NEW YORK theater critics don't seem to have the same clout they used to. They panned American Hostage when it opened last November but today, 255 performances later, the show still packs 'em in at the old Schubert in Tehran, across the street from Sardik's.

Like the censors who battled Oh Calcutta! and the judges who smothered Caligula, President Carter and Associates have been searching for a way to close the Ayatollah Ruhollah Khomeini's smash hit. An attempt to airlift the 53 performers en masse from the theater wings failed when a pulley strap of the deus ex machina snagged on a piece of scenery.

Now the directors in Washington have unveiled a new plan that may enable the actors starring in American Hostage to leave the show one at a time. The scheme involved smuggling disease to each member of the cast, prompting the New York Daily News to headline its Friday edition, CARTER TO HOSTAGES: DROP DEAD.

Administration sources insist, however, that none of the diseases presently being smuggled into Iran are lethal. "If the cast of Hostage were to die now," says Dr. Peter Born, White House aide-de-camp, "President Carter's image would suffer drastically. It's important for the public to understand that the Carter Administration is doing everything possible to secure the safe--if unhealthy--release of those Americans."

Richard Queen, a stagehand and spear-carrier in Hostage, was the first to benefit from Mission Innoculation. Today, Queen is strolling the streets of Geneva, buying shoes for the first time in nine months and seeing a doctor for debriefing.

According to Iranian sources, the remaining cast members were torn over Queen's departure. Some found the 28-year-old bachelor to be a good actor and attributed his release to his subtle performance as a man with a mental disorder. Others, more skeptical, deny that Queen had any talent. "The CIA gave him pills," said one unnamed source in the holy city of Qum. "I just hope they don't give me hepatitis. I'd prefer migraines."

Feigned or not, Queen's illness and subsequent release will make him rich. He has signed to write a book for Doubleday and will be technical adviser for the upcoming motion picture Man From Tehran. That picture will star Marlon Brando as Col. Charles Beckwith with Omar Sharif as the deposed shah of Iran.

In addition, Queen's presence in Geneva will make it easy for him to open a Swiss Bank Account for funds derived from the impoundment of Iranian holdings in the U.S. As the first American released, Queen will have his pick of oil wells in Texas, coal mines in Wyoming, or a deluxe embassy mission in Washington.

"Ham Jordan won the White House betting pool with his guess of May 4," Born disclosed, adding Jordan came closest without going over the actual date of the release of the first hostage. "Carter had $10 on April 1," he confided.

"Predictions were limited to dates before November 4. "Any hostage release after then was deemed useless," Born continued, dispelling the rumor that Jordan planned to keep his winnings to himself. "There's no question that Ham will split the pot with Richard Queen. After all, Queen did the time for this caper."

Other Hostage cast members expressed polite envy over Queen's new wealth. "What can you say?" asks Howard Staggart, a professional hostage who was held at Entebbe and the B'nai Brith offices in Washington. "This is a tough business. It demands long hours of punishing work and it can be very boring. It's not as glamorous as people think. But success is possible and Dick Queen's an example. I only wish I had gotten the break."

Analysts and theater critics agree that Queen's release indicates Iranian production values may be changing. "I think we're seeing a new, softer Khomeini," says Walter Mutt of The New York Times. "He's still living in a glass house, but he's getting other people to throw his stones."

The future of Mission Innoculation depends on the proper diagnosis of American illnesses--and the CIA's strength at smuggling bacteria into Tehran. "We're working on a new strain of dysentery," agent Frank Snepp reported cheerfully. "It's called Ayatollah's Revenge."