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for answers. What is the Step Study?The Step Study is the name of a clinical trial to test an experimental HIV
vaccine. The trial will be run by a pharmaceutical company, which developed the investigational vaccine, and
by the HIV Vaccine Trials Network (HVTN).
The main purposes of this trial are to obtain more information about the safety of the study vaccine in people and to learn if the study vaccine can prevent HIV infection. For vaccine recipients who become HIV-infected through high-risk behavior, the trial will test whether the study vaccine lowers the level of HIV in the blood.
The products in this trial are not produced from live virus or from HIV-infected human cells. There is no possibility that they contain live (or killed) HIV virus. The experimental vaccine in this trial cannot cause HIV infection.
The main purposes of this trial are to obtain more information about the safety of the study vaccine in people and to learn if the study vaccine can prevent HIV infection. For vaccine recipients who become HIV-infected through high-risk behavior, the trial will test whether the study vaccine lowers the level of HIV in the blood.
The products in this trial are not produced from live virus or from HIV-infected human cells. There is no possibility that they contain live (or killed) HIV virus. The experimental vaccine in this trial cannot cause HIV infection.
What is a vaccine trial?A vaccine is given to prevent infection or fight disease. Currently there is no vaccine against HIV.
Part of the process of finding an HIV vaccine is testing study vaccines that seem
most likely to help the body fight HIV. A vaccine trial is a standard way to test a specific
study vaccine so that researchers can prove that the study vaccine is safe, and can
find out more about whether it might work to prevent or fight disease. Volunteers who participate in
HIV vaccine trials play an important part in this scientific research.
Who are the people who participate in HIV vaccinetrials?
Many types of people volunteer for HIV vaccine trials. In this trial, all participants must be generally
healthy and HIV-negative (free of HIV infection). People have many reasons for joining HIV vaccine
trials, including altruism (a desire to help others) and to advance scientific knowledge. Before
deciding to enter the trial, potential participants are provided with information about HIV and AIDS,
about the reasons for the trial, about possible risks and benefits of participation, and about trial
procedures. People who participate in this trial may not be
eligible for future HIV vaccine trials.
Can a study vaccine cause HIV infection?It is impossible to get HIV infection or develop AIDS from experimental vaccines. They are not made
from live HIV, killed HIV, weakened HIV, or HIV-infected cells.
The investigational vaccine in this trial cannot cause HIV infection.
The investigational vaccine in this trial cannot cause HIV infection.
What kind of vaccine is being tested?The investigational vaccine is called Ad5 HIV-1 gag/pol/nef. It is made of an adenovirus vector and an HIV gene insert.
A vector is like a suitcase, used to carry a few non-reproducing HIV genes into the body to create an immune response. In this study, the vector is made from adenovirus type 5 (Ad5), a virus that causes the common cold and sore throats, but the vector has been crippled so that it cannot grow or spread in the body or to other people. It cannot cause you to get sick.
The HIV gene insert is made of the HIV genes gag, pol, and nef that have been added into the vector.
Neither the vector nor the HIV genes can cause HIV or AIDS.
A vector is like a suitcase, used to carry a few non-reproducing HIV genes into the body to create an immune response. In this study, the vector is made from adenovirus type 5 (Ad5), a virus that causes the common cold and sore throats, but the vector has been crippled so that it cannot grow or spread in the body or to other people. It cannot cause you to get sick.
The HIV gene insert is made of the HIV genes gag, pol, and nef that have been added into the vector.
Neither the vector nor the HIV genes can cause HIV or AIDS.
Why is this trial being done?Based on the research that has been done to date, the investigational vaccine has shown
promising characteristics. After testing the investigational vaccine in the laboratory, in animals, and
in small groups of people to see if it is safe and if it causes an immune response, researchers feel that it is important to test the study vaccine in a large group of people. We want to learn more about the safety of the study vaccine and see if the vaccine can prevent HIV infection completely, or at least lower the level of HIV in the blood if infection is not completely prevented.
How could this study vaccine help prevent HIV/AIDS?The investigational vaccine carries man-made HIV genes into the cells. These genes could cause the body to make a cellular immune response to HIV, producing an
army of killer T cells that recognize and kill HIV-1 infected cells.
