среда, 23 ноября 2011 г.

Top 10 Myths About HIV Vaccine Research

Dec. 1 is World AIDS Day, and in commemoration of the occasion, the HIV Vaccine Trials Network, headquartered at Fred Hutchinson Cancer Research Center, debunks the top 10 myths about HIV vaccine research.
HIV prevalence, 2009
Myth No. 1: HIV vaccines can give people HIV. HIV vaccines do not contain HIV and therefore a person cannot get HIV from the HIV vaccine. Some vaccines, like those for typhoid or polio, may contain a weak form of the virus they are protecting against, but this is not the case for HIV vaccines. Scientists make HIV vaccines so that they look like the real virus, but they do not contain any HIV. Think of it like a photocopy: It might look similar, but it isn't the original. In the past 25 years more than 30,000 volunteers have taken part in HIV vaccine studies worldwide, and no one has been infected with HIV by any of the vaccines tested because they do not contain HIV.

Myth No. 2: An HIV vaccine already exists. There is no licensed vaccine against HIV or AIDS, but scientists are getting closer than ever before to developing an effective vaccine against HIV. In 2009, a large-scale vaccine study conducted in Thailand called RV144 showed that a vaccine combination could prevent about 32 percent of new infections. Researchers are starting to understand why this vaccine combination worked and how to improve upon it.

Researchers around the world continue to search for an HIV vaccine that is even more effective. Leading this effort is the HIV Vaccine Trials Network, the largest publicly funded group of HIV vaccine researchers in the world. The HVTN is an international effort to find a safe and effective vaccine to stop the spread of HIV. It is funded by the U. S. National Institutes of Health.

Myth No. 3: Joining an HIV-vaccine study is like being a guinea pig. Unlike guinea pigs, people can say yes or no to participating in research. All study volunteers must go through a process called informed consent that ensures they understand all of the risks and benefits of being in a study, and those volunteers are reminded that they may leave a study at any time without losing rights or benefits. The HVTN takes great care in making sure people understand the study fully before they decide whether or not join. All HVTN research adheres to U.S. federal regulations on research, as well as the international standards for the countries in which it conducts research.

Myth No. 4: A person must be HIV positive to be in an HIV vaccine study. Not so. While some research groups are conducting studies of vaccines that might be used in people who are already infected with HIV, the vaccines being tested by the HVTN are preventive vaccines. They must be tested on volunteers who are not infected with HIV.

Myth No. 5: Vaccine researchers want study participants to practice unsafe behaviors so they can see whether the vaccine really works. Not true. The safety of study participants is the No. 1 priority of HIV vaccine researchers and study site staff. Trained counselors work with study participants to help them develop an individual plan on how to keep from contracting HIV. Participants also are given supplies such as condoms and lubricant as well as instructions on how to use them properly. HIV efficacy trials enroll thousands of participants over several years, and with even with the best counseling some participants will still become infected through their risky behavior. Changing human behavior is never easy; after all, many people still smoke, even though it is widely known that smoking is the major cause of lung cancer. An AIDS epidemic would not exist if prevention was as simple as counseling people to change their risky behavior.

Myth No. 6: Now that there are pills that can prevent HIV infection, an HIV vaccine is no longer necessary. HIV-negative people who are at high risk can take antiretroviral medication daily to try to lower their chances of becoming infected if they are exposed to the virus. This type of therapy called PrEP, short for PreExposure Prophylaxis has been shown to be effective among those at high risk. However, it has not yet been recommended for widespread use. PrEP is unlikely to be an option for everyone because the pills are expensive and are not always covered by insurance, may cause side effects, and not everyone has access to them. Remembering to take a pill every day is also challenging for some people. The most effective way to eliminate a disease is by using an effective vaccine. It was a vaccine that eliminated small pox and has almost eliminated polio. Most likely it will be an HIV vaccine that eliminates HIV from the world. Vaccines are an effective, affordable and practical option.

Myth No. 7: An HIV vaccine is unnecessary because AIDS is easily treated and controlled, just like diabetes. While treatment for AIDS has dramatically improved over the last 30 years, it is no substitute for prevention. Current HIV medications are very expensive, and there are also many side effects. Sometimes people develop drug resistance and have to change the regimen of pills they take. Access to these drugs for the uninsured in the U.S. and those in the developing world is also very limited.

Myth No. 8: The search for an HIV vaccine has been going on for a long time and it's just not possible to find one that works. The science of HIV-vaccine development is challenging, but scientific understanding continues to improve all the time. In just the past two years there have been promising results from the RV144 study in Thailand as well as exciting laboratory work, such as the discovery of new broadly neutralizing antibodies against HIV. HIV is a powerful opponent, but scientists are constantly learning from one another and using advanced technology to fight it. Science has come a long way in the 30 years since AIDS was discovered. In comparing preventive HIV vaccine work to other vaccine development, the time it has taken is not so surprising; the polio vaccine took 47 years to develop.

Myth No. 9: Vaccines cause autism and just aren't safe. This is not true. Numerous studies in the past decade have found this claim to be false. The British doctor who originally published the finding about vaccines and autism has since been found to have falsified his data. There is actually no link between childhood vaccination and autism. It is true that vaccines often have side effects, but those are typically temporary (like a sore arm, low fever, muscle aches and pains) and go away after a day or two. The value of protection to vaccinated individuals and to the public has made vaccines one of the top public health measures in history, second only to having a clean water supply.

Myth No. 10: People who aren't at risk don't need an HIV vaccine. A person currently may not be at risk for HIV, but life situations can change along with disease risk. Such a vaccine also may be important for one's children or other family members and friends. By being knowledgeable about preventive HIV vaccine research, a person can be part of the solution by educating friends and family about the importance of such research and debunking the myths that surround it. Even if a person is not at risk, he or she can be part of the effort to find a vaccine that will hopefully save the lives of millions of people worldwide.

source: medicalnewstoday.com