Also AAV, adeno-associated viruses . . . (but not preferable in a clinical setting/application usually, since they apparently can sometimes elicit immune responses and may contribute to the deaths of some patients historically in gene therapy trials https://www.nature.com/articles/s41587-020-0642-9 High-dose AAV gene therapy deaths, liver dysfunction, sepsis . . . )

Edit: I suspect that if we can use nanolipid particles as vectors, that may be more safe instead of AAV vectors.

The main mechanism is less exposure to estrogen. The title is a bit misleading & makes it sound like the writer(s)/scientist(s) have an agenda to spur population growth, but one can achieve similar results without being pregnant (reducing levels of estrogen through other means, e.g., small molecule therapeutics, aromatase inhibitors like letrozole, anastrazole, et cetera).