Drug – bio-affecting and body treating compositions – Antigen – epitope – or other immunospecific immunoeffector – Virus or component thereof
Patent
1998-08-13
2000-11-21
McKelvey, Terry
Drug, bio-affecting and body treating compositions
Antigen, epitope, or other immunospecific immunoeffector
Virus or component thereof
435239, A61K 3912, C12N 702
Patent
active
06149917&
DESCRIPTION:
BRIEF SUMMARY
This is a National Stage of International Application No. PCT/FR96/01195, filed Jul. 29, 1996.
The present invention relates to a process for the production of a vaccine for the prevention of Japanese encephalitis, based on Japanese encephalitis virus (JEV) and in particular on a vaccine which can be used in man. The invention also relates to a vaccine obtained by this process.
Japanese encephalitis virus, whose transmission vector is a mosquito, is the cause of serious infections, known as Japanese encephalitides, in many Far Eastern countries and in other areas of the world.
Vaccines against Japanese encephalitis are known, these being obtained by processes which consist in injecting JEV intracranially into baby mice and in harvesting the infected tissues. The tissue emulsion obtained is then purified, generally by precipitation methods, in particular with protamine. Other techniques for purification of these tissue preparations have also been proposed in the literature, such as techniques of ultrafiltration, of filtration and centrifugation, or of precipitation with polyethylene glycol, it being possible for these techniques to be combined with each other or with techniques of gel filtration or of chromatography on cellulose sulphate or on crosslinked polysaccharide sulphate (JP-B-65,000,611, JP-A-53,133,627, JP-A-50,048,118, JP-A-2,223,531, U.S. Pat. No. 4,725,546, JP-A-49,020,322 and B-81,005,204, JP-B-67,025,408)
In the prior art, the viral preparations are inactivated, as recommended by the World Health Organization, by chemical agents such as formaldehyde according to standardized procedures, namely long-term inactivation for 50 to 60 days at +4.degree. C. at a formaldehyde concentration of 1/2000, on account of the instability of the viruses at higher temperatures in this environment.
The commercial vaccines thus obtained are effective but are difficult and expensive to prepare, to purify and to inactivate. They may moreover lead to side reactions due to contaminants originating from the baby mouse tissues, thereby occasionally limiting their application.
It is thus desirable to be able to produce a vaccine by other more industrial techniques and in particular by using a multiplication and a propagation of the virus on a cell line. However, the production of a vaccine in large quantities, using highly industrialized methods, is much more difficult than in the case of intracranial multiplication, not only on account of the considerable quantities which must be dealt with, but also on account of the difficulties in obtaining and controlling high yields and also on account of the purification problems posed by contaminants which are then encountered and which may originate from the cells or from the viral multiplication medium.
It is known in the prior art that Japanese encephalitis virus can propagate on various cell cultures, including cultures of cell lines, in particular Vero cells. However, the culturing methods disclosed do not make it possible to obtain satisfactory yields under large-scale industrial culturing conditions, the only conditions allowing production at moderate cost. Nor does the prior art describe any methods for purifying to a high degree the viral preparations originating from propagation and multiplication on cell lines.
The invention thus proposes to overcome these drawbacks and to provide a process for the production of a vaccine against Japanese encephalitis, which process may be used on a large scale and under safe, rapid and economic conditions and makes it possible to obtain an effective vaccine of very high purity in a very good industrial yield.
In order to achieve these aims, the subject of the invention is a process for the industrial production of a vaccine against Japanese encephalitis, characterized in that it comprises the following steps: in the presence of a viral multiplication medium, of viruses produced by the cells, chromatographic step and a gel permeation step, pharmaceutical form in order to ensure its conservation up to the time of its use.
According to
REFERENCES:
patent: 4725546 (1988-02-01), Sakamoto et al.
Venkateshan et al., (1977) "Comparative Studies of Different Methods For Concentration of Japanese Encephalitis Virus Antigens Prepared From Vero Cell Culture." Biological Abstracts, vol. 64, pp. 245. Abstract No. 2449.
Fanget Bernard
Francon Alain
Heimendinger Pierre
McKelvey Terry
Pasteur Merieux Serums et Vaccins
LandOfFree
Industrial production process for a vaccine against Japanese enc does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Industrial production process for a vaccine against Japanese enc, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Industrial production process for a vaccine against Japanese enc will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1254305