If Chazal knew all the science we know today yet failed to let Jews know about antibiotics and vaccines, then they were murderous monsters.
Of course they didn’t know, and in fact they were the greatest moral leaders since the Neviim! It is not just apikoros but blasphemous to say otherwise!!! How can any supposedly frum Jew think like that! More people have died from either plague or smallpox than were murdered by Hitler, Stalin, or Mao and you say that Chazal would deny the world treatments and prevention? Chas v’shalom!