One of the common symptoms of the coronavirus is the loss of the sense of taste. If a coronavirus patient cannot taste food, can he fulfill the Misva of Marror at the Seder on Pesah?
The answer to this question seems to emerge from the Gemara’s ruling in Masechet Pesahim that "Bala Marror Lo Yasa" – if one swallowed the Marror without first chewing it, he has not fulfilled the Misva of Marror. Although one fulfills the Misva of Masa at the Seder if he swallows the Masa without first chewing it, the Misva of Marror is not fulfilled in this fashion. The Rashbam (Rav Shemuel Ben Meir, France, 1085-1158) explains that the Misva of Marror requires one to experience a taste of "Merirut" – "bitterness" – and therefore, one who swallows the Marror without chewing, and thus does not experience the bitter taste, does not fulfill his obligation.
It would therefore seem that a person who is unable to taste food cannot fulfill the Misva of Marror. Although the patient certainly can, and perhaps should, eat the Marror, he should not recite the Beracha of "Al Achilat Marror," and should instead hear somebody else’s recitation of this Beracha.
It should be noted that a person in such a condition recites "Birkot Ha’nehenin" – the regular blessings required before eating. Although he does not enjoy the taste of the food he eats, he nevertheless experiences "Hana’at Me’ayim" (literally, "benefit of the stomach"), in that he receives nourishment and sustenance from the food, and so he recites a Beracha. The Hid"a (Rav Haim Yosef David Azulai, 1724-1806) mentions that there were people in his day who would eat raw eggs, which has no taste, and they recited the Beracha of "She’ha’kol" before eating, because they received nourishment from the egg. By the same token, one recites a Beracha over food even if he suffers from an illness which prevents him from tasting the food.
Summary: A coronavirus patient who is unable to taste food likely cannot fulfill the Misva of Marror at the Seder, and so he should not recite the Beracha of "Al Achilat Marror." He does, however, recite the usual Berachot before eating food, even though he cannot taste it.