Condoms and the Prevention of AIDS

Steven D Pinkerton & Paul R Abramson. American Scientist. Volume 85, Issue 4. Jul/Aug 1997.

Among contraceptives, condoms merit special attention for their performance in a dual role. While preventing pregnancies, they also protect their users against all common sexually transmitted diseases, or STDs—even those transmitted by viruses. For that reason, publichealth experts recognize that condoms offer the best defense available against the growing international AIDS epidemic-available, but not always utilized.

AIDS killed an estimated 1.5 million people in 1996, according to the World Health Organization (WHO). In some hard-hit regions, such as sub-Saharan Africa, the epidemic has decimated many communities. In America, each case of AIDS costs society about $100,000 in lifetime expenditures for medical care. That sum grows to several million dollars when one factors in lost productivity due to premature debility and death. The case for widespread use of condoms, then, could begin with simple cost effectiveness. In comparison to the huge cost of the disease they combat, condoms cost pennies to manufacture and about a dollar to purchase, even at greatly marked-up retail prices.

How reliably do they save lives? Our mathematical models show that the consistent use of condoms (protected sex) can reduce the risk of contracting AIDS by a substantial margin. For example, an uninfected individual who has protected sex with an infected partner can reduce the probability that he or she will contract AIDS by about a factor of 10. Our results show that consistent condom use is even more effective at preventing AIDS than is monogamy We found that an individual who engages in protected sex with numerous partners has a much smaller chance of contracting AIDS than does a monogamous individual who does not use condoms.

Although its devastation is now at the forefront of public consciousness, AIDS is just the latest in a long line of sexually transmitted disease epidemics. Before AIDS there was “incurable” genital herpes, and before that, syphilis. As Philippe Ricord, the famous 19th-century syphilographer, once remarked, “in the beginning, God created the heavens, the earth, man and venereal diseases.” It is unlikely that AIDS will be the last catastrophic STD. Because it is a barrier to such diseases, the condom is thus a device for the ages.

In this article, we hope to trace the history of the condom and sexually transmitted disease and explain why condoms are tremendously important now. It is clear that for the time being, condoms have a tremendous potential for disease control that is not fully exploited. Therefore we offer some suggestions as to how we should go about making them more widely used.

A Brief History of the Condom

Penile sheaths were worn by our early human ancestors, as evidenced by artwork from ancient Egypt and the prehistoric cave paintings of Les Combarelles, France. Although the purpose of these ancient sheaths has not been determined, perhaps they served as decoration or provided protection for the male anatomy. Even today, a similar protective service is provided by a strategically placed gourd or shell in tribal societies stretching from the Amazon jungle to the highlands of Papua New Guinea.

The first reliable description of a penile sheath used as protection from “venereal diseases” appears in the 1564 book De Morbo Gallico, by the Italian doctor Gabriello Falloppio, who is best known for his discovery of the oviducts that bear his name. Falloppio’s book, the title of which translates to “The French Disease,” describes a linen sheath used for preventing transmission of syphilis, which was then reaching epidemic proportions in Western Europe. In reporting the results of perhaps the first clinical trial of condom efficacy, Falloppio proclaimed: “I tried the experiment [the use of condoms] on 1,100 men, and I call immortal God to witness that not one of them was infected.” By all accounts, however, linen sheaths remained a little-used prophylactic, or preventive, against disease.

The popularity of condoms among upperclass gentlemen was greatly enhanced with the development of the “natural” or “skin” condom made from the caeca, or intestinal sacs, of sheep and lambs in the 17th century. Legend has it that an early proponent of their use was a British Army surgeon named Dr John Condom (or Condon, or Quondam, or various other spellings hence the modern appellation. But Condom is also the name of a small town in France. Thus some historians have suggested that the word “condom” derives from the village butcher who perfected the use of animal-membrane prophylactics. Whatever the origin of the term, the ability of natural sheaths to protect against sexually transmitted diseases (and potential bastard offspring) was well known and widely appreciated among the upper crust of European society by the end of the 17th century

The next major advancement in condom technology occurred in the mid-19th century, when Charles Goodyear discovered a novel means of curing rubber called vulcanization. This process permitted the mass production of condoms that were less expensive and better fitting than their sheep-gut counterparts. But rubber condoms remained relatively expensive and beyond the reach of the “common man.” They also provided protection against STDs and pregnancy that was inferior to skin condoms because the rubber contained microscopic holes. For these and other reasons-most notably, restrictions on the advertising and distribution of condoms in the U.S. and elsewhere-the market remained small for both rubber and natural condoms into the 20th century.

