The new WHO guidelines for antiretroviral therapy were updated in November 2009 with several major changes: Advocacy of early treatment, i.e. initiation of antiretroviral therapy (ART) at CD4 below 350. Advocates starting ART in pregnant women from the 14th week of gestation, with the possibility of continued dosing during breastfeeding. The guidelines also recommend replacing D4T with AZT and TDF as the first-line drug combination for treatment. Antivirals for co-infection: If co-infected with hepatitis B, the ART combination needs to include TDF, 3TC or FTC. The guidelines were updated in the 2006 edition to align treatment in resource-poor areas with the standard of care that has been in place in developed countries for several years.