COVID-19: Flurona, neither extraordinary nor necessarily more serious

In recent days a new term has emerged in relation to the COVID-19: fluron, a simultaneous infection of coronavirus and virus of the gripe, something that does not have to be extraordinary or necessarily more serious.

The microbiologist José Antonio López Guerrero, director of the Department of Scientific Culture of the Severo Ochoa Molecular Biology Center and director of the Neurovirology Group of the Autonomous University of Madrid, explains what flurone is, a term that arises from the combination of the words “ flu ”(flu) and“ coronavirus ”.

What is flurone?

It is a name that has been given to a mixed infection by coronavirus and influenza virus detected in Israel in a pregnant woman, not vaccinated and with practically no symptoms. They have identified it, perhaps, because they have gone to look for the presence of the two viruses in that person.

Fluron is not a chimera formed by the genomic mixture of the two viruses, but a simultaneous infection of both.

Is co-infection with two similar viruses common?

It’s something that doesn’t have to be extraordinary with the omicron variant of SARS-CoV-2 as widespread as it is. Especially now, in flu season, mixed infection is something that we are surely going to see, but they will be undetectable cases unless the specific search for the genome of the flu virus is carried out.

Surely there have been more cases than have been detected, but they have not been sought. If a person with certain flu symptoms undergoes a coronavirus diagnostic test and tests positive, they stop looking for other pathogens. Mixed infections may be underdiagnosed.

Although we have been in a pandemic for two years, protective measures against the coronavirus have protected us against other respiratory viruses; Very few cases of influenza, respiratory syncytial virus, and other airborne pathogens have been detected.

Does a co-infection make the result more serious?

It is not something mathematical that two viruses add up clinically. It may be occasionally more serious, but not necessarily; in fact, women in Israel had virtually no symptoms.

The symptoms of a mixed infection vary, depending on the viral load with which one is infected with each of the viruses and also on age, immune status, other pathologies suffered …

It can also influence whether or not we have previously passed the coronavirus infection, if we are vaccinated against one or both viruses. More serious cases can occasionally occur, but there is a lot of casuistry around infections.

What is the best way to protect against a possible co-infection?

Observe the protection measures that we already know for the coronavirus: masks, distancing, hygiene, avoiding being in poorly ventilated spaces, and, of course, vaccination, which is now a priority against the coronavirus. In addition, vaccination of risk groups for influenza would also be a good measure.

Mixed infection does not, in principle, have the profile of a more susceptible person, although obviously those vaccinated against coronavirus and influenza should have a narrow window of positivity for both viruses and, if they suffer it, they should be practically asymptomatic or silent infections.