Updated on October 22, 2025.
Once summer gives way to fall, the air chills, indoor spaces get more crowded, and many people (parents, in particular) brace for a seemingly endless string of sore throats, headaches, and runny noses.
But there are effective vaccines to help protect against three of the biggest seasonal threats: the flu, COVID, and RSV.
Vaccination rates go a long way in determining how cold and flu seasons play out. There are vaccines to protect against all three of these viruses. It’s the best way to protect yourself and others from getting sick or avoiding severe infections and related complications. But there are a few other ways experts can predict what’s to come. Here is what we know so far.
What Australia’s flu season means for U.S.
Flu season in the Southern Hemisphere starts in April and lasts until September, while it spans October to May in the Northern Hemisphere. So, flu season in Australia, South America, and Africa is ending just as it’s about to begin in the United States. U.S. health officials monitor what happens in the southern hemisphere to help predict what’s in store for the northern hemisphere. In other words, if Australia just had a bad flu season, chances are we’re next.
So how was it?
From January to April 2025, there were 70,279 laboratory-confirmed flu cases reported in Australia—a 58.6 percent increase from the same period the year before. It’s also more confirmed cases at that point in the year since 1991. But a September 2025 report from the CDC, which examined the effectiveness of the flu vaccine in eight Southern Hemisphere counties, estimates that vaccination reduced flu-related medical visits and hospitalizations by 50 percent
In the U.S., the CDC cautions that vaccination will also play a key role in reducing flu hospitalizations this season. Last year, the flu shot prevented at least 9.4 million infections, at least 170,000 flu-related hospitalizations, and up to 39,000 deaths, the CDC estimates.
How COVID and RSV may complicate flu season
COVID is still circulating. Over the past year, at least 380,000 people were hospitalized with COVID and at least 44,000 people died from the disease, according to the Centers for Disease Control and Prevention (CDC.
The virus that causes COVID is always changing. Meanwhile, people’s immunity to the disease declines over time. The best way to restore that protection is to get an updated COVID vaccine. The shot can also help reduce the odds of getting Long COVID. Ask your healthcare provider (HCP) when and where you can receive this shot.
And just as flu season gets underway, there is a third virus to consider: RSV. Respiratory syncytial virus (RSV) also tends to spread in the fall and winter months. Anyone can get it and most kids are infected by the age of 2.
Like flu, most people with RSV recover within a couple weeks. But for some people, these infections can be more serious and lead to complications—or even death.
Children and the elderly are especially vulnerable to RSV-related complications. Among children younger than 5 years old, the virus accounts for 58,000 to 80,000 hospitalizations in the U.S. every year. Among adults ages 65 and older, RSV leads to roughly 60,000 to 160,000 hospitalizations and between 6,000 and 10,000 deaths, according to the Centers for Disease Control and Prevention (CDC).
What vaccines to get—and when
The good news: There are vaccines to help protect against the flu, COVID—and now RSV.
Flu: The CDC recommends that nearly everyone aged 6-months or older receive a flu vaccine each year. September and October are the best months to get vaccinated against the flu. Ideally, everyone should get their shot by the end of October. But it’s never too late.
And for people older than 65, high-dose flu vaccines are recommended. These high-dose shots can help older people develop a stronger immune response against the flu.
Don’t be deterred by the fact that the flu vaccine isn’t a perfect shield from needing medical help for the flu (its average efficacy is about 40 percent to 60 percent). The percentage of people who get the vaccine is far more important to public health than its efficacy.
For example, a flu vaccine that’s only 20 percent effective could still save nearly 62,000 lives if 43 percent of the population got one, a 2018 study published in Proceedings of the National Academy of Sciences found. Boost that vaccination rate to 50 percent of the population, and nearly 8,500 additional flu deaths are avoided.
COVID: While updated FDA guidelines restrict COVID vaccinations to older adults or those with preexisting conditions, the Advisory Committee on Immunization Practices (ACIP)—a committee within the Centers for Disease Control and Prevention—recommends that COVID vaccines be administered to anyone 6 months of age or older after weighing the possible risks and benefits with a healthcare provider (HCP). In some areas, this includes local pharmacists.
If are unsure if you should be vaccinated or where to go if you do want the vaccine, talk to your HCP. Your provider can help you make the decision that is best for you and help you access the vaccines you need to protect your health.
You can get your flu shot and a COVID booster at the same time. It’s both safe and effective. The CDC also says that side effects are about the same whether a vaccine is given alone or at the same time as other vaccines. Tip: If you tend to get a sore arm or muscle, you can receive your shots in different arms. If you get them in the same arm, the two injections should be spaced at least one inch apart.
RSV: Since they became available in 2023, the CDC also recommends vaccines that offer protection against RSV.
- Arexvy: This is the world’s first RSV vaccine. It is a protein subunit vaccine made by GSK. A protein subunit vaccine contains protein fragments—not live, weakened forms of the virus.
- Abrysvo: This vaccine is similar to Arexvy, but developed by Pfizer.
- mRESVIA: This is an mRNA vaccine made by Moderna. This type of vaccine works by using mRNA to deliver a piece of genetic material that carries instructions for making the protein that a virus uses to infect cells. This triggers an immune response in the body.
Who should be vaccinated?
- Everyone ages 75 and older
- Adults ages 60 to 74 at increased risk of severe RSV
- Pregnant people between 32 and 36 weeks of pregnancy
The CDC also recommends nirsevimab to protect babies and some young children from RSV. This is not a vaccine. It is a monoclonal antibody made by AstraZeneca. Monoclonal antibodies are lab-made proteins that mimic the antibodies made by the body naturally. Some babies may not need this shot if their mother received the RSV vaccine at least 2 weeks before they were born. If not, one dose is given at the following ages: If not, one dose is given at the following ages:
- Babies born between October and March should get 1 dose by the time they are 1 week old.
- Babies born between April and September should get 1 dose before the start of their first RSV season (usually October).
- Some babies who are at high risk for serious illness from RSV may need another dose at the start of their second RSV season.
