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US 4,057,626 AGranted
Process for detoxifying influenza B virus
AssigneeRichardson-Merrell Inc.
InventorsDon P. Metzgar, Raymond H. Newhart
Life of this patent
Estimating the term…
Abstract
A detoxified influenza virus of the B group is obtained by treating an inactivated virus with formaldehyde.
Claims4
A method of detoxifying a virus of the influenza B group which comprises treating an aqueous concentrate of said virus with from 250 to 500 micrograms of formaldehyde per ml of virus concentrate at a temperature of from 17 37.degree. C. for a period of time ranging from 5 to 30 days.
A process for the preparation of a detoxified, inactivated, influenza B virus vaccine concentrate which comprises:
- a. cultivating a live influenza B virus in the allantoic fluid of embryonated chicken eggs;
- b. harvesting the allantoic fluid containing said live virus;
- c. inactivating said live virus so obtained with from 160 to 200 micrograms of formaldehyde per ml of allantoic fluid at 25.degree. C. for 18 hours;
- d. concentrating said inactivated virus by zonal centrifugation using a sucrose density gradient;
- e. purifying said inactivated virus concentrate by adsorption and elution on barium sulfate;
- f. further purifying said inactivated virus eluate by dialysis;
- g. treating said purified virus concentrate with ultraviolet light to ensure inactivation of said virus;
- h. detoxifying said inactivated virus concentrate with formaldehyde at a concentration of 350 to 400 micrograms/ml. of said virus concentrate at a temperature of 25.degree. C. for a period of 7 to 10 days;
- and
- i. neutralizing excess formaldehyde with sodium bisulfite solution to obtain a detoxified, inactivated, influenza B virus vaccine concentrate.
7 more elements
Dependencies are inferred from the claim text.