Updated on September 9, 2024.
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.
In the U.S., COVID cases are already on the rise as flu and RSV season are about to get underway. But as of 2023, there are vaccines to help protect people them from all three of these seasonal threats.
Vaccination rates go a long way in determining how cold and flu seasons play out. Getting vaccinated is 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 these countries just had a bad flu season, chances are we’re next.
What did we learn this year? Some notable takeaways:
- Chile experienced very high levels of flu activity. Ecuador and Uruguay also saw high levels of severe flu-related disease, including very high levels of flu-related hospitalizations.
- Most African countries have remained at low and moderate levels of influenza detections during the 2024 season.
- Australia’s flu season peaked at the end of June—about two weeks later than last year. But it was the worst season on record since 2019, with a 10 percent increase in flu cases compared to the year before.
How COVID and RSV may complicate flu season
In 2023, more than 916,300 people in the United States were hospitalized with COVID and more than 75,500 people died from the disease. 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 2024-2025 COVID vaccine, which protects against the variants causing most infections right now. The shot can also help reduce the odds of getting Long COVID.
Ongoing wastewater surveillance shows that COVID activity is currently high or very high in many states. Since children across the country have returned to the classroom, the virus could have more opportunity to spread.
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).
Which 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.
Getting the flu vaccine doesn’t guarantee that you won’t get the flu. But in seasons when the vaccine is well-matched to most circulating influenza viruses, getting a flu shot may decrease the risk of needing medical care for the flu by 40 percent to 60 percent. And the more people who vaccinate, the better. 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: Everyone ages 6 months and older should receive the updated 2024-2025 COVID-19 vaccine.
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: For the first time in 2023, the CDC recommended three new vaccines, which 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 (Beyfortus) to protect babies and some young children from RSV. This is not a vaccine. It is a monoclonal antibody made by Sanofi and AztraZeneca. 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:
- 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.