Although rubber condoms had been manufactured in the United States since 1888, the industry remained disorganized until Merrill Youngs entered the business in 1916. Prior to then, condoms with colorful names (Man-OWar, Vikings, Hercules) and packaging (barebreasted mermaids) were hawked like peanuts by bell hops, shoe shiners, peddlers and others. Condom sellers occasionally were of dubious character, and the reliability of their wares was questionable. Youngs changed all that by creating a company specifically aimed at producing and distributing reliable condoms.

Youngs quickly recognized that condoms had two main problems: an inconsistent product and poor distribution. To solve the latter, he turned to the retail pharmacists, who could provide the condom with respectability and a pervasive outlet. For the condom itself, Youngs promised a reliable and inexpensive product with an identifiable trademark. Thus, in 1926, he unveiled the first “Trojan” brand condoms. Trojans proved profitable both for Youngs and the drugstores, which enjoyed a 100-percent retail markup. Together, the manufacturer and distributors successfully lobbied against the sale of condoms in all other venues-an effort that resulted in “druggist only” laws in 20 states. Although this lobbying was ostensibly aimed at illicit condoms and their shady salespeople, it created a strong partnership between the condom industry and retail pharmacies that endures to this day.

The reliability of condoms also was improved through testing by the federal government. Although modern condoms are quite reliable, this has not always been the case. In 1938, the U.S. Food and Drug Administration began spotchecking condoms. The results were appalling. As the Consumers Union reported: “Sixty per cent of the total [condoms] sold have been defective in some way which might cause a hole or a tear in actual use. Careful commercial testing appears to be rare. For safety, the consumer himself should test the condoms he buys.” That, of course, was a rather alarming message for consumers. But much has changed since then to ensure the reliability of this product. Condoms are now strength-tested by inflating them to 1-1/2 cubic feet, about the size of a watermelon. They also are tested individually with an electric current, which passes through a condom only if it has an imperfection.

A number of other factors led to wider acceptance of the condom in the early to mid-20th century, including advances in both manufacturing and distribution. But the single most important factor was the invention of latex, which resulted in a stronger, safer and more comfortable condom. Unlike their rubber predecessors, latex condoms have no seam and can be easily shaped, permitting the addition of reservoir tips and textured ribs to enhance pleasure.

The acceptability of condoms also was increased by the pragmatic approach to the prevention of venereal diseases (primarily gonorrhea and syphilis) adopted by the American and European armed forces in World War II. Both Allied and Axis forces apparently learned from the failure of the “moral training” employed to prevent the widespread infection among soldiers during World War I, when venereal diseases and their lengthy preantibiotic treatments produced a significant drain of needed manpower. Other factors that led to increased condom use include the promotion of birth control as “family planning” and the perception among some policy makers that condom use among the lower classes could benefit society-by reducing the welfare rolls and supposedly helping maintain the integrity of the genetic pool. Together, these factors resulted in the relaxation of the Comstock laws, which had limited the advertisement and distribution of condoms in the United States since 1873.

Although the introduction of the Pill in the 1960s led to a reduction in U.S. condom sales for a while, condoms remained the contraceptive of choice for millions of American couples throughout the 1960s and 1970s. More recently, the herpes scare of the 1980s and the current HIV/AIDS epidemic have driven worldwide condom sales to all-time highs. Still, the continued prevalence of STDs indicates that only a fraction of those who could benefit from the protection of condoms do so.

