Table 1.

Cellular mechanisms of immune control in resistance to human immunodeficiency virus (HIV)-1 infection

Exposure route	Cohort types	Cohort definition	Immune mediated mechanism(s) and references
Sexual exposure (male/female)	• Discordant couples	Individuals exposed to HIV-1 via unprotected vaginal intercourse with an HIV-infected person	HIV-1-specific T cell responses [3,5,7,25,27,36,37,58]
	• Sex workers		Heightened innate immune cell activity [6,110]
Sexual exposure (male/male)	• Discordant couples	Individuals exposed to HIV-1 via unprotected anal intercourse with an HIV-infected person	HIV-1-specific T cell responses [3,4,23,26]Heightened innate immune cell activity (no data available)
Direct blood exposure	• Injection drug users	Individuals exposed intravascularly to blood or blood products from an HIV-infected person	HIV-1-specific T cell responses [14,24]
	• Health-care workers		Heightened innate immune cell activity [19,20,91]
	• Haemophiliacs
Mother-to-child exposure	• Vertical transmission	Children exposed to HIV-1 through carriage from HIV-1-infected mother	HIV-1-specific T cell responses [11]Heightened innate immune cell activity [10,12]
Oral exposure	• Breastfeeding	Children exposed to HIV-1 through nursing.	HIV-1-specific T cell responses (no data available)
	• Discordant couples (oral sex)	Sexually active adults	Heightened innate immune cell activity (no data available)