Posted 12 февраля 2021,, 08:33

Published 12 февраля 2021,, 08:33

Modified 24 декабря 2022,, 22:38

Updated 24 декабря 2022,, 22:38

Doctors predict unexpected and dangerous return of influenza

Doctors predict unexpected and dangerous return of influenza

12 февраля 2021, 08:33
Фото: Cleveland Clinic
Humanity has spent the last year practically without seasonal respiratory viral infections. However, the current situation in the Southern Hemisphere shows that this respite has made us more vulnerable than ever, and the next flu season threatens to be unpredictable.

This year, doctors have seen almost no cases of influenza and other seasonal viruses, including respiratory syncytial virus (RSV), cold coronaviruses, and parainfluenza viruses that cause upper and lower respiratory tract infections. This is most likely due to the precautions taken around the world due to the pandemic: wearing masks, physical distance, hand washing and travel restrictions. However, this means that future outbreaks of respiratory viral infections could be especially serious - and occur at the most unexpected times, The Atlantic warns. Experts predict that a respite from seasonal viruses could make us especially vulnerable, because there are few people who have acquired immunity to circulating strains, and the susceptibility of the general population is growing.

For example, children this year were born as usual, but they encountered viruses much less frequently than in previous years. At the same time, the immunity developed during past outbreaks is weakening, and in adults. If we liken the flu to fire, then people with absent or reduced immunity are like fuel for it. And the more fuel there is, the faster the flash will happen. It could happen when there are fewer cases of covid, precautions are relaxed, and the population susceptible to seasonal viruses grows. Experts believe that this time you need to be prepared for outbreaks in the offseason.

These forecasts are confirmed by the situation in New South Wales in Australia. Typically, the peak of respiratory syncytial virus (RSV), which causes upper respiratory tract infections, occurs there from April to June, but in the 2020 season, the number of positive tests fell by more than 85%. However, at the end of December, when the covid restrictions were lifted, cases of RSV increased dramatically. If in past years, at the end of December, only a few hundred cases were reported, but in 2020, in just two weeks, 6,000 positive tests for RSV appeared. According to experts, the Australian case may be an omen of what will happen in the Northern Hemisphere.

It is difficult to predict the future now: the lack of circulating strains of influenza makes it very difficult to prepare for the season. Scientists usually track how different strains of influenza mutate, and based on this, predict which versions of the virus might be spread in the coming season. This early sampling helps advance the development of new influenza vaccines. But with a paltry number of flu cases this year, data is scarce.

It is possible that low circulation could theoretically kill some strains of influenza. On the other hand, completely new strains may appear that scientists do not know about. One thing is clear: the next flu season could be completely unpredictable and potentially very difficult.

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