It is unimaginable what could be the situation at the present if the smallpox vaccine had not been discovered. One development that has been hailed to save mankind from a dreaded disease is the discovering of the vaccine. From the audio interview, Richard Preston author of “Demon in the Freezer” and Dr. John Neff a smallpox expert talked about smallpox being the mother of all biological weapons with a death rate of 1 in every 3. They were of the view that mass vaccination cannot be a solution as it will bring some serious complications. At the end of the interview, it was held by Neff that smallpox vaccine confers immunity for a period of between 3 and 5 years meaning that individuals vaccinated in 1970s are no longer immune to the virus. This is the centre for discussion as I tend to hold a contrary view.
Interestingly, people who have survived smallpox infections are known to exhibit a lifelong protection or immunity from the dreadful virus. Similarly, it has been found out that a greater proportion of individuals vaccinated for smallpox do have certain neutralizing antivaccine that is capable of offering protection against smallpox. On the same note when individuals are subjected to multiple vaccinations, there was slight increase in levels of antibodies; however the level of the same doesn’t reduce as time elapse. Although it has been suggested that high risk individuals opt to be revaccinated after a period of 5 years, studies have shown that once vaccinated for smallpox, recipients are offered protection from lethal infection of smallpox for longer period. This means that there will be no need for multiple re-vaccinations since a single vaccine “elicit functional antibody that will remain stable in human body for lifetime” (Taub et al., 2008: 1059). Another study using subjects between the ages of 1 and 52 years were revaccinated; there was no or very little response in the antibody. In conclusion, all people vaccinated either once or several times do maintain antivaccine IgG as well as neutralizing antibody titers. It is worth noting that the titers are stable for about 90 years. Various studies concluded that individuals vaccinated show immunity to vaccinia indefinitely and do not need booster vaccination.
In the article “Smallpox Vaccine: Looking beyond the next generation” written by Enserink, Martin and published in 2004, the author compares and contrasts DryVax and MVA vaccines. DryVax is older, developed and used to eradicate smallpox back in 1970s and was amazingly very effective in eradicating the infectious disease. However it has been shown to pose some negative effects such as increased rate of encephalitis, severe skin infections and heart inflammation. A more recent vaccine MVA (modified vaccine Ankara) does not result in lesion; it is deemed to be safer than DryVax and other traditional smallpox vaccine developed. However its efficacy cannot be successfully predicted in protecting mankind from smallpox. Using booster doses of the vaccine will help in providing strong immunity.
Because there is need to subject the victims to between 2 and 3 doses of MVA, it will be potentially difficult to use it during high risk situations. It is worth noting that despite the shortcoming mentioned, MVA can be successfully used by individuals who are immune-compromised (suffering from HIV and AIDS, cancer among others). Similarly it can be applied in a pre-event scenario. In my view there is no need to jump into conclusion regarding the vaccine of the future. There is need to carry more research to establish the immunogenicity as well as preventive efficiency of MVA as well as other vaccines with regards to their abilities to curb smallpox epidemic. This is guided by the fact that the experiment was carried using monkey and the results obtained might not be a true reflection of what will happen when used in human beings (Enserink, 2004).
Ring vaccination has been define as the act of giving a vaccine to a group of individuals who are in close contact with those who are infected with a communicable diseases such as polio, smallpox among others (Preson, 2002). This kind of vaccination helps prevent or cure infectious diseases from spreading. It has been hailed to use resources effectively because it is only those primarily affected who are vaccinated. This is followed with closed surveillance of the infected people. It is worth noting that ring vaccination is best suited for dealing with a localized smallpox infection. On the other hand, herd immunity is used to describe a situation in which a given group of people are resistant to a certain pathogen as a result of larger proportion of the population being immune to the pathogen in question. The theory holds that in cases where mankind is faced with contagious diseases, the paths or chains of infection is most likely interfered with when majority of the population are immune or less vulnerable to such kind of diseases. Thus if the number of resistant individuals within a population exists then there is a smaller chance that high risk individuals will come in contact with infected persons (John & Samuel, 2000). Thus the two concepts are distinct but offer the same desired outcome of saving mankind from contracting infectious diseases. Finally people who have been directly exposed to the smallpox virus should indeed get the vaccine, regardless of their health status (Preson, 2002).
References
Enserink, M. (2004). Smallpox Vaccine: Looking beyond the next generation. Science Scope, 304(2): 1.
John, T. & Samuel, R. (2000). Herd immunity and herd effect: new insights and definitions, Eur. J. Epidemiol, 16 (7): 601–606.
Preson, R. (2002). The demon in the freezer. New York: Random House.
Taub, D., et al (2008). Immunity from smallpox vaccine persists for decades: A longitudinal study. Am J Med. 2008 December, 121(12): 1058–1064.