Condoms in the War on AIDS

In 1996, 22.6 million people were infected with HIV, according to WHO figures. The epidemic is growing by more than 3 million cases a year. Predictions of the pandemic suggest that by the year 2000 between 40 and 110 million people will be infected with the virus. In most cases, HIV will have been acquired heterosexually, the result of sexual intercourse between a man and a woman. In the Western world, including the United States, Europe and Australia, homosexual intercourse now dominates as the leading cause of HIV transmission, but heterosexual cases account for a growing proportion of the total number of new infections each year. With as many as 20 million AIDS-related deaths projected by the year 2000, effective action must be initiated now to halt the further, tragic dissemination of HIV.

People generally are reluctant to give up sex. As one World War II medical officer remarked, “It is difficult to make the sex act unpopular.” Thus, practically speaking, the most promising strategies for controlling the spread of sexually transmitted HIV are to educate people about the risks of unprotected sex and encourage them to use condoms or substitute nonpenetrative sexual activities whenever possible.

But just what are these risks, and how effective are condoms at reducing them? To examine these issues rigorously, we have developed several models that quantitatively examine the extent to which condoms can prevent the spread of HIV. These models can be applied at both the personal level (how much do condoms reduce an individual’s risk of becoming infected?) and the societal level (how does condom usage shape the course of the epidemic?). They also let us compare the effectiveness of condoms in reducing the risk of infection and the epidemic potential of HIV with other preventive strategies, such as reducing the number of partners with whom one has sex.

Our basic model treats each act of sexual intercourse with an HIV-infected partner as an independent Bernoulli trial-much like the flip of a coin, a very badly weighted coin for which the probability of heads (HtV transmission) is much smaller than the probability of tails (no transmission). Thus, for each sexual contact there is a very small probability that HIV will be transmitted, and a much greater probability that it won’t. And, like repeated tosses of a weighted coin, the more acts of intercourse that take place, the greater the cumulative probability that heads will come up, or HIV will be transmitted.

The probability of HIV being passed from an infected person to his or her partner from a single unprotected contact depends on a number of factors. These include the particular sexual act engaged in (such as vaginal or anal intercourse), the respective roles assumed by the participants (receptive or insertive) and the presence of facilitating cofactors such as other STDs. Evidence also suggests that the stage of disease of the infected partner is an important factor in the risk of transmission. It appears that infectiousness is greater in the early stages of HIV disease and again in the later stages, when symptoms associated with AIDS often appear.

In our models, we lump together the insertive and receptive roles and assume a constant infectivity of one chance in 1,000 for unprotected penile-vaginal intercourse. This estimate is intended for illustration only. For condom-protected intercourse, of course, the risk of transmission is much less. Although condoms do not provide perfect protection, our recent analysis of the available data on condom effectiveness suggests that condoms can reduce the per-contact risk of HIV transmission by at least 90 to 95 percent. When used consistently and correctly, the effectiveness of condoms is probably much greater than these figures imply-as much as 99.5 percent. Nevertheless, we use a conservative estimate of 90-percent effectiveness to illustrate our points.

Under these assumptions, the probability of transmission is either one in 1,000 or one in 10,000, respectively, for a single act of unprotected or condom-protected intercourse with an infected partner. But what about the risk from repeated exposure? According to our model, the probability of HIV transmission rises rapidly (in an essentially linear fashion) with the number of contacts, reaching about one in 10 after 100 acts of unprotected intercourse with an infected partner. The consistent (100 percent) use of condoms can reduce the risk by about a factor of 10, but it remains relatively high nonetheless.

Of course, this model applies only to sex with an infected partner and therefore does not accurately reflect the risk faced by most sexually active people, who do not necessarily know whether or not their partner is infected. For sexual contacts with a partner of unknown HIV status, we incorporated an additional factor into our model to reflect this uncertainty Clearly, it is riskier to have sex with a partner drawn randomly from a population with a high prevalence of HIV infection than from one in which the prevalence is low. (Our model assumes that this probability is the same as the prevalence of HIV infection in the pool from which potential sexual partners are selected.)

