Projecting the transmission dynamics of SARS-CoV-2 through the postpandemic period

Aries

Administrator
Abstract

It is urgent to understand the future of severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) 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 recurrent 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 whether critical care capacities are exceeded. To avoid this, prolonged or intermittent social distancing may be necessary into 2022. Additional interventions, including expanded critical care capacity and an effective therapeutic, would improve the success of intermittent distancing and hasten the acquisition of herd immunity. Longitudinal 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.


(CNN) This may be the new normal for quite a while.

The US may have to endure social distancing measures -- such as stay-at-home orders and school closures -- until 2022, researchers projected on Tuesday. That is, unless, a vaccine becomes quickly available.

That's according to researchers from the Harvard T.H. Chan School of Public Health, who published their findings in the journal Science on Tuesday. Those findings directly contradict research being touted by the White House that suggests the pandemic may stop this summer.

The team at the Harvard School of Public Health used what's known about Covid-19 and other coronaviruses to create possible scenarios of the current pandemic.

"Intermittent distancing may be required into 2022 unless critical care capacity is increased substantially or a treatment or vaccine becomes available," they wrote in their report. "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."

The Harvard team's projections also indicate that the virus would come roaring back fairly quickly once restrictions were lifted.

"If intermittent distancing is the approach that's chosen, it may be necessary to do it for several years, which is obviously a very long time," Dr. Marc Lipsitch, an author on the study and an epidemiology professor at the Harvard School of Public Health, told reporters.

Another important factor: Whether people become immune to the new coronavirus after they have been infected. That's not yet known.

Potential challenges include finding a reliable test to determine who has antibodies for the coronavirus, establishing the level of immunity conferred by previous infection and how long it lasts, and the capacity of overstretched health systems to carry out reliable, widespread antibody tests in the general population.

There's also the difficult social questions around immunity certificates, which have been floated as a possibility in the UK. Would they create a kind of two-tier society, where those who have them can return to a more normal life, while others remain locked down?

The study researchers say they are aware that such prolonged distancing, even if intermittent, would likely have "profoundly negative economic, social, and educational consequences."

 
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