In natural HIV disease, a small fraction (1-2%) of infected individuals develops exceptionally high titres of HIV-1 neutralizing serum activity. Antibodies isolated from these individuals have been shown to be highly active against a broad range of different HIV strains and are therefore called broadly neutralizing antibodies (bNAbs). These antibodies are in fact able to prevent (S)HIV infection in animal models and therefore of great interest for the development of an HIV vaccine. Information of neutralizing antibodies in patients from Africa is still scarce and would be of great value in the development of adapted HIV vaccine strategies in these regions. This study aims to investigate African HIV-infected individuals, who have developed neutralizing antibodies using highly specialized laboratory methodologies.

Inclusion Criteria:

1. Voluntary and informed consent
2. ≥18 years of age
3. Documented HIV infection.
4. Willing to consent to active tracing including home tracing

Exclusion Criteria:

1. Deficiency, rendering it difficult, if not impossible, to take part in the study or understand the information provided. This includes alcoholism, drug dependency as well as psychiatric illnesses, suicidal tendencies or any other inability.
2. Prisoners
3. If within the discretion of the investigator study participation would possibly add not acceptable risk or burden to patient (e.g. significant health deficiencies, social harm)
4. Unlikely to comply with protocol as judged by the principal investigator or his designate

Adult HIV-infected, preferentially ART-naïve patients within the Mbeya region. The prevalence of elite neutralizers is expected to be 1-2% from the overall population. The study therefore targets to recruit 500 subjects in order to identify at least 5 elite neutralizers, which will be subjected to further in depth antibody characterization.