Table 2 Challenges with performing an HIV cure trial in Guinea-Bissau and strategies to overcome these

Reluctance to accept high volume blood samples if not sick

Consent for 10 ml EDTA can usually be obtained

Keeping the cold chain

Samples can be transported in cooler to National Health Laboratory and placed in − 80 °C freezer or on dried ice

Cell recovery

Standards for transport of viable PBMCs in place to be analysed elsewhere [18]

Ethical concerns for vulnerable HIV population with limited health literacy [161]

Audio-visual teaching materials can be produced to inform patients relevantly for informed consent

Taboo/stigma of HIV

Staff trained in enrolling and following patients on trials without breaching confidentiality and keeping HIV a secret to other family members in the house

Loss-to-follow-up [98, 162]

Strategies to reduce loss-to-follow-up, including staff trained in mobile phone contact and home visits in place [163]

Considerable adherence challenges, difficult to achieve long-term viral rebound-free treatment [164]

Within the framework of a clinical trial, adherence and follow-up can be improved [126]