Vlad was a cosmonaut who appeared as a supporting character in four issues of Y: The Last Man, published by the Vertigo imprint of DC Comics. Vlad (whose last name was not revealed) appeared in Y: The Last Man #s 11-14.
The central plot in the comic book series Y: The Last Man centers around the last man remaining on Earth after a plague kills every male mammal on the planet except for Yorick Brown (the titular "Y") and his capuchin monkey "Ampersand." After many issues, Yorick, along with the women he is travelling with en route to a genetics and cloning research facility, encounter a Russian intelligence agent who has been sent to the United States to retrieve the a Russian cosmonaut due to land in Nebraska. This cosmonaut is Vlad, who was on board an international space station when the plague struck Earth, and was thus spared the fate of all other males on the planet. With Vlad are Joe, a black astronaut who is the mission commander, and Dr. Ciba Weber, a woman.
From the prayer uttered by Vlad as he and his crewmates are leaving their space station about to embark on a dangerous trip to Earth, it is evident that Vlad is Russian Orthodox.
From: Y: the Last Man #13, DC Comics: New York City (2003), written by Brian K. Vaughan, pencilled by Pia Guerra, inked by Jose Marzan, Jr.; page 1; reprinted in Y: The Last Man: One Small Step (2004):
The plague caused massive turmoil and the lost of industry, electricity, etc. all over the planet. Mission Control for Vlad's space mission and NASA were in disarray, and the three space-farers were unable to return via space shuttle to Earth as they had planned. Finally, after extending their trip for months, they had to come leave the space station in an escape pod, lest they run out of air and food.
Unfortunately for the future of the human race, Vlad and Joe both died after their landing pod burst into flames when it landed on Earth. The women who met the landing vessel and rescued Ciba from the burning landing pod just before it exploded, killing the two men, asked her pointedly why the men had sacrificed themselves, when, as human males, they were such a rare commodity compared to herself, just another surplus woman. They pushed their co-worker, Ciba, out of the escape pod, telling her, "Women and children first."
As Dr. Mann, a female scientist who was of the main characters in Y: The Last Man, and one of Ciba's rescuers, asked incredulously: "They jeopardized the future of mankind for chivalry?" (Y: The Last Man #15, page 17)
But their sacrifice was more than simple chivalry. In the over-extended months of their space mission, both Joe and Vlad had become Dr. Weber's lovers, and they knew that she was pregnant with the child that one of them had fathered. Vlad and Joe were not only saving the life of the woman they loved, they were also saving the life of their unborn child.
Which, yes, is chivalrous, and is even a manifestation of their biological imperative to safeguard their offspring. But, from a strictly pragmatic and mathematical perspective, this was a pretty dumb move.
The death of Vlad the cosmonaut and Joe the astronaut meant that once again, as far as anyone knew, Yorick was once again the "Last Man" on Earth.
(And Yorick was apparently working hard to be chaste and true to the woman he was engaged to, which is another story altogether.)