iMAP3
Research type
Research Study
Full title
Immunising Mums Against Pertussis 3
IRAS ID
240776
Contact name
Paul Heath
Contact email
Sponsor organisation
St George's Joint Research Enterprise Office
Duration of Study in the UK
2 years, 0 months, 1 days
Research summary
Summary of Research
In the UK all pregnant women are offered a whooping cough-containing vaccine during pregnancy. This protects newborn infants against whooping cough, but there have been some concerns that this vaccination in pregnancy may affect the response to childhood vaccinations. This study will follow up children who participated in iMAP2 (immunising Mums Against Pertussis 2), to investigate the sustained impact of whooping cough vaccination in pregnancy on childhood vaccine responses. In the iMAP2 study women had been randomised to receive one of two different whooping cough-containing vaccines, with a control group also recruited, and the antibody levels in their infants were measured at 2, 5 and 13 months.This study will investigate the antibody levels in these children before and after the routine pre-school booster vaccine. It will help the Department of Health continue to ensure the best protection is offered to the population.
Those eligible for the study are children who participated in the iMAP2 study who have reached the age for pre-school booster vaccination (from age 3 years 4 months).
The study period will be approximately 4-6 weeks with two study visits. The first visit will take place when the child is around 3 years and 4 months of age. After informed consent a blood sample will be obtained followed by administration of the pre-school booster vaccine. At the second visit another blood sample will be obtained. These blood tests will measure the level of protective antibody against the components of the pre-school booster vaccine. Visits will take place either in the child’s home or at a suitable clinical setting within the study team's sites.
The study will be run by St. George’s, University of London, in collaboration with St George's University Hospitals NHS Foundation Trust, Oxford Vaccine Group and Bristol Children's Vaccine Centre.
Summary of Results
An antenatal pertussis vaccination programme was introduced in 2012 in the UK in the context of a national outbreak of pertussis. It has been shown that a lower antibody response to primary immunisation can be seen for certain pertussis antigens in infants born to women who received pertussis-containing antenatal vaccines, a phenomenon known as blunting. The longer-term impact of this has not been documented previously, and accordingly was evaluated in this study.Children were predominantly recruited from a previous study in which their mothers had received acellular pertussis-containing antenatal vaccines (dTaP3-IPV [diphtheria toxoid, tetanus toxoid, three antigen acellular pertussis and inactivated polio] or dTaP5-IPV [diphtheria toxoid, tetanus toxoid, five antigen acellular pertussis and inactivated polio]), or no pertussis-containing vaccine. Blood samples were obtained prior to and one month after the acellular pertussis-containing preschool booster (dTaP5-IPV) was given at around age 3 years 4 months. Pre- and post-booster immunoglobulin G (IgG) geometric mean concentrations (GMCs) against pertussis toxin, filamentous haemagglutinin, fimbriae 2 & 3, and pertactin, were compared.
Prior to the receipt of the preschool booster, there was no difference in the IgG GMCs against pertussis-specific antigens between children born to women vaccinated with dTaP3-IPV and dTaP5-IPV; however, IgG GMCs against pertussis toxin were significantly lower in children born to women vaccinated with dTaP3-IPV compared with children born to unvaccinated women (geometric mean ratio 0.42 [95% CI 0.22-0.78], p=0.03). One month after the receipt of the preschool booster there was no differences between the groups.
The blunting effect of antenatal pertussis vaccine on pertussis responses in children can persist until preschool age, although it is overcome by the administration of a booster dose.
REC name
North West - Haydock Research Ethics Committee
REC reference
18/NW/0095
Date of REC Opinion
9 Feb 2018
REC opinion
Favourable Opinion