Warning: contains major spoilers for Alien #4!
Marvel's Alien series has confirmed that it's possible to survive a Xenomorph birth. Alien #4 provides more background for the series' protagonist - Gabe Cruz. He has a lengthy history with Weyland-Yutani and there is more to him than readers may have initially believed.
Alien (2021) takes place 21 years after the events of Alien 3 and 179 years before Alien: Resurrection. Epsilon Station is a lab owned and operated by Weyland-Yutani. It is the site where the company developed a deadlier alien, which Gabe has been sent to retrieve. In addition to collecting the Alpha Xenomorph specimen, he is also hoping to rescue his son Danny, who was part of an attack on the station, which resulted in freeing the Alpha.
Created by the team of Phillip Kennedy Johnson, Salvador Larroca, Guru Efx, and Vc Clayton Cowles, Alien #4 completely changes the survivability of a Xenomorph embryo. Xenomorphs' lifecycles begin with the alien egg that contains a facehugger, which explosively latches onto a host to birth a chestburster. The chestbursters then grow into full-grown Xenomorphs. In most cases, once a human host has been infected by a facehugger, their fate has been sealed. This is no longer the case, as Gabe has become the first known survivor of a Xenomorph birth.
Alien #4 fully reveals that Gabe knows what Danny is going through after a facehugger attack, because he has had a Xenomorph inside of him. In 2180, Gabe was on Epsilon Station with an alien inside of him. This is indicated by the reveal that the "alien inside" panel from the first issue features him on the interior of the hypersleep tube. While it could have been assumed, it wouldn't be the first thing Alien fans would think possible - because it would mean someone survived a chestburster in some way or another. This is unheard of. Although Ripley 8 technically survived a Xenomorph birth by having the embryo cut out, this was a genetically altered clone of Ripley. She had Xenomorph DNA and was not fully human in the way Gabriel currently seems to be. Furthermore, Gabe's incident occurred in 2180, while Ripley 8's embryo was cut out of her in 2379. Interestingly enough, it is implied that the only thing that allowed Ripley 8 to survive her procedure was the Xenomorph aspect of her modification.
It has long been assumed - and shown - that being infected by a facehugger is a death sentence. No normal human has survived being infected by a Xenomorph. In Alien 3, Ripley threw herself into the foundry's furnace at the same moment that a Xenomorph queen embryo was bursting through her chest and her return in Resurrection was as a clone. The destruction caused by the chestburster on the way out is fatal. It has also been implied that surviving the initial burst would shortly after lead to health complications that are also fatal.
So far, Marvel has not revealed how it is that Gabe survived, though there are some clues within the rest of the Alien franchise. Alien Resurrection showed Ripley undergoing a surgical procedure to remove her embryo, while Elizabeth Shaw underwent a similar procedure in Prometheus to remove a Trilobite from inside of her. Considering the valuable nature of the Alpha specimen it seems likely that Gabe survived his experience by having the Alpha cut out in a similar way. Regardless of how he survived, Marvel has confirmed that Gabe Cruz is the first person in the Alien timeline to survive a Xenomorph "birth."