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Herpevac Trial for Women

Study Overview & FAQs


It is estimated that one out of four adult American women has genital herpes, and this percentage is rising. Because there is no medication that eliminates the herpes virus, an investigational vaccine is being developed and researched to help stop transmission of genital herpes. ("Investigational" means the vaccine is currently being tested and is not yet approved for sale by the U.S. Food and Drug Administration.) This vaccine does not contain live virus and cannot cause herpes infection. It has passed preliminary testing for safety and effectiveness and is now in its final phase of clinical trials.

This clinical trial, the Herpevac Trial for Women, is testing the vaccine in women who have not been infected with herpes simplex virus (HSV), which causes cold sores and genital herpes. The trial, co-sponsored by the National Institute of Allergy and Infectious Diseases and GlaxoSmithKline Biologicals, will be conducted at more than 40 trial sites in the United States and Canada. Approximately 7,550 women will be enrolled and randomly assigned (by computer, similar to a coin flip) to receive either the candidate herpes vaccine or an investigational hepatitis A vaccine. Participants will receive three doses of either vaccine within the first six months of the trial and will be followed for a total of 20 months through periodic clinic visits and contacts.


What is known about the effectiveness of the herpes vaccine?
Among the 7,400 subjects in earlier studies, the vaccine was shown to decrease the risk of developing symptomatic HSV infection in women who were not previously infected with herpes simplex. For these women, the risk of contracting genital herpes and developing symptoms was reduced by about three quarters. The risk of developing antibodies to herpes (representing infection) was reduced by about 40%. Unfortunately, however, women who were already infected with herpes simplex virus type 1 (HSV-1), the usual cause of cold sores, did not benefit from the herpes vaccine in these earlier studies, and the vaccine was not effective in men. (Results were published in the New England Journal of Medicine in November 2002.)

Could the vaccine actually cause herpes?
No, the investigational herpes vaccine will not cause HSV infection. The vaccine formulation used in this trial contains no live or infectious virus. Instead, it uses only a specific fragment of a herpes virus protein that stimulates immune response.

For women who receive the herpes vaccine, the protective effects against genital herpes are promising. However, in previous trials the vaccine was not 100% effective. As a result, for all participants (regardless of whether they are given the herpes vaccine or the hepatitis A vaccine), there is a chance that HSV could be transmitted and cause symptoms if one is exposed to HSV during intimate contact with a person who has herpes.

What is known about the safety of the vaccines in this study?
The vaccines used in the Herpevac Trial for Women have been studied previously in thousands of individuals. Both vaccines have met safety requirements needed for larger clinical trials such as this one, which focus on further evaluating the vaccine's effectiveness in preventing disease.

The investigational herpes vaccine was studied in approximately 7,400 volunteers in previous Phase III trials and was generally well-tolerated. Non-serious side effects at the site of the injection associated with the herpes vaccine included soreness, redness, or swelling, usually lasting between 1-3 days. Other side effects noted were tiredness (fatigue), headache, general feeling of not feeling well, and less often, mild fever. These symptoms usually did not last more than 24 hours, nor did they prevent the volunteers' normal daily activities. There were only 9 reports of side effects that were considered by the investigators to be serious and related-or possibly related-to the herpes vaccine.

The investigational hepatitis A vaccine being used in this study has actually been given to millions of people. Based on a licensed hepatitis A vaccine, the vaccine utilized in this study is considered investigational because it will be given at a lower dose and in a smaller volume compared to the approved hepatitis A vaccine. The most common side effects associated with the vaccine included injection site soreness, redness, swelling or hardening, headache, fatigue, fever, not feeling well, loss of appetite and nausea.

Additional information on risks associated with the study can be found in the section titled Study Procedures and in the informed consent document that is provided to, and discussed with, potential study participants by study staff.

Why should a woman participate?
There are many benefits to volunteering to participate in a clinical trial. Participants gain access to new research developments before they are widely available and help others by contributing to medical research. Carefully conducted clinical trials, such as this one, are the fastest and safest way to find treatments that work in preventing or treating disease. The Herpevac Trial for Women is leading the way in the development of vaccine that may protect women against the risks associated with genital herpes. As such, it may be a major medical breakthrough that could help millions of people. Participants should carefully weigh the possible risks and benefits after discussions with study staff and after reading the informed consent in order to decide whether or not participating in a clinical trial is right for them.

