Smallpox Vaccines and Future, Essay Example

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Dr. Neff’s claim regarding the efficacy of the smallpox vaccine being eliminated after a few years does not have a strong evidential basis. According to existing medical evidence, typical efficacy of the small pox vaccine typically lasts for five years (on average) after primary vaccination (Fenner, Henderson, Arita, Jezek&Ladnyi, 1988).  In addition, waning (note: not eliminated) immunity can persist for more than ten years depending on the individual, with studies suggesting that antibody levels against small pox remain longer after a “booster” vaccination (Lublin-Tennenbaum, Katzenelson, El-Ad & Katz, 1990).  Thus, Dr. Neff’s claim is not only incorrect when compared against existing evidence, but it also lacks critical nuance to incorporate the variance in individuals’ immunity vis-à-vis smallpox.

References for Paragraph 1

Fenner, F., Henderson, D.A., Arita, I., Jezek, Z, Ladnyi, I.D. (1988). Smallpox and its eradication. Geneva, Switzerland: World Health Organization.

Lublin-Tennenbaum, T., Katzenelson, E., El-Ad, B., Katz, E (1990). Correlation between cutaneous reaction in vaccinees immunized against smallpox and antibody titer determined by plaque neutralization test and ELISA. Viral Immunology, 3(1), 19–25.

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In an attempt to increase the overall efficiency of the small pox vaccine and lessen undesirable side effects, different derivations of the original vaccinia are being researched. USAMRIID’s “next generation” small pox vaccine is a DNA-based vaccine composed from genes of the vaccinia proteins (Enserink, 2004, p. 809). Some purported advantages of the DNA-based vaccine (versus conventional vaccines) are increased efficacy and safety.  The DryVax vaccine, a derivative of the traditional smallpox vaccine, has continued to be used despite concerns over safety in the use of a live virus.  Indeed, in a recent trial conducted by the US Army, a small number of vaccinated individuals suffered from heart inflammation; the company that produces the vaccine halted a clinical trial after three vaccines developed myioperuicardtis (Enserlink, 2004, p.809). In order to address these safety concerns, the MVA vaccine was developed with a weaker form of the live virus. While the MVA virus is largely thought to be “safer”, there is an apparent tradeoff with the immunological potency of the coverage (Silfka, 2005).  While derivations of the original vaccinia are the best current option, the DNA-based virus will likely be the best bet over the long-term, particularly as safety concerns over using the live virus remain.

Magazine Article

Enserink, M. (2004, May 7). Smallpox vaccines looking beyond the next generation. Science, 304, 809.

Slifka, M. (2005).  The future of smallpox vaccination: is MVA the key?  Medical Immunology, 4(2),

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Ring vaccination is the vaccination of all susceptible individuals in an outbreak area based on a relationship to an existing carrier. The logic behind ring vaccinations is that through forming a medical buffer between at-risk individuals and the general population, the disease can be stopped.  Herd immunity is a concept quite different from ring vaccination.  Under the principles of herd immunity, all individuals (or at least a majority) of individuals in the general population would be vaccinated, regardless of disease status, in order to stop the halt of disease.  Thus, the main differences between a strategy of ring immunization and herd immunity are the scope and probabilistic assumptions related to the disease spread.

True/ False Question

It is probably not a good idea to propose a blanket requirement for exposed individuals irrespective of health condition. The decision to receive a vaccine is based on a careful cost-benefit analysis of the purported benefits of vaccination versus the expected costs.  In the case of some individuals who are immunocompromised (e.g., HIV, individuals receiving chemotherapy ,etc.), the vaccine may lead to direct death (CDC, 2007).

References

CDC. (2007).  Frequently asked questions about smallpox vaccine.  Accessed at: http://www.bt.cdc.gov/agent/smallpox/vaccination/faq.asp.