2020-04-17

It is urgent to undersatnd the future of severe acute respiratory syndrome -coronavirus2 transmission.we used estimates of seasonality,immunity, and  cross-immunity for betacoronaviruses OC43 and HKU1 from  time series data from the USA to inform a model of SARS-COV-2 transmission.We projected that recuurent wintertime outbreaks of SARS-COV-2 will probably occur after the initial ,most severe pandemic wave. Absent other interventions, a key metric for the success of social distancing  is wether critical care capacities are exceeded. To avoid this ,prolonged or intermittent social distancing may be necessary into 2020. Additional interventions,including expanded critical care capacity and an effective theapeutic ,would improve the success of intermittent distancing and hasten the acquisition of herd immunity. Longtitudinal serological studies are urgently needed to determine the extent and duration of immunity to SARS-COV-2. Even in the event of apparent elimination ,SARS-COV-2 surveillance should  be maintained since a resurgence in contagion could be possible as late as 2024.