By J. E. Hinners, MD MPH
The Australian company Starpharma has put out an “HIV-killing condom” (otherwise called the “VivaGel condom”) that was first approved for Japanese marketing by Okamoto Industries earlier in March of this year. Later this last July, the Australian Therapeutic Goods Association (TGA) also awarded a Conformity Assessment Certification to the product, which is currently the only one of its kind on the market.
The condom is under the brand name LifeStyles Dual Protect and is currently being marketed in Australia by Ansell. One can only anticipate that marketing and sales approvals will be sought after in other countries as well, as international consumer research had found that >90% of condom-using survey participants indicated that they would buy such a product.
What is the VivaGel condom?
The VivaGel condom is a condom with the VivaGel lubricant–a microbicide lubricant that contains 0.5% astrodimer sodium (also referred to as VivaGel or previously SPL7013). One study reports that VivaGel inactivates 99.9% of HIV (human immunodeficiency virus) and other sexually transmitted diseases (herpes simplex virus and human papillomavirus). Another study indicates roughly a 96% inactivation of HIV and an 86-94% inactivation of herpes simplex virus.
The application of VivaGel on the condom is designed to add further protection against sexually transmitted diseases, as protection may be occasionally compromised in the event of condom breakage or incorrect application.
Tell me more about microbicides
Well, since you asked….
Microbicides may be formulated as gels, creams, or suppositories and contain compounds that help protect against sexually transmitted diseases when applied to the vagina or rectum (or to the condom, as in the case of the VivaGel condom). Some contain spermicidal activity, some don’t. Microbicides are still primarily undergoing efficacy and safety investigations.
One highly beneficial use of microbicides is for providing some degree of personal protection power to women, especially where the man’s use of a condom is not guaranteed or in the woman’s control.
Types of microbicides
There are different types of microbicides that each work by different mechanisms. Some types are more effective than others.
Past topical microbicide investigations have examined the efficacy of polyanions, surfactants, and acid buffering gels–all broad-spectrum antimicrobial agents that have tended to show contraceptive properties but did not effectively prevent HIV.
Much research now focuses on antiretroviral microbicides (namely, tenofavir 1% gel); however, this microbicide appears to only reduce HIV infection by 39%.
Additional research has also been ongoing for nanoscale dendrimer microbicides (such as the one in the VivaGel condom). VivaGel’s nanoscale dendrimers appear prevent infection by way of a highly charged polyvalent surface that causes attachment to the virus’s gp120 proteins, preventing the virus from attaching to the body’s cells. As mentioned earlier, HIV has been reported to be inactivated anywhere from 96–99% with VivaGel.
So what’s the drawback of VivaGel and the VivaGel condom?
Preliminary studies had indicated no significant negative effects on the vagina other than some cases of mild erythema (redness). However, one study by Cohen indicated a more frequent occurrence of mild epithelial irritation and inflammation; and another study by McGowan reported a higher frequency of similar types of mild vaginal effects. Irritated and inflamed vaginal tissue could potentially weaken the white blood cells’ ability to do their disease defense job, thereby increasing susceptibility to HIV.
Starpharma CEO Jackie Fairley, however, points out that the concentration of VivaGel in these studies was 3%, in contrast to Starpharma’s clinical trials with VivaGel concentrations of only 1% among a subject population exceeding 1,000 participants.
The future of the VivaGel condom…
…has yet to be determined, as there is the current question mark of mild adverse vaginal effects. It could be that the studies showing these effects are indeed reporting exaggerated effects, given the possibly important difference in the VivaGel concentration of the VivaGel condom.
If further evidence does, however, show that the VivaGel condom causes adverse vaginal effects, then perhaps its primary function will be directed more towards non-vaginal sex HIV prevention.
Time will tell.