Background: Pneumonia and diarrhoea are very common infectious causes of childhood hospital admission both globally and in Hong Kong. Since these two diseases share a number of risk factors and strategies for their prevention are inter-related, a Global Action Plan for the Prevention and Control of Pneumonia and Diarrhoea (GAPPD) was launched in 2013. These strategies include promotion of exclusive breastfeeding and usage of oral rehydration solution, and increasing coverage of specific vaccines (rotavirus vaccination [RVV] for diarrhoea, Haemophilus Influenzae type b [HibV] and Pneumococcal conjugate vaccinations for pneumonia). Although not specifically included in GAPPD, influenza vaccine (FluV) will also reduce mortality and morbidity from pneumonia.
In Hong Kong, very few mothers exclusively or fully breastfeed for six months as recommended and the use of oral rehydration solution is also low. RVV, FluV and HibV are available in Hong Kong but not included in the Government’s Childhood Immunisation Programme (CIP). Their uptakes are low compared to the high coverage rates of CIP vaccines. This research aimed to identify barriers to implement these wellestablished interventions and explore how to lower these barriers.
Methods: Identifying barriers: 500 mother-infant pairs (Pneumonia Diarrhoea Knowledge Attitudes and Practices, PDKAP cohort) were recruited postnatally. Mothers’ knowledge and attitudes towards pneumonia and diarrhoea and the respective interventions were collected from questionnaires based on the Health Belief Model. Vaccine uptake or intention to vaccinate were documented when children were around six months old and associations of related factors were investigated.
Evidence to inform policy makers: Two test-negative case-control studies were conducted to assess effectiveness of RVV in acute gastroenteritis patients and FluV in febrile respiratory patients. Casepatients were defined as enrolled subjects with specimens obtained in the first 48 hours of hospitalisation that tested positive for rotavirus/ influenza and control-patients were those with specimens testing negative. Vaccine effectiveness was calculated as one minus the odds ratio for vaccinated case-patients versus non-vaccinated controlpatients.
Lowering barriers: A randomised controlled trial was conducted in two groups of mother-infant pairs: (1) 208 pairs from PDKAP cohort and (2) 625 pairs from postnatal ward. Controlsubjects received the publicly available leaflets about a FluV subsidy scheme. Intervention-subjects additionally received concise information about influenza and FluV, help with completion of documentation necessary to utilise vaccination subsidy, contacts of clinics and reminders for vaccination.
Results: The overall coverage of vaccines included in the CIP were much higher than the non-CIP vaccine uptakes. Hong Kong-born mothers, compared to China-immigrants, and mothers who perceived rotavirus vaccination as beneficial were more likely to give RVV in their children. China-immigrants, compared to Hong Kong-born mothers, mothers with lower household income and mothers with higher confidence in safety of non-CIP vaccine were more likely to have a plan to vaccinate their children with FluV in the future. At least one dose of RVV and FluV was 89%-96% and 63%-67% effective in preventing rotavirus or influenza hospitalisation respectively. An influenza vaccination status record form was developed and could be used as part of a routine system to estimate FluV effectiveness. A simple intervention package effectively increased FluV uptake in children by absolute increases of 22% by one year and 36% by two years.
Conclusions: With evidence of effectiveness of RVV and FluV and mothers’ higher confidence in the safety of CIP vaccines than non-CIP vaccines, incorporation of RVV and FluV into the CIP would be of significant public health benefit. However even for those vaccines not included in the CIP, simple interventions could increase vaccination uptake.
|Advisor:||Li, Man Chim Albert Martin|
|Commitee:||Nelson, Edmund Anthony Severn, Neuzil, Kathleen, Tarrant, Marie, Wong, Carmen|
|School:||The Chinese University of Hong Kong (Hong Kong)|
|School Location:||Hong Kong|
|Source:||DAI-B 79/07(E), Dissertation Abstracts International|
|Subjects:||Medicine, Public health, Epidemiology|
|Keywords:||breastfeeding, influenza vaccine, knowledge attitudes practices, randomised controlled trial, rotavirus vaccine, vaccine effectiveness|
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