Antibodies, vaccines and adjuvants - Pharmaceutical Biotechnology: Concepts and Aapplications - page 401

• heat treatment;

• treatment with formaldehyde or acetone;

• treatment with phenol or phenol and heat;

• treatment with propiolactone.

13.4.1.2 Attenuated and inactivated viral vaccines

Viral particles destined for use as vaccines are generally propagated in a suitable animal cell cul-
ture system. Although true cell culture systems are sometimes employed, many viral particles are
grown in fertilized eggs or cultures of chick embryo tissue (Table 13.7).
Many of the more prominent vaccine preparations in current medical use consist of attenuated
viral particles (Table 13.6). Mumps vaccines consist of live attenuated strains of Paramyxovirus
parotitidis . In many world regions, it is used routinely to vaccinate children, often a part of a com-
bined measles, mumps and rubella vaccine.
Several attenuated strains have been developed for use in vaccine preparations. The most com-
monly used is the Jeryl Linn strain, which is propagated in chick embryo cell culture. This vaccine has
been administered to well over 50 million people worldwide and, typically, results in seroconversion
rates of over 97 per cent. The Sabin (oral poliomyelitis) vaccine consists of an aqueous suspension
of poliomyelitis virus, usually grown in cultures of monkey kidney tissue. It contains approximately
1 million particles of poliomyelitis strains 1, 2 or 3 or a combination of all three strains.
Hepatitis A vaccine exemplifi es vaccine preparations containing inactivated viral particles. It
consists of a formaldehyde-inactivated preparation of the HM 175 strain of hepatitis A virus. Viral
particles are normally propagated initially in human fi broblasts.

13.4.1.3 Toxoids and antigen-based vaccines

Diphtheria and tetanus vaccines are two commonly used toxoid-based vaccine preparations. The
initial stages of diphtheria vaccine production entail the growth of Corynebacterium diphtheriae .

Table 13.7 Some cell culture systems in which viral particles destined for
use as viral vaccines are propagated

Viral particle/vaccine Typical cell culture system

Yellow fever virus Chick egg embryos

Measles virus (attenuated) Chick egg embryo cells

Mumps virus (attenuated) Chick egg embryo cells

Polio virus (live, oral, i.e. Sabin, and
inactivated injectable, i.e. Salk)

Monkey kidney tissue culture

Rubella vaccine Duck embryo tissue culture, human

tissue culture

Hepatitis A viral vaccine Human diploid fi broblasts

V. zoster vaccines (chickenpox vaccine) Human diploid cells