The idea is to train the immune system to kill cells that show signs of HIV infection, thus
potentially reducing the damage that HIV can do to the body. If a person later becomes infected with
HIV, hopefully the immune system would be prepared to respond.
If the study vaccine is effective, will it be licensed after this trialis completed?
No. This study will not produce enough data to support a vaccine licensing
application. If the data show that the investigational vaccine offers some protection against HIV, or
that it lowers the viral load in those participants who become infected with HIV, this information will guide future research efforts.
What does the study vaccine contain?The study vaccine contains the following:
A weakened form of a cold virus, called adenovirus type 5
the HIV genes gag, pol, and nef
saline solution (salt water)
Has this vaccine been studied before?The investigational vaccine was first tested in mice, rabbits and monkeys. Then it was tested in more than 250 people. More than 60 people were given
the study vaccine at the same dose or higher than the dose used in this trial, the Step Study. Two similar
HIV investigational vaccines have been tested in more than 450 people.
Who is eligible to participate in this trial?Participants must be HIV-negative (not HIV infected) adults between 18 and 45 years old,
and considered to be at risk of HIV infection due to behavior, mainly sexual, that puts them at
risk. Special efforts are being made to enroll women into the trial.
All participants must meet certain medical and non-medical criteria for eligibility, and volunteers are carefully screened to make sure they meet the eligibility requirements. One of the main medical criteria is having a low level of antibodies against adenovirus type 5, the vector component of the study vaccine. These antibodies may exist even in very healthy people. If a volunteer is ineligible for the trial because of adenovirus antibodies, this does not mean that they have a health problem.
All participants must meet certain medical and non-medical criteria for eligibility, and volunteers are carefully screened to make sure they meet the eligibility requirements. One of the main medical criteria is having a low level of antibodies against adenovirus type 5, the vector component of the study vaccine. These antibodies may exist even in very healthy people. If a volunteer is ineligible for the trial because of adenovirus antibodies, this does not mean that they have a health problem.
How can people find out if they are qualified to join this trial?People who are interested in joining the study should contact the trial site closest to them. Staff members at the trial site will provide information about the study. Each potential participant is asked for a medical history and is given a physical examination. Blood is
taken to see if the person meets the medical eligibility criteria. The potential participant is asked to answer a series of personal questions about sexual
activity and drug use.
A woman who wants to join the trial will be given a pregnancy test. A woman who is pregnant or breastfeeding is not allowed to participate in the trial, and all female participants must agree to avoid pregnancy during the trial.
All volunteers are tested to make sure they are HIV-negative (not HIV infected). A volunteer who is HIV-positive at screening cannot enroll in the trial.
Information about participants will be kept confidential and will be used only for trial purposes.
A woman who wants to join the trial will be given a pregnancy test. A woman who is pregnant or breastfeeding is not allowed to participate in the trial, and all female participants must agree to avoid pregnancy during the trial.
All volunteers are tested to make sure they are HIV-negative (not HIV infected). A volunteer who is HIV-positive at screening cannot enroll in the trial.
Information about participants will be kept confidential and will be used only for trial purposes.
When and where is this trial being conducted?The Step Study is an international trial, and there are research sites in a
number of countries. The trial
will be conducted in 14 US cities: Birmingham, AL; Boston, MA; Chicago, IL; Atlanta, GA; Denver,
CO; Houston, TX; Los Angeles, CA; Miami, FL; New York, NY; Philadelphia, PA; St. Louis, MO;
San Francisco, CA; San Juan, PR; and Seattle, WA. It will also be conducted in Rio, Brazil; Santo Domingo,
Dominican Republic; Port-au-Prince, Haiti; Iquitos, Peru; Lima, Peru; Montreal, Canada; Toronto, Canada; Vancouver, Canada; and Sydney,
Australia. To contact any of these sites, please see the Locations page.
What is the design of this trial?The trial will enroll about 1500 people. Over the course of six months, half of these people will be
given three shots of the investigational vaccine, and the other half will be given three shots of a
placebo (an injection without any active vaccine) made of a saline solution (salt water).
For the rest of their time in the trial (about four more years), participants will be tested for HIV infection every six months. All trial participants will be given state-of-the-art counseling to reduce risk behavior. Because the trial enrolls people whose behavior puts them at high risk for HIV infection, it is expected that some people will become infected, even though they are being counseled about ways to stay safe. Some of these people will have received placebo, but others may have received the investigational vaccine. These people will get more blood tests to see if the investigational vaccine lowers the level of HIV in their blood.