Because the prevalence of HIV infection is relatively low in the “general population” (e.g., five in 1,000), the overall risk for most Americans is fairly small, even if condoms aren’t used. The cumulative probability after 100 contacts with a randomly selected partner is about one in 2,000; condom use drops it to about one in 20,000. However, as the number of sexual contacts and partners increases, so does the risk of becoming infected with HIV. The two extreme cases are monogamy, in which all contacts are with a single partner, and promiscuity, in which each contact is with a different partner.

For years, the U.S. government has touted monogamy as the best way to avoid becoming infected with HIV, short of sexual abstinence. More generally, in the early years of the pandemic many authorities recommended limiting the number of sexual partners as an effective strategy for avoiding HIV. Surprisingly, our models show that unless the HIV status of each partner is positively known, the number of partners with whom one has sex is not nearly as important as using condoms consistently.

This is illustrated in Figure 6, which shows the cumulative probability of infection under two extreme scenarios: either 100 unprotected monogamous contacts, or 100 “one-night stands” in which condoms are used consistently. As this figure shows, unprotected monogamy (with a partner of unknown HIV status) is actually riskier than condom-protected promiscuity under these conditions! (Indeed, the lowest-risk behavior is always monogamy with consistent condom use. But the curves for monogamy with 100-percent condom use and for promiscuity with 100-percent condom use are indistinguishable at the scale of this figure.) We also have modified our models to examine the impact of behavioral changes on HIV risk for the population as a whole, rather than for a particular individual. One of the key parameters of infectious-disease epidemiology is a quantity known as the reproductive rate of infection, which equals the average number of secondary infections that arise for each primary infection early in an epidemic.

The reproductive rate must exceed unity to sustain an epidemic. That is, each infected person must propagate the virus to at least one other person on average. If the reproductive rate falls below unity, then the virus will eventually die out with a rapidity determined by the relative magnitude of the reproductive rate. (This model assumes a measure of homogeneity of sexual behavior that is unlikely to be present in most populations. Nevertheless, it provides a useful conceptual tool for assessing the relative effectiveness of different HIV-prevention strategies.)

As with the models discussed earlier, our research shows that in most cases the reproductive rate of infection is reduced more through the consistent use of condoms than by limiting the number of sexual partners. Thus, if the choice is between monogamy without condoms and a series of one-night stands with condoms, epidemiologic considerations would favor the latter as less risky behavior.

Moreover, provided that the infectivity is low, the reduction in risk afforded by condoms is directly proportional to the amount of time they are used. That is, if consistent use results in a 90-percent reduction in the probability of transmission, then using them half the time will reduce the risk of transmission by about 45 percent. Although maximum effectiveness demands that condoms be used for every act of intercourse, any amount of condom use helps decrease the epidemic potential of HIV. It follows that even small increases in condom usage rates could exert a profound impact on the future course of the pandemic.

Condoms and Future STDs

As our mathematical models demonstrate, condoms provide an effective impediment to the sexual transmission of HIV But AIDS is just one of many STDs. Sexually transmitted diseases, in one form or another, are here to stay. Millions of lives were destroyed by the scourge of virulent, epidemic syphilis in the 16th and 18th centuries. Yet syphilis has endured and even flourished into modern times-despite its legacy of pain, death, disfigurement and debility; despite countless educational campaigns warning people of its dangers; and despite the availability of preventive measures and modern antibiotic cures. The history of syphilis thus provides a valuable and instructive analogy to the current AIDS epidemic (Abramson and Pinkerton 1995).

More recently, gonorrhea, herpes and endemic forms of syphilis have emerged as significant public-health threats. Other STDs also are proliferating among sexually active Americans, among whom as many as half may be infected with chlamydia. Moreover, recent clinical and epidemiological evidence suggests that cervical cancer is in many cases caused by a sexually transmitted virus (HPV, or human papillomavirus).

