Good news for those who advocate for prevention of mother to child transmission.
The following articles report on a journal article published Friday. Women who take nevirapine to prevent HIV infection in their newborns are not at risk of having their virus develop resistance to nevirapine. But the main task is to develop prevention strategies that do more than create orphans …
The World Health Organisation and most UN agencies define "prevention of mother-to-child transmission of HIV" to include a four or five component programme including:
• information and counselling on preventing HIV transmission
• family planning for pregnant women living with HIV/AIDS
• use of antiretroviral drugs to prevent HIV transmission from mother to child
• infant feeding counselling and
• HIV treatment and care for infected mothers, infants and other family members
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Finds Pregnant Women Can Take Anti-AIDS Drug
By DONALD G. McNEIL Jr.
New York Times
January 10, 2007
Women can take the anti-AIDS drug nevirapine to protect their unborn children without endangering their ability to undergo life-saving antiretroviral treatment later on, a new study has found.
The results are good news for poor women in Africa, Asia and Latin America who must take nevirapine, an inexpensive first-line drug that often prevents the transmission of H.I.V. from mother to child.
The drug lingers in the blood up to three weeks, and if the mother has the AIDS virus, its presence encourages the growth of nevirapine-resistant strains. That has led to fears that any antiretroviral drug cocktail containing nevirapine would be useless.
But the new study, being published on Thursday in The New England Journal of Medicine, finds that such a cocktail is still effective if women simply delay it for six months after taking the protective dose of nevirapine.
The study was done by Harvard researchers working in Botswana, but has implications for poor women everywhere. Early reports of data gathered in the study, along with evidence from similar ones, influenced the World Health Organization's new AIDS treatment guidelines last year, helping keep nevirapine in the arsenal of first-line AIDS drugs.
"This is a real glimmer of hope," said Dr. Catherine Hankins, chief scientist for Unaids, the United Nations AIDS agency. "There was real concern that single-dose nevirapine was blowing the use of that whole class of drugs."
Nevirapine has never been a perfect drug; in prolonged use, it can poison the liver and cause rashes, and the AIDS virus only needs to make a single mutation to develop resistance to it.
In wealthy countries, women are usually given a short course of two or three antiretroviral drugs late in the pregnancy to prevent passing the virus to their babies, and birth infections are now rare in the West.
But in poor countries, many women in rural villages give birth without ever seeing a doctor, or make the trek to hospitals or clinics only when they are in labor, leaving medical workers with little choice but single-dose nevirapine.
The drug is so simple and effective that health workers in small clinics often leave pregnant women one pill to take when labor starts and a syringe full of liquid nevirapine to squirt into the newborn's mouth, said Dr. Shahin Lockman, a researcher for the Harvard School of Public Health's AIDS Initiative and author of the study. In some cases, she said, they must do this without even knowing whether the mother is infected. In Africa, many women still refuse AIDS tests for fear family or neighbors will shun them if they prove positive.
Under those circumstances, nevirapine is usually harmless, and cuts in half the chance that the baby will get infected.
The drug is also a cornerstone of antiretroviral AIDS treatment in poor countries. It is commonly found in the three-in-one pills used in treatment programs supported by Western donors, and many start-up programs have no or few alternatives. In generic form, it costs one-eighth as much as efavirenz, the most closely related drug.
The Botswana study concludes that waiting six months after single-dose nevirapine allows the nevirapine-resistant strains to disappear from the body.
For 70 to 80 percent of mothers infected with H.I.V., waiting that long is safe, said Dr. Catherine M. Wilfert, scientific director of the Elizabeth Glaser Pediatric AIDS Foundation, which supports treatment and prevention for mothers and children. Women healthy enough to carry a pregnancy to term are usually not yet so sick that they need AIDS cocktails immediately, she said.
Although her foundation prefers to offer mothers more than just single-dose nevirapine, Dr. Wilfert said, she was glad to see that potential resistance to it could be overcome.
Dr. Thomas A. Kenyon, chief medical officer for President Bush's $15 billion Emergency Plan for AIDS Relief, said the study was "good news" in that it "gives us more assurance that what we're recommending is scientifically sound."
Other studies, including one of about 4,000 women in Zambia released last year, have shown that most women getting triple therapy containing nevirapine do well even if they had single-dose nevirapine to protect their babies. That study noted that letting more time pass between the two events made a difference, and this study indicated that six months seemed to be the right amount of time.
