Pig Trypsin Used in Making Polio Vaccine

You will be aware that WHO has been, for about a decade, carrying out a campaign to exterminate polio so that it may disappear completely from the globe. This will obviously save the world a large number of cases of disability and death and keep this terrible disease away from mankind forever, Allah willing.The polio vaccine is prepared from the polio virus, wh ich is grown on tissue culture. In order to have a successful culture, the cells must be separated from one another. This separation is accomplished by using an enzyme called trypsin, which is taken from pigs. Trypsin is added in very tiny or almost negligible amounts, for enzymes function at extremely low concentration. The separated cells are washed to remove all traces of trypsin. Then the polio viruses are planted on the cells to grow. The cultured viruses are harvested and inactivated, then added to a solution, about which there is no question of being halal. Only two or three drops of vaccine are administered orally to each child.Some of our Muslim brothers in several regions in the world, particularly in East Asia, out of piety, give the fatwa that it is impermissible to give this vaccine to Muslim children because of the use of trypsin that is prepared from pigs.Our view on the subject is as follows:Allah prohibits eating pork, and trypsin has nothing to do with pork (flesh of swine).The very tiny amount of trypsin—assuming it is unlawful—is too small to have any effect, according to the rule “if water exceeds the amount of two qullas (a measure) it carries no filth” while filth exists in it.The added trypsin is washed so well that no traces of it are left behind—even if we regarded it unlawful because of its impurity.Necessities permit unlawful things even if the three previous pleas are not sufficient.Would you please show the legal ruling in light of the above-mentioned criteria. Please keep in mind that if some Muslims refuse to immunize their children with this vaccine, only Muslim children will be at risk. Such refusal also gives a bad impression of Muslims because it hinders the eradication of the disease from all over the world forever, Allah willing, for this eradication will be incomplete as long as there remains even a single child carrying the polio virus.