Wild poliovirus contamination of oral poliomyelitis vaccine
In the period November 2002 to February 2003, several cases of poliomyelitis were observed in one country after vaccination and the MEF-1 reference wild-type poliovirus type 2 strain was isolated in each case (5). Initial investigations excluded cross-contamination within the diagnostic WHO polio laboratory network that cultured the viruses as an explanation for the findings. Further examination demonstrated the presence of MEF-1 in vials of one vaccine batch that had been filled locally from imported bulk material. Samples of the batch that had been collected from the field, from retained samples and from other bulks were tested. Only samples from the field were positive so that contamination had taken place downstream from manufacture although it could not be established whether this was during storage or distribution. Enhanced security measures have now been put in place by the manufacturer concerned.
The Committee was asked to consider the wider implications of this episode; whether current WHO GMP guidance is adequate and whether additional control measures on the final product should be laid down. The Committee considered that prevention of deliberate interference with a product requires safeguards different to normal GMP and that no changes to existing GMP guidance for this reason were necessary. However, the Committee drew attention to measures that ensure that vials are tamper-proof and to procedures that are available to detect counterfeiting. In this context WHO was advised to obtain additional specialist advice, and to make this available to all vaccine manufacturers, their distributors and national regulatory authorities.
References
1. http://www.who.int/biologicals
2. World Health Organization. Expert Committee on Biological Standardization. Technical Report Series, No. 924 (in press)
3. World Health Organization. Expert Committee on Biological Standardization.Technical Report Series, No. 878, Annex 1 (1998).
4. World Health Organization. Expert Committee on Biological Standardization.Technical Report Series, No. 872, Annex 2 (1998).
5. Weekly Epidemiological Record, 78: 88 and 284 (2003)
Table 1. New or replacement International Standards established by the Fifty-fourth WHO Expert Committee on Biological Standardization
ADDITIONS |
Antibodies |
anti-toxoplasma IgG, human |
20 IU/ampoule |
First International Standard 2003 |
This substance is held and distributed by the International Laboratory for Biological Standards, National Institute for Biological Standards and Control, Potters Bar, Herts. EN6 3QG, England. |
Antigens and related substances |
yellow fever vaccine |
104.5 IU/ampoule |
First International Standard 2003 |
pertussis toxin |
10 000 IU/ampoule |
First International Standard 2003 |
These substances are held and distributed by the International Laboratory for Biological Standards, National Institute for Biological Standards and Control, Potters Bar, Herts. EN6 3QG, England. |
Blood products and related substances |
Factor VIII, concentrate, plasma, human |
11.0 IU/ampoule |
Seventh International Standard 2003 |
Factor VIII/von Willibrand Factor, plasma, human |
0.68 IU/ampoule |
Fifth International Standard 2003 |
| |
Factor VIII:C |
|
| |
0.94 IU/ampoule |
|
| |
Factor VIII:antigen |
|
| |
0.91 IU/ampoule |
|
| |
VWF:antigen |
|
| |
0.78 IU/ampoule |
|
| |
VMF:ristocetin cofactor |
|
| |
0.94 IU/ampoule |
|
| |
VWF: collagen binding |
|
prekallikrein activator, human |
29 IU/ampoule |
Second International Standard 2003 |
low molecular weight heparin |
1097 IU/ampoule |
Second International Standard 2003 |
| |
Anti-Xa |
|
| |
326 IU/ampoule |
|
| |
Anti-IIa |
|
These substances are held and distributed by the International Laboratory for Biological Standards, National Institute for Biological Standards and Control, Potters Bar, Herts. EN6 3QG, England. |
Table 1. New or replacement International Standards Continued
Cytokines, growth factors and endocrinological substances |
Interferon, beta, human, recombinant, glycosylated |
40 000 IU/ampoule |
Third International Standard 2003 |
tumour necrosis factor, Aapha, human, recombinant |
46 500 IU/ampoule |
Second International Standard 2003 |
luteinizing hormone, human recombinant |
189 IU/ampoule |
First International Standard 2003 |
thyroid-stimulating hormone, human, for immunoassay |
11.5 x 10-3 IU/ampoule |
Third International Standard 2003 |
These substances are held and distributed by the International Laboratory for Biological Standards, National Institute for Biological Standards and Control, Potters Bar, Herts. EN6 3QG, England. |
Diagnostic reagents |
hepatitis B surface antigen |
33 IU/vial |
Second International Standard 2003 |
hepatitis B surface antigen panel (set of 4 dilutions and control) |
No assignment |
First International Reference Panel 2003 |
These substances are held and distributed by the International Laboratory for Biological Standards, National Institute for Biological Standards and Control, Potters Bar, Herts. EN6 3QG, England. |
lipoprotein (a) for immunoassay |
0.107 nanomoles/vial |
First Reference Reagent 2003 |
This substance is held and distributed by Northwest Lipid Research Laboratories, University of Washington School of Medicine, 2121 North 35th Street, Seattle, WA 98103, USA. |
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