Another new alternative described by Dr. Kenyon was to give women a "tail" of two other drugs, AZT and lamivudine, for four to seven days after the single dose of nevirapine, while it lingered in their blood. That would temporarily suppress replication of all AIDS virus enough to prevent nevirapine-resistant strains from growing, he said.
A quick course of three drugs is relatively safe; it is given to health workers stuck with needles and rape victims whose attackers might be infected. But as is always the case with AIDS treatment in poor countries, the logistical problems make it hard to administer on a wide scale.
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The Boston Globe
Waiting to take 2d dose of AIDS drug may be key step
New mothers in poor countries stand to benefit
By John Donnelly, Globe Staff | January 11, 2007
WASHINGTON -- A Harvard study has found a way around one of the thorniest problems in preventing HIV transmission from mother to child during birth in poor countries.
In recent years, efforts to prevent transmission of the deadly virus that causes AIDS were set back by the discovery that many mothers who received a single dose of the drug nevirapine during labor developed a resistance to it, foreclosing the chance to use the drug later to fight AIDS in their bodies.
But the study, which is being published today in The New England Journal of Medicine, found that if the mother waited six months after birth to take a nevirapine-based, antiretroviral treatment, resistance from that single dose during labor had vanished in the vast majority of cases.
The findings should give greater confidence to many governments in Africa to promote use of nevirapine at birth, which cuts the chances of transmission to babies by nearly 50 percent, researchers and a US policymaker said.
"If you can hold off on treatment for six months, if it's safe to, hold off," said Shahin Lockman , the lead author of the report and an assistant professor at the Harvard School of Public Health.
If the woman needs AIDS treatment after giving birth, Lockman's advice is to "do your best to get her on non-nevirapine based treatment."
Other studies have found that of the pregnant women who receive a dose of nevirapine at birth, a nevirapine-based treatment afterward is not effective in betwe
en 20 and 69 percent of them. The highest rates of resistance have been found in sub-Saharan Africa, the epicenter of the AIDS pandemic. Around the world, roughly 40 million people are now infected with HIV or have full-blown AIDS.
Thomas A. Kenyon , principal deputy coordinator for the US global AIDS program, a $15 billion, five-year effort to fight the virus, said the issue of resistances developing during anti-retroviral treatment needs to be monitored closely in the coming years.
"But what this [study] does provide is reassurance in the vast majority of instances, we're not creating a new problem of resistance by introducing single-dose nevirapine," Kenyon said.
The study began in 2001 and was based in Botswana, where Harvard AIDS researchers have long worked. The study followed 218 HIV-infected women who had received a single dose of nevirapine during labor as well as a short treatment of anti-retroviral drugs during pregnancy. Sixty women started a nevirapine-based treatment within six months of giving birth, while the remainder, 158, started on the drugs six months afterward.
The outcomes were dramatically different. Of those taking the drugs soon after birth, 41 percent experienced treatment failure. Of those who waited, just 12 percent had the treatment fail.
Shahin speculated the better results were because the amount of nevirapine-resistant HIV in the body decreases as time passes.
The best-known way to prevent mother-to-child transmission is to put HIV-positive pregnant women on anti-retroviral treatment during pregnancy; during labor, a single dose of nevirapine also can be given. In the United States, other rich countries, and some parts of the developing world, including Thailand, the Ivory Coast, and South Africa, healthcare workers have used this technique to lower the risk of transmission to between 1 and 4 percent.
But in sub-Saharan Africa, just an estimated 10 percent of HIV-infected pregnant mothers receive any type of intervention to prevent transmission of the virus. In the cases in which drugs are available, nevirapine during labor is often the only intervention. Researchers estimate that more than 875,000 women and infants in poor countries have received single-dose nevirapine at birth.
Max Essex , chair of the Harvard School of Public Health AIDS Initiative and one of the authors of the study, said doctors, nurses, and community health workers should use common sense when they oversee women who have just given birth. World Health Organization guidelines recommend that when a patient's CD4 count -- a measure of the strength of a person's immune system -- falls below 200, they should start antiretroviral therapy.
But that shouldn't be automatic with women who received single-dose nevirapine during labor, Essex said. "For many of them, it's almost certainly OK to wait for six months and then you can put them on" a nevirapine-based treatment.
John Donnelly can be reached at donnelly@globe.com.
(c) Copyright 2007 The New York Times Company
