Heather Hartle and Heidi Hartle were twins geneticists who appeared 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 12-15.
From: Y: the Last Man #14, DC Comics: New York City (2003), written by Brian K. Vaughan, pencilled by Pia Guerra, inked by Jose Marzan, Jr.; page 6; reprinted in Y: The Last Man: One Small Step (2004):
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 was with two American astronaust, stranded on board an international space station when the plague struck Earth.
The women that Yorick Brown (the titular "last man" on Earth) is travelling with en route to a genetics and cloning research facility decide to take a detour to help this Russian intelligence agent safely retrieve the cosmonaut and two astronauts. They want to isolate the men from the space station away from any possible biological agent or pathogen that may have caused the male-killing plague. It is important to the future of human race to preserve any males left, and if there are two more from space in addition to Yorick, it will give the species a better change at surviving.
To this end, Yorick's travelling companions (including Dr. Mann and the mysterious Agent 355), with the help of the female Russian agent, locate a "hot suite." This is a secret location built by the U.S. federal government for the purpose of isolating and protecting important leaders and government workers during catastrophic emergencies such as these.
When the women bring Yorick to the "hot suite" (which is mostly underground, with its above ground entrance disguised as a simple barn on a farm), two women in hazmat suits rush out of the building and spray Yorick with decontaminant foam. This is the first time that Yorick and his companions meet Heidi and Heather Hartle, the twins who operate the hot suite facility. They introduce themselves, explaining that they are geneticists and that the facility has never before been used. Yorick and his companions are disappointed to learn that nobody ever came to the hot suite facility when the plague struck. It happened too fast and killed males too quickly.
When Israeli intelligence agents, secretly working for Congresswoman Brown (Yorick's mother) try to abduct Yorick from the hot suite facility, the Hartle twins expess surprise. "We're Jewish!" one of them explains, indignant that fellow Jews attacked them.
Yorick Brown's mother arranged for Israeli agents to retrieve her son, an an attempt to get him to safety, away from Agent 355, whose motives she does not trust. Congresswoman Brown did not trust anybody left in the U.S. government to do the job, and she called in a favor from an Israeli military leader who owed her a favor.
In addition to Heather and Heidi Hartle, the Jewish-American geneticists, there were a number of other Jewish characters in the Y: The Last Man. These other Jewish characters were among the female Israeli soldiers who repeatedly attempted to retrieve Yorick, including their squad leader, who decided to take Yorick back to Israel to give her country a strategic advantage, especially over the Arab nations for which she felt particular enmity.
It was clear from the writing and illustration that at least some of the Israeli soldiers were Jewish, but none of them identified themselves as such as overtly as the Hartle twins did.