Social distance nearly extinguished the spread of flu and other respiratory viruses. But that means future outbreaks could be serious – and they could occur at strange or unexpected times, experts warn.
In the short term, there are fewer cases of flu means fewer deaths and hospitalizations in influenza, which reduces some of the burden on healthcare systems already closed with COVID-19, Atlantic Ocean reports. Cases of other seasonal viruses, including respiratory syncytial virus (RSV), colds coronavirus and parainfluenza viruses, which cause upper and lower respiratory tract infections, also declined to noticeably low levels this year, probably due to coronavirus-related precautions such as masking, physical distance, hand washing and limited international travel.
But experts predict that this delay in seasonal viruses could make us vulnerable, as fewer people will be exposed and given immunity to the circulation.
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“The susceptibility is increasing in the population,” said Shweta Bansal, a disease ecologist at Georgetown University in Washington, DC. told The Atlantic.
Children without prior exposure to the viruses, for example, will be born, but fewer will encounter the viruses than in an average year; meanwhile the immunity previously exposed adults will begin to decline. People with no or reduced immunity ‘are like fuel for the flu fire’, Bansal said. “The more fuel available, the easier an outbreak can happen.”
The contest could take place if COVID-19 precautions are taken, resulting in a surge in infections, said Rachel Baker, an epidemiologist at Princeton University. told Science News. As the size of the susceptible population increases, “we need to be prepared for out-of-season outbreaks and potentially large outbreaks,” Baker said.
In New South Wales, Australia, RSV cases usually peak between April and June, but during the 2020 season, the number of positive RSV tests dropped by more than 85% compared to recent years, Science News reports. But at the end of December, after the COVID-19 restrictions were lifted in New South Wales, the RSV consequences worsened; At the end of December, only a few hundred cases are usually reported, but by 2020, 6,000 positive RSV tests had emerged in just two weeks.
“This Australian case could be an interesting preview of what’s going on in the Northern Hemisphere,” Baker told Science News.
Scientists do not yet know if the coming flu seasons will be bad, reports The Atlantic. But the lack of circulating flu strains makes it harder to prepare for the season. Scientists will normally notice how different flu strains exist mutate over time to predict which versions of the virus may occur in the coming season. This early sampling helps them to formulate new flu vaccines before.
But with so few flu cases to sting this year, scientists do not have enough information. Florian Krammer, a virologist and flu expert at the Icahn School of Medicine on Mount Sinai, said the low circulation theoretically wiped out certain flu substances. But on the other hand, brand new strains can emerge without scientists knowing about it, he said.
You can read more about future flu seasons at Science News and The atlantic ocean.
Originally published on Live Science