How to Prepare for Respiratory Illness Season: Get Vaccinated.

An infectious disease expert at Rutgers Health explains the importance of getting crucial shots this fall

Between Oct. 1, 2024, and May 17, an estimated 47 million to 82 million people contracted the flu, with hundreds of thousands hospitalized and 27,000 to 130,000 deaths, including 266 children- the highest number of pediatric deaths reported in any non-pandemic influenza season since the condition became reportable in 2004 - according to preliminary data from the U.S. Centers for Disease Control and Prevention (CDC).

The CDCestimates that in the 2024-2025 flu season between 610,000 and 1.3 million people were hospitalized for flu and 27,000 to 130,000 died. During the season, the CDC also estimates 370,000 to 530,000 hospitalizations and 42,000 to 61,000 deaths resulted from COVID-19and 190,000 to 350,000 hospitalizations and 10,000 to 23,000 deaths resulted from respiratory syncytial virus (RSV).

Mid-September to late October is the optimal window for people to receive the updated vaccinations to protect against severe illness this fall and winter.

David Cennimo

Rutgers New Jersey Medical School

Mid-September to late October is the optimal window for people to receive the updated vaccinations to protect against severe illness this fall and winter, said David Cennimo, an infectious disease expert at Rutgers New Jersey Medical School.

Cennimo discusses what is known about the upcoming respiratory illness season and how to protect yourself.

What can we learn from last year's flu season - and what should we expect this year?

The 2025-2026 influenza season is predicted to peak sometime between late fall and early spring with the CDC currently predicting a "moderate" number of infections.

The southern hemisphere influenza season is ending now and may provide some clues and predictions for the U.S. In Australia, the influenzas season peaked earlier than average and was augmented by high levels of co-circulating COVID-19 and RSV infections.

What strains or variants will this year's vaccines cover?

The 2025-2026 U.S. flu vaccine is trivalent, meaning that it contains three different strains of influenza predicted to be most like what will be seen this year.

Past years have been quadrivalent - four stains - however, the Yamagata lineage of Influenza B has not been seen in circulation since COVID-19 and has been removed.

Slightly different virus strains are used for the egg-based vaccine versus cell culture-based vaccines. These changes address the ability of the virus to replicate and provide the best vaccine. At the individual patient level, they are interchangeable.

The only advice I routinely give related to the specific type or brand of vaccine is for people 65 or older to attempt to get a "high dose" or adjuvanted flu shot. These stimulate more response in older immune systems. However, if they are not available, a standard influenza vaccine should be given.

Multiple studies have demonstrated significantly reduced symptoms and a milder infection in vaccine recipients who become infected.

Who should receive a vaccination for the flu and COVID-19?

The CDC recommends that people 6 months and older receive vaccinations for the flu.

As recommendations for COVID-19 are changing, you should speak with your doctor. The New Jersey Department of Health recently issued an executive directive, allowing anyone 6 months of age and older to receive a COVID-19 vaccine for the 2025-2026 respiratory illness season. The department also issued a standing order authorizing pharmacists in New Jersey to administer COVID-19 immunizations without a prescription.

Is RSV a concern again this year?

RSV is a common respiratory virus that usually causes mild, cold-like symptoms. The CDC recommends that infants 8 months and younger during RSV season receive an RSV immunization unless their mother was adequately vaccinated during the pregnancy. Older babies with certain medical conditions - in their second RSV season - may remain at high risk for complications from RSV infection and may require a second immunization.

Adults ages 50 to 74 with increased risk of severe RSV infection and everyone 75 or older should consider being vaccinated with one of three available RSV vaccines. Pregnant people should consider being vaccinated with the Abrysvo vaccine between 32- and 36-weeks gestation. Currently, RSV vaccines are only recommended for a one-time dose.

Why is mid-September to late October the best time to receive these vaccinations?

The influenza vaccine is effective for about six months, so if you get vaccinated too early there is a chance your immunity might wane. Children receiving their first influenza vaccine need a second dose at least four weeks later. Check with your doctor. The RSV season varies but usually starts in the fall and the rates of COVID-19 tend to increase in fall winter.

These vaccines take two weeks to be effective, so people still could contract these viruses during this period.

Since RSV season starts in October, vulnerable people should receive the vaccine as soon as possible.

Are these vaccines safe?

Extremely rare side effects - like allergic reaction - can happen, but the risk is still lower than with many other common medications. You can get a flu shot even if you are allergic to eggs. Serious reactions to the small amount of egg protein in flu vaccines are unlikely.

Can you get the flu, COVID or RSV from the vaccine?

These vaccines take two weeks to be effective, so people still could contract these viruses during this period. COVID-19 vaccines contain no live virus so there is no way to become infected from the vaccine. With the flu vaccine, live viruses are grown but killed so there is no possibility of infection after vaccination, either.

How can I tell if I have the flu, COVID-19 or RSV?

Flu symptoms can be confused with COVID. If you start feeling ill, it is important to quarantine and test for COVID to rule it out.

The symptoms for RSV are like the common cold. They tend to run their course with only mild intensity in adults and older children. In infants and the elderly, symptoms tend to be more severe and can include fevers and wheezing.