Clinical Associate Professor K.C. Rondello, M.D., Sets the Record Straight About Influenza

As the flu season hits its stride, a lot of misconceptions about the illness come along with it. Following a deadly 2017–2018 influenza season, with high rates of hospitalization and mortality, it is crucial to know the facts about influenza and the benefits of getting the annual flu vaccine.

While influenza is a commonly known disease, the facts surrounding it are not. To combat some of the myths surrounding influenza, K.C. Rondello, M.D., clinical associate professor in the College of Nursing and Public Health, is setting the record straight by addressing a few common questions about the illness.

What is influenza?

Influenza (flu) is a contagious respiratory illness caused by influenza viruses. Different from a common cold, flu usually comes on suddenly and can cause mild to severe illness —and at times can lead to hospitalization or death. Some, such as older people, young children and those with certain health conditions, are at higher risk of serious complications.

People who have flu often feel some or all of these symptoms:

Fever (not all people with influenza have a fever), cough, sore throat, runny or stuffy nose, body aches, headache, chills, fatigue, diarrhea, and vomiting (not as common).

Why do we need to get a flu shot every year?

Influenza is a disease that is constantly evolving. Two surface proteins on the viral shell, hemagglutinin and neuraminidase, escort the virus into our host cells, causing infection. These surface proteins are regularly mutating and, in order for a seasonal vaccine to be effective, it must target these surface proteins. The virus targets for this year’s influenza season may or may not be the same targets as next year’s, so it is important to get a flu shot each year to combat the current season’s strain.

Why was the 2017–2018 flu season so deadly?

Last year’s influenza season was one of the worst seasons on recent record. It was considered a high-severity season with elevated levels of outpatient clinic and emergency department visits for influenza-like illness (ILI), high influenza-related hospitalization rates, and elevated and geographically widespread influenza activity for an extended period. These high levels were due to the considerable change in flu strain in the community that occurred between the time the flu vaccine was developed and when it was disseminated to the public. Because of this change, the flu vaccine was only about 40 percent effective. In a good year, the vaccine is about 70 to 80 percent effective.

What are some of the myths about the flu?

There are several myths surrounding influenza:

“Getting the flu is not serious…it’s just a bad cold.”

Influenza remains one of the most significant causes of morbidity and mortality due to infectious disease both in the United States and around the world. In fact, each year, influenza is responsible for more deaths in this country than those caused by all other vaccine-preventable diseases combined. Even if it does not prevent you from getting the flu, getting the vaccine will reduce the likelihood that you will experience severe symptoms.

“The influenza vaccine can give you the flu.”

It is a scientific impossibility. The vaccine is manufactured using a killed (inactivated) influenza virus or a single gene from the virus. Either form will induce an immune response, but neither has the ability to cause active influenza. If individuals become ill following a flu shot, they may have a different respiratory illness, they may have been exposed to influenza before they developed an adequate immune response (usually two weeks following vaccination), or they may have been exposed to a strain of the flu not covered in the vaccine.

“The flu shot is not very effective.”

The influenza vaccine will prevent influenza in those exposed to the virus more often than not. The effectiveness of the vaccine in an average year ranges from 70 to 90 percent, depending on how well the circulating viruses that year match those covered in the vaccine. While the vaccine’s efficacy in the elderly population is somewhat less, it is still more likely than not to reduce the severity of the disease, the incidence of complications (by 50 to 60 percent), and the incidence of death (by around 80 percent). Scientific studies have repeatedly shown that getting vaccinated remains the most effective way to protect against influenza and its serious outcomes.

“It’s too late for me to get the flu vaccine this year.”

Regardless of when you get vaccinated, you can still benefit from vaccination provided that the influenza virus is still circulating in the community. While flu season historically peaks between December and March, some year’s influenza is still active as late as May.

Are there plans to develop a universal, one-time flu vaccine? How would it work?

There have been several efforts underway, but the one showing the most progress has been by Vaccitech, a private spin-off of the University of Oxford’s Jenner Institute. Its vaccine targets the core protein of influenza A, which is largely stable and does not change year to year. Currently, that vaccine is being tested on just under 1,000 people, ages 65 and older, in the United Kingdom. Phase 1 testing has determined that the vaccine is safe, and now Phase 2 testing will evaluate the vaccine’s efficacy (until October 2019). If it proves to be as effective as it appears preliminarily, then the vaccine will enter Phase 3 clinical trials, which would widen the study population to other groups (such as those younger than 65) and a greater number of test subjects. If all goes according to plan, the universal flu vaccine could be on the market and available to the public in five to seven years.