Respiratory virus season is here: flu, COVID and RSV, and how to prepare this fall

Every year, as fall arrives in the Northern Hemisphere, health services brace for the same thing: a rise in respiratory infections. We spend more time indoors, ventilate less, and viruses find favorable conditions to spread. The three main players are influenza, COVID-19 and respiratory syncytial virus (RSV), along with the many viruses behind the common cold.

Why infections climb in fall and winter

It isn't the cold itself that makes us sick but a combination of factors. In colder months we spend more hours indoors, close to other people and with windows shut, which makes it easier for viruses to spread through the air. Some studies also suggest that dry air helps certain viruses survive longer and that the nose's defenses work a little less well at low temperatures. The return to school plays a role too: children share viruses easily and bring them home.

Vaccines: the first line of defense

Specific recommendations vary by country, so check with your doctor, pharmacy or local health department. In general, health authorities tend to recommend:

• A flu shot every year for older adults, pregnant people, those with chronic conditions (heart, lung, diabetes, kidney), health workers and, in many countries, young children. Some places, including the United States, recommend it for nearly everyone aged six months and older. Because the virus changes, the vaccine is updated every season.
• An updated COVID-19 vaccine for older adults and higher-risk groups, according to each country's schedule.
• RSV protection: in recent years, vaccines have become available for older adults and pregnant people, along with antibody shots to protect babies during their first season. RSV is one of the leading causes of bronchiolitis in infants.

Vaccines don't prevent every infection, but they significantly reduce the risk of severe illness, hospitalization and complications.

Simple measures that work

1. Ventilate. Opening windows for a few minutes several times a day refreshes the air and lowers the concentration of virus-laden particles. Air purifiers with HEPA filters can also help in rooms that are hard to ventilate.
2. Wash your hands with soap and water, especially before eating and after blowing your nose.
3. Cover coughs and sneezes with your elbow or a disposable tissue.
4. Stay home when you're sick whenever possible, so you don't infect others.
5. Wear a mask in specific situations: if you have symptoms and need to go out, when visiting vulnerable people or in health care settings.
6. Look after your habits: good sleep, a varied diet and staying active help your immune system work better.

Cold, flu or COVID: telling them apart

Symptoms overlap a lot, and only a test can confirm which virus you have. As a rough guide:

• Cold: usually comes on gradually, with congestion, sneezing and a mild sore throat. High fever is rare.
• Flu: starts suddenly, with high fever, intense muscle aches, chills and exhaustion.
• COVID-19: can resemble either. It sometimes includes loss of smell or taste, though that's less common than early in the pandemic.
• RSV: in healthy adults it often looks like a cold, but in babies and older adults it can cause breathing difficulties.

Rapid antigen tests sold at pharmacies can help detect COVID-19, and some combination home tests also detect flu.

Caring for yourself at home

Most respiratory infections clear up on their own within one to two weeks. In the meantime: rest, plenty of fluids, acetaminophen (paracetamol) or ibuprofen for fever or aches (following the label and without combining products that contain the same active ingredient), and honey to soothe a cough in adults and children over one year old. Antibiotics don't work against viruses and shouldn't be taken without a prescription. For people at high risk, doctors may prescribe antiviral medicines for flu or COVID, which work best when started early, so call promptly if you fall into a risk group.

Warning signs

Seek medical care if you notice:

• Difficulty breathing or very rapid breathing.
• Chest pain or pressure.
• A high fever lasting more than three days, or one that returns after improving.
• Confusion, excessive sleepiness or difficulty waking up.
• Bluish lips or face.
• In babies: refusing feeds, pauses in breathing, ribs pulling in with each breath or fewer wet diapers.
• A chronic condition such as asthma or heart failure getting worse.

Get ready early

The best time to get vaccinated is before viruses circulate widely, usually in October or November in the Northern Hemisphere. Checking your medicine cabinet, keeping a thermometer handy and knowing whom to call if you're unsure also help you get through the season with more peace of mind. With a few simple steps, we can protect ourselves and the people who need it most.