The HIV/AIDS epidemic, of course, provides further testimony to the tenacity of STDs. Although the biological origin of HIV and related retroviruses remains a mystery, the epidemic’s sociocultural origins are known to include the sexual revolution of the past decades, the continuing expansion of the “global village” and the persistence of poverty among segments of society. As humankind continues to encroach on nature, it will undoubtedly encounter new pathogens, some of which are likely to be of the sexually transmitted variety. Furthermore, even comparatively benign microorganisms can evolve toward increased virulence under suitable conditions-as may have happened with HIV Because condoms provide protection against all sexually transmitted pathogens, the widespread adoption of condoms as a normal accompaniment of sexual relations could prevent epidemics of such diseases before they begin.

There is yet another way in which widespread condom use could help prevent future epidemics, in addition to simply blocking transmission of infectious pathogens. In theory, it is possible to alter a microorganism’s evolutionary trajectory toward decreased virulence by reducing the ease with which it is transmitted from one host to another. The key to this theory is the observation that a microorganism will quickly become extinct if it kills its host before the host has successfully passed the microorganism to another person. If the natural mutation rate of the microorganism is high (as with HIV), then evolutionary pressures will select for strains that do not incapacitate the host so quickly and so completely that further propagation of the microorganism is severely impeded. For example, human beings clearly are not the primary host for the dreaded African Ebola virus, which rapidly liquefies the internal organs of most people it infects. Ebola is such an efficient killer of people that it soon runs out of victims and must return to its natural reservoir species, which has yet to be identified.

Because condoms reduce the probability that a pathogen will pass from one host to another, a greater number of attempts are needed, on average, to ensure at least one “successful” transmission. This means that the host must be healthy enough to have sex. A host who lives a longer, healthier life increases the pathogen’s odds of genetic survival. In sum, by reducing the chances of propagation, condoms exert a positive selection pressure that favors less-virulent strains of sexually transmitted microorganisms. This theory is largely speculative at present. However, emerging evidence suggests that HIV may indeed be evolving toward decreased virulence, although it is not yet clear whether this is due to increased condom usage.

Building a Better Condom

The importance of condoms in the fight against STDs is readily apparent, whether one focuses on the past, the present or the future. But condoms clearly have not been used as widely as they must be to significantly slow the spread of infection. One solution is the greater promotion of condoms through advertising, education and public-awareness campaigns. We believe another necessary step is to improve condoms-making them more user-friendly, sexy and pleasurable.

As we argue in our book, With Pleasure: Thoughts on the Nature of Human Sexuality, pleasure is a primary motive for human sexual contact. Thus people will shun anything-including condoms-that interferes with the experience of pleasure. Indeed, many surveys have blamed decreased pleasure as a main reason why men dislike wearing condoms. Other factors include perceptions that condoms interrupt the flow of the sexual encounter and introduce an artificial element into a natural act. Although condoms may never feel as good to the wearer as unprotected sex, it is likely that condoms would be embraced if the diminution in pleasure were small enough. What is needed, we believe, is a better condom. Condoms should be made thinner, stronger, less likely to slip or break, and more comfortable. Novel shapes and lubricants should be developed that increase sensual pleasure for both the wearer and his partner.

Condom technology (“condomology”) has advanced little for quite some time; progress has, in fact, been virtually nonexistent since the advent of the latex condom. Basic manufacturing and marketing procedures have changed little in the past few decades. Perhaps this stagnation can be blamed on the Pill, that wonderful little pharmaceutical that ushered in the Sexual Revolution-and consequently relegated the condom to a secondary contraceptive role, at least among adults.

An improved condom should interfere as little as possible with the pleasurable aspects of sex. The subjective experience of sexual pleasure is a multifaceted phenomenon with physical, emotional and psychological underpinnings, all of which must be addressed. Obviously, the primary objective of condomologists everywhere should be to make protected sex feel as good as or better than sex au naturel. Although penises come in but one basic shape, condoms need not be so restricted. In addition to designing novelshaped condoms that maximize tactile pleasure, condoms should be developed that please other senses as well. Scented and flavored condoms can enhance the sexual experience, as can visually appealing colors, textures and so on.

