaccines are thus efficient tools to reduce disparities in wealth and inequities in health.

A pilot study of the quality of informed consent materials for Aboriginal participants in clinical trials.

OBJECTIVE: To pilot informed consent materials developed for Aboriginal parents in a vaccine trial, and evaluate their design and the informed consent process. METHODS: Cross sectional quantitative and qualitative survey of 20 Aboriginal and 20 non-Aboriginal women in Alice Springs. Information about the proposed research was presented to Aboriginal participants by an Aboriginal researcher, using purpose designed verbal, visual, and written materials. Non-Aboriginal participants received standard materials developed by the sponsor. Questionnaires were used to evaluate recall and understanding immediately and five days later. Qualitative analysis of Aboriginal participants' interviews was performed. RESULTS: There were no differences between the groups in understanding of diseases prevented by the vaccine, the potential risks of participating, or the voluntary nature of participation. Most Aboriginal participants had difficulty with the concept of a "licensed" versus "unlicensed" vaccine. The non-Aboriginal group had a good understanding of this. Aboriginal participants identified the use of the flipchart, along with a presentation by a doctor and Aboriginal health worker, as preferred delivery modes. Group presentations were preferred rather than one-on-one discussions. The use of the questionnaire posed considerable methodological difficulties. CONCLUSIONS: A one-off oral presentation to Aboriginal participants is unlikely to produce "informed consent". Key but unfamiliar concepts require identification and particularly considered presentation.

Biological weapons preparedness: the role of physicians.

The real risk posed by biological weapons was demonstrated with the distribution of anthrax spores via the USA postal service in 2001. This review outlines the central roles of physicians in optimizing biopreparedness in Australia, including maintaining awareness of the risk, promptly recognizing an event, notifying appropriate authorities upon suspicion of an event, and instituting appropriate management. Management aspects covered include appropriate diagnostic tests, infection control procedures, and empirical therapy of agents considered possible biological weapons. The critical role of physicians as public health advocates working to prevent the use of biological weapons is also outlined.

The effectiveness of the infant hepatitis B immunisation program in Fiji, Kiribati, Tonga and Vanuatu.

The aims of this project were: (1) to determine the extent to which infant hepatitis B immunisation is preventing chronic hepatitis B infection in children living in a sample of Pacific Island countries; and (2) to identify factors associated with the successful prevention of hepatitis B infection in these populations. A regional hepatitis B immunisation project which supplied hepatitis B vaccine to 10 Pacific Island countries began in 1995. Seroepidemiological surveys were conducted in Fiji, Kiribati, Tonga and Vanuatu in early 1998. These included immunised pre-school children and their biological mothers, and a historical control group of unimmunised students. Prevalence rates for hepatitis B surface antigen (HBsAg) in the populations of students, mothers and their pre-school children were respectively: Fiji: 6.9, 6.6, 0.7%; Kiribati: 27.4, 15.1, 3.8%; Tonga: 11.1, 18.6, 3.8%; Vanuatu: 16.3, 12.3, 3.0%; and for all four countries: 13.2, 12.5, 2.6%. Compared to the historical control group of students, the pre-school population had a much lower probability of HBsAg positivity (relative risk [RR]=0.19 [95%CI: 0.12-0.31]). Statistically significant differences in risk were apparent for all the countries: Fiji: RR=0.10; Kiribati: RR=0.14; Tonga: RR=0.34; Vanuatu: RR=0.19. This is equivalent to an overall program effectiveness of 81% (95%CI: 69-88%) in reducing chronic carriage. Also, the overall protective effectiveness against vertical hepatitis B transmission resulting in HBsAg positivity among children exposed to HBeAg positive and negative carrier mothers, was estimated to be 70%. By age 6 months, when all children should have had three vaccine doses, completed immunisation rates ranged from 22 (Fiji) to 84% (Vanuatu). Coverage of the first dose being given within 2 days of birth varied from 43% in Kiribati to 92% in Tonga. In conclusion hepatitis B immunisation of infants in these four countries is having a substantial beneficial effect in preventing chronic hepatitis B infection. Nevertheless, there is significant scope for further improving the timeliness of immunisation.

At-birth immunisation against hepatitis B using a novel pre-filled immunisation device stored outside the cold chain.

We evaluated the immunogenicity of hepatitis B (HB) vaccine in UniJect, a pre-filled, non-reusable injection device, stored at tropical temperatures for up to one month and used to give the first dose of HB vaccine to newborns. Infants in Tabanan district, Bali, Indonesia, were given their first dose of HB vaccine with UniJect stored out of the cold chain, UniJect stored in the cold chain; or standard syringe, needle and multidose vial stored in the cold chain. Subsequent doses were given by usual means and blood samples drawn 4-6 weeks after the third dose. No significant differences were found in seroconversion rates or geometric mean titres of HB surface antibody between the three groups.

Malaria. The latest in advice for travellers.

BACKGROUND: Malaria prevention in travellers is typically the most complex travel health issue faced by practitioners. Approximately 300 to 500 million people in the world are infected with malaria and between 1.5 and 2.7 million people die from it every year. Although the disease is mainly confined to the tropical areas of Africa, Asia and Latin America, it remains a serious and worsening health problem. OBJECTIVE: In this article recommendations are provided to assist doctors giving advice to travellers visiting regions where malaria is endemic. The focus is on prophylactic medications and self treatment regimens. DISCUSSION: Advice to travellers should include information on the need for prompt diagnosis and treatment of febrile illness, on minimising exposure to mosquitoes, and the use of repellents and contact insecticides. A simplified chemoprophylaxis regimen is chloroquine for chloroquine sensitive malaria areas, mefloquine or doxycycline for areas with chloroquine resistant malaria and doxycycline for areas with mefloquine resistant malaria. With the advent of new self treatment regimens and 'in the field' rapid diagnostic tests, self treatment has become a reasonable option in certain circumstances.

