A follow-up study among mothers with HIV-1 and their infants in this week's issue of The Lancet provides further evidence for the sustained efficacy of nevirapine as a low-cost option to help prevent vertical HIV-1 transmission from mothers to newborn children in less-developed countries.
The provision of antiretroviral therapy to women at the onset of labour and for a short period postnatally to the infant is thought to be sufficient to decrease vertical transmission around the time of childbirth and the start of breastfeeding. This might offer a more affordable approach for HIV-1 infected pregnant women in less-developed countries.
The HIVNET 012 study team reported in 1999 that a single-dose intrapartum and neonatal nevirapine regimen significantly decreased the risk of transmission of HIV-1 from mother to child by 47% compared with a short intrapartum/neonatal zidovudine regimen when 87% of babies in the trial had reached age 14-16 weeks.
The same investigators led by Brookes Jackson from Makerere University-Johns Hopkins University Research Collaboration (part of the NIH funded HIV Prevention Trials Network) report the safety and efficacy of the nevirapine regimen in all study mothers up to six weeks after delivery and for all babies up to 18 months of age.
From late 1997 to early 1999, HIV-1 infected pregnant women in Kampala, Uganda, were randomly assigned nevirapine (200 mg at labour onset and 2 mg/kg for babies within three days of birth) or zidovudine (600 mg orally at labour onset and 300 mg every 3 hours until delivery, and 4 mg/kg orally twice daily for babies for 7 days). Infant HIV-1 testing was done at birth, age 6-8 and 14-16 weeks, and age 12 months.
645 mothers were enrolled in the study, half received nevirapine, the other half received zidovudine. 99% of babies were breastfed for an average of nine months. Infants were around 40% less likely to have had maternal HIV-1 infection up to 18 months of age if mothers and infants had been given nevirapine around the time of childbirth compared with those given zidovudine.
Brooks Jackson comments: "The absolute 8.2% reduction in transmission at 6-8 weeks was sustained at age 18 months…This simple, inexpensive, well-tolerated regimen has the potential to significantly decrease HIV-1 perinatal transmission in less-developed countries."
In an accompanying Commentary, Dr Karen Beckerman from Bellevue Hospital at New York University School of Medicine cautions against the widespread use of single-dose agents such as nevirapine because of the potential for resistance to develop against other similar antiretroviral drugs. She concludes: 'Generic antiretrovirals, prepared in convenient single-pill triple combinations for once and twice daily dosing, are now available for less than US$1 a day. The HIVNET 012 protocol was modified in 1998 to accommodate the changing realities of the HIV-1 pandemic. 5 years later, these realities have shifted yet again. Suboptimum single-agent and double-agent prophylaxis protocols no longer have a justifiable place in the front lines of the global struggle against HIV/AIDS. It is up to all of us to focus on development of equitable distribution and effective use of these agents now. Once they are widely available, it may be too late.'
References
Beckerman KP. Long-term findings of HIVNET 012: the next steps. The Lancet 362: 842-3, 2003.
Jackson BJ et al. Intrapartum and neonatal single-dose nevirapine compared with zidovudine for prevention of mother to child transmission of HIV-1 in Kampala, Uganda: 18 month follow-up of the HIVNET 012 randomised trial. The Lancet 362: 859-868, 2003.
Source: Lancet press release.
Further information on this website
HIV & AIDS Treatment in Practice - Preventing mother to child transmission of HIV - overview of key issues for resource-limited settings.
Nevirapine efficacy underestimated for protecting babies from HIV - news story, August 14 2003.
South African drug agency questions use of nevirapine for mums to be - news story August 1 2003.
Formula feed is `medicine to prevent HIV` - news story July 18 2003.
Treatment for babies can block HIV breast milk transmission - news story July 16 2003.
HIV Resistance Workshop 2003: resistance in non-B HIV subtypes (see section on Resistance following single dose nevirapine) - News story July 8 2003.