It's a long paper, but it helps explain some of the reasons for the resurgence in infection rate:
https://www.cell.com/action/showPdf?pii=S0092-8674%2820%2930820-5If one works their way through this paper, one will begin to understand the challenges in designing a vaccine that would be effective for more than a season, ala the influenza vaccines we currently have every year.
New variant of SARS-CoV-2 spreads more readily
