Should the US develop and Stockpile Vaccines and Antiviral Medications Against. A(H5N1) Avian Flu?

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Alban Hicks
6 years ago
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1 Spring Upshaw Biology Due: 7/7/06 Should the US develop and Stockpile Vaccines and Antiviral Medications Against A(H5N1) Avian Flu? The A(H5N1) avian flu, which has existed since 1997 is lethal in humans and some believe that it has the potential of becoming a human pandemic virus. This virus has caused deaths in more than half of the people who have contracted it. The available options that scientists have to prevent and treat a potential avian flu pandemic are uncertain due to unpredictable changes that the virus may undergo, limited resources and unknown vaccine and antiviral drug immune responses. Scientists are now challenged to predict the next potential viral strain, determine the probability of the next occurrence of a pandemic, and develop preventative measures and treatments to protect and preserve human lives. Scientists must communicate all of their findings to political authorities and together they must decide how to combat the potential pandemic. After looking at history s time line of pandemic causing viruses, some scientists believe that another is in the near future. Because of the high mortality rate of those who have contracted A(H5N1) avian flu and the possibility for it to exchange genetic information with a highly transmissible human flu, some fear that this virus will mutate, spread rapidly, and destroy millions of lives. Evidence from past viral infections show that only Type A viruses have caused pandemics and they have all originated as a bird 1

2 flu. The known information about past viruses including but not limited to mortality rates, ability to mutate, molecular make up, susceptibility, and the rate and mode of transmission are used to predict the behavior of potential viruses (Monto, 2006) Using all acquired information about past viruses, scientists are still presented with four major obstacles. 1) Scientists can not prove with certainty that there will be a pandemic. 2) Past observations and experiences will not provide scientists with absolute certainty that the A(H5N1) bird flu will mutate and become a pandemic. 3) Scientists can not predict with certainty that the A(H5N1) bird flu will become a pandemic in its current state. 4) If the A(H5N1) bird flu becomes a pandemic in its current state or if it mutates and becomes a pandemic, scientists can not predict with certainty when the pandemic will occur. A swine flu outbreak occurred in the 1970 s, took a few human lives, and initiated a response by scientists and the government to spend millions on vaccines to prevent a pandemic from occurring. The flu never became a pandemic, but the vaccine elicited a response in some and had a more devastating effect than the virus itself. To prevent a repeat of this situation with the A(H5N1) bird flu, scientists are performing observational and experimental studies to gain knowledge about vaccine and antiviral drug production and its potential effects. Observational studies from those who received vaccination for the swine flu has been used to influence decisions about the current avian flu. Studies show that people who were never exposed to any type of the swine virus need to get two doses of a weaker vaccine to produce an immune response without being negatively effected. Those who have been exposed to a type of the swine virus in the past could get one stronger dose of the vaccine to produce an immune response without being harmed 2

3 (Monto, 2006). This information is significant as scientist try to decide if they should use the same strategy with the A(H5N1) bird flu. Another strategy suggested by scientists would be to use an adjuvant with the vaccine, which would require less of the vaccine, allowing more people to receive preventative treatments. However, because the strain of bird flu that may cause a pandemic is not known, some scientists debate about whether stockpiling vaccines would be wasteful or provide greater relief and maybe prevention than no vaccine at all. Another alternative that has been suggested is prevention and/or treatment by taking antiviral drugs that inhibit viral neuraminidases. The benefit of antiviral drugs is that they have a wider range of effectiveness than vaccines. Although there are various methods that are suggested to prevent and/or treat A(H5N1) avian flu, some concerns include the possibility of harmful or deadly effects from any treatment, viral resistance from low doses, ineffectiveness of the vaccine due to a viral mutation, and limited productivity of the virus and antiviral medication. Although scientists may be working diligently to provide answers to this bird battle, there are limiting factors that impede the process. Because the bird flu is currently infecting a greater species of birds and people, and the certainty of the occurrence of a pandemic remains unknown, scientists have a limited amount of time and resources to perform observational and experimental studies to gain knowledge of and develop vaccines and antiviral medications. Time and money are necessary to determine how various doses of vaccines and antiviral medications affect individuals based on their age, immune system, and health. Resources are also needed to perform comparison studies between the effectiveness of individual and combined treatments or preventative methods, such as vaccines alone or vaccines with antiviral medication. Conclusions, 3

4 although they may not be definitive, must be reached quickly to begin the process of producing enough vaccines and antiviral medications for large populations, which can take months. Waiting until a pandemic occurs to develop a vaccine, may be as ineffective as closing schools, quarantine, and advising people to wear face masks and stay away from infected people (MacKenzie, 2006). The process for making vaccines will most likely be hindered, because there is a need for vaccines for the human seasonal flu, which uses the same resources as the avian flu. Even after all of these attempts to protect people from the A(H5N1) avian flu, there is still the likelihood that it will not become a pandemic and money and resources will have been wasted. After reviewing the articles, I am led to believe that with the known strain of virus and certainty about a pandemic, a combination of adjuvant and vaccines along with antiviral medications should be stockpiled because it would provide the best protection for A(H5N1) avian flu, provided there are no side effects. In an ideal situation, after stockpiling the preventative treatments, those who are most likely to be susceptible to the vaccine should first receive the treatments. However, according to scientists current understanding of the time and resources needed to produce massive amounts of vaccines and antiviral medications, there will be limited amounts if they are not produced and stockpiled. If everyone is equally as susceptible, and there are not enough treatments, what will we do? Because of the uncertainties concerning the possibilities of the A(H5N1) avian flu pandemic before or after it mutates and the lack of knowledge about the effects of vaccines and antiviral medication, I believe that scientists should continue to obtain multiple types of convergent evidence before reaching developing stockpile vaccines and antiviral medications. 4

5 Works Cited Altman, 2006, With Every Epidemic, Tough Choices, New York Times Grady and Kolata, 2006, How Serious Is the Risk of Avian Flu?, New York Times Grady, 2006, Doubt Cast on Stockpile of a Vaccine for Bird Flu, New York Times MacKenzie, 2006, Stockpile Human Bird Flu Vaccine Now, Say Experts, New Scientist MacKenzie, 2006, Only Drugs and Vaccines Will Deflect Bird Flu Pandemic, New Scientist MacKenzie, 2006, Today s Bird Flu Vaccine Will do, New Scientist Monto, 2006, Vaccines and Antiviral Drugs in Pandemic Preparedness, Emerging Infectious Disease 5

Should the U.S. develop and stockpile vaccines against A(H5N1) avian flu?

Amy Dewees July 7, 2006 Biol 501 Should the U.S. develop and stockpile vaccines against A(H5N1) avian flu? A(H5N1) is a strain of flu virus that infects many species of birds, including domestic and migratory