Fall has arrived, which means respiratory illness season is around the corner. While COVID-19 hasn’t yet settled into a predictable seasonal pattern, respiratory pathogens tend to circulate in the fall and winter.

Respiratory illnesses are caused by germs that enter the nose or mouth and establish infection in the respiratory tract. These include the SARS-CoV-2 virus that causes COVID, other coronaviruses and rhinoviruses that cause common colds, influenza viruses, respiratory syncytial virus (RSV) and Streptococcus pneumoniae bacteria that cause pneumococcal pneumonia.

Respiratory illnesses share some common symptoms, including nasal congestion, coughing and a sore throat. Some people have fever, headaches and body aches. But many experience only mild or asymptomatic illness. Testing is the only way to know what you have.

Common colds usually resolve on their own with supportive care. COVID, flu and RSV also usually resolve, but they can lead to severe, even life-threatening, complications. Seniors, young children and immunocompromised people are more likely to develop severe illness.

People with cancer, especially those with lung cancer or blood cancers and those receiving treatment that impairs immune function, are more prone to severe respiratory illnesses, and they may need to take precautions, such as wearing a well-­fitted mask and avoiding indoor gatherings. While many have thrown away their masks, you can still take steps to protect yourself and vulnerable loved ones.

Vaccines work by stimulating antibody production and triggering longer-lasting memory B-cell and T-cell responses. They can lower the risk for serious illness, hospitalization and death even if they don’t always prevent infection itself.

The Centers for Disease Control and Prevention (CDC) recommends that adults should receive an annual flu vaccine in the fall. Each year, scientists design new ones based on the current circulating strains.

For COVID, adults and children should get recommended primary vaccine doses and appropriate boosters. This fall, the CDC recommends new boosters from Moderna, Pfizer-BioNTech and Novavax that target the predominant omicron XBB.1.5 variant. Some cancer patients may be eligible for extra doses.

RSV vaccines are being offered for the first time this year. The CDC advises that adults ages 60 and older should discuss with their provider whether to get the single-dose GSK or Pfizer RSV vaccine. The agency recommends a one-time pneumococcal vaccine for adults ages 65 and older.

It takes around two weeks after vaccination to reach maximum antibody levels, so get vaccinated early enough to gain full protection before a winter wave. While RSV vaccines offer protection for a year or more, SARS-CoV-2 and flu antibodies typically wane after a few months, so don’t get these vaccines too soon.

Vaccines are generally safe and well tolerated. Some people experience temporary injection site reactions, which may be accompanied by flu-like symptoms. More severe side effects are possible but rare.

People with respiratory illnesses can often manage their symptoms with supportive care at home. Seek medical care if you develop a high fever, have difficulty breathing or experience other concerning symptoms. Whatever bug you have, stay home from work or school while ill, cover coughs and sneezes, and wear a mask to prevent transmission.