Even if they're not perfect, correctly and consistently using condoms will decrease the risk of getting AIDs. From a public health perspective, this would be a good thing to reduce transmission rates in Africa.
I take it from your screen name you've got some scientific perspective on this question. Is it correct to say that even with correct and consistent use the device itself will have a certain level of failure?
If the answer is affirmative, then that will be the insurmountable hurdle for any examination from the ethical perspective of the Church. There will be, in fact, no "lesser evil" to consider. Only the greater evil of transmission of a potentially fatal disease delayed. (Unless you have the statistical bad luck to have your first use be a failure. Then there will be no delay.)
There is a way to reduce the rate of AIDS transmission to virtual zero: abstinence outside of marriage. This is what the Church teaches. Any sideline allowing condoms where abstinence is the moral answer would be a moral wrong and the Church is not going to teach that.
Now, inlike fornication, sex inside a marriage is good. This is why it is proper for the Church to examine the use of condoms in this narrow case, where sex itself would have been salutary but for the AIDS infection of one spouse. Whichever way the Church goes in that narrow case is not going to have any implication to the broad condemnation of contraception in any other case, even for the purposes of AIDS prevention.
"The infected spouse who wears a condom, and then goes about a "normal" sex life might as well take a shotgun to their "beloved's" head. <[> "Condoms have efficacy rates of about 95% in preventing pregnancy, but much lower in preventing HIV. And studies suggest only 50% of those who use condoms do so faithfully and correctly. Still, suppose the efficacy rate for preventing HIV transmission was 99%, including 100% "success rate" in properly wearing the condom. What would that mean?
"Well, for someone having several one-night stands and very-short-term relationships, that'd probably work. The condom would allow a person to have 100 times more sex partners with the same chance of catching AIDS as someone who didn't. Again, of course, condoms are not nearly this effective, but we're just being hypothetical.
"Now, suppose someone has a perfectly monogamous relationship with an HIV-infected spouse. Maybe they have intercourse maybe four times a month... hardly an excessive sex life! But here's the problem: Every instance of intercourse is another chance to become infected. So in just one year, there is a FORTY PERCENT CHANCE (.99^100) that the HIV+ person will expose their spouse to AIDS. And that's with 99% effectiveness for the condom, there is a 99.99% chance that the spouse will become exposed to AIDS. (Mrs. Don-o added emphasis/)
"And it's really worse than that. Not only are condoms WAAAAAAYYYYY less than 99% effective, but, believe it or not, monogamous sex with an HIV+ person is WORSE than promiscuous sex with many HIV+ people:
"The truth is that exposure does not mean that a person contracts the AIDS virus. But repeated sex with the same person means that the same regions experience repeated wear and tear. OK, it's an ugly choice of words, but it's the truth. And, well, it's the places that experience wear and tear that are where AIDS transmissions are most likely to occur."
Well stated, dangus. Return volley, retMD?