Vaccine-Associated Paralytic Poliomyelitis and BCG-osis

This week's MMWR published by the CDC reports a case of vaccine-associated paralytic poliomyelitis and disseminated BCG infection in a vaccinated child brought to a San Antonio hospital. This case is important for the general public to be aware of for two reasons, and it's not to avoid vaccinating children.

The first complication here is that the child did not have the appropriate immune system to handle vaccination with a live vaccine, of which both BCG and the OPV received are. This child lacked an essential enzyme required to make both cells of the immune system and protective antibodies. The absence of this enzyme meant that the child lacked the ability to fight infections and resulted in the child and siblings suffering from recurrent infections. There exist certain conditions, such as SCID or lack of an immune system, that preclude one from being vaccinated. It is important that our physician know of any and all possible complications and that you yourself are award of those complications as well.
        For you altruists, because there are people that cannot get vaccinated, it is essential to maintain a high level of immunized people in the population surrounding those unfortunate individuals. This provides a strong pressure to keep infections out of the general populace and away from individuals who cannot be vaccinated.

The second important point to consider here is that this child, from India, was vaccinated with the live BCG vaccine (against tuberculosis which is still rampant in the developing world) and OPV (the live oral poliovirus vaccine). Neither of these vaccines are used in the United States. With the last case of natural polio occurring in 1979. Since 2000, the US has switched from vaccinating individuals with the live OPV to vaccinations with the safer inactivated (or dead) poliovirus vaccine (IPV). This vaccine cannot grow and so there is no risk of developing polio from this dead vaccine.
       In addition, the US no longer routinely vaccinates against tuberculosis. The only, mildly, effective vaccine is the live, related BCG strain. However, this vaccination interferes with surveillance, turning all vaccinees positive. The US has decided to monitor for infections (PPD skin test many receive) instead of vaccinating the populace with a questionably effective vaccine. However, in developing countries where tuberculosis still kills many children, something is better than nothing.

In conclusion, don't let reports such as these scare you away from vaccinating children. Talk with your doctor about any potential complications or risks.



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This is a personal blog. The views expressed herein may not represent those of my employer.