The Step Study is a multicenter, randomized, placebo-controlled, doubleblind trial. 'Multicenter' means that people in more than one place volunteer for the study.
'Randomized' means that participants are randomly assigned to get the study vaccine or placebo.
'Placebo-controlled' means that some people are given placebo, so the researchers can tell if the investigational vaccine makes a difference. 'Double-blind' means that neither the participants nor the scientists know who is getting the investigational vaccine and who is getting the placebo.
For the rest of their time in the trial (about four more years), participants will be tested for HIV infection every six months. All trial participants will be given state-of-the-art counseling to reduce risk behavior. Because the trial enrolls people whose behavior puts them at high risk for HIV infection, it is expected that some people will become infected, even though they are being counseled about ways to stay safe. Some of these people will have received placebo, but others may have received the investigational vaccine. These people will get more blood tests to see if the investigational vaccine lowers the level of HIV in their blood.
The Step Study is a multicenter, randomized, placebo-controlled, doubleblind trial. 'Multicenter' means that people in more than one place volunteer for the study.
'Randomized' means that participants are randomly assigned to get the study vaccine or placebo.
'Placebo-controlled' means that some people are given placebo, so the researchers can tell if the investigational vaccine makes a difference. 'Double-blind' means that neither the participants nor the scientists know who is getting the investigational vaccine and who is getting the placebo.
How will the safety and rights of participants be protected?
Trial participants play a very important role in the search for an HIV vaccine, and the safety and rights of participants are given the highest priority. This trial meets international standards for ethical research that were created by the Helsinki Declaration of the World Medical Association and Council for International Organizations of
Medical Sciences (CIOMS) guidelines.
During the study, all of the data is reviewed by a Safety Monitoring Board. This group of experts can stop the study at any time if they feel that the risks for participants are too great.
In addition, every study location works with a location Institutional Review Board, sometimes called an Ethics Committee, that reviews all of the details of the trial. These groups also make certain that the rights of participants are protected.
It is important for participants to know that any new study vaccine may have both medical and non-medical risks, and there may be additional risks that we do not know about yet.
Before they join the trial, volunteers are provided with information about HIV and AIDS, about the reasons for the trial, about possible risks and benefits, and about trial procedures. Clinic staff allow plenty of time to talk with volunteers and answer their questions, and information is also provided in writing.
For more information on participants' rights and responsibilites, visit www.hvtn.org/community/rights.html.
During the study, all of the data is reviewed by a Safety Monitoring Board. This group of experts can stop the study at any time if they feel that the risks for participants are too great.
In addition, every study location works with a location Institutional Review Board, sometimes called an Ethics Committee, that reviews all of the details of the trial. These groups also make certain that the rights of participants are protected.
It is important for participants to know that any new study vaccine may have both medical and non-medical risks, and there may be additional risks that we do not know about yet.
Before they join the trial, volunteers are provided with information about HIV and AIDS, about the reasons for the trial, about possible risks and benefits, and about trial procedures. Clinic staff allow plenty of time to talk with volunteers and answer their questions, and information is also provided in writing.
For more information on participants' rights and responsibilites, visit www.hvtn.org/community/rights.html.
How do I join the trial?
After the trial has been fully explained, volunteers are asked to sign an informed consent form before
enrolling. This form will help to make sure that participants have been given all the information they need.
Volunteers will be given plenty of time to consider whether or not they want to join the trial. They
may decide not to join the study. If they do enroll, they may still leave the trial at any time
without losing the benefits of their standard medical care or any other services provided at that location.
During the trial, clinic staff will monitor participants to make sure the investigational vaccine is not causing problems. Throughout the trial, any new information researchers learn about the safety of the study vaccine will be given to participants. Participants will be able to decide whether or not to stay in the study based on any new information they learn.
Participants are reminded frequently that being part of a vaccine trial does not mean they are protected from HIV infection. They are counseled at each clinic visit on ways to avoid HIV infection (for example, correct and consistent condom use).
During the trial, clinic staff will monitor participants to make sure the investigational vaccine is not causing problems. Throughout the trial, any new information researchers learn about the safety of the study vaccine will be given to participants. Participants will be able to decide whether or not to stay in the study based on any new information they learn.
