The article is horribly wrong about CCR5 being the only pathway of the HI Virus to infect your cells and ultimately cause AIDS.

A problem of this approach is that, while CCR5 is the major co-receptor by which HIV infects cells, it is not the only such co-receptor. It is possible that under selective pressure HIV will evolve to use another co-receptor. [1]

Why this treatment still worked is because:

However, examination of viral resistance to AD101, molecular antagonist of CCR5, indicated that resistant viruses did not switch to another co-receptor (CXCR4), but persisted in using CCR5: they either bound to alternative domains of CCR5 or to the receptor at a higher affinity. However, because there is still another co-receptor available, it is probable that lacking the CCR5 gene does not make one immune to the virus; it would simply be more challenging for the individual to contract it. [1]

So a mixture of anti-retroviral treatments, which suppress the HIV replication to a point of not showing up in PCR tests anymore (while taking the medication), and (partially?) inhibiting the remaining viruses from infecting cells via the CCR5 pathway, further limiting their replication, caused these patients to be cured.

I don't know if the replication slowed down so much that their body was able to kick HIV out once and for all, or blocked it outright because the already reduced number of viruses simply could not beat the odds of infecting via a alternative pathway. Kudos to the researchers!

Why is this important: The CRISPR babies[2] had this exact gene removed, and everybody claimed that he cured them from ever getting HIV, even though it's simply not true.

Note that there are also drugs which disable CCR5, without gene modification (Selzentry).

[1] https://en.wikipedia.org/wiki/CCR5 [2] https://en.wikipedia.org/wiki/He_Jiankui_affair