Great vaccines against Covid-19 have been developed at breath-taking speed, and they all are very effective. However, the most effective against the omicron variant seems to be a third shot (a booster shot) of the BioNTech/Pfizer vaccine (I give you this information without guarantee).
Doctors and hospitals have learned a lot as regards how to treat patients with Covid-19, for example, the use of dexamethasone, a medicinal drug that had existed long before the Covid-19 pandemic.
Many new medicinal drugs and new monoclonal antibodies to treat patients with Covid-19 have been developed. It has been a sad story so far. Most of them are marginally effective. However, molnupiravir seems to be promising. Molnupiravir currently is under evaluation by the EMA (European Medicines Agency) and could be approved soon.