Participants are reminded frequently that being part of a vaccine trial does not mean they are protected from HIV infection. They are counseled at each clinic visit on ways to avoid HIV infection (for example, correct and consistent condom use).
Is this investigational vaccine safe?Based on the data from animal studies and earlier trials in people, scientists believe that the
investigational vaccine is safe enough to use in this trial. One purpose of this trial is to get more
information about the safety of the investigational vaccine.
Previous studies have tested the investigational vaccine in more than 250 people, more than 60 of whom were given the investigational vaccine at the same dose or higher than the dose used in this trial. Two similar HIV vaccines have been tested in more than 450 people.
Before being given to people, the investigational vaccine was tested in mice, rabbits, and monkeys.
While scientists believe that there are no serious safety risks with the investigational vaccine, there is always the possibility that there could be problems that no one expected. This is why this investigational vaccine, like any new drug or vaccine, needs to be tested in participants in a controlled clinical setting. Participants' health and safety will be closely monitored throughout the trial.
Because the investigational vaccine does not contain live HIV virus, there is no way for the study vaccine to cause HIV infection.
Previous studies have tested the investigational vaccine in more than 250 people, more than 60 of whom were given the investigational vaccine at the same dose or higher than the dose used in this trial. Two similar HIV vaccines have been tested in more than 450 people.
Before being given to people, the investigational vaccine was tested in mice, rabbits, and monkeys.
While scientists believe that there are no serious safety risks with the investigational vaccine, there is always the possibility that there could be problems that no one expected. This is why this investigational vaccine, like any new drug or vaccine, needs to be tested in participants in a controlled clinical setting. Participants' health and safety will be closely monitored throughout the trial.
Because the investigational vaccine does not contain live HIV virus, there is no way for the study vaccine to cause HIV infection.
How is the safety of the investigational vaccine monitored?Several groups monitor this trial for safety and to make certain the study is being conducted
according to scientific and ethical standards. These groups include the US Food and Drug
Administration (FDA), the US National Institutes of Health (NIH), the HIV Vaccine Trials Network and local Institutional Review Boards (also called Ethics Committees).
Physicians on the team that designed the Step Study will monitor the safety of the trial. This team carefully considered all of the available information to decide that the investigational vaccine was safe enough to study in this trial.
In addition, there will be an independent Data and Safety Monitoring Board (DSMB). A DSMB is a group of experts that are not part of the HVTN, or the researchers, who will carefully monitor the safety of the trial participants. If there are safety concerns, the DSMB can recommend that the trial be changed or stopped.
Physicians on the team that designed the Step Study will monitor the safety of the trial. This team carefully considered all of the available information to decide that the investigational vaccine was safe enough to study in this trial.
In addition, there will be an independent Data and Safety Monitoring Board (DSMB). A DSMB is a group of experts that are not part of the HVTN, or the researchers, who will carefully monitor the safety of the trial participants. If there are safety concerns, the DSMB can recommend that the trial be changed or stopped.
Are there non-medical (social) risks?Participants are asked to carefully consider all risks before joining a trial. Some risks are medical, but there are also social risks. Trial participation takes time and
commitment. It can also lead to complications with others who do not agree with the participant's
choice to join the trial, or who do not have enough information about HIV vaccines. For example,
some people have reported that being in a trial has upset their spouse, friends or family members.
Participating in a trial may also restrict the volunteer's behavior. For instance, participants are asked not to donate blood, and women should not get pregnant during the trial.
Some people have experienced discrimination when they told people they were participating in clinical research for an HIV vaccine. In the case of discrimination, study staff can (at a participant's request and with their permission) talk to insurance companies, employers, and others to explain a participant's involvement in a trial.
The investigational vaccine could cause a false positive result on a standard HIV test (see below), and such a result may lead to being treated unfairly by others. This will be explained to potential participants in more detial during the informed consent process.
It is important to remember that being given the study vaccine does not mean the participant is protected from HIV infection that is due to sexual contact, sharing of injection drug equipment, or any other transfer of blood or bodily fluids. We still do not know if this study vaccine protects against infection. Trial participants also will not know whether they have gotten the study vaccine or the placebo, which is an inactive substance (saline solution) that does not provide any protection. Participants are counseled at every clinic visit to avoid behavior that will put them at risk of HIV infection.
