Smallpox Vaccine Term Paper
- Length: 7 pages
- Subject: Disease
- Type: Term Paper
- Paper: #95380333
Excerpt from Term Paper :
The recent concerns regarding bio-terrorism have given rise to calls for a mass vaccination program against smallpox. The Bush administration has floated plans to administer the smallpox vaccine to healthcare and military workers, to protect against a smallpox outbreak in the United States. This paper examines the symptoms and morbidity rates of smallpox, and studies the arguments both for and against a mass smallpox vaccination campaign.
Smallpox first appeared in northeastern Africa or the Indus Valley of south-central Asia nearly 12,000 years ago (Mayo Clinic 2002).
Throughout history, outbursts of smallpox broke out in various parts of the globe.
The smallpox contagion was also played a decisive role in the colonization of the Americas. In the 15th century, European explorers acted as the unwitting carriers of smallpox to the New World. Because they lacked natural resistance, Native Americans quickly succumbed to the disease. They also transmitted the virus to other populations. In South America and the Caribbean, an estimated 8 to 20 million people died, many without even encountering a white man (de las Casas 2002).
However, the seeds of the smallpox vaccine were sown when scientists observed that people who survived smallpox were immune to the disease. To induce immunity, Chinese scientists thus used tubes to inhale powdered smallpox scabs. Turkish scientists scratched pus from other people's lesions into their skins. In 1788, English scientist Edward Jenner developed a variola vaccine from the less virulent cowpox virus. By the 1800s, the cowpox vaccinations became the widely accepted method of preventing smallpox (Mayo Clinic 2002).
The last occurrence of smallpox in the United States was documented in 1949 (CDC 2002) and smallpox vaccinations were discontinued in 1972. In 1980, in light of the eradication of smallpox, the World Health Organization (WHO) recommended that all countries discontinue vaccinations.
Stocks of the virus, however, remain in high-security labs in the United States and in Russia. But in the 1980s, the Russians allegedly developed virulent smallpox strains for use as biological weapons. Health officials fear that the collapse of the former Soviet Union may have left some of this stock into the wrong hands.
B. What happens to the body
Smallpox causes pus-filled blisters or pustules on skin. These eruptions leave severe, pitted scars. Experts estimate that up to one-third of the victims who experience smallpox lesions will die from the disease.
1. Signs and symptoms
The first symptoms of smallpox usually appear 12 to 14 days after the initial infection. Patients experience the sudden onset of flu-like symptoms. These symptoms include fever; bodily discomfort; headache; severe fatigue and back pain (CDC Smallpox Factsheet 2002).
Once a host is infected, however, the virus immediately begins replicating. The virus targets the lymph nodes first, before invading the host's spleen and bone marrow. The virus then invades and multiplies in the host's blood vessels. Most of the variola virus mass on host's vessels in the skin and the mucous membranes.
By this time, flat, red spots called lesions appear on the host's face, hands and forearms. These spots later spread throughout the infected person's body.
The virus infects a victim's saliva through mouth lesions. Since the mucous membranes and saliva are the main areas of infection, a smallpox carrier usually transmits the virus through bodily fluids such as saliva. Furthermore, the pattern of distribution of lesions throughout the body is a hallmark of smallpox and a primary way of diagnosing the disease (CDC Smallpox Factsheet 2002).
Smallpox is one of the most devastating of human diseases. In its 12,000-year history, it has probably killed more people than any other illness, including the bubonic plague.
There are four major types of smallpox. "Ordinary" smallpox accounts for 90% of all smallpox cases. The "modified" smallpox, a milder form of the disease, can occur among people who have already been vaccinated. The "flat" or "hemorrhagic" form of smallpox, is extremely rare, accounting for less than 1% of all smallpox cases (CDC Smallpox Fact Sheet 2002).
Smallpox is fatal in an estimated 30% of people who contract the disease.
People who recover from smallpox will have severe and disfiguring scars, particularly on their faces, arms and legs. In many cases, smallpox could even lead to blindness. Those who contract the milder modified smallpox could also suffer from scars and pockmarks. The morbidity rate in the rare hemorrhagic smallpox, however, is 100%.