Immunisation strategies for viral diseases in developing countries.

In just under a quarter of a century, the Expanded Programme on Immunisation has been associated with an increase in infant immunisation coverage from around 5% to 80%, and the prevention of at least 3 million deaths annually, at very low cost. The global target of poliomyelitis eradication by the year 2000 appears feasible. Measles is the next likely target for eradication via immunisation, through 'catch-up', 'keep up' and 'follow-up' strategies which have proven highly effective in the Americas. Yet much needs to be done in order to extend readily achievable immunisation benefits equitably to all the world's people and to realise the potential of existing and soon to be available vaccines for disease control and eradication, as experience with yellow fever and hepatitis B vaccines demonstrates. Unsafe injection practices are widespread, have received inadequate attention, and cause a substantial global burden of blood-borne infections. The risk of increasing global inequity in immunisation highlights the centrality of resource allocation priorities in determining the extent to which the benefits of immunisation will be realised, particularly for new vaccines which are significantly more costly than established EPI vaccines. WHO/UNICEF strategies to target more effectively immunisation support to the neediest countries, to prioritise new vaccines, and to target carefully vaccine procurement and encourage sharply tiered vaccine pricing support both equity and sustainability. However, increasing the resources available to immunisation is vital and requires powerful advocacy on public health, moral, cost-effectiveness and legal grounds. More appropriate resource allocation priorities could readily provide the means necessary to address both technical and operational immunisation challenges.

Hepatitis B immunisation rates among infants in ethnic groups with high prevalences of hepatitis B surface antigen carriers.

To determine hepatitis B immunisation rates in infants from ethnic groups with hepatitis B surface antigen chronic carrier prevalence over 5 per cent, a questionnaire was sent to all Maternal and Child Health Centres in Victoria, requesting information on the hepatitis B and diphtheria-tetanus-pertussis (DTP) or combined diphtheria-tetanus (CDT) immunisation status for all infants born between 1 July 1992 and 30 June 1993 and at risk of hepatitis B infection because of maternal ethnicity. We received data on 3611 of 5744 infants (62.9 per cent) in targeted ethnic groups. Of these, 12.8 per cent had not received hepatitis B vaccine, and 81.6 per cent, 76.8 per cent and 64.0 per cent had received at least one, two and three doses respectively, while 84 per cent had received at least three doses of DTP vaccine and/or CDT vaccine. Coverage with DTP or CDT was higher than for hepatitis B vaccine (P < 0.001), and coverage was better in areas with a higher percentage of infants in high-prevalence ethnic groups (P < 0.001). Changes in the program in Victoria in terms of timing of the first dose of vaccine plus greater attention to follow-up may lead to improved hepatitis B immunisation rates among infants in targeted ethnic groups. Adoption of universal infant hepatitis B immunisation, by increasing familiarity with hepatitis B vaccine, is likely to be the best way to increase immunisation coverage for these infants.

Managing HIV. Part 6: People living with HIV. 6.7 Travellers with HIV.

Many HIV-infected people travel abroad, and although most can travel in relative safety there are a range of issues and risks to be considered by their medical advisers.

Lombok Hepatitis B Model Immunization Project: toward universal infant hepatitis B immunization in Indonesia.

The Lombok Hepatitis B (HB) Model Immunization Project was the first mass infant HB immunization project in Indonesia. Key aspects were the procurement of low-cost HB vaccine, integration into routine infant immunization services, and delivery of the first dose in the home within 1 week of birth. The project achieved > 90% coverage with 3 doses of vaccine. The prevalence of HB surface antigen was 1.4% in infants who received 3 doses (with the first dose within 7 days of birth) and 3.0% in those who received the first dose > 7 days after birth, compared with a baseline prevalence of 6.2% (P < .001 in each case). Most vaccine failures occurred in children born to HBe antigen-positive mothers. Antibody prevalence and titers did not correlate with protection. HB vaccine can be successfully integrated into the Expanded Programme on Immunization (EPI), strengthening the EPI and significantly reducing chronic HB infection.

Travel medicine. 2. Upon return.

The volume of international travel and diversity of destinations have increased dramatically in recent decades and continue to grow. The scope and variety of travel related health problems increase accordingly, with 15% to more than 50% of travellers to developing countries reporting some illness. Infections acquired abroad may be acute and life-threatening, requiring urgent, sometimes empirical, intervention. They may also be chronic and associated with late complications, particularly in immigrants, refugees and long term travellers. We present a perspective on and practical approach to the management of illness in returned travellers.

Hepatitis in the tropics.

Viral hepatitis, caused by one of five different viruses, is an important cause of illness in tropical countries and a significant cause of death. Vaccines against hepatitis A and B are now available and, if used widely, have the potential virtually to eliminate both these diseases (and also hepatitis D). Vaccines against hepatitis C and E are being developed.

Prevention of viral hepatitis.

Viral hepatitis is one of the more common potentially serious infections that may be acquired during international travel. Clinically indistinguishable syndromes may be produced by a variety of enterically and parenterally transmitted hepatitis viruses, with widely differing implications and outcomes. Most travel-related hepatitis can be prevented by a combination of sensible precautions and appropriate immunoprophylaxis.

Ciguatera in the Pacific: a link with military activities.

Ciguatera fish poisoning is widespread in the Pacific. Outbreaks and the rise in incidence of the disease are related largely to military activities that disturb coral reef ecology. Nuclear test explosions and the setting up of the infrastructure for these tests are major components of such military activity.