A new study has found that an oral cholera vaccine appears to work in people infected with HIV, protecting them from the highly infectious, diarrhea disease. 

Cholera is spread through drinking water and food that have been contaminated by the feces of infected individuals.  The onset of the disease is sudden, and can result in severe life-threatening dehydration.  Cholera outbreaks are common in many developing countries where the prevalence of HIV is also high.

Experts say people infected with the virus that causes AIDS are more vulnerable to cholera, because of their weakened immune systems. 

A group of researchers from Asia, Africa and Europe wanted to see whether a cholera outbreak could be contained in a mass immunization campaign that includes individuals infected with HIV.

They gave an oral cholera vaccine to 172 people, including children, in Beira, Mozambique between December 2003 and January 2004.

A cholera epidemic struck in mid-2004, and investigators say 78 percent of the test group, or 130 people did not contract the disease.

Experts say Mozambique has a high rate of HIV infection.  About 30 percent of women are infected with the virus that causes AIDS, according to one of the study's authors, John Clemens of the International Vaccine Initiative in Seoul.

"Although our study did not test participants for their HIV status, the high levels of protection observed in our study in a population with very high prevalence of HIV suggests that the vaccine may be efficacious [effective] in HIV-infected persons," said Mr. Clemens.

The results of the study are published this week in the New England Journal of Medicine.

Writing in the journal, magazine editor Jeffrey Drazen says the study shows the vaccine is highly effective in preventing the spread of cholera, not only among those who are HIV infected, but in other settings.

"As you know if you are malnourished you can become immune compromised, and that may be something that would go hand in hand with refugees from the tsunami," said Mr. Drazen.

Dr. Drazen says the study shows the vaccine is safe and effective for use in a cholera epidemic, and both he and Dr. Clemens hope the findings prompt donor nations to contribute money to make the drug available worldwide.