The worry has been raised in recent weeks by news stories of earlier and more severe RSV and flu outbreaks than in years past. A deadly concoction of viruses is created when COVID-19 is added, prompting several specialists to urge caution and look for reasons.
RSV and influenza According to William Schaffner, MD, professor of preventive medicine and infectious diseases at Vanderbilt University School of Medicine in Nashville, “are definitely getting greater attention, and they’re getting more attention for two reasons.”
“The first is that both of them are incredibly early. The second is that they are both spreading out there quite quickly “He claims.
RSV typically exhibits a seasonal trend, with January and February seeing a rise in cases. In general, both viruses tend to strike various parts of the nation at various times, but this won’t be the case in 2022. According to Schaffner, RSV typically doesn’t strike the entire nation at once.
According to Kevin Messacar, MD, an associate professor at the University of Colorado School of Medicine and a paediatric infectious disease specialist at Children’s Hospital Colorado in Aurora, CDC data shows that RSV is causing more hospitalizations and that they are occurring earlier than in any previously documented season. The rise in RSV and flu cases “is a real phenomenon for multiple reasons,” according to Peter Chin-Hong, MD, professor in the University of California, San Francisco, Health Division of Infectious Diseases, even though there may be some increase in diagnoses as a result of greater awareness.
People are moving around more now that there are less COVID-related limitations. Additionally, individuals tend to congregate indoors in the fall and winter. Because “the droplets are just simply lighter,” Chin-Hong claims that colder temperatures and lesser humidity also play a role.
He states, “I think those are all aspects.
The unusual timing and intensity of RSV and flu this year, according to Paul Auwaerter, MD, clinical head of the Division of Infectious Diseases at Johns Hopkins University School of Medicine in Baltimore, are both likely the result of a number of different factors.
According to Auwaerter, “Change in behaviour is a leading factor.” He cites examples such as more people returning to the workforce and kids attending school without masks.
According to him, fewer populations had their immune systems strengthened by exposure to these three viruses. Due to the relative lack of a virus that has been circulating in recent years, this can result in “greater susceptible populations, especially newborns and younger children.”
A Prominent Theory
Are there any consequences for those who complied with official orders to wear masks, keep to themselves, and take other safety measures during the COVID-19 pandemic?
It’s conceivable, but it’s not necessarily the complete picture.
“I believe that the theory of isolation, social withdrawal, mask use, and non-attendance at school is a very valid one when it comes to RSV,” adds Schaffner. That is [everyone’s] preferred justification.
He asserts that he is certain that prior COVID-19 public health protections are what are causing the increase in RSV infections. He is, however, “a little more cautious about influenza, in part because to influenza’s high level of variability.
If you’ve had one influenza season, you’ve experienced one influenza season, Schaffner said.
There is a lot of discussion, he continued. “Nobody can say with certainty whether the immunological deficit or debt is caused by not being stimulated and restimulated by the influenza virus over the past two seasons,” the statement reads.
An ideal storm
Chin-Hong observes, “Now you kind of have the ideal storm.” “With the new varieties that are appearing, the situation for COVID is not positive. We’re definitely more prone to contracting influenza because we haven’t seen a lot of it in the last two years.”
RSV incidence increased in the summer of 2021, but now that it’s cooler, more people are interacting. And it’s really, extremely transmittable, he adds.
Additionally, Chin-Hong asserts that “although though COVID isn’t prevalent right now, it will likely increase.”
Some scientists weren’t expecting the increase of RSV. Schaffner adds, “This early influenza is also a little surprising and may be impacted by the fact that many of us are returning and meeting each other again up close, face to face in many enclosed spaces.”
According to him, the 2022–2023 flu season began four to six weeks early “and it launches into space like a rocket. The Southeast was where it began, and it swiftly spread to the Southwest and up the East Coast. It is currently and will continue to move dramatically through the Midwest. If it hasn’t already, I’m confident it will reach the West Coast.”
Any Other Name for a Phenomenon
Others refer to the state of affairs as a “immunity deficit,” “immunity halt,” or even a “immunity debt.” The phrase “immunity debt” has drawn criticism from a number of medical professionals and immunologists who claim it is being misused to demonise COVID-19 measures.
Because the phrase “immunity debt” has recently been politicised, Messacar prefers the term “immunity gap,” which is more well-established in the epidemiology field.
According to him, the immunity gap is a scientific observation rather than a subject of debate.
Messacar and his colleagues claimed in a July 2022 article published in the journal The Lancet that “A group of susceptible people avoided infection due to decreased exposure to endemic viruses, leaving them without pathogen-specific immunity to guard against infection in the future. This immunity gap for vaccine-preventable diseases like influenza, measles, and polio is a result of declining childhood immunisation rates and disruptions to healthcare delivery brought on by pandemics.”
Older kids and new babies are being exposed to RSV for the first time, according to the researchers, as a result of isolation during the pandemic. “Youngsters are being exposed to RSV, and that’s likely the reason why RSV is moving early and very, very dramatically through this now expanded pool of vulnerable children,” says Schaffner. This includes returning to birthday parties, playing with friends, and going to school without masks.
Coinfections: How Likely Are They?
How likely is it that someone could become ill with multiple infections at once, given the predicted peaks in RSV, flu, and COVID-19 cases in the upcoming months?
People at several facilities on the West Coast were reported to have both the flu and COVID-19 early in the epidemic, according to Auwaerter. Any prognosis is now challenging due to “the unpredictable character of the Omicron subvariants and the possibility for additional alteration,” as well as the dramatic decline in flu cases over the previous two years.
Given the current level of population protection to SARS-CoV-2, Auwaerter said, “I do think it is less plausible.”
If we have high community rates of the SARS-CoV-2 and influenza circulating this autumn and winter, he says, “I’m particularly concerned about viral coinfections…in those with compromised immune systems.”
According to studies conducted during the pandemic, co-infection with the coronavirus and another respiratory virus was either extremely uncommon or non-existent.
These findings, according to Schaffner, are consistent with what he has seen at Vanderbilt University, which is a part of a network supported by the CDC that monitors laboratory-confirmed RSV, flu, and COVID-19 cases among hospitalised patients. Coinfections are quite rare, at least thus far.
Schaffner claims that should have an asterisk next to it. Looking back over the past two years, we haven’t seen a lot of influenza and our RSV seasons have been short. Therefore, there hasn’t been a lot of room for dual infections to happen.
Messacar and colleagues wrote in The Lancet and that the future is uncertain.
Chin-Hong compares the current and future state of affairs to a horse race.
RSV is the front-runner, while flu is trailing but attempting to make up ground.
“Then COVID is the underdog. Although it is currently in last place, all these variations are giving the horse extra vitamins.
Furthermore, he predicts that the COVID horse will be very competitive with the front-runner.
Chin-Hong explained that because the race is just getting started, “we’re concerned that these three [viruses] will be even more prominent come later in the year.”