"I cannot say I have experienced anti-Semitism personally because well-known figures are usually excepted from the daily harassment," said violinist Isaac Stern, who last night received the Anti-Defamation League's prestigious Joseph Prize for Human Rights. "But it's a virus that has outlived any medicine given to fight it . . . One must stay vigilant."

Last night about 1,000 members of the national Jewish community kicked off the 70th annual meeting of the ADL with a black-tie fund-raiser at the D.C. Convention Center. Proceeds from the $300-a-couple event will go to ADL, B'nai B'rith's public education arm.

Interior Secretary James G. Watt, one of a dozen or so officials on the podium, was booed as he was introduced. In April, Watt, who has been instrumental in bringing a Holocaust memorial museum to Washington, upset the Jewish community by comparing the persecution he said he had experienced as an evangelical Christian with the persecution experienced by Holocaust survivors.

A spokesman for Interior later said that it was "not unusual" for Watt to be at such a dinner and did not know why Watt might have been booed. "He meets with Jewish groups all the time," said spokesman Robert Wood. "He's very empathetic to their causes."

One of the high points of the evening was a performance by singer Natalie Cole, who was invited by the Marriott Corp. J. Willard Marriott, the company's board chairman, received the league's Americanism Award for his "contributions to hundreds of civic, religious and charitable causes."

One of the low points was the dinner--cold, late and disorganized.

"I have one announcement to make," W. Reid Thompson, chairman of the Potomac Electric Power Co., told the crowd. "The dinner was not catered by the Marriott Corporation tonight." Everyone laughed.

The evening began with a VIP reception and a fancy array of kosher hors d'oeurves for some of the league's wealthier benefactors. Like Burton Joseph, the Minnesota businessman who gives $10,000 annually for the Joseph Award. Stern shared this year's award with conductor Zubin Mehta, another vocal supporter of Israel, who was not present at the ceremony.

"I wish we could go out of business, but it's not going to happen," said Joseph of the league. "It's a terrible thing but there is still anti-Semitism in this country."

Last night's keynote speaker was Sen. Henry Jackson (D-Wash.), a longtime friend of Israel.

"Despite all the uncertainties in the Middle East, there is one thing we can now be thankful for," he said, "the Israeli-Lebanese agreement to end hostilities and to bring about troop withdrawal from Lebanon."

Everyone applauded heartily, and then got down to dessert: strawberries and cream. It arrived on time.