FluMum: A prospective cohort study of mother-infant pairs assessing the effectiveness of maternal influenza vaccination in prevention of influenza in early infancy

Multi national, multi centred observational trial studying the effectiveness of maternal influenza immunisation in infants up to 6 months of age. The aim is to recruit about 420 women in Australia in each site each year so that, after 4 years, we expect to have just over 10,000 women and their babies who are part of the study. There are six sites: Darwin, Brisbane, Sydney, Melbourne, Adelaide and Perth. Recruitment will be through ante-natal care providers, maternity units within participating hospitals or through clinics providing routine postnatal services at 6 weeks post delivery in Darwin, Brisbane, Sydney, Melbourne, Adelaide and Perth. The study will be explained to potential participants utilising a Plain Language Statement approved by the relevant Human Research Committee (HREC). The study is aimed at mothers immunised against Influenza in the 12 months prior to the birth of their infant. The vaccine must not have been given =<14 days prior to the birth of the infant.A minimal dataset summarising the outcomes from those approached for the Plain Language Statement will be recorded through a Screening Log. Informed consent will be sought from each potential participant in accordance with HREC approval. Participant Workbook approved by the HREC will be used to document an entry questionnaire. Brief maternal questionnaire administered at enrolment (maximum 55 days post delivery). Information sought will be limited to self-reported influenza vaccination status, information relating to the barriers/influences of influenza vaccination, contact details for the participant’s usual medical practitioner, self reported maternal medical/obstetric history, and some socio-demographic indicators. The workbook is structured so that the component conducted at entry into the study can be completed over two separate sessions should the participant so choose. The workbook also includes a telephone follow-up once the child reaches 6 months of age where parent reported episodes are sought for medically diagnosed influenza in the infant. In addition to the informed consent process, the participant must also be considered to have sufficient verbal English to permit questionnaire completion at study entry and at 6-month follow-up. Each participant’s usual medical practitioner/vaccine provider will be contacted to confirm the date of vaccination: (a) when a participant self reports receipt of influenza or pertussis vaccination but is unable to cite the date given from a written record; or (b) where the participant is unsure of her vaccination history. Participants who state that they have not been vaccinated will be considered unvaccinated to validate self-report of exposure status as vaccinated or unvaccinated. Brief maternal telephone questionnaire at participant exit will be conducted once the child reaches 6 months of age, includes parent reported episodes of medically diagnosed influenza in the infant. Data linkage to influenza and / or any other vaccine preventable diseases recorded on the notifiable diseases database within each State/Territory for the infant (6 months post delivery) and for maternal influenza from 12 months prior to delivery – 6 months post delivery will be undertaken. Parent reported episodes of medically diagnosed influenza where a specimen was collected from the mother or the infant that were identified but not confirmed will be followed-up with the treating physician to establish if they were laboratory confirmed and had not been notified to the relevant public health authority.