To help avoid problems that could come from participating in a trial, participants will be offered an identification card that shows that they have joined an HIV vaccine study. A telephone number will be listed on the card that may be called for information or for help in resolving problems.
Participating in a trial may also restrict the volunteer's behavior. For instance, participants are asked not to donate blood, and women should not get pregnant during the trial.
Some people have experienced discrimination when they told people they were participating in clinical research for an HIV vaccine. In the case of discrimination, study staff can (at a participant's request and with their permission) talk to insurance companies, employers, and others to explain a participant's involvement in a trial.
The investigational vaccine could cause a false positive result on a standard HIV test (see below), and such a result may lead to being treated unfairly by others. This will be explained to potential participants in more detial during the informed consent process.
It is important to remember that being given the study vaccine does not mean the participant is protected from HIV infection that is due to sexual contact, sharing of injection drug equipment, or any other transfer of blood or bodily fluids. We still do not know if this study vaccine protects against infection. Trial participants also will not know whether they have gotten the study vaccine or the placebo, which is an inactive substance (saline solution) that does not provide any protection. Participants are counseled at every clinic visit to avoid behavior that will put them at risk of HIV infection.
To help avoid problems that could come from participating in a trial, participants will be offered an identification card that shows that they have joined an HIV vaccine study. A telephone number will be listed on the card that may be called for information or for help in resolving problems.
Could the investigational vaccine cause a "false positive" result on an HIV antibody test?
Some investigational vaccines may cause a trial participant to have an HIV test that appears HIV
positive. Standard HIV tests look for antibodies (a part of the immune system) that recognize HIV.
This investigational vaccine could cause the body to produce these antibodies. In this case, the
standard HIV test could show a positive result. If the investigational vaccine causes this result, it does
not necessarily mean the study participant is infected with HIV. A false positive means that some
tests make a person appear infected; other, more specific tests can prove that there is actually no
infection.
Participants are counseled to get HIV testing done only at their trial site, because the site has access to the specific tests that can show false positives and true HIV infection. These tests will be available even after the study ends.
No medical side effects or health problems are associated with a false positive HIV test result. But such a result may lead to being treated unfairly by others. People with a positive HIV test, even a false positive, are not allowed to donate blood. They may also have difficulties with getting insurance, medical/dental care, traveling to other countries, employment, service in the military or Peace Corps, or relationships with friends and family. Clinic staff members are available to help with any difficulty, and services exist to help any study participant with a false positive HIV result.
Participants are counseled to get HIV testing done only at their trial site, because the site has access to the specific tests that can show false positives and true HIV infection. These tests will be available even after the study ends.
No medical side effects or health problems are associated with a false positive HIV test result. But such a result may lead to being treated unfairly by others. People with a positive HIV test, even a false positive, are not allowed to donate blood. They may also have difficulties with getting insurance, medical/dental care, traveling to other countries, employment, service in the military or Peace Corps, or relationships with friends and family. Clinic staff members are available to help with any difficulty, and services exist to help any study participant with a false positive HIV result.
What will be done with a participant's trial records?Information about trial participants will be used for HIV vaccine or vaccine trial-related research
only. Any information collected about participants will be kept as private as possible. Most records
have only a participant ID number, not a name. Samples used for tests are identified by number only,
not by name. Any test results are confidential, and will not be made part of a participant's general medical
records.
We cannot guarantee absolute privacy. For example, certain information about trial participants may be released if required by law. In addition, most groups that review the safety and conduct of the trials will be able to review the records-but all the members of these groups are required to keep all information confidential.
A Certificate of Confidentiality from the US Food and Drug Administration (FDA) helps protect participant confidentiality. This certificate means that researchers and clinicians cannot be forced to give identifiable information to anyone not connected to the study, even in court proceedings. There are some exceptions to the Certificate of Confidentiality, such as in the case of government audit. These exceptions will be explained to volunteers at the trial sites.
We cannot guarantee absolute privacy. For example, certain information about trial participants may be released if required by law. In addition, most groups that review the safety and conduct of the trials will be able to review the records-but all the members of these groups are required to keep all information confidential.
