COVID-19 Distancing May Be the New Normal

The April 14th report in Science from researchers at the Harvard T.H. Chan School of Public Health, Projecting the transmission dynamics of SARS-CoV-2 through the postpandemic period, offers the headline-grabbing conclusion that prolonged or intermittent social distancing may be necessary into 2022 to avoid exceeding critical care capacities. (The model runs through 2025.) That conclusion is premised on the absence of new therapeutics, a vaccine, or "aggressive contact tracing and quarantine" that might be more practical once distancing policies have adequately suppressed transmission.

Come for the headlines, stay for the two-strain ordinary differential equation (ODE) susceptible-exposed-infectious-recovered-susceptible (SEIRS) compartmental model describing the transmission dynamics of human coronaviruses OC43 and HKU1.

The authors identify viral, environmental and immunologic drivers of SARS-CoV-2 transmission dynamics to develop a model that is informed by observed transmission dynamics in the U.S. of those two human coronaviruses (e.g., seasonal variation, duration of immunity and degree of cross-immunity) as well as observations to date of SARS-CoV-2. Multiple simulations were run that yielded several key points.

• SARS-CoV-2 can proliferate at any time of year
• If immunity to SARS-CoV-2 is not permanent, it will likely enter into regular circulation
• High seasonal variation in transmission leads to smaller peak incidence during the initial pandemic wave but larger recurrent wintertime outbreaks
• If immunity to SARS-CoV-2 is permanent, the virus could disappear for five or more years after causing a major outbreak
• Low levels of cross immunity from the other betacoronaviruses against SARS-CoV-2 could make SARS-CoV-2 appear to die out, only to resurge after a few years

Among other things, this modeling underscores the critical need to (1) understand SARS-CoV-2 immunity and cross-immunity, requiring long-term serological studies, and (2) implement widespread surveillance in order to most effectively dial distancing policies up and down to maintain a level of control over transmission.

Note the absolutely essential role of well validated and high sensitivity/specificity RNA and antibody tests, and widespread, ongoing, high volume test deployment. This is a critical focus right now for AdvaMed and AdvaMedDx, our diagnostics division.

For a wealth of additional information on COVID-19 and how the medical technology industry is fighting the pandemic, see AdvaMed's COVID-19 MedTech Resource Center.