Bacteriophages, viral vaccines, and poliovirus

13 March 2009

gavelThe readers of virology blog are a savvy group – they determined that the bacteriophages present in viral vaccines originate from bovine serum present in cell culture medium. Animal virus vaccines prepared in cell cultures are contaminated with the bacteriophages, which are not removed when the harvests are sterilized by filtration. But what is the source of the bacteriophages in bovine serum?

Fetal bovine serum is obtained in slaughterhouses where cows are prepared for the meat industry – some of the cows are pregnant, and the fetuses fall to the ground during the grisly procedure. The floor of the slaughterhouse is contaminated with fecal material, which contains bacteria and their viruses. Hence, when serum is collected from the fetuses, it is contaminated with bacteriophages, which are not removed when the serum is sterilized by filtration.

When bacteriophages were discovered in live viral vaccines in the 1970s, a controversy ensued – could they harm humans? Ultimately there was no evidence that bacteriophages caused any ill effects in humans. The regulations for producing human virus vaccines were therefore modified to allow for the presence of ‘unavoidable bacteriophages‘.

I discovered this interesting fact because, for the past few weeks, I have been preparing to testify as an expert witness in a product litigation trial dealing with poliovirus vaccine. I have been reading extensively about poliomyelitis and poliovirus vaccines, which also explains why this virus dominated virology blog this week. I took the stand yesterday, but can’t provide any details yet about this experience, because the case has not yet gone to jury. When it is finished I’ll write about this interesting intersection of science and law.

I greatly enjoyed NB’s conjecture about why I was focused on polio this week: the March of Dimes was formerly the charity organization known as the National Foundation for Infantile Paralysis, founded during the presidency of Franklin D. Roosevelt to defeat polio. And it happens to be the third month of the year.

  • Raj

    Although there is no evidence that bacteriophage can cause illness in humans, their presence in vaccine can lead to serious problems. When person gets vaccine with bacteriophages there is possibility of disruption of natural bacterial flora in the body which might have adverse effect in the individual, 2. certain bacteria when lysed release toxins which can cause illness (e.g. diphtheria) 3. gene transfer can occur which might lead to cancer. Nevertheless, if serum used in vaccines are not properly monitored bovine viruses can be introduced in humans. With the evidence of infectious bovine rhinotracheitis virus can cause persistent infection and malignant transformation of cultured hamster cells, I think we must not forget use of bovine serum with bacteriophage might lead us into harm.
    In retrospect, live vaccines have been used for years now and we are quite confident to say it has done more good than bad. In another argument, bacteriophages are present in abundant so humans are constantly exposed to them.
    The argument can keep on going, however we must come with a technique to sterilize our serum in such that it is free of bovine viruses and bacteriophages yet fully efficient for cell growth.

    Michalski, F., and G. D. Hsiung. 1975. Malignant transformation of hamster cells following infection with a bovine herpesvirus (infectious bovine rhinotracheitis virus). Proc. Soc. Exp. Biol. Med. 148:891-896.

    Michalski, F. J., and G. D. Hsiung. 1976. Persistent infection with bovine herpesvirus-l (infectious bovine
    rhinotracheitis virus)in culturedhamstercells.InVitro12:682-686.

  • Raj

    Although there is no evidence that bacteriophage can cause illness in humans, their presence in vaccine can lead to serious problems. When person gets vaccine with bacteriophages there is possibility of disruption of natural bacterial flora in the body which might have adverse effect in the individual, 2. certain bacteria when lysed release toxins which can cause illness (e.g. diphtheria) 3. gene transfer can occur which might lead to cancer. Nevertheless, if serum used in vaccines are not properly monitored bovine viruses can be introduced in humans. With the evidence of infectious bovine rhinotracheitis virus can cause persistent infection and malignant transformation of cultured hamster cells, I think we must not forget use of bovine serum with bacteriophage might lead us into harm.
    In retrospect, live vaccines have been used for years now and we are quite confident to say it has done more good than bad. In another argument, bacteriophages are present in abundant so humans are constantly exposed to them.
    The argument can keep on going, however we must come with a technique to sterilize our serum in such that it is free of bovine viruses and bacteriophages yet fully efficient for cell growth.

    Michalski, F., and G. D. Hsiung. 1975. Malignant transformation of hamster cells following infection with a bovine herpesvirus (infectious bovine rhinotracheitis virus). Proc. Soc. Exp. Biol. Med. 148:891-896.

    Michalski, F. J., and G. D. Hsiung. 1976. Persistent infection with bovine herpesvirus-l (infectious bovine
    rhinotracheitis virus)in culturedhamstercells.InVitro12:682-686.

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