Two recent developments in condomology deserve special mention. First, a polyurethane condom has been introduced in Britain and the United States. Because they are made of plastic, polyurethane condoms provide an important option for people who are allergic to latex-as much as 5 percent of the population. They also are safe for use with oil-based lubricants, such as Vaseline, which can severely weaken latex condoms. The manufacturer of these condoms claims that their product is thinner and “more sensitive” than latex counterparts, but no weaker. However, plastic condoms have not yet undergone rigorous testing, and thus have not received Food and Drug Administration approval as a preventive against STDs.

The second important condomological advance is the development of a “female condom,” also made of polyurethane, that lines the vagina rather than being worn on the penis. Although functionally similar to the “male” condom, the female condom has been hailed as a true advance because it places control in the hands of the woman. Indeed, a woman is often at greater risk of becoming infected with an STD than is her male partner-and she is certainly more likely to become pregnant. The female condom allows women to protect themselves, even with limited cooperation from their male partners. Available research indicates that it is both safe and reliable. Moreover, studies suggest that once they are accustomed to the female condom, many women and men find it quite acceptable. Some men enjoy being freed from the responsibility of wearing condoms. A reusable female condom might also be feasible, as might a similar device or “pouch” for use in anal intercourse.

The Marketing Challenge

Of course, once a better condom has been developed, it will need to be marketed effectively. This, paradoxically, may prove to be a more formidable obstacle than enhancing the condom itself. Marketing involves a variety of issues, including pricing, promotion, accessibility and supply. If the new, improved condom is expensive, its utility and global coverage will be severely reduced. Price is relevant to the individual consumer in Western countries, as well as to the distribution of free condoms in developing countries. Obviously, if condoms are expensive, people will be less likely to buy or use them regularly.

In the developing world, where health-care budgets are often in the tens of dollars per capita, the free-market price of a yearly supply of condoms can be prohibitive. But it may be in everybody’s best interests to supply free condoms to those who cannot otherwise afford them, because overpopulation or an STD epidemic in one country invariably affects all countries. Incentives should be devised to encourage governmental and private-sector cooperation in this strategy. In addition, the development of an effective, reusable condom should be a top priority for condomology research. In any case, a necessary proviso for condom improvement is: Keep it cheap.

One important way to keep condoms inexpensive is to mass-produce them at local factories throughout the world. In 1994 alone, 450 million condoms were sold in the United States. Demand for a better, improved condom would obviously increase this number. To ensure that supply meets demand, global production would need to be greatly expanded, preferably with numerous local manufacturing plants employing indigenous labor.

Once developed, the new improved condom must be successfully promoted. Advertising campaigns need to be devised that effectively target the relevant populations, such as heterosexuals, gays, adolescents, truck drivers and brothel patrons. In Africa, Latin America and Asia, condoms have been promoted through social marketing campaigns, which use commercial marketing techniques and existing commercial outlets to distribute donated or subsidized products at reduced costs. In Africa, for example, several “brands” of condoms are available at retail prices that are often below the manufacturer’s cost. These brands are vigorously promoted using local mass-media outlets, including print, radio, television, posters and special events.

Some studies suggest that such promotional efforts may be paying off. For example, one recent study documented a decline in the rate of HIV infections among young soldiers in Thailand, coinciding with a vigorous campaign to promote condom use in that country The incidence of HIV infection among young soldiers in the Royal Thai Army dropped from 12.5 percent in 1993 to 6.7 percent in 1995, according to the 1996 study by investigators at Chiang Mai University in Thailand and The Johns Hopkins University.

In the United States, the promotion of condoms is now severely impeded by proscriptions against condom advertising on television, and to a lesser extent in other media. For example, the federally funded Centers for Disease Control and Prevention once had hoped to air a series of radio ads that promoted condom use. One ad would have featured Whoopi Goldberg proclaiming, “Ain’t making no Whoopi without a condom,” and another had George Burns confessing, “I first started using condoms when I was a young man. I think I was 72.” The ads were scrapped because they were deemed “too explicit” for the American public.

