Epidemiologists lay out 3 future scenarios for pandemic, warning COVID-19 crisis not over

Similarities, differences between 1918 and 2020 pandemics

In many ways, 2020 is looking like 1918, the year the great influenza pandemic raged. Like then, science is unable to crush an insidious yet avoidable infectious disease before hundreds of thousands die from it.

LOS ANGELES - Authorities around the world are beginning to ease their coronavirus lockdown restrictions despite warnings from medical experts and no concrete date as to when a vaccine will be available.

As new cases and deaths continue to climb daily in the United States, some government officials have argued that the warmer weather of the summer may result in a retreat of the virus, but researchers have warned of a deadly second wave even as the first wave of the virus has yet to abate.

The question many health experts are seeking to answer is: Have we learned lessons from the past few months under strict social distancing orders that can prepare American society for what is yet to come in the future of the COVID-19 pandemic?

Epidemiologists for the University of Minnesota Center for Infectious Disease Research and Policy (CIDRAP) have laid out three possible scenarios for how the U.S. will likely be impacted by COVID-19 in the months to come as the death toll for the virus topped 77,000 and reported cases neared 1.3 million in the country as of May 8, according to data from Johns Hopkins.

The medical experts warn that “we must be prepared for at least another 18 to 24 months of significant COVID-19 activity.”

Drawing upon lessons learned from eight major pandemics that have occurred since the early 1700s, the epidemiological report lays out a grim scenario for the ongoing COVID-19 era as the world barely begins to grapple with the already devastating effects the novel coronavirus has had on the social and economic fabric of the U.S.

Millions of people have been sheltering inside their homes as authorities around the world have implemented various social distancing measures in hopes of stopping the spread of the novel coronavirus. While the pandemic has sent the U.S. economy crashing into Great Depression-era unemployment numbers, the appearance of summer has been cited, with little evidence, as a beacon of hope for many desperate to return to normalcy, with speculation over the potential for warmer weather to help tamp down the virus.

FILE -In this photo illustration the Coronavirus COVID-19 Global Cases world map by the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University (JHU) seen displayed in internet on a pc screen. (Photo Illustration by Pavlo Gonchar/SOPA Images/LightRocket via Getty Images)

But according to the CIDRAP report, out of nearly every pandemic that has occurred since the the 18th century, “no clear seasonal pattern emerged for most.”

“Two started in winter in the Northern Hemisphere, three in the spring, one in the summer, and two in the fall,” according to the report.

Some of the key points from observations made about previous pandemics suggest that the COVID-19 pandemic will likely persist over 18 to 24 months before any level of “herd immunity gradually develops in the human population.”

The CIDRAP epidemiologists cautioned that considering the extraordinary transmissibility of COVID-19, “60% to 70% of the population may need to be immune to reach a critical threshold of herd immunity to halt the pandemic.”

The concept of “herd immunity” is further complicated by the fact that scientists still do not know the duration of immunity conferred to people through natural novel coronavirus infection.

But with millions of people barreling toward a return to social behaviors through the loosening of lockdown measures across the country, the CIDRAP report lays out three possible “wave scenarios” for the future of the ongoing COVID-19 pandemic.

Each scenario is dependent on the specific types of social distancing and mitigation measures that are put into place, and each scenario assumes that some level of mitigation will occur.

Scenario 1: Peaks and Valleys

Epidemiologists say this scenario involves a series of “repetitive smaller waves” which occur consistently over a one to two-year period, with the waves of new infections gradually diminishing over time.

“Depending on the height of the wave peaks, this scenario could require periodic reinstitution and subsequent relaxation of mitigation measures over the next 1 to 2 years,” the report says.

Scenario 2: Fall Peak

In this situation, a larger wave of the novel coronavirus in the fall or winter of 2020 follows the spring 2020 outbreak, which will then be followed by “one or more smaller subsequent waves in 2021.”

Mitigation measures will have to be swiftly enacted again in order to prevent the health care system from becoming overwhelmed, according to the report.

Epidemiologists say this pattern is similar to what was observed in the 1918-19 Spanish Flu pandemic, during which the virus subsided in the summer months only to return in a much larger peak in the fall of 1918. A third peak occurred in the winter all through spring of the following year, until eventually subsiding again in the summer of 1919.

Scenario 3: Slow Burn

A “slow burn” of the pandemic would look like a sustained continuation of cases over a long period of time with “no clear wave pattern.” Epidemiologists say this third pattern has not been identified in previous influenza pandemics, but remains a possibility for COVID-19.

“This third scenario likely would not require the reinstitution of mitigation measures, although cases and deaths will continue to occur,” according to the report.