So far, 2025 has been the winter of respiratory ailments, with influenza, COVID-19, and respiratory syncytial virus (RSV) making up three-fourths of what some are referring to as the “quademic.” But one we haven’t heard relatively much about is pneumonia.

“One in approximately five patients who develops pneumonia ends up in the hospital in this country,” says Dr. Mark Metersky, chief of UConn Health’s Division of Pulmonary, Critical Care and Sleep Medicine.

We’re hearing more about it now, with Pope Francis in an Italian hospital and reported to have bilateral pneumonia, meaning pneumonia in both lungs.

“Pneumonia is often on both sides, not always, but the more lobes that are involved, the more lung tissue that’s involved, the more serious it is, on average,” says Metersky, who is a coauthor of the American Thoracic Society’s guidelines for pneumonia diagnosis and treatment, published in the American Journal of Respiratory and Critical Care Medicine in 2019.

“Pneumonia itself refers to an infection of the lower respiratory tract – so, the lungs themselves – whereas typical viral respiratory organisms usually cause upper respiratory symptoms — so runny nose, congestion, sometimes sinusitis, sore throat, even a cough,” says Dr. Lisa Chirch, UConn Health infectious disease physician.

Flu, RSV, COVID-19, and bronchitis can lead to pneumonia, as well as upper respiratory problems.

“There’s a ton of influenza circulating right now, and people with flu can then develop bacterial pneumonia on top of the viral infection, which puts them at higher risk,” Chirch says. “Lower respiratory tract infections more typically are caused by bacteria than are upper respiratory tract infections. There are certain bacteria that are often most problematic. Streptococcus pneumoniae, otherwise known as pneumococcus, which is vaccine preventable, is most common.”

The Centers for Disease Control and Prevention recommends the pneumococcal vaccine for adults 50 and older, children younger than 5, and anyone considered at increased risk for pneumococcal disease. The vaccine is not seasonal and offers protection for several years. Chirch says there are nuances to the vaccine schedule because the pneumococcal vaccine is available in multiple versions.

“Depending on the timing of your last pneumococcal vaccine, you may be eligible to receive a newer one,” she says.

We also can protect ourselves from pneumonia by keeping current on other vaccinations, including influenza and RSV — ideally in the fall, though it’s still not too late for those to be helpful this winter and spring — and by following the CDC recommendations on COVID-19 vaccine.

Metersky published a paper in the journal Chest in 2012 showing that half the people who die within 30 days of being hospitalized with pneumonia die after leaving the hospital.

“Some of them are complications related to pneumonia, some of them are complications related to their underlying disease that made them at risk for pneumonia, so it’s a combination,” he says.

Other contributors to pneumonia risk include smoking, diabetes, alcohol use, opioid dependence, and benzodiazepine use (drugs similar to Valium).

For those dealing with bacterial pneumonia at home, especially an older person with other health problems, Chirch recommends monitoring closely for fever and other symptoms like worsening cough and difficulty breathing, at which point, hospitalization may be appropriate.

“Watch for high-grade fevers, chills, shortness of breath, feeling more winded just walking around the house, severe cough, chest pain, things like that,” she says. “From my perspective, probably the most concerning things would be difficulty breathing and high fever.”

Once in the hospital, “the mainstay is antibiotics and supportive care, so antibiotics, fluids, electrolytes, if they need it, oxygen, if they need it, a ventilator if they’re really severe, but the key thing is antibiotics,” Metersky says. “Unfortunately, many pneumonias are viral, and for most of these viruses, we don’t have any treatment. So, it’s really supporting them until they improve.”

Learn more about pulmonary medicine and critical care at UConn Health.

Learn more about UConn Health’s Infectious Diseases Division.