A 24-year-old woman with HIV presents in labor. She has struggled taking antiretroviral therapy during the pregnancy due to severe nausea and vomiting and the most recent HIV RNA level 3 weeks ago was 3,467 copies/mL. She receives intravenous zidovudine and has a cesarean section. After the delivery, she asks whether she can safely breastfeed. An HIV RNA level obtained from the mother 2 weeks after birth shows an HIV RNA level of 1,256 copies/mL.