  This paper introduces new methods to track the offset between two
multivariate time series on a continuous basis. We then apply this framework to
COVID-19 counts on a state-by-state basis in the United States to determine the
progression from cases to deaths as a function of time. Across multiple
approaches, we reveal an "up-down-up" pattern in the estimated offset between
reported cases and deaths as the pandemic progresses. This analysis could be
used to predict imminent increased load on a healthcare system and aid the
allocation of additional resources in advance.
