Infectious disease specialist expects flu to be more significant than COVID-19

One look at the latest Centers for Disease Control and Prevention (CDC) tracking map for influenza is likely to have you seeing red – so many shades of red, in fact, that you may eventually see purple. For the week ended Dec. 2, Florida was in the “high,” or red, category, while other states, including Georgia, North Carolina, Kansas, Illinois, were all a darker red, for “very high,” with Texas and Kentucky rising to the purple peak.

While the flu “season” may vary from year to year, the most common peak month – meaning the month of highest risk – is February. And though it doesn’t happen too often, flu season can last well into May.

With winter still a couple of weeks away, “It’s a little bit hard to tell how long or how severe it’s going to be,” said Vincent Hsu, MD, AdventHealth's executive medical director for infection prevention and epidemiology. “In normal years, pre-pandemic, it could be suggested that if you have an earlier start to the season, as we have, maybe it’s over a little bit earlier. But post-COVID, all bets are off.”

It stands to reason that the earlier a vaccine is received the earlier protection ensues. Much like COVID-19 vaccines, it takes a couple of weeks for the flu vaccine to become effective. Now, at the beginning of National Influenza Vaccination Week, Dr. Hsu reminds those who have not been vaccinated against the disease that is filling hospital beds across the country, “It’s never too late.”

As flu cases continue to climb, Dr. Hsu said human behavior and lack of flu immunity are the driving forces behind what is expected to be a significant flu season. “I think it’s going to be more significant than COVID this year” in terms of both the number of cases and deaths. Unlike the CDC’s flu map, the COVID-19 tracking map offers a view of a nation covered mostly in green, denoting low community levels.

"In normal years, pre-pandemic, it could be suggested that if you have an earlier start to the season, as we have, maybe it’s over a little bit earlier. But post-COVID, all bets are off."

Though the perception may be that flu is not that serious, that it’s something that happens every year, Dr. Hsu noted that flu causes up to 52,000 deaths a year in the U.S. per season based on CDC estimates. “Getting flu can cause increases in kidney damage, heart disease, heart attacks and stroke because it causes significant inflammation of many vital organs, and that’s not well-known,” he said.

“We’ve got to get out of the mindset to focus on just one virus,” Dr. Hsu said. “We have to be looking at multiple respiratory viruses. They’re spread the same way. They cause similar symptoms.”

Most cases of flu will present as mild or moderate illness and not require hospitalization, but Dr. Hsu said the risk factors for flu are similar to those for COVID-19: the very young, the elderly and those who are immunocompromised or have other chronic health conditions.

Because different antivirals are used to treat flu and COVID-19, distinguishing between the two illnesses is important. Unlike with COVID-19, an at-home test does not exist for the flu, though Dr. Hsu predicts that time is coming.

“If you’re not feeling that sick and you’re going to stay home, you don’t necessarily need to get tested,” Dr. Hsu advised. “When it’s important to really focus on a treatment because you are at greater risk for severe illness, that’s when you should get tested because knowing what you have can make a difference when there are antivirals available.”

Combining significant science with a dose of prediction continues to render a flu vaccine that “still can be improved,” Dr. Hsu said. However, until a better-designed vaccine is available – perhaps one that uses the mRNA technology of the COVID-19 vaccines – it remains true that “the risks associated with getting the vaccine are very low while the benefits, though not as great perhaps as we’d like them to be, are still significant.”

As for this holiday season, Dr. Hsu said, “You should have fun. But you should also exhibit behaviors that will keep yourself or others as safe as possible.”