One of the flu viruses has disappeared. What could this mean? Two scenarios and a question mark

The restrictions introduced in connection with the attacking COVID-19 pandemic had an effect that surprised the world (or at least part of it). Flu has fallen to unprecedented levels. Scientists from the University of Melbourne claim that due to the lack of people to be infected, one of the main lines of the flu virus – the Yamagata line – may have died out. Where do these conclusions come from and what does it mean for us?

1. The COVID-19 pandemic may have exterminated the Yamagata influenza virus
2. It turned out that from April 2020 to August this year, no infection with this pathogen has been registered anywhere in the world.
3. Scientists ask themselves whether B / Yamagata is gone for good or just hiding. As they note, B lines of the influenza virus “periodically go into a” dormant “state”
4. When will we be sure of the fate of B / Yamagata, and what impact might his extinction have on mankind?
5. More information on interesting information can be found on the Onet homepage.

“Side” effect of the COVID-19 pandemic: a drastic decrease in flu cases

Since April 2020, the number of detected influenza viruses has decreased drastically – scientists from the University of Melbourne write in the pages of Nature Reviews Microbiology. As they note, compared to the previous years, this decrease amounts to approx. 99%. despite more or less similar test levels. This is all thanks to behavioral changes that the SARS-CoV-2 coronavirus has forced on us. It goes, among others for social distance, wearing protective masks, observing hand hygiene, but also restrictions in traveling and moving around. Researchers point out that the declines are not only related to the flu, but also to other common respiratory infections.

As for the flu itself, scientists noticed another change. The genetic diversity of influenza viruses has also decreased dramatically. At this point, we must remind you that influenza viruses are divided into four types – A, B, C and D. The first two annually take their toll on us, especially in the fall and winter season (as reported by the National Institute of Public Health – National Institute of Hygiene since the 2009/2010 epidemic season, there are cases in Poland caused by an infection caused by influenza A and B viruses).

Type C causes mild infections (usually asymptomatic), and the influenza D virus causes infections in cattle. Influenza A viruses are genetically very variable, so different variants can attack us every season. Type B is more stable in this respect – there are only two genetic lines: Victoria and Yamagata.

Data collected in the international GISAID database (including information on influenza viruses, but also on SARS-CoV-2) show that the number of A and B / Victoria variants detected has decreased since the beginning of the pandemic. What is most noticeable are the statistics related to the Yamagata lineage.

Has the Yamagata influenza virus gone – extinct or “dormant”?

It turned out that from April 2020 until August this year, no infection with the Yamagata influenza virus has been registered anywhere in the world. While public health officials have reported 31 cases of suspected type B / Yamagata infection, it has not been possible to establish whether he was actually responsible for the disease.

The researchers note that the Yamagata lineage has always been less contagious than other major strains of influenza. This variety does not evolve as vigorously as others. These factors, “combined with the suppressive conditions of the COVID-19 pandemic, may have facilitated the strong suppression of the global B / Yamagata circulation and the potential extinction of this lineage,” the researchers write in a report published in Nature Reviews Microbiology. The word “potential” is key here. The question is whether B / Yamagata is gone for good, or is he just hiding. As Australian scientists note, B-lines of the influenza virus “periodically” go to sleep “”. This was the case of the B / Victoria line in the 90s – it remained largely undetected all over the world and then struck again.

There are many question marks, but there is no doubt that it will take more than one flu season to determine whether B / Yamagata is actually extinct. “I would have doubts, calling it a finite process, flu is a capricious beast,” said Richard Kennedy, a leading vaccine researcher at the prestigious Mayo Clinic in Rochester (USA) on webmd.com. The researcher noted that B / Yamagata tends to increase at certain times and virtually disappear at other times. Could that be this flu season? It remains to be seen, but there are concerns that the fact may be difficult. “These viruses make up for lost time very well,” warns Kennedy.

What does the disappearance of the Yamagata virus mean for us? Two scenarios

However, if the entire B / Yamagata line were to die, it would open up new avenues for tackling the seasonal flu. It is primarily about vaccines. Australian scientists see two possible scenarios.

The first assumes a return to the trivalent vaccine (protects against two types of virus A and the B / Victoria line), thanks to which the preparation will be cheaper and easier to produce. This, in turn, creates the possibility of increasing the global production and distribution of these preparations from 500 million to 700 million doses annually. The second option is to add two more strains of influenza A to the vaccine, which would improve its effectiveness. As explained by professor of preventive medicine William Schaffner, replacing B / Yamagata with another more infectious and dangerous strain may improve the effectiveness of the preparation.

Both Richard Kennedy and William Schaffner agree that if we get the flu vaccine and adhere to the COVID-19 sanitation regime (facials, distance, hygiene), there is a chance that B / Yamagata may disappear for good .

You may be interested in:

1. COVID-19 and the flu at the same time? It is possible. Doctor: disastrous consequences
2. Expert: Flu and COVID-19 vaccines can be given in one visit
3. Flu vaccine free for adults. How to sign up?

The content of the medTvoiLokony website is intended to improve, not replace, the contact between the Website User and their doctor. The website is intended for informational and educational purposes only. Before following the specialist knowledge, in particular medical advice, contained on our Website, you must consult a doctor. The Administrator does not bear any consequences resulting from the use of information contained on the Website. Do you need a medical consultation or an e-prescription? Go to halodoctor.pl, where you will get online help – quickly, safely and without leaving your home.