New indicators of BCG vaccination programme performance related to better child health: BCG coverage at 1 month and BCG scar assessment at 6 months as possible replacements for coverage at 12 months
The Bacillus Calmette-Guerin (BCG) vaccine is given to protect against the infectious disease tuberculosis and is part of the vaccination programme in Guinea-Bissau and other low-income countries. In addition to the specific protection against tuberculosis, the BCG vaccine has non-specific effects. The vaccines protect against other infections than TB and has been shown to lower mortality in new-borns. During the first 4 weeks of life, children weighing less 2.5 kg for whom vaccination is normally delayed, the risk of dying was 38% lower if they were given BCG at birth.
A successful BCG vaccination usually causes a scar at the injection site, and among BCG vaccinated children, those with a scar have lower mortality. The recommendation of the World Health Organisation is that children receive the BCG vaccination at birth, but in practice it is often given later. Today less than 50% of all children in rural Guinea-Bissau receive the BCG vaccination before they turn one month old. This entails that they do not benefit from BCG’s beneficial effects during the first weeks of life when mortality is highest.
Part of the explanation for this delay is the restricted vial opening policy. The BCG vaccine is provided in 20-dose vials and any leftover doses must be discarded 6 hours after opening – if 8 children are vaccinated on a given day, 12 doses are therefore wasted. To avoid wastage of doses, it is a widespread practice to only open a BCG vial if 10 children are present. In Guinea-Bissau many health centres plan BCG vaccination days in advance aiming to ensure that enough children are present. Even on the planned vaccination days, a vial will only be opened if enough children are present. When the research group interviewed mothers of young children on their experience with seeking BCG vaccination, they reported that it was common to go two or more times to get the child vaccinated (mean number 1.3 times) and that the expenses for transport and waiting time at the centre for each visit was comparable to the price of a 20-dose vial of BCG.
BCG coverage estimates state which proportion of children are vaccinated at 12 months of age. This, however, does not reveal whether BCG is given timely or with correct vaccination technique and gives no incentive to prioritise vaccination opportunities over wasted doses.
The purpose of this project is to evaluate two alternative indicators for the performance of the BCG vaccination programme, which are both linked to better survival and if implemented could improve child health. The indicators are:
1.BCG coverage at 1 month – as a proposed more informative indicator on timing. 2.BCG scarring at 6 months – as a proposed more informative indicator on the quality of vaccination technique.
The applicant will carry out the project in Guinea-Bissau since data material for the studies either has been or will be collected through the Bandim Health Project’s health and demographic surveillance system. The system provides a unique opportunity to obtain extensive data in a low-income country. In 4 studies, the applicant will describe the current delay of BCG vaccination in both urban and rural Guinea-Bissau and assess the implications thereof. Furthermore, she will play a central role in implementing a randomised controlled trial to assess if making BCG available at first health facility contact can improve child survival and assess the effect of refresher training in vaccination technique.
This PhD project will be an extension of the applicant’s current 6-month employment as a research assistant at the Bandim Health Project, where she began a creole language course and gaining familiarity with the surveillance system. Her background in both paediatrics and clinical research in combination with the extensive experience of the supervisor group within the fields of epidemiology, paediatrics, statistics and global health, makes this the optimal team to carry out the project. If this project shows that BCG coverage at 1 month and BCG scarring at 6 months serve as better indicators for the performance of the BCG vaccination programme than BCG coverage at 12 months, this may inform and potentially improve the implementation of future health policies. If the vaccination programme was evaluated on indicators associated with improved survival, it could help ensure that the maximum number of children in low-income countries survive early childhood and get a chance at life.