Many have mixed feelings on HIV vaccine research

Thu Aug 18, 2005 09:20 PM ET

NEW YORK (Reuters Health) - Most adults in the U.S. believe that a vaccine against HIV infection offers the best chance of controlling the global AIDS epidemic and are confident that an effective vaccine against the virus will be developed. However, only a minority said they would strongly support a friend or family member who participated in an HIV vaccine trial.

These are among the findings of a telephone survey designed to gauge attitudes, knowledge, and awareness of HIV vaccine research in the U.S. For the survey, researchers polled 2,008 Americans 18 years of age or older who were randomly selected from the general population, as well as 1,501 randomly selected from three groups highly affected by HIV infection -- African-Americans, Hispanics and men who have sex with men (MSM).

Full results of the survey conducted by Matthew Murguia, director of the Office of Program Operations and Scientific Information in the National Institute of Allergy and Infectious Diseases (NIAID) Division of AIDS, and colleagues were posted online this month by the Journal of Acquired Immune Deficiency Syndromes and will appear in an upcoming print issue.

The researchers report that 62.5 percent of the general population felt that a vaccine to prevent HIV is the best way to control and end the AIDS epidemic, while 61.9 percent, 74.3 percent, and 70.6 percent, respectively, of African-Americans, Hispanics, and MSM, felt this way.

However, only 28.8 percent of the general population would welcome the idea of having someone they know participating in an HIV vaccine trial. The corresponding figures for the three highly impacted populations were 34.9 percent, 45.9 percent, and 67.8 percent, respectively.

Among the other survey findings: 47.1 percent of African Americans, 26.5 percent of Hispanics, and 13.4 percent of MSM believed an HIV vaccine already exists and is being kept secret.

Also, 78.0 percent of African Americans, 57.8 percent of Hispanics, and 68.0 percent of MSM incorrectly believed, or did not know if, the vaccines being tested could cause HIV infection.

Subgroup analyses showed that women tended to have less knowledge of or a decreased awareness of HIV vaccine research.

"It is clear that we have a lot of work to do in explaining HIV vaccine research," Murguia said in a statement.

"Tens of thousands of volunteers are required for the more than 30 HIV vaccine clinical trials currently planned or under way," added NIAID director Dr. Anthony S. Fauci. "It is essential that current and future trials involve volunteers from diverse communities to enable us to find a vaccine that works for all populations."

SOURCE: Journal of the Acquired Immunodeficiency Syndromes, 2005.

The HIV Vaccine Challenge

By Swapna Majumdar
The Indian government recently announced that it had begun trials for an HIV/AIDS vaccine as part of a global initiative - the International AIDS Vaccine Initiative (IAVI) - involving Germany and Belgium. “Developing a vaccine to prevent AIDS is one of the most difficult scientific challenges of our time. It is also one of the most urgent health needs,” stated Dr Anbumani Ramadoss, Union Minister of Health and Family Welfare, while announcing the trials.

Volunteers

In February 2005, 10 healthy Indian volunteers, uninfected by HIV, were injected with the vaccine. The vaccine candidate - tgAAC09 - is modelled after subtype C of HIV, the subtype that accounts for the most infections worldwide and is prevalent in many developing countries, including India and South Africa. The vaccine will be tested on around 30 volunteers (both men and women) during Phase 1 of the trials. Simultaneous trials will take place in Belgium and Germany.

The vaccine (tgAAC09) consists of a synthetic copy of a portion of HIV’s genetic material inserted into adeno-associated virus, a virus that is unrelated to HIV and does not infect humans. The decision to use it for human trials was taken after test results on animals showed its ability to protect some of them from developing AIDS after they became infected with an HIV-like virus.

Scientists from the three countries believe the vaccine could prompt immune system responses helpful to combat the HIV infection. If it does not prevent infection, it may delay infection from progressing to AIDS, provided the vaccine is taken before the infection occurs.

In India, the Phase I trials are being conducted by the Pune-based National AIDS Research Institute (NARI), an affiliate of the Indian Council of Medical Research, and are slated to be completed by May 2006.

An independent international Safety Review Board (SRB), comprising of one scientist from each of the three countries and one from a non-participating country, will review the data emerging from the trials of the low-dose group. Once SRB gives the green signal, enrollment will begin for the mid-dose group.

India has over 5.1 million people infected by HIV. While the medical community and several NGOs and health groups have responded positively to the vaccine project, a few have raised some fundamental issues.

Celina DeCosta, member of the Indian Network for Persons Living with HIV/AIDS (INP+), says: “When NARI asked for my view, I raised concerns about the safety of the volunteers. They told me that no one could get the infection through the injection. However, if they indulged in high-risk behaviour while being enrolled, then NARI could not guarantee their safety.

So, even though the volunteers are informed about this aspect, I feel that the importance of adhering to the rules related to the trials must be stressed at every meeting.”

