Will COVID-19 ultimately just become a seasonal nuisance? Scientists model possible futures of COVID-19 – ScienceDaily
Over the next decade, the novel coronavirus responsible for COVID-19 could become little more than a nuisance, causing only cold coughs and sniffles. This possible future is predicted by mathematical models that incorporate lessons learned from the current pandemic about how our bodies’ immunity changes over time. Scientists at the University of Utah conducted the research, now published in the journal Viruses.
“This shows a possible future that has yet to be fully addressed,” says Fred Adler, PhD, professor of mathematics and biological sciences at U. . “
The results suggest that changes in the disease could be brought about by adaptations in our immune response rather than changes in the virus itself. Adler was the lead author of the publication with Alexander Beams, lead author and graduate student in the Department of Mathematics and Division of Epidemiology at the University of Utah Health, and undergraduate co-author Rebecca Bateman.
Although SARS-CoV-2 (the sometimes fatal coronavirus that causes COVID-19) is the most well-known member of this virus family, other seasonal coronaviruses circulate in the human population – and they are much more benign. There is some evidence to indicate that one of these cold-causing relatives may have already been severe, giving rise to the “Russian Flu” pandemic at the end of the 19th century. The parallels have led scientists at the U of U to wonder if the severity of SARS-CoV-2 might similarly decrease over time.
To test the idea, they built mathematical models incorporating evidence on the body’s immune response to SARS-CoV-2 based on the following data from the current pandemic.
- There is likely a dose response between exposure to the virus and the severity of the disease.
- A person exposed to a small dose of the virus will be more likely to contract a mild case of COVID-19 and shed small amounts of the virus.
- In contrast, adults exposed to a high dose of the virus are more likely to have serious illness and to spread more of the virus.
- Masking and social distancing decrease the viral dose.
- Children are unlikely to develop serious illness.
- Adults who have had COVID-19 or who have been vaccinated are protected against serious illness.
Running multiple versions of these scenarios has shown that the three mechanisms combined create a situation in which an increasing proportion of the population will become predisposed to long-term mild illness. Scientists felt the transformation was significant enough to require a new term. In this scenario, SARS-CoV-2 would become “Just Another Seasonal Coronavirus” or JASC for short.
“When the pandemic started, no one had seen the virus before,” says Adler. “Our immune system was not prepared.” Models show that as more adults become partially immune, whether through previous infection or vaccination, severe infections will practically disappear over the next decade. Ultimately, the only people who will be exposed to the virus for the first time will be children – and they are naturally less prone to serious illnesses.
“The new approach here is to recognize the competition that exists between mild and severe COVID-19 infections and ask which type persists in the long term,” Beams says. “We have shown that mild infections will win, as long as they train our immune systems to fight off severe infections.”
The models do not take into account all potential influences on the disease trajectory. For example, if new virus variants overcome partial immunity, COVID-19 could take a turn for the worse. In addition, the forecast is based on the key assumptions of the successful model.
“Our next step is to compare our model predictions with the most recent disease data to assess the direction in which the pandemic is moving as it occurs,” says Adler. “Do things seem to be going in the wrong direction or in the right direction? Is the proportion of mild cases increasing? Knowing that this could affect the decisions we make as a society.”
The research, published under the title “Will SARS-CoV-2 Become Just Another Seasonal Coronavirus?” Was supported by COVID MIND 2020 and the University of Utah.
Source of the story:
Material provided by Utah University of Health. Note: Content can be changed for style and length.