III. Smallpox vaccine
The smallpox vaccine contains live vaccinia virus, a milder cousin of the smallpox virus variola (CDC Smallpox Factsheet 2002). It does not contain smallpox virus and cannot cause smallpox. The vaccine contains lyophilized calf lymph and traces of polymyxin B, streptomycin, tetracycline and neomycin (Maurer, Harrington and Lane 2003). The vaccine diluent is 50% glycerin with a small amount of phenol. The vaccine does not contain egg byproduct or thimerosal. Once the smallpox vaccine is reconstituted, it can be refrigerated and used for up to 60 days (Maurer, Harrington and Lane 2003).
A. Arguments in favor of vaccination
In light of the recent terrorist efforts to spread anthrax spores, many Americans feared the possibility of more serious biological attacks. These fears have led some groups to call for the production of smallpox vaccines and a campaign to vaccinate the general public in an effort to stop a smallpox plague.
The success of the WHO's smallpox campaign is testament to the effectiveness of the smallpox vaccine. While receiving the vaccination before exposure to the variola virus is the greatest level of protection, receiving the smallpox vaccine within three days of exposure can still prevent or at least lessen the severity of the disease in most people. A vaccination up to a week after exposure can still lessen the severity of the smallpox disease in most people (CDC Smallpox Vaccine Overview 2003).
After a single vaccination, 95% of patients are protected within 10 days, and immunity lasts at least 5 years. The immunity period is believed to be longer after revaccination (Maurer, Harrington and Lane 2003).
The Bush campaign initially broached the idea of a smallpox vaccination campaign among soldiers and healthcare workers, who would be on the frontline during the early stages of a smallpox terrorist attack. Since the smallpox virus is spread through people to people contact, vaccinating the likely first victims would thus form a protective wall to contain an early outbreak, before it begins to manifest in members of the general public.
As a result of the successful worldwide eradication of smallpox, few health care workers today are trained to deal with or even recognize the symptoms of smallpox. Even a small outbreak can affect thousands, since outbreaks typically occur in two-week intervals. This two-week pattern is based on the disease's incubation period, as well as the very fast rate of transmission (Landers 2001).
Proponents of a vaccination program in the United States thus point out that though the vaccine poses risks to some people, the disease itself is fatal to the vast majority of people who are infected. There is no known cure for smallpox, making the vaccination even more important.
B. Arguments against vaccination
Despite the smallpox vaccine's success, many experts argue against vaccinations at the present time. May and Silverman (2003) argue that the lack of a clear threat of an outbreak does not justify the risks associated with the smallpox vaccine. Because the vaccine involves a live virus, there is a long list of potential side effects. These side effects range from fevers to encephalitis and even death.
Gilmore (2003) further notes that past statistics show that the smallpox vaccine poses a much higher level of risk compared to other vaccinations. For every million people vaccinated in the past, 14 to 52 persons experienced severe reactions. Furthermore, 1-2 people out of every 1 million who received the smallpox vaccine died. Authorities in the United States are further studying the possibility of a causal relationship between smallpox vaccination and subsequent deaths due to previously undiagnosed cardiac disease.
Even Donald Henderson, who had helped to develop the smallpox vaccine, believes that the present climate does not warrant mass smallpox vaccinations. He notes, "without having had a case of smallpox in the world since the early 1980s, there is no reason to use smallpox vaccine" (qtd in Landers 2001).
A mass smallpox vaccination would also be contraindicated for many patients with a variety of illnesses. This includes people with skin diseases like eczema or dermatitis, inflammatory eye diseases, and people who are undergoing chemotherapy and radiation therapy. The smallpox vaccine would also have cause severe birth defects in the fetuses of pregnant women.
The smallpox vaccine would be fatal to patients with compromised immune systems. There is always the danger that people who are asymptomatic would not realize they are ill or pregnant. To people who are unaware that they are pregnant or ill, the administration of a live smallpox vaccination could have deadly consequences (Maurer, Harrington and Lane 2003).
Furthermore, many experts on smallpox argue that a terrorist attack using smallpox is an unlikely scenario. Unlike anthrax, which…