Atlanta ? Nearly a million Americans now have the AIDS virus, and the nation’s ability to keep others from becoming infected still lags despite a government pledge four years ago to “break the back” of the AIDS epidemic by 2005.

The campaign, launched by the Centers for Disease Control and Prevention in February 2001, intended to cut in half the estimated 40,000 new HIV infections that have occurred every year since the 1990s.

However, the rate of new cases remains about the same, according to CDC data released Wednesday as part of the federal health agency’s commemoration of World AIDS Day.

“We have a ways to go before we reach the mark of reducing new infections by half in the United States,” said Dr. Ronald Valdiserri, the director of the CDC HIV and AIDS prevention program. He called the country’s HIV infection rate “relatively stable.”

“Clearly we want to continue, and are continuing, to fund programs to reach out to people who are high-risk and are not infected,” he added.

In 2001, the CDC’s campaign focused on outwardly healthy people who did not realize they had HIV — about one-fourth of those infected. Officials then said targeting them was key, because if they knew they were infected, they would be more likely to take steps not to spread the virus.

Such an effort “could possibly break the back of the epidemic in the United States,” the CDC’s Dr. Robert Janssen said then.

But the agency found that just targeting people who didn’t know they had the AIDS virus was not enough. So last year, the CDC shifted gears, focusing on counseling those who knew they had HIV in an attempt to get them not to spread the virus.

Yet some advocacy groups say that effort fails to focus on drug users, or very sexually active young men, which advocacy groups say is key in preventing new infections.

Kim Cunningham-Foster, left, and Helen Frank, both of Sioux Falls, S.D., join others in lighting candles in memory of those who have died of AIDS at a World AIDS Day service in Sioux Falls. World AIDS Day was Wednesday.

“It just doesn’t seem like much is really happening,” said Terje Anderson, executive director of the National Association of People Living With AIDS. “There just is a lack of imagination or spark in terms of the kinds of programs they support. I think they are politically afraid.”

The CDC believes up to 950,000 people in the United States are infected with HIV and up to 280,000 of them don’t know it, Valdiserri said.