GB2197193A - Preparing vaccines - Google Patents

Abstract

An autogenous vaccine e.g. Haemophilus Pleuropneumonia vaccine is obtained by growing bacteria in a liquid culture medium at 37 DEG C for 6 to 48 hours. The bacterial suspension is checked for purity and a sterilisation fluid comprising Thiomersal and Formalin is then added. The suspension is incubated at 37 DEG C for typically 48 hours. After 24 and 48 hours sterility checks are carried out by immersing a swab in the suspension, inoculating a blood agar plate and incubating the plate at 37 DEG C for between 48 hours aerobically. The plates are then examined for sterility. A second sterility check includes inoculating the vaccine into a Thioglycollate broth and soya bean-casein digest media.

Description

SPECIFICATION A method of preparing an autogenous vaccine The invention relates to a method of preparing an autogenous vaccine. The invention also relates to a vaccine whenever prepared by the method.

According to the invention there is provided a method of preparing an autogenous vaccine comprising the steps of: growing bacteria for the desired vaccine in a liquid culture medium at between 35 and 40"C for from 6 to 48 hours; checking the baterial suspension of purity; adding a sterilisation fluid to the bacterial suspension to form a bacterial and sterilisation fluid suspension; incubating the suspension at a temperature of between 35 and 40"C for a period of between 24 and 72 hours; carrying out a first sterility check after an initial period; adjuvanting the suspension; and carrying out a second sterility check at the end of the incubation period.

In a preferred embodiment of the invention the first and second sterility checks include the step of immersing a swab in the suspension, inoculating a blood agar plate with the swab, incubating the plate at a temperature of between 35 and 40"C for a period of between 24 and 72 hours aerobically and examining the plates for sterility.

Preferably the blood agar plate is inoculated at a temperature of 37"C for a period of 48 hours.

In a preferred embodiment of the invention the second sterility check includes the step of inoculating the suspension into a thioglycollate digest medium, incubating the digest medium at a temperature of between 30 and 32"C for approximately 14 days, and examining the medium for sterility.

The second sterility check may also include the step of inoculating the suspension into a soyabean-casein digest medium at a temperature of between 22 and 25"C for approximately 14 days, and examining the medium for sterility.

In one embodiment of the invention the sterilisation fluid comprises a mixture of Formalin and Thiomersal.

In a preferred embodiment of the invention the suspension is adjuvanted with aluminium hydroxide gel.

Preferably the initial period is approximately 24 hours.

Usually the liquid culture medium is inoculated at a temperature of 37"C.

In another aspect the invention provides an autogenous vaccine whenever prepared by the method according to the invention.

The invention will be more clearly understood from the following non-limiting example.

Preparation of materials used in the vaccine production (A) Yeast Extract Solution Yeast extract solution is prepared by dissolving 1009 of yeast extract (Oxoid L.21) in water and adding approximately 300cc of distilled water to bring the total volume up to approximately 400cc. The extract solution is then placed in a 1 litre beaker and boiled for 20 minutes, keeping the volume at 400cc by adding further boiled distilled water as required. The solution is then filtered through a sterile filter paper and the pH is adjusted to 8. When cooled, the solution is stored in a fridge.

(B) Thiomersal Solution Thiomersal stock solution is prepared by making up a solution containing 3.2% Thiomersal (C2H5Hg.S.C5H4.COONa, Min assay 97%). 16g of Thiomersal is suspended in 500 ml of water and the suspension is autoclaved at 121"C for 15 minutes.

(C) Thioglycollate Medium .4359 Thioglycollate Broth USP Oxoid CM 391 is made up to 15 mls with distilled water in tubes of 20x 150 mm. The broth is then autoclaved for 15 minutes at 121"C.

(D) Soya Bean casein digest medium 159 of Tryptone Soya Broth Oxoid CM 129 is made up to 500ml with distilled water. 20ml aliquots are then distributed into 30ml containers which are autoclaved for 15 minutes at 121"C and stored at 3"C.

(E) Blood agar plates 4.09 DST agar is weighed and transferred to a 500ml bottle. 200ml of cold distilled water is added and the bottle is shaken vigorously. The media is then allowed to stand for 15 minutes to allow the agar to swell up and take up the liquid. The bottles are autoclaved at 121"C for fifteen minutes and allowed to cool to 50"C. 7cc sterile defibrinated blood are then added per 100mls of agar. The suspension is swirled gently and poured onto plates. The plates are then allowed to cool and are stored at 4"C.

Example 1-Haemophilus Pleuropneumonia Vaccine.

500cc bottles containing 350cc of brain/heart infusion broth (Oxoid CM.225) are placed in an incubator for 12 hours at 38"C.

