Not yet. I believe Novavax's protein subunit vaccine would use the same mechanism as the MMR vaccine. Well outside my domain but my understanding is that you're given a premade dose of SARS-CoV-2 spike proteins and an adjuvant to boost an immune rsponse to them, instead of producing the spike proteins yourself (as is the case for both mRNA and viral vector vaccines). [1] gives results of their phase 3 trials. The Atlantic [2] gives an overview aimed at a popular audience.