A Certificate of Confidentiality from the US Food and Drug Administration (FDA) helps protect participant confidentiality. This certificate means that researchers and clinicians cannot be forced to give identifiable information to anyone not connected to the study, even in court proceedings. There are some exceptions to the Certificate of Confidentiality, such as in the case of government audit. These exceptions will be explained to volunteers at the trial sites.
What will happen to participants if they become HIV-infected fromtheir behavior during this trial?
While the investigational vaccine cannot cause HIV infection there is no guarantee that the
investigational vaccine will prevent HIV infection. All participants must be HIV negative when they
enroll in the trial.
It's important to note that participants can still get infected with HIV through sexual contact, sharing of injection drug equipment, or any other exchange of blood or bodily fluids, even if they are receiving the study vaccine.
Participants are counseled to avoid behavior that would put them at risk of HIV infection. Those who become infected during the trial will stop receiving injections, but clinic staff will ask to continue monitoring their health for the rest of their scheduled time in the trial, and the researchers will test their blood to see how the body fights the HIV infection.
There are many drugs that can be used to treat HIV infection, but none of these drugs can cure HIV infection. These drugs are not provided as part of this trial. Participants who become infected during the trial will be referred to an appropriate doctor or medical agency for medical care, including antiretroviral therapy, and counseling.
It's important to note that participants can still get infected with HIV through sexual contact, sharing of injection drug equipment, or any other exchange of blood or bodily fluids, even if they are receiving the study vaccine.
Participants are counseled to avoid behavior that would put them at risk of HIV infection. Those who become infected during the trial will stop receiving injections, but clinic staff will ask to continue monitoring their health for the rest of their scheduled time in the trial, and the researchers will test their blood to see how the body fights the HIV infection.
There are many drugs that can be used to treat HIV infection, but none of these drugs can cure HIV infection. These drugs are not provided as part of this trial. Participants who become infected during the trial will be referred to an appropriate doctor or medical agency for medical care, including antiretroviral therapy, and counseling.
How long will it take to find out if the study vaccine works?Depending on the results of this trial and other trials, this investigational vaccine might be tested
further in a larger trial. Such a trial would test safety in more people, and give a better idea of whether the immune system responds to a vaccine.
Who is sponsoring this trial?This trial is sponsored by the pharmaceutical company that developed the vaccine in collaboration with the HIV Vaccine Trials Network.
Who is conducting this trial?The trial will be run by the pharmaceutical company that developed the vaccine and by the HIV Vaccine Trials Network (HVTN).
The HVTN is a global partnership of researchers, governments, pharmaceutical companies, academic institutions, and community members. The HVTN is dedicated to conducting international clinical HIV vaccine trials in the safest, most efficient way possible. The HVTN is funded and supported by the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH), an agency of the US Department of Health and Human Services (DHHS).
The HVTN is a global partnership of researchers, governments, pharmaceutical companies, academic institutions, and community members. The HVTN is dedicated to conducting international clinical HIV vaccine trials in the safest, most efficient way possible. The HVTN is funded and supported by the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH), an agency of the US Department of Health and Human Services (DHHS).
Who reviewed and approved this trial?The study vaccine is considered experimental, meaning that the FDA allows its use only in research studies.
It has been manufactured according to FDA guidelines and was reviewed by the FDA. The protocol
team (the people from the HVTN, the pharmaceutical company, and DAIDS) who designed the trial also
carefully reviewed the information about the investigational vaccine before deciding to begin the trial.
The trial has also been reviewed by the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS).
The safety and rights of participants in the Step Study are monitored by Institutional Biosafety Committees (IBC) and Institutional Review Boards (IRB) at to each research center. Community members are involved throughout the trial to ensure that the rights and needs of participants are being met.
The trial has also been reviewed by the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS).
The safety and rights of participants in the Step Study are monitored by Institutional Biosafety Committees (IBC) and Institutional Review Boards (IRB) at to each research center. Community members are involved throughout the trial to ensure that the rights and needs of participants are being met.
For more information
About the HIV Vaccine Trials Network: www.hvtn.org
About AIDS vaccine clinical trials: AIDS Clinical Trials Information Service, 1-800-TRIALS-A (USA only); www.clinicaltrials.gov
About AIDS vaccine clinical trials: AIDS Clinical Trials Information Service, 1-800-TRIALS-A (USA only); www.clinicaltrials.gov