40mls of the Yeast Extract Solution are added to 350mls of brain heart infusion broth to give a concentration of 2.5% yeast in the warm liquid broth.

Each bottle is inoculated with the Haemophilus Pleuropneumonia culture. The bottles are then incubated at 37"C for 8 hours. A purity check is then carried out on each bottle by immersing a sterile swab in the liquid and plating the swab onto a blood agar plate. A Staph streak is then applied and the plates are incubated at 37"C for 24 hours. The plates are examined for satelitism and culture purity by gross, microscopic and biochemical examination. A sterilisation fluid comprising 2cc of Formalin and Thiomersal is added to the vaccine suspension to a concentration of .013% Thiomersal. The suspension is thoroughly mixed for 15 minutes using a rotary shaker and incubated at 37"C for 24 hours.

The first sterility check is then carried out. A cotton tipped sterile swab is immersed in the suspension and inoculated onto blood agar plates. The blood agar plates are incubated at 37"C for 48 hours aerobically and then examined for sterility.

When the first sterility check is being carried out the bacterial suspension is adjuvanted by adding 100 ml of aluminium hydroxide gel to each bottle.

24 hours later a second sterility check is carried out. The bottles are removed from the incubator and shaken vigorously for 15 minutes using a rotary shaker. A sterile cotton tipped swab is immersed in the suspension and inoculated onto blood agar plates as in the first sterility check.

Further sterility tests are carried out by inoculating 2ml of vaccine into 20ml of Thioglycollate broth and soya bean-casein digest media. The Thioglycollate suspension is incubated at 30-32"C for 14 days and the soya bean casein digest medium at 22-25"C for 14 days.

If evidence of baterial or fungal growth is found in any of the tests the vaccine batch is rejected.

To ensure that the vaccine is safe a double dose (4ml) of the vaccine is injected subcutaneously into each of two animals at the location where the vaccine is intended for use and the animals are observed for at least seven days. If any abnormal local or systemic reaction occurs the vaccine batch is rejected.

It will be appreciated that while the invention has been specifically described with reference to the preparation of Haemophilus Pleuropneumonia Vaccine the method may be applied to the preparation of any suitable autogenous vaccines such as: Escherichia Coli Slamonella Cholera Suis Bordatella Bronchiseptica Slamonella Dublin Pasteurella Multocida Salmonella Typhimurius Pasteurella Haemolytica Staphylococcus Hyicis Haemophilus Parasuis Klebsiella Species Streptococcus Suis Typ I Streptococcus Suis Typ 2 The growing period for the bacteria specific for the vaccine being produced are grown in a liquid culture media at 37"C for from 6 to 48 hours, depending on the desired vaccine.

Claims (11)

1. A method of preparing an autogenous vaccine comprising the steps of: growing bacteria for the desired vaccine in a liquid culture medium at between 35 and 40"C for from 6 to 48 hours; checking the bacterial suspension of purity; adding a sterilisation fluid to the bacterial suspension to form a bacterial and sterilisation fluid suspension; incubating the suspension at a temperature of between 35 and 40"C for a period of between 24 and 72 hours; carrying out a first sterility check after an initial period; adjuvanting the suspension; and carrying out a second sterility check at the end of the incubation period.

2. A method as claimed in claim 1 wherein the first and second sterility checks include the step of immersing a swab in the suspension, inoculating a blood agar plate with the swab, incubating the plate at a temperature of between 35 and 40"C for a period of between 24 and 72 hours aerobically and examining the plates for sterility.

3. A method as claimed in claim 2 wherein the blood agar plate is inoculated at a temperature of 37"C for a period of 48 hours.

4. A method as claimed in any of claims 1 to 3 wherein the second sterility check includes the step of inoculating the suspension into a thioglycollate digest medium, incubating the digest medium at a temperature of between 30 and 32"C for approximately 14 days, and examining the medium for sterility.

5. A method as claimed in any of claims 1 to 4 wherein the second sterility check includes the step of inoculating the suspension into a soyabean-casein digest medium at a temperature of between 22 and 25"C for approximately 14 days, and examining the medium for sterility.

6. A method as claimed in any of claims 1 to 5 wherein the sterilisation fluid comprises a mixture of Formalin and Thiomersal.

7. A method as claimed in any of claims 1 to 6 wherein the suspension is adjuvanted with aluminium hydroxide gel.

8. A method as claimed in any of claims 1 to 7 wherein the initial period is approximately 24 hours.

9. A method as claimed in any of claims 1 to 8 wherein the liquid culture medium is inoculated at a temperature of 37"C.

10. A method substantially as hereinbefore described with reference to the examples.

11. An autogenous vaccine whenever prepared by a method according to any preceding claim.