It's Pavlovian. Someone makes an inaccurate, out-of-context, stereotypical comment about Israel or Jews. Jews react, condemning the comment as false, feeding anti-Semitism, being anti-Semitic, and coming from an anti-Semite.
The defenders of the comment or commenter then respond that the Jews are using anti-Semitism to protect Israel, that not every critique of Israel is anti-Semitic, that Jews are trying to stifle legitimate debate, that Jews are too sensitive, that Jews exploit the Holocaust, and on and on.
The pattern is so common, it is tiresome. And we are now seeing it repeated in the case of Michael Che's "joke" on SNL that since Israel has vaccinated half of its population, it is only vaccinating Jews.
The point is not whether Che is anti-Semitic or even whether the “joke” was anti-Semitic. The questions are whether it is true, fair in the context of the situation, and whether, given the history of bigotry and persecution of Jews, it unnecessarily contributes to the atmosphere that encourages prejudice against Jews and violence against Jews and Jewish institutions.
Critiquing Israel is fine. Israelis and Jews do it all the time. However, a one-off joke about Jews keeping a vaccine only for themselves, with no background, no context, and devoid of any truth is not, given Jewish history and current threats, a critique.
And the joke did not appear out of nowhere. The joke would not have been made, and SNL viewers would not have had any reference point, if the audience had not been subjected to weeks of misinformation and unfair allegations against Israel for the alleged sin of not providing vaccines to Palestinians in the West Bank and Gaza. In short, it was the natural outcome of a sustained campaign of lies, the types of lies that have led to injury and death to Jews in the past.
Israel is vaccinating all of its citizens regardless of religion or ethnic or national background. This includes the almost two million Israeli citizens who are Arab/Palestinian. This is unremarkable because all Israelis are covered equally by Israel's universal health care system.
What prompted the “joke” was undoubtedly the unfair and unjustified charges that Israel is not providing the vaccine to the West Bank and Gaza. The "joke" was neither funny nor accurate.