Smallpox Prophylaxis

Smallpox General Information

Smallpox is the generic name given to a highly infectious disease caused by the variola virus, which often causes disfiguration and the death of the patient. This disease has been the cause of devastating epidemics, causing the death of over 300 million people in the 20th century alone. Few other diseases have caused so many deaths in human history and consequently, it is considered one of the diseases with the greatest impact on human society.

The Smallpox incubation period is of about 14 days, after which it begins manifesting through flu-like signs and symptoms such as headaches, fever and fatigue. After a period of time, the patient’s skin becomes covered with pus-filled blisters that, after healing, leave pitted, deep scars. There is no cure and no effective treatment for the disease once the symptoms begin manifesting.

By 1980, a large scale immunization campaign was led to the eradication of the naturally-occurring disease; however the virus was not completely destroyed. Stocks of the virus are still being preserved for research purposes in two locations on the globe (high security laboratories in Siberia and the United States), and there are concerns regarding the future involvement of the virus as an agent of biological warfare. However, at this time the disease is no longer a threat to public health.

Smallpox Prophylaxis

Smallpox Prophylaxis mainly consists of the large scale vaccination of the population. Until 1980, the immunization on a large scale of the population was employed in order to prevent further deaths. As the last reported case was in 1977, in 1980 the mass vaccination was deemed unnecessary and was therefore stopped. Currently, there is a sufficient supply of the vaccine to render a large part of the population immune to the disease if the situation demands it. However, at this time immunization is no longer employed, mainly due to the fact that the vaccine may cause lethal side effects in 1 out of 1 million cases. Less severe side effects, such as painful sores and scarring, occur in many more cases. Residual brain damage is also possible to occur due to encephalitis (an infection of the brain with possible lethal consequences). Myocarditis (inflammation of the heart) and pericarditis (inflammation of the membranous layer covering the heart) or a combined form of the two (myopericarditis) may also occur, as it has been shown from the vaccination of medical and military personnel. In some cases, angina (heart pain) and heart attacks are also possible. Because of these complications and due to the eradication of the naturally occurring disease, public health officials have decided that Smallpox Prophylaxis through vaccination should no longer be employed on a large scale.

Smallpox Prophylaxis through vaccination still needs to be employed in a small number of cases, mainly involving military personnel, researchers and health care professionals. However, the vaccination should not be performed if the individual suffers from certain skin conditions (such as eczema or other chronic skin conditions, or if he or she has any medical history of such affections), impaired immune system (as caused by certain medical conditions – cancer, organ transplants - or medication). Pregnant females should also not undergo vaccination, as although the vaccine does not generally cause any birth defects, in a small number of cases it may lead to the death of the unborn child.

Individuals suffering from AIDS or those that are HIV positive should not be vaccinated either, as their immune system is weakened due to the infection. Smallpox Prophylaxis through vaccination is not recommended in individuals that are allergic to any of the ingredients of the vaccine (the main ingredients are Polymyxin B sulfate, Chlortetracycline hydrochloride, Streptomycin sulfate and Neomycin sulfate). Patients suffering from underlying heart diseases or those with three or more risk factors for such diseases should also not receive the vaccine – this includes patients suffering from diabetes, high blood pressure, high cholesterol or smokers and patients with family history of heart diseases.

Smallpox Treatment

Unfortunately, there is no known cure for Smallpox. Some studies indicate that Cidofovir may prevent the disease in cases where it is administered within at most two days after the accidental exposure to the virus. Cidofovir is an antibiotic drug that is typically employed in the treatment of the Cytomegalovirus disease. However, no extensive information on this subject is currently available, and studies are still being performed in order to obtain more detailed information on the possible effects of this drug.

The Smallpox vaccine can also be employed as a means to treat the disease. Administering the vaccine within four days from exposure may reduce the severity of the disease and in some cases it is possible to completely prevent it. At this time, the exact conditions required for post-exposure vaccination to prevent the apparition of the disease are not clear, and scientists are working to obtain more information on the subject.

None of the above two methods are of any use in cases where the disease has already developed to the symptomatic stage. In such situations, treatment can only attempt to reduce the severity of the symptoms and prevent additional infections (that may affect the individual) through antibiotic therapy. Isolation of the patient is also required in order to prevent further spreading of the disease.