Center News

Proof in packaging

Virologist Anna Wald's research shows herpes risk cut in half for consistent condom users, lends substance to debate over labeling

Jan. 5, 2006
Dr. Anna Wald in office

Dr. Anna Wald's research is among the first pieces of scientific evidence to show that regular condom use can prevent the spread of genital herpes, a sexually transmitted disease affecting more than one in five Americans. She believes condom labels should reflect their now-proven effectiveness.

Photo by Todd McNaught

Sometimes fine print does more than make readers squint. Occasionally, it launches another round in the American culture wars. And every so often it prompts research, as in the case of Dr. Anna Wald's studies on herpes and condom use.

Despite intuitive understanding that condoms prevent the spread of sexually transmitted diseases, data to support that assumption has been lacking. Proposed condom labeling reflecting the absence of research has prompted many scientists to spring into action with evidence to support condom effectiveness, including Wald.

Wald's research, published in the Nov. 15 issue of Annals of Internal Medicine, found consistent use of condoms is associated with lower rates of genital-herpes infection. It is one of the first strong pieces of evidence to show that regular condom use protects both men and women from acquiring or transmitting genital herpes, a condition affecting more than one in five Americans.

Wald, an attending physician at the Seattle Cancer Care Alliance and director of the University of Washington Virology Research Clinic, said her work lends a voice of science to an ongoing battle over condom labeling.

"This area of research is so important because there's a push right now at the Food and Drug Administration (FDA) to put labels on condoms listing their limitations and to really imply that their use is not effective," Wald said, referring to a 2000 congressional mandate for NIH to produce evidence as to whether or not condoms work. At that time, there wasn't enough data to support claims of effectiveness.

"The way this was translated in the media was not, 'We don't have evidence that condoms work' — instead, the message was, 'Condoms don't work,'" Wald said. "So during the last five years, a lot of people, including our group, have been very concerned with generating evidence to support condom effectiveness. That evidence has now been produced for several sexually transmitted diseases, and in fact, condoms do work."

Wald's research is an extension of a vaccine-candidate study for herpes simplex virus-2 (HSV-2) led by Dr. Larry Corey, one of the paper's co-authors and head of the Center's Program in Infectious Disease. HSV-2 is the main cause of genital herpes. While the trial vaccine was ineffective, the data offered Wald and colleagues an opportunity to look at other risk factors for HSV-2 acquisition.

Of the 1,843 high-risk participants followed at numerous sexually transmitted disease clinics (including one in Seattle), 118 (6.4 percent) became infected with HSV-2 over an 18-month period. Participants who reported more frequent use of condoms were at lower risk for acquiring HSV-2 than those who used condoms less frequently. While the protection was not absolute, risk decreased by about 50 percent for both genders. Greater numbers of African-American, younger and more sexually active participants acquired HSV-2.

An earlier parallel study of monogamous couples conducted by Wald and colleagues showed women are protected by condom use from acquiring genital herpes.

No significant association between condom use and infection with herpes simplex virus-1 (HSV-1) was found. HSV-1, the most common form of herpes, usually infects the mouth and lips, causing sores known as fever blisters or cold sores. HSV-1 can also cause genital sores. Most HSV-1 acquisition occurs from oral-genital contact, where condoms are less likely to be used.

Proposed condom labels

Currently, the FDA requires condom boxes and packets to state: "If used properly, latex condoms will help to reduce risk of transmission of HIV infection (AIDS) and many other sexually transmitted diseases."

The draft guidelines, issued in November for a 90-day public-comment period, mandate that within 12 months of final approval, all labels contain several new warnings, including this one: "When used correctly every time you have sex, latex condoms greatly reduce, but do not eliminate, the risk of pregnancy and the risk of catching or spreading HIV, the virus that causes AIDS." Previously, the FDA warning labels on condoms warned only of allergic reactions to latex.

Wald feels the proposed labels are designed to discourage condom use and encourage abstinence. I hope that our paper fits into a scientific response to this issue," she said.

Condom cons

Some groups contend that unwarranted reliance on condoms encourages risky sexual choices and can contribute to the spread of disease. However, many public-health groups worry that adding caveats to condom labels could discourage their use and thus increase the likelihood of unprotected sex.

According to the National Institutes of Health, condoms are impervious to the smallest viruses and only break or slip off 1 percent to 2 percent of the time. Latex condoms reduce the chance of pregnancy over a one-year period to 3 percent, compared to 85 percent without birth control. Likewise, correct and consistent condom use cuts risk of HIV infection by 80 percent to 95 percent.

Wald is currently doing further research on herpes and condoms. She has obtained data sets from other similar studies to do a meta-analysis of condom use and acquisition of HSV-2.

While the verdict on condom labeling is still out, Wald is pleased to add the facts from her research to the discussion. "It's nice when scientific evidence can support intuitive findings," she said. "There's been a lot of work to demonstrate that our sense of what works is actually true. Pretty consistently, the studies have supported condom effectiveness."

Fred Hutchinson Cancer Research Center is a world leader in research to prevent, detect and treat cancer and other life-threatening diseases.