Actually to be accurate I should say that both SARS and COVID19 are CAUSED by coronaviruses. Semantics, but I suppose it's best to be accurateTLDR: There was work on corona vaccines and functional corona vaccines for dogs before COVID19 became really known because COVID19 is a novel corona virus.
To clarify on this, COVID19 is a novel coronavirus, which has existed long before COVID became well known. SARS is also a type of coronavirus. There was work on a SARS vaccine prior to COVID, and there were corona vaccines available for dogs, which provided framework for the COVID19 vaccinations which may have allowes the work to progress more quickly.