COVID-19 - What Does Antibody Testing Reveal?

Estimated Mortality Rate (0.4%-0.82%)

Serological studies (aka: antibody tests) are taking place for SARS-CoV-2, and we are beginning to understand the larger picture of this virus. As of May 2020, these studies show that roughly 1% to 7% of the US population was already infected with SARS-CoV-2. Many of these cases were minor or asymptomatic, and they went undetected. Because of the large number of undetected cases, the current mortality rate is estimated to be somewhere around 0.4% to 0.82%, just a bit deadlier than the seasonal flu.

Potential Herd Immunity (60%–80%)

If and only if antibodies guarantee immunity, we will eventually reach some level of herd immunity in the future. Herd immunity is estimated to be somewhere between 60%-80%.

Herd Immunity — Infection vs Vaccination

Herd immunity can be achieved in a couple ways: widespread infection, widespread vaccination, or a combination of the two.

Four Possible Scenarios

With the current information available, I see four possible scenarios. The United States seems to be in scenario 4 (and trying to make scenario 2 & 3 a reality).

  • Scenario 2 — Vaccine. A safe and effective vaccine becomes available. We would artificially reach a level of herd immunity while avoiding the number of deaths as seen in scenario 1.
  • Scenario 3 — Treatment. A viable and effective treatment for COVID-19 becomes available. We would reduce the number of deaths as seen in scenario 1.
  • Scenario 4 — Slow the Spread. Implement ways to slow the spread of the virus (e.g. masks, social distancing, increased cleaning, contact tracing, testing, quarantine, etc.). Avoid spreading the virus to the most vulnerable. Overall death burden is lessened. Race to find an effective vaccine or treatment.

Unknowns & Other Assumptions

We don’t exactly know how immunity from SARS-CoV-2 works. Would immunity last a lifetime or would it only last a few months? Would a single-dose vaccine work, or would there be a need for booster shots? Can the virus remain dormant within the body and suddenly reactivate later in life, as with chickenpox/shingles?

The Fog of War

The “fog of war” is a military saying about the uncertainties for a given situation or military operation. There are many unknowns about this virus, and we are currently operating in that fog. We have to study and learn more about this virus to clear the fog. Continuing efforts like this antibody study will help in our fight against this virus.


Commercial Laboratory Seroprevalence Surveys | Coronavirus | COVID-19