According to Anjali Gopalan of Naz Foundation, a Delhi-based NGO working with people living with HIV/AIDS (PLWHAs), if everything goes according to schedule, it will take another eight to10 years before the vaccine is finally produced. “Naz was one of the organisations involved in drafting the consent form that every volunteer has to sign before being enrolled. We ensured that all ethical concerns were addressed.”

Gopalan says that the vaccine should not be seen as the only option and there should be no let-up in care and prevention efforts. One of the biggest challenges faced by India is the lack of adequate health care for HIV/AIDS patients. Access to treatment is also difficult because of the stigma attached to the disease. Several government hospitals still refuse patients, and several infected persons (largely women) continue to be discriminated against.

Ever since volunteer screening for the trials began in February, the response has been tremendous. “Many of them (volunteers) were senior citizens who said that they wanted to do something for the country. But we couldn’t take them because they were not compatible with our main eligibility criteria - that volunteers should be healthy male or female adults between the ages of 18-50,” revealed Dr Sanjay Mehendale, Deputy Director, NARI, who is also the principal investigator for the trials.

In fact, volunteers were chosen in strict accordance with the eligibility conditions. The chosen candidate had to be uninfected, not fall within the category of high-risk behaviour for HIV infection and was available for follow-up up to 13 months after receiving the vaccine. The volunteer also had to undergo the HIV test before and after he was enrolled. Furthermore, the volunteer had to be willing to use condoms or reliable contraception up to four months after being vaccinated.

However, even if the volunteer complied with these eligibility conditions, s/he had to pass a test that assessed understanding of all possible risks. They include possible HIV infection, inability to donate blood for four months and side effects of the vaccine like dizziness and severe headaches.

An equally big concern is the risk of infection among volunteers. During the period of study, each volunteer will be monitored for 12 months after vaccination. The volunteer would receive counselling throughout the trial and access to care, support and treatment including Anti-Retroviral Therapy for five years from the time of enrollment.

According to Dr Mehendale, NARI is following care and treatment guidelines drawn out by all the trial partners. “We have made provisions for treatment free of cost if there are trial-related disabilities. Medical insurance and appropriate compensation will be given if recommended,” he said.

Zero growth
Volunteers also have the option of taking their grievances to the chairperson of the NARI Ethics Committee. In the case of disputes, the matter will be referred to the Arbitration Board comprising of a senior physician, lawyer and social scientist. If the vaccine tests are successful, India may be able to achieve its goal of zero growth rate of HIV infection by 2007.

Antibiotics-to-go may increase STD treatment

Wed Aug 17, 2005 04:22 PM ET

By Amy Norton

NEW YORK (Reuters Health) - Take-home antibiotics may be an effective way to ensure that the partners of men with certain sexually transmitted diseases (STDs) get treatment, a new study suggests.

Researchers found that giving male STD patients a dose of antibiotics to bring to their partners appeared more effective than the traditional method for getting at-risk partners treated.

Typically, people with STDs like chlamydia and gonorrhea are instructed to tell all their sexual partners to see a doctor for testing and treatment. But studies have suggested that relatively few partners ever get treated, and in some places in the U.S. clinics are trying a new tactic, known as patient-delivered partner treatment.

In these cases, patients with chlamydia or gonorrhea -- two common bacterial STDs -- are given a dose of antibiotics, along with written instructions on how to use the medication, to pass on to their sexual partners.

The practice is already common in Europe but has been slow to catch on in the U.S., said Dr. Patricia Kissinger of Tulane University in New Orleans, the lead author of the new study.

One obstacle is that some doctors worry about their legal liability if a patient's partner were to have side effects from treatment. But, Kissinger told Reuters Health, there is little risk of side effects from the single-dose antibiotics used to treat chlamydia and gonorrhea.

Still, only three U.S. states have made patient-delivered treatment "explicitly legal," Kissinger said, and similar measures in other states may be needed before the practice becomes more routine.

Her team's study, published in the journal Clinical Infectious Diseases, involved 977 men who received treatment for chlamydia or gonorrhea at a public STD clinic in New Orleans.

Patients were randomly assigned to one of three groups. Men in one group were instructed to tell their partners to seek testing and treatment; a second group also received information cards to give to their partners; the third group received a single dose of antibiotics for up to four partners.

When the men were interviewed a month later, 56 percent of those given antibiotics said their partners had taken the medication. Only 35 percent of those in the traditional partner-referral group said their partners had gotten treatment.

In addition, the researchers found, men who received antibiotics for their partners were less likely to have a recurrent infection at the one-month mark.

For women, infection with chlamydia or gonorrhea can lead to pelvic inflammatory disease and infertility, making it vital to track and treat an infected man's female partners.

The current study and similar ones, according to Kissinger, have "made it pretty obvious" that patient-delivered antibiotics can help achieve this goal.

The tactic is not appropriate for all STDs, however, she pointed out. In the case of syphilis, a serious disease linked to an increased risk of HIV, public health professionals contact patients' partners themselves to ensure that they know of their risk.

