The SARS-CoV2 virus, which causes COVID-19 disease in humans, emerged in late 2019.  The virus has a combination of features that unfortunately make it an extremely dangerous pandemic:

  1. It is a newly emerged pathogen to which the vast majority of humans is susceptible
  2. It predominantly produces infections that do no require medical attention and are thus never identified. Persons with these undocumented infections often experience mild symptoms and, as for common colds, typically go about their normal routine–going to work, going to school, using public transportation, shopping, taking business trips, etc.  Yet these persons are still contagious, and consequently spread the virus broadly in the community.  There is also some pre-symptomatic shedding–release of the virus into the environment prior to the appearance of symptoms.
  3. While most infections are undocumented and likely mild, more serious infections and death result for a substantial number of people.

The Response

Initially, no vaccine or effective therapeutic currently existed to combat COVID-19.  As a consequence, we need to use non-pharmaceutical interventions (NPIs) to combat and control the spread of the virus.  These include:

  • Social distancing, which limits contact between people and reduces the opportunity for transmission
  • Isolation, which removes infected persons from circulation in the general population
  • Quarantine, which preemptively sequesters persons who have been in contact with infected persons and who may themselves be infected
  • Face masks and other personal protective equipment (PPE), which limit the opportunities for virus transmission

These measures infringe on civil liberties; however, without them, model simulations of the outbreak indicate the virus will quickly overwhelm the capacity of hospital and healthcare services, will infect billions, yes, billions, of people worldwide, and will kill millions.  In addition, the quality of patient care deteriorates in these circumstances, not just for COVID-19 patients but also for routine services (e.g. childbirths, dialysis, chemotherapy, emergency services, etc.). At the same, the responses proposed are incredibly disruptive– they will elevate unemployment, shutter businesses and shock the economy.  They also will likely impose a psychological and emotional toll, and the overall economic effects may persist for years after NPI restrictions are lifted.

We are, in effect, caught between a rock and a hard place.  As a country, the US has been sheltered from such broad disruptive effects on our own soil for some time.  Not since World War II has the country been asked to collectively sacrifice on this scale.


Toward the end of 2020, a number of vaccines completed Phase III testing and were approved for administration.  These vaccines are being produced and distributed presently.  It is important that vaccine production and distribution reaches all corners of the world.  This is an ethical issue, and one that will likely help limit selection for new variants of concern.  As the vaccines are distributed, it is critical that we maintain NPI controls and ramp up distribution.  It is a race, and we want to vaccinate as many people as possible before they are infected.


Information on the outbreak, COVID-19 symptoms and seeking care can be found at WHO, CDC , New York State Department of Health, NYC DOHMH, and CUIMC websites.

Tracking of the outbreak is found at JHU CSSE, here, and the New York Times.

Research findings on the outbreak are appearing throughout the literature; many postings appear on medRxiv and bioRxiv.

Our own research and links to model outputs and movies are found here.

Interviews with various print, radio, podcast and television outlets regarding the pandemic are listed here.