Washington: On Thursday, a team of well known pandemic experts released a report which predicts that the Coronavirus will keep spreading for another 18 months to two years, until it infects 60% to 70% of the population.

The team included Mike Osterholm, Director, Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota; Marc Lipsitch, an expert on pandemics & Epidemiologist, Harvard School of Public Health; Dr. Kristine Moore, Medical Director, CIDRAP who was a former epidemiologist at Centers for Disease Control and Prevention and historian John Barry, who wrote the 2004 book “The Great Influenza” about the 1918 flu pandemic.

The team has cautioned the US to be prepared for the worst-case scenario that includes a second wave of coronavirus infections in the fall and winter. Even in a best-case scenario, fatalities due to the virus will continue to be on rise.

“The idea that this is going to be done soon defies microbiology.” said Mike Osterholm. He further added that “This thing is not going to stop until it infects 60 to 70 percent of people.”

The report states that since Covid-19 is a new virus, no one is immune against it. As herd immunity gradually develops in the human population, it might take 18 to 24 months for the pandemic to last.

Earlier, the models presented by groups such as the Institute for Health Metrics and Evaluation (IHME) at the University of Washington or the one produced by Imperial College London, predicted that millions of deaths in the US and UK helped galvanize responses by both governments.

However, the recent report predicts differently.

The CIDRAP-led team used those reports, historical data on past pandemics, and published reports about the medical details of Covid-19 to put together their forecast.

Marc Lipsitch of Harvard School said that while trying to understand the course of a disease and how it would unfold, one should rely on history as well as models. For instance, pandemic infections don’t tend to die down in the summer, like seasonal flu does, he further added.

The report suggests that Covid-19 is most comparable to a pandemic strain of influenza. It further states that “Because of a longer incubation period, more asymptomatic spread, and a higher R0, COVID-19 appears to spread more easily than flu.” A higher R0 implies that more people will need to get infected and become immune before the pandemic can end. R0 is the average number of other people infected by each patient.

The team said that the Governments should stop telling people that the pandemic is ending and instead prepare them for a long haul.

According to the report, there are three scenarios which are possible: 

Scenario 1: The first wave of Covid-19 in spring 2020 is followed by a series of repetitive smaller waves that occur through the summer and then consistently over a one- to two-year period, gradually diminishing sometime in 2021.

Scenario 2: The first wave of Covid-19 is followed by a larger wave in the fall or winter and one or more smaller waves in 2021. “This pattern will require the reinstitution of mitigation measures in the fall in an attempt to drive down spread of infection and prevent healthcare systems from being overwhelmed,” they wrote. “This pattern is similar to what was seen with the 1918-19 pandemic.”

Scenario 3: A “slow burn” of ongoing transmission. “This third scenario likely would not require the reinstitution of mitigation measures, although cases and deaths will continue to occur.”

They recommended States and territories to plan for scenario 2, the worst-case scenario.

“Government officials should develop concrete plans, including triggers for reinstituting mitigation measures, for dealing with disease peaks when they occur,” they advised.

Lipsitch and Osterholm are perplexed by the decision of many nations to lift the restrictions with an aim to control the spread of the virus as it could certainly cost many more lives. 

“I think it’s an experiment. It’s an experiment that likely will cost lives, especially in places that do it without careful controls to try to figure out when to try to slow things down again,” Lipsitch said.

Concluding the report and thinking of the challenges that could arise during vaccine development they said that “A vaccine could help, but not quickly. The course of the pandemic also could be influenced by a vaccine; however, a vaccine will likely not be available until at least sometime in 2021.”