Visit the "Links" section on the menu to the left for more information about participating in clinical trials.

Does the study pay participants?
Women who undergo screening to determine their eligibility to participate in the Herpevac Trial for Women will be compensated for time spent during this visit. Women who choose to enroll in the study will also receive compensation for the time taken by study visits. Compensation levels vary, depending on the rules of each local research institution.

Who is eligible to participate in the study?
The Herpevac Trial for Women is seeking healthy females between the ages of 18 and 30 who are negative for both HSV-1 and HSV-2 as determined by an accurate blood test for herpes, performed at the initial (screening) study visit.

All potential participants must sign an informed consent form at the first study visit.

Women will not qualify to participate in the study if any of the following apply:

  • They are pregnant or breastfeeding, or they are planning to become pregnant during the vaccination phase of the study (i.e., between months 0-8).

  • They are not in sufficiently good health as determined by the health care provider (investigator or the staff that participates in the study).

  • They are planning to receive a vaccine that is not allowed as part of this study.

  • They are, or have previously been, infected with HSV-1 or HSV-2.

  • They have a history of allergic disease or reactions likely to be made worse by any component of the vaccine.

  • They have abnormal immune function caused by disease (including HIV infection) or by medications (including high doses of corticosteroids).

  • They are not likely to be available to return for study visits for the next 20 months.

How do women who seem to meet the criteria to participate know that they don't already have HSV?
Women who are interested in volunteering for the clinical trial will receive a very accurate blood test that looks for antibodies (the immune system's response) to both HSV-1 and HSV-2. Participants can obtain results of the test by calling the Herpevac Trial for Women Test Result Hotline two weeks after having the blood drawn. In addition to providing results, this Hotline has trained counselors to answer questions about the test and test results so that women who test positive for herpes can understand what this means to them.

It is important to keep in mind that only a small percentage of women will be eligible to participate in the trial, because of the wide prevalence of both oral and genital herpes. It is estimated that 66% of adults have HSV-1 and an estimated 25% of women have HSV-2. Therefore, it is expected that most women screened for the study will test positive for HSV-1, HSV-2, or both.

What about confidentiality?
Protecting the privacy of volunteers is a high priority for study staff. At the time of enrollment, women who are eligible to participate in the Herpevac Trial will receive a consent form detailing specific confidentiality requirements. This consent form will be thoroughly explained by the study staff before the volunteer is asked to sign. Throughout the study every effort will be made to keep personal information confidential. Even in the event that the findings of the study are published, only collective data will be used and participants will not be identified by name.

What kinds of things will participants be required to do during the study?
Eligible females who become enrolled in the study will be randomly selected to receive either the investigational herpes vaccine or the investigational hepatitis A vaccine. To ensure the study's reliability, neither the participant nor the study doctor will know which vaccine the participant receives.

Throughout the study there are a total of eight scheduled study visits. At three of the visits the health care provider will administer the vaccine. The injections will be given into the muscle of the upper arm.

Blood will be collected at seven of the scheduled visits to test for herpes infection and to test for antibody and cellular immune responses to the vaccine. Also, throughout the study, participants will be asked to look for and record any signs and/or symptoms of herpes. Because the study is examining how well immunization with the herpes vaccine can protect women against HSV if exposed to the virus through a sexual partner, all study participants will be assessed for the development of herpes symptoms and for antibodies that would represent a herpes infection. Participants who experience possible herpes symptoms will be encouraged to visit their study site to have the symptomatic area examined and a herpes culture performed.

Six times throughout the study, participants will be asked to complete, in private, a confidential questionnaire about condom and contraceptive use and sexual history.

I am interested in participating in the Herpevac Trial for Women! How do I become involved?
Click on the "Study Sites" link on the menu to the left to see if there is a study site in your area and to find out how to contact them.

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