Ethical guidelines recommend that experimental interventions should be tested in adults first before they are tested and approved in children. Some challenge this paradigm, however, and recommend initiating paediatric testing after preliminary safety testing in adults in certain cases. For instance, commentators have argued for accelerated testing of HIV vaccines in children. Additionally, HIV cure research on the use of very early therapy (VET) in infants, prompted in part by the Mississippi baby case, is one example of a strategy that is currently being tested in infants before it has been well tested in adults. Because infants’ immune systems are still developing, the timing of HIV transmission is easier to identify in infants than in adults, and infants who receive VET might never develop the viral reservoirs that make HIV so difficult to eradicate, infants may be uniquely situated to achieve HIV cure or sustained viral remission. Several commentators have now argued for earlier initiation of HIV cure interventions other than (or in addition to) VET in children. HIV cure research is therefore a good case for re-examining the important question of when to initiate paediatric research. I will argue that, despite the potential for HIV cure research to benefit children and the scientific value of involving children in this research, the HIV cure agenda should not accelerate the involvement of children for the following reasons: HIV cure research is highly speculative, risky, aimed at combination approaches and does not compare favourably with the available alternatives. I conclude by drawing general implications for the initiation of paediatric testing, including that interventions that have to be used in combination with others and cures for chronic diseases may not be valuable enough to justify early paediatric testing.