From the Rabbinical Alliance of Ameria/Igud HaRabbonim Halacha Commission:
1) Follow your doctor’s orders. Most people should go to shul and fulfill the Purim mitzvos as usual. However, every person’s health situation is different.
2) For the protection of the community, if you are under quarantine or showing symptoms of illness you must stay home even if that means refraining from fulfilling the mitzvos of Parshas Zachor and Purim. Going to shul may mean endangering the lives of the elderly and of children.
3) Someone in quarantine should try to pray at the same time as the community, if possible.
4) The fast of Taanis Esther should be observed as always unless you have doctor’s orders to eat or your local circumstances are so dangerous that you must eat.
5) Under normal circumstances, the custom to give Machatzis HaShekel with half-dollar coins should be fulfilled before or on Purim. If you cannot do so because of quarantine, you should appoint a messenger to give it to the shul collection Pushka. If none of this is possible, you can fulfill the custom of Machatzis HaShekel anytime.
6) It is a biblical obligation to hear Parshas Zachor read from a Torah. Under normal circumstances, every effort should be made to hear it. However, you are required to hear it once a year and can also fulfill it with Maftir of Parshas Ki Seitzei during the summer, and according to some with the Purim Torah reading. If you cannot attend shul for Parshas Zachor, you should read it from a Chumash on that Shabbos and make sure to listen carefully to Maftir of Ki Seitzei. (Ask the Ba’al Korei at that time to have in mind to be motzi you.)
7) Under normal circumstances, every effort must be made to hear Megillas Esther in shul. If you cannot, you can read it to yourself from a scroll with all the blessings except “Horav es riveinu.” If you do not have a scroll, you should read it from a Chumash — even without the trop (tune) — without the blessings.
8) You can give Matanos LaEvyonim by appointing someone (via telephone) as aa messenger to do it for you. You can also fulfill the mitzvah by donating with a credit card or bank transfer. Make sure to give to a legitimate charity that gives money to the poor on Purim day itself.
9) Similarly, you can give Mishloach Manos by appointing someone else to give for you or ordering a delivery from a shul or online service. Make sure the Mishloach Manos is delivered during the day of Purim.
10) Under normal circumstances, your Purim meal must consist of at least bread, wine, and meat. When sick or in danger, eat appropriate foods in proper measures based on your doctor’s guidelines. It is a mitzvah to drink even a little more wine than your usual, provided your doctor approves.