SOURCE: Clinical Infectious Diseases, September 1, 2005.

Crocodile blood may yield powerful new drugs

Tue Aug 16, 2005 03:33 PM ET

By Michael Perry

SYDNEY (Reuters) - Scientists in Australia's tropical north are collecting blood from crocodiles in the hope of developing a powerful antimicrobial drugs for humans, after tests showed that the reptile's immune system kills HIV.

The crocodile's immune system is much more powerful than that of humans, preventing life-threatening infections after savage territorial fights that often leave the animals with gaping wounds and missing limbs.

"They tear limbs off each other and despite the fact that they live in this environment with all these microbes, they heal up very rapidly and normally almost always without infection," said U.S. scientist Mark Merchant, who has been taking crocodile blood samples in the Northern Territory.

Initial studies of the crocodile immune system in 1998 found that several antibodies in the reptile's blood killed bacteria resistant to penicillin, such as Staphylococcus aureus, Australian scientist Adam Britton told Reuters on Tuesday. It was also a more powerful killer of HIV than the human immune system.

"If you take a test tube of HIV and add crocodile serum it will have a greater effect than human serum," Britton said from Darwin's Crocodylus Park, a tourism park and research center.

Britton said the crocodile immune system works differently from the human system by directly attacking microbes immediately an infection occurs.

"The crocodile has an immune system which attaches to bacteria and tears it apart and it explodes. It's like putting a gun to the head of the bacteria and pulling the trigger," he said.

For the past 10 days, Britton and Merchant have been carefully collecting blood from wild and captive crocodiles, both saltwater and freshwater species. After capturing a crocodile and strapping its powerful jaws closed the scientists extract blood from a large vein behind the head.

"It's called a sinus, right behind the head, and it's very easy just to put a needle in the back of the neck and hit this sinus and then you can take a large volume of blood very simply," said Britton.

The scientists hope to collect enough crocodile blood to isolate the powerful antibodies and eventually develop an antibiotic for use by humans.

"We may be able to have antibiotics that you take orally, potentially also antibiotics that you could run topically on wounds, say diabetic ulcer wound," said Merchant.

However, drugs derived from the crocodile's immune system may need to be synthesized for human consumption.

"There is a lot of work to be done. It may take years before we can get to the stage where we have something to market," said Britton.

Rectal bacteria may lower vaginal infection risk

Mon Aug 15, 2005 08:28 PM ET

NEW YORK (Reuters Health) - The presence of a specific type of bacteria in the rectum appears to reduce the risk of vaginal infections, researchers report.

"The gut has been seen as a site which harbors pathogens, which can cause vaginal infection, principal investigator Dr. Sharon L. Hillier of the University of Pittsburgh commented. These findings are the "first to document that the lower gastrointestinal tract can also harbor the lactobacilli, which are beneficial for vaginal health."

"Further," she told Reuters Health, "when women harbor these organisms in the gut, they have a reservoir for replenishing vaginal lactobacilli should they decrease following sexual exposure or douching."

As they report in The Journal of Infectious Diseases, Hillier and her colleagues studied vaginal and rectal swabs obtained from 531 women and recovered lactobacilli from the vagina of 74 percent and the rectum of 51 percent.

Overall, 80 percent of the women had evidence of lactobacilli in the vagina, or in the vagina and the rectum. Most women (67 percent) had lactobacilli that produced hydrogen peroxide.

The absence of hydrogen peroxide-producing lactobacilli in the vagina is associated with an increased risk of bacterial vaginosis, which is associated with higher concentrations of HIV in women with this infection and higher rates of preterm birth in pregnant women, the investigators explain.

Conversely, the presence in the vagina of lactobacilli that produce high levels of hydrogen peroxide is associated with lower rates of bacterial vaginosis and certain pregnancy complications.

Hillier and her associates speculated that the presence of rectal lactobacilli may help maintain the healthy balance of normal vaginal flora and that this, in turn, is associated with a lower rate of the adverse effects of bacterial vaginosis.

The most common types of rectal hydrogen peroxide-producing lactobacilli were Lactobacillus crispatus (16 percent), L. jensenii (10 percent) and L. gasseri (10 percent).

Only 13 (9 percent) of the 147 women with vaginal, or rectal and vaginal L. crispatus or L. jensenii had bacterial vaginosis compared with 12 (44 percent) of those with other hydrogen peroxide-producing lactobacilli.

The lowest prevalence of bacterial vaginosis (5 percent) was seen in women with vaginal and rectal hydrogen peroxide-producing lactobacilli. Those who had only vaginal, only rectal, or no lactobacilli at either site, had an increased risk of vaginosis.

The researchers add that the dairy-related lactobacilli, L. acidophilus and L. delbrueckii bulgaricus, were not seen either rectally or vaginally, and that it is possible that L. crispatus and L. jensenii "may be better suited to probiotic use."

SOURCE: The Journal of Infectious Diseases, August 1, 2005.

Seven Indian AIDS Drugs Reinstated