U.S. Rep. Henry Waxman (D-Calif.) took the television networks to task in 1987 for their implicit prohibition on condom advertising in his testimony before a Senate committee: “Information regarding condoms and AIDS has been restricted by the largest and most effective communications medium in America-television. The routine promotion of condoms through advertising has been stopped by networks who are so hypocritically priggish that they refuse to describe disease control as they promote disease transmission. While portraying thousands of sexual encounters each year in programming, and while marketing thousands of products using sex appeal, television is unwilling to give the life saving information about safe sex and condoms … The networks’ continued refusal to allow condom advertising is media malpractice.” (Treichler 1996)

Similarly, although condom advertisements occasionally appear in venues such as GQ and Playboy and on MTV, this coverage is anemic in comparison to that achieved by multimilliondollar advertising campaigns for products such as soft drinks, sneakers, automobiles and computers. It is time for condom use to be normalized, and for condoms to be promoted and advertised like any other consumer product.

Moreover, the inextricable connection between condoms and sex should be capitalized on, whenever possible. Advertisements should emphasize the pleasures of safe sex, rather than just fear of disease. An imaginative ad campaign for Kama Sutra condoms in India featured one of the country’s most famous female actresses in a steamy pictorial for Debonnaire magazine, the Bombay-based equivalent of Playboy. Several cable-television commercials also were developed for Kama Sutra. In one sexy spot-deemed too risque for the government-controlled broadcast network-a young couple is shown sitting on a bed playing chess. The woman sweeps the pieces off the board and mouths the word “check,” to which her partner mouths replies “mate.” The tag line then appears: Kama Sutra, “for the pleasure of making love.” As these advertisements cleverly remind us, sex sells. That being the case, let sex be used to sell condoms, and thereby to make it safer.

Conclusion

We hope our discussion has convinced readers of the past and present utility of the condom as an epidemiological warrior, as well as the need for improving this venerable device. Could a condom really be developed that feels as good as, or better than, “the real thing?” We don’t know, largely because no one has ever devoted the resources necessary to tackle this problem. Our models of HIV transmission highlight the importance of condom use in the fight against AIDS. Our research also suggests that even very small improvements, in either the condom itself or in condom-usage rates, could have a profound impact on the future course of the pandemic.

Hundreds of millions of dollars have been spent in the effort to develop a preventive vaccine against HIV, yet the condom has been all but forgotten. Research leading to the development of an HIV vaccine must remain a top priority. However, it could take years to perfect such a vaccine. And, even with a vaccine, substantial questions would remain. Would the vaccine work against the numerous strains of HIV now in existence and the many more likely to arise in the future? How effective would the HIV vaccine be, as many existing vaccines are less than 100 percent effective? How expensive would the vaccine be to produce? Would society be willing to pay for the tremendous costs of vaccinating people around the world?

Similar questions surround the development of drugs for treating AIDS. Very encouraging results have recently been obtained in preliminary trials of anti-HIV drug regimens. This research has fueled optimism that eventually HIV will be transformed into a chronic yet manageable disease. Unfortunately, these drug therapies are very expensive, costing from $10,000 to $20,000 per year. Therefore, they are out of reach of the 90 percent of the world’s HIV-infected people, who live in developing countries. In America also, expensive drug therapies are likely to be restricted to those with progressive private insurance plans.

Condoms have some significant advantages compared with vaccines and other biomedical treatments. Notably, as mentioned above, condoms are not disease-specific; they are effective against all known STDs. As any investment counselor will tell you, diversification is the key to long-term success and stability. This same advice can be applied to the battle against AIDS and other STDs-arguing for a much more aggressive condom research-and-development program, to complement the search for biomedical treatments and cures. Even in the presence of such “magic bullets,” the old adage remains true: An ounce of prevention is still worth a pound of cure. And condoms, as the most effective form of HIV prevention available, are worth their weight in gold.