Thus far, the experience of the current swine influenza pandemic, suggests that there is an elevated risk of serious illness and death in pregnancy which has already attractred considerable media attention. This is not unexpected as previous pandemics have had the same effect. On this basis it seems likely that when vaccine supplies become available in the UK, pregnant women will be offered the vaccine as a high priority group. Although policy can already be set (to vaccinate pregnant women) based on the currently available information, successful implementation will depend upon the acceptance of vaccine by pregnant women. This might well be questionable in the UK given the background of the MMR debacle and general view and advice given about 'drugs' in pregnancy, etc. In addition to the issues for pregnant women themselves, existing data clearly show an increased risk of influenza related illness and death in the very young associated with seasonal and previous pandemic viruses. None of the antiviral drugs available are licensed for use in children under 12 months of age, presenting additional treatment challenges in an already vulnerable group. Seasonal flu vaccine is not licenced under 6 months of age and pandemic vaccines are even less likely to be licensed at young ages. It would therefore be considerably advantageous to policy implementation if data existed that could demonstrate a high likelihood that pregnant women, vaccinated during pregnancy, passed on immunity against the virus to their newborn children through antibodies crossing the placenta prior to birth. The researchers' aim to generate these data rapidly in the early stages of the UK pandemic vaccination programme, because such a message will encourage women to accept vaccine for themselves and for the benefit of their babies.
The researchers propose to investigate the immune status of new born infants by obtaining samples from umbilical cord blood for serological (immune status) examination from those of mothers who have been vaccinated during pregnancy against H1N1 v.swine influenza. This can be done at birth from the placenta (afterbirth) after it is delivered and does not involve taking blood from the mother or her baby. This would be an observational study establishing the level of antibody in this group of babies and comparing it to those of mothers who have chosen not to receive vaccination. The proposed study would be a short, focussed investigation, concentrating on pregnant women vaccinated during the very early stages of the UK pandemic vaccination programme. The precise timing of the study will depend upon close coordination with the Department of Health over vaccine availability. The researchers will study women vaccinated in either the second or (more likely) third trimester of pregnancy and measure the passive cord blood immunity at delivery from mother to baby . Acknowledging the need for a timely policy steer, the researchers will focus on vaccinated women (any number of doses - 2 are likely to be recommended and at any stage post vaccination) who deliver in the time frame early to mid autumn 2009. Due to the tight timelines demanded by the research call, in practice this is likely to mean women in the late stages of the 3rd trimester (after 35 - 36 weeks).
The researchers will study 3 maternity units (University Hospital's Nottingham - Queen's Medical Centre and City Hospital and University Hospital Leicester). Pregnant women (vaccinated and unvaccinated) will be approached for their consent to obtain samples of cord blood at delivery for serological investigation. The study will be advertised widely in the midwifery and obstetric units. Samples obtained will be analysed at a laboratory with a validated assay for novel A(H1N1) virus. Parents and GPs will be informed of the result and advised accordingly. The recruitment of subjects will be undertaken by research midwives. The researchers' will also arrange for the attachment of Office for National Statistics (ONS) flags to newborns and mothers associated with the study for longer term follow up. Although the numbers will be small, the researchers' consider this to be advantageous in terms of providing longer term data on outcomes. About 100 subjects will be needed.
There are few ethical barriers relating to this study. The women recruited will be those already vaccinated / who have declined vaccination, no blood will be taken from the baby or mother. The only possible issue would be the long term follow up flags with the ONS although this is not considered to be particularly contentious; notwithstanding, maternal consent will be obtained for this (after ethical approval has been granted).
The team includes well established experts in the fields of obstetrics, virology, vaccinology and influenza public health, with solid research track records and the team contains at least three international influenza experts. Additionally, the team is well placed to carry out the research due to the critical mass of pregnant women likely to pass through the respective units in the period of the study and the prior experience of recruiting pregnant women to obstetric research studies from these units.
The costs proposed, are largely to cover the costs of the research midwives who will undertake the recruitment and sampling and serological analysis (and associated costs), with only small additional amounts to cover the academic researcher costs.
The outcomes which will indicate success from the study will be serological samples obtained and analysed from the cord blood of the required number of cases and controls.
Subject to obtaining separate funding and ethical approval (an optional part of this application), the researchers' will seek to follow up the children born over winter 2009/10 and obtain data on influenza like illness events by taking swabs and laboratory analysis. Patterns of infection in the two groups will be compared. These data are important scientifically but will not be available until late Spring 2010. |
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