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Three years into the pandemic, COVID-19 is still gaining momentum, triggering wave after wave as cases spike, subside, and then rise again. But this fall, we’ve seen something new, or rather an old one: the resurgence of the flu. In addition, respiratory syncytial virus (RSV), a virus that is usually barely talked about, has surged, causing a ‘triple infection’.
Influenza and RSV mostly disappeared during the first two winters, so the surge in these old adversaries was particularly impressive. pandemicMore surprisingly, certain versions of the flu extinct During the early COVID pandemic.of the World Health Organization monitoring program has not positively detected a B/Yamagata influenza strain since March 2020. Memphis. But “I hope it’s squeezed out,” he adds. Webby says such an extinction would be a very rare event.
But then, the last few years have been a very unusual time for the human-virus relationship, and lockdowns and masks have gone a long way in keeping the flu and RSV from entering the human nostrils. suspect another factor kept them at bay while COVID was raging. This is called virus interference and means that the presence of one virus can block another virus.
Viral interference can occur in individual cells in a laboratory, and in individual animals and people exposed to multiple viruses, but enough people are infected with one virus to pass other viruses. It can occur in whole populations if it prevents large-scale prosperity. “Looking back over the past few years, I am confident that COVID can definitely block the flu and his RSV,” he says.
This isn’t the first time scientists have observed such patterns. For example, in 2009, the feared virus was swine flu, which passed from pigs to humans in the spring of that year. It seemed to pick up steam in the fall, but suddenly it stalled in some parts of Europe.Rhinovirus, the cause of the common cold and likely spread by children returning to school, played a central role in the series of weeks before swine flu regained control. delayed the typical fall rise of RSV Two and a half months maximum.
running interference
There are many ways interference can occur within the body. One is when two viruses use the same molecule to enter the host cell. If Virus A gets there first and grabs all those molecular doorknobs, Virus B is out of luck.
Another kind of interference can occur when two viruses compete for the same resources in the cell. For example, the machinery for making new viral proteins or the means of escaping the cell and infecting other viruses. “Think of it as a race between two viruses,” he says Webby.
However, the best-understood method of interference involves defense molecules called interferons. made by the cells of all animals with backbones (and possibly some invertebrates too).In fact, viral interference Why was it named interferon First things first. When the cells sense the virus, they start making interferon. And it in turn numerous protective genesSome of the products of these genes function within cells or at their boundaries, preventing additional viruses from entering and blocking already existing viruses from replicating or exiting the cell.
Cells secrete interferon into their surroundings, warning other cells to be vigilant. The result of all this: If a second virus occurs, the cells have already activated their defenses and may be able to shut them down.
