The question addressed to HaRav Yitzchok Zilberstein by HaRav Dr. Akiva Tatz from London and HaRav Dr. Tzvi Distnik from Bnei Brak was as follows:
"Lately, medical literature has been dealing with the question of a harsh disease called dengue fever, a viral infection causing hemorrhage in the body, considerably severe with a high fatality rate. Throughout the world today some 400 million people are suffering from it, most of them in Asia and South America. Of this number, some 2.3 million cases each year are considered harsh with a death rate of 9,000 each year.
"There is a vaccine against it which, if administered to a million children, can prevent 11,000 hospitalizations and 2,500 harsh developments. However, this vaccine per se has been known to cause the disease itself with 1,000 hospitalizations and 500 harsh cases.
"In other words, while the vaccine can prevent a tenfold number of people from contracting the disease and a fivefold number of people from severe complications, it can, nevertheless, cause one thousand healthy people to become ill, with half of this number becoming very ill. We would like to ask what daas Torah has to say about the vaccine. Is it worthwhile to administer it in order to save a large number of people, or since we are willfully harming some people, it is not advisable to inoculate them altogether?"
HaRav Zilberstein referred the audience to the comment of the Chazon Ish (Ohalos 22:32): "There is no question of possible pikuach nefesh regarding the future if, in the present, it is nonexistent. We are not expert in anticipating the future since on occasion, what we consider as life saving can turn out to be detrimental. Subsequently, we need not consider repercussions of the distant future."
HaRav Zilberstein added that "since at the present, we are endangering many people, we need not consider future risks, especially according to what the Chazon Ish wrote (Sanhedrin 25) that one must not endanger the individual in order to save the public.
"Nonetheless, it appears permissible to give the inoculation even if the prevention is in the future while the danger is in the present. Every individual of the population is in a high risk group of contracting the disease while if he does take the shot, the chances are good that it will be beneficial, since there is less than a ten percent chance that he will come down with the disease from the sum total of those who will be spared.
"In other words, if one does not take the vaccine, his chances are one out of 11,000 of hospitalization, while if he does, the chances are one out of a thousand hospitalized. It turns out that each one of the patients has a 90% chance of being saved.
"This does not compare to the Chazon Ish's example of sacrificing an individual to save a large number of people. The vaccination is less harmful because we are endangering each individual by a small percent in order to spare him in the future by a much greater percentage."
The audience reaction was spontaneous, since the measles vaccine was uppermost in everyone's mind. Was this psak applicant?
The vaccine is very controversial since many claim that it involves a serious risk, especially for babies, though medical authorities throughout the world deny this. Nevertheless, the grapevine claims otherwise and doctors here and there advise against the inoculation.
HaRav Zilberstein emphatically stated: "The Torah says `and he [the physician] shall surely heal.' The Shulchan Aruch writes: `...on condition that he is sanctioned to do so by beis din.' We don't have such an authorized beis din in our times. The Aruch Hashulchan determines that in our times, the Ministry of Health is that determining body. To be sure, in a stabilized country, which applies to Israel, the Israeli Health Ministry can, therefore, rule accordingly. Period.
A pediatrician attending this lecture sought to clarify this statement. "The media blames the chareidi sector for not `sharing the public responsibility.' In my opinion, not sharing the public accountability in a big way is by not vaccinating."
HaRav Zilberstein replies, "You are right! The gemara says that if one can be healed and does not avail himself of this chance, he is considered to be shedding blood! As HaRav Dr. Menachem Chaim Breuer stated explicitly in his responsa whereby he gathered three doctors and rabbonim, that the Halacha requires everyone to be vaccinated. The Health Ministry determined that medical statistics prove that the measles vaccine saves lives. In several cases, individuals may be harmed but the vast majority of the public is spared. Therefore, it is obligatory to be vaccinated."
