Flu Season Comes With High Levels of Uncertainty, Concern

Whether it was because of increased mask use, social distancing, or general trepidation of gathering in crowds, last year was a notoriously slow influenza season.

But as more and more individuals are getting vaccinated against COVID-19 and congregating more in public, what does this year hold?

Could we see a return of the flu or are the lessons learned from almost completely mitigating against the flu here to stay?

The ContagionLive® team with the help of some infectious disease experts are hoping to answer some of those questions with Twindemic: Potential Ramifications of COVID-19 and Flu Convergence.

Predicting Flu Season

The headline article of the flu e-book is article on remaining diligent against influenza penned by Saskia v. Popescu, PhD, MPH, MA, CIC.

Popescu said a summer surge of respiratory syncytial virus (RSV) is worrisome and could forecast some issues with influenza in the coming months.

“This is rather unusual and shows a shift in what we saw during the 2020-2021 respiratory virus season,” she said. “Despite historical lows of influenza and other respiratory viruses during this past flu season, the worry is that as schools go back and travel increases, and as more ‘over COVID-19’ feelings arise due to fatigue and vaccines, we will see an increase in these viral infections.”

But as the US is not out of the woods yet with COVID-19, many are still taking some precautions that could have an impact in combating the spread of the flu.

For example, the attention to hygiene and use of hand sanitizer and disinfecting wipes are critical in helping reduce not just COVID-19, but other respiratory viruses like influenza.

One potential bright spot can be found from other countries whose influenza seasons generally begin earlier in the year than it does in the US.

So far, Australia and other countries in the southern hemisphere have had minimal or nominal numbers of influenza cases.

However, another potential concern is that because of last year’s light season, a far less percentage of the population have flu immunity.

Protecting Yourself

But regardless of the season, there are ways to mitigate against influenza that the general population should follow.

First and foremost, there are several vaccines available including inactivated influenza vaccine both as egg-based and cell-culture-based products, adjuvanted vaccine, recombinant flu vaccine product, and intranasal formulation.

All of these vaccines are now quadrivalent and a high-dose vaccine is available for individuals 65 years and older.

Looking Back at Last Year

What happened last year that brought down flu cases to such historic lows?

For example, only 273 total positive cases were reported in the United States for the week ending January 16, according to CDC FluView data. Just a year before, positive influenza cases in the same week had exceeded 3000.

Looking back, there was not 1 singular measure that resulted in the extreme reduction of flu cases, but masking, distancing, and other COVID-19 mitigation measures all played a part in this.

For example, there was an 11% increase in total distribution of influenza vaccines with 194 million doses distributed last season in the US.

Per a CDC survey in early February, 55% of all US adults had already received an influenza vaccine compared to the 48% reported at the end of the 2019-2020 season.

Closing the Gaps

While the COVID-19 pandemic offered an opportunity to improve and expand diagnostic testing and care for respiratory viruses, there are still gaps that need to be closed.

One of the ways COVID-19 exposed issues in healthcare can be found in testing accessibility, timeliness, and accuracy. All 3 of these measures have improved drastically.

“[COVID-19] has brought attention to the notion of the varieties of respiratory infections that are out there,” William Schaffner, MD, a professor of preventive medicine and health policy at Vanderbilt University School of Medicine in Nashville, Tennessee, said in an interview with Contagion®.

The previous standard of nearly a week turnaround time for test results has been reduced to 3 days or fewer as reliable clinical- and home-based assays have become available.

But there is still work to be done, as multiplex tests, which can more accurately differentiate between the different influenza strains, still need to be refined.

For example, rapid influenza molecular assays with high sensitivities and specificities have been developed that can detect a virus—and sometimes discriminate between strains—quickly.

Rapid influenza diagnostic tests allow for quicker detection of both influenza A and B viruses, but the ability to further identify the subtypes of influenza viruses is limited.

And expanding and refining new technologies in these areas is paramount for public health, whether it is combating current strains of influenza, new COVID-19 variants, or preparing for the next pandemic.

Even with caseloads low, technologies and practices for respiratory virus diagnostics will constantly undergo review while access to care should be prioritized to close some of the disparities seen in the past.

But public health officials and other decision makers have the opportunity to now learn from the mistakes of the past to better prepare for the future.

“We Americans have a very short attention span,” Schaffner said. “There’s always the new frontier. We look to the future much better than we look at the past—and we frequently forget our lessons.”

To read interviews with experts, insights into influenza therapies, how one large US health system is preparing for the season, and more, go here to download the free e-book.