Serosurveillance study of maternally derived anti-GBS antibody

• Research type

  Research Study

• Full title

  Using Guthrie cards for a serosurveillance study of maternally-derived antibody against Group B Streptococcus (GBS)

• IRAS ID

  222427

• Contact name

  Kirsty Mehring Le Doare

• Contact email

  k.mehring-le-doare@ic.ac.uk

• Duration of Study in the UK

  2 years, 2 months, 1 days

• Research summary

  Research Summary

  Group B Streptococcus (GBS) is a bacterium (germ) that can cause serious infections such as meningitis, blood poisoning and pneumonia in newborns. Infection during the first 6 days of life may be prevented by antibiotics given to the mother during labour, but will offer no protection for infections occurring later. A vaccine against GBS has also been developed and is currently being tested. If effective this could be offered to pregnant women. However, we do not know what level of antibody is needed to protect infants against GBS. We need to collect comprehensive information about the amount of antibody that protects infants from GBS in order to estimate the correct amount of vaccine to give to pregnant women as part a maternal vaccination programme. Taking blood from babies is difficult and we have identified that dried blood spots (DBS) from newborn bloodspot cards, taken for national newborn screening are a good alternative. Cards from 2014 are due to be disposed of in 2017 giving us an ideal opportunity to test for baby antibody without the need for baby blood tests. We aim to undertake a study comparing antibody from DBS from 150 infants with GBS that occurred during 2014 with DBS from 300 healthy controls. We will do this by using the BPSU national surveillance that identifed babies with GBS disease and requesting laboratories storing the cards to take up to two of the DBS that remain on the card for analysis. We will also ask the laboratories to pick two other cards taken at the same time to act as our healthy controls. We will then use the antibody test developed at Public Health England to measure antibody concentrations to work out how much antibody is needed to protect babies from GBS.

  Summary of Results

  The project demonstrated that Group B Streptococcus antibodies can be measured in dried blood spots but was unable to measure a difference in antibody concentrations between cases and controls. This was largely determined to be due to poor sample storage conditions that resulted in a small number of viable cards. For dried blood spots to be a useful resource for sero-correlate studies, correct storage (such as storage at −20 ◦C as soon as possible after the spots have dried) immediately after collection is crucial. There is a lack of clear guidance on the storage conditions in England, which impacts our ability to use this potentially very valuable resource to answer a range of important research questions.

• REC name

  London - Harrow Research Ethics Committee

• REC reference

  17/LO/0890

• Date of REC Opinion

  23 Jun 2017

• REC opinion

  Favourable Opinion