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Report of an International collaborative study to establish the first WHO reference reagents for BCG vaccines of
Mei M Ho1, Kevin Markey, Peter Rigsby
1Bacteriology Division, NIBSC-HPA, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK. mei.ho@nibsc.hpa.org.uk
Insights
The World Health Organization
Area of Science:
- Vaccinology and immunology
- Microbiology
- Biotechnology
Background:
- The existing WHO First International Reference Preparation for BCG vaccine is outdated and unavailable.
- There is a need for new BCG vaccine reference materials specific to sub-strains.
Purpose of the Study:
- To evaluate candidate BCG vaccine reference reagents.
- To establish new WHO Reference Reagents for BCG vaccines.
Main Methods:
- An international collaborative study was conducted.
- Viability of candidate BCG sub-strains (Danish 1331, Russian BCG-I, Tokyo 172-1) was assessed.
- Cultural viable counts and modified ATP assays were used for quantification.
Main Results:
- Three candidate BCG vaccine sub-strains were evaluated for their suitability as WHO Reference Reagents.
- Viability assays provided quantitative data on the candidates' potency.
Conclusions:
- The study evaluated potential replacements for the outdated BCG vaccine reference preparation.
- The findings informed the WHO Expert Committee on Biological Standardization regarding the establishment of new reference reagents.
Abstract:
The WHO First International Reference Preparation for BCG vaccine is over forty years old and is no longer available for distribution due to stock depletion and its significant loss of viability. International consultations identified a demand for replacement with sub-strain specific BCG preparations. An International collaborative study was carried out to evaluate three candidates for WHO Reference Reagent for BCG vaccine of Danish 1331, Russian BCG-I and Tokyo 172-1 sub-strains. These candidates were quantified for viability using both cultural viable count and modified ATP assays. The proposal for the establishment of these First WHO Reference Reagents for BCG vaccines was discussed in the WHO Expert Committee on Biological Standardization meeting, October 2009.
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