Are hard-to-reach populations being reached with immunization services? Findings from the 2005 Papua New Guinea national immunization coverage survey.

OBJECTIVE: To measure immunization coverage among children aged 12-23 months in Papua New Guinea (PNG) and to assess if and why there are differences between hard-to-reach and more accessible communities. METHODS: WHO cluster sampling methodology was employed to measure immunization coverage in PNG's four regions. Survey data were re-analyzed according to a local assessment of geographical accessibility indicated by census unit type: urban, rural and hard-to-reach. Census units were designated as hard-to-reach if they were five or more km from a health centre. FINDINGS: Nationwide coverage for most antigens falls below the national target of 80% although there are regional differences with Islands performing the best. Late doses are a major concern: just 4% were fully immunized with valid ("on time") doses by 1 year of age. Coverage was lower in both rural and remote communities: at 6 months 48% of children from urban units had received three valid doses of DTP-3 but only 16% in rural areas and 13% in hard-to-reach communities. Reasons for failure to immunize varied: 21% of mothers said their child was not immunized because distance, travel conditions or cost of transportation prevented access to local health centres; 27% cited a lack of knowledge or misconceptions about immunization; while 29% believed it was because of an issue with the health system. CONCLUSIONS: Throughout PNG there is an urgent need to increase immunization coverage and to ensure that children are immunized on time according to the schedule. Both coverage and timeliness of doses are worse for children living in hard-to-reach and rural areas. Achieving national immunization targets requires improvements in health service delivery, including outreach, especially for remote and rural communities, as well as greater community education and social mobilisation in support of immunization services.

A vaccine cold chain freezing study in PNG highlights technology needs for hot climate countries.

Fourteen data loggers were packed with vaccine vials at the national vaccine store, Port Moresby, Papua New Guinea (PNG), and sent to peripheral locations in the health system. The temperatures that the data loggers recorded during their passage along the cold chain indicated that heat damage was unlikely, but that all vials were exposed to freezing temperatures at some time. The commonest place where freezing conditions existed was during transport. The freezing conditions were likely induced by packing the vials too close to the ice packs that were themselves too cold, and with insufficient insulation between them. This situation was rectified and a repeat dispatch of data loggers demonstrated that the system had indeed been rectified. Avoiding freeze damage becomes even more important as the price of freeze-sensitive vaccines increases with the introduction of more multiple-antigen vaccines. This low-cost high-tech method of evaluating the cold chain function is highly recommended for developing and industrialized nations and should be used on a regular basis to check the integrity of the vaccine cold chain. The study highlights the need for technological solutions to avoid vaccine freezing, particularly in hot climate countries.

Prevalence of influenza immunisation in Australia and suggestions for future targeting of campaigns.

OBJECTIVES: Reports on the results of a national survey conducted in Australia, in 2000. The objectives were to determine national estimates of influenza vaccination coverage for each state and territory of Australia, to obtain information related to attitudes towards and influences on immunisation decisions and explain the factors involved with failure to immunise. METHOD: The survey was conducted using the Computer Assisted Telephone Interview (CATI) system. The overall participation rate for the survey was 88.6% and the final number of completed interviews across Australia was n = 10,505. RESULTS: Two target groups, those aged 65 years and over and those "at risk" of influenza aged between 40 and 64 years were defined. The overall immunisation rates in these two groups were 74% and 32% resp. The rate of immunisation among females generally exceeded that of males. A multivariate model provided the best joint set of explanatory variables for not getting immunised. These include sex, income, general practitioner recommendation, and general perceptions regarding the influenza injection. CONCLUSION: This study identified important issues in the decisions of people to immunise. It also highlighted the need to target the findings in effective immunisation policies and strategies to improve health outcomes for those at risk of adverse influenza events.