| 摘要 |
<p>1,212,952. Myxovirus vaccines. MERK & CO. Inc. 31 March, 1969 [2 April, 1968], No. 16740/69. Heading A5B. [Also in Divisions B1 and C6] A method of obtaining sterile, sedimented myxovirus (influenza, para-influenza, measles and mumps) from a liquid growth medium in which the virus has multiplied involves: (A) successively passing the growth medium through filter pads having the determined porosity of (i) relatively large pore filter (cellulosic pads, diatomaceous earth or spun glass), (ii) 0.8 to 2.0 micron pores (preferably 1.2 microns) and (iii) 0.22 to 0.6 micron pores (preferably 0.45 micron), and (B) centrifuging the filtrate in a 50,000 to 89,000 g field. The filtration may be preceded by a clarifying centrifugation of about 15,000 g. There should be about 100 sq. cm. of filter pad area for each 1 to 1.5 litres of the growth medium passed, and flow rates of I to 1.5 litres per 10 minutes. Air pressure of about 20 lbs. per sq. in. may be applied at each filtering step. The virus may be killed, e.g. with formalin, at any stage in the method. The final concentrated virus may be diluted with physiological phosphate buffer to produce a vaccine, or lyophilized for subsequent resuspension. Examples 1 and 2 are directed to the recovery of A2 and B strains of influenza, respectively, from their liquid growth medium.</p> |
