At Last, New Weapons to Help Banish Colds and Flu

This piece is part of “The Cure for Everything:” A series of stories that looks at the breakthroughs, setbacks, and overall status of vaccines and cures for hard-to-treat diseases and viruses, from HIV and herpes to the flu and hangovers.

COLD AND FLU VIRUSES have been making people sneeze and hack for millennia. Ancient Egyptians described a flu-like illness on papyrus. Researchers in Denmark say at least one cold virus goes back 700,000 years, predating humans. Most Americans get two to four colds per year, and about eight percent get the flu, typically between December and March.

Over centuries, however, no one has managed to cure these irritating illnesses. “The actual treatments that we have for respiratory viruses are quite limited,” says Matthew Kelly, M.D., M.P.H., Associate Professor of Pediatrics (Infectious Diseases), Global Health, and Molecular Genetics & Microbiology at Duke University. There are no shots to prevent the common cold or medications to help you heal faster from it. Antiviral medications for the flu can shorten the struggle, but only if you start them early enough.

“During the COVID-19 pandemic, antivirals and vaccines were developed in record time for this new virus in human populations,” says Dr Kelly. “I think that has renewed and kind of reinvigorated the whole push to develop vaccines and antivirals for other viruses that can cause upper respiratory infections.”

You can try to avoid catching a cold or flu in the first place. You can treat the symptoms. For the flu, you can take antiviral medication to shorten the struggle. Otherwise, you’re on your own to heal. Here’s why—and how to stay healthy.

It Starts With a Sneaky Shape-Shifting Virus

Cold and flu viruses are easy to catch. You breathe them in when a sick person talks, coughs, or exhales in your direction or when you touch your mouth or nose after touching something they handled. A few viral particles bypass your mucus and bind to receptors in the cells lining your nose, mouth, and throat. Then, the viral particles invade and multiply, triggering inflammation that makes you feel sick. A virus as routine as a cold should be easy enough to stop though, right? Not so much.

“It’s the most common disease, but it’s probably one of the most complicated diseases because of the number of different viruses,” says Ronald Eccles, Ph.D., Emeritus Professor and former director of the Common Cold Centre at Cardiff University. More than 200 viruses cause colds, and the most common ones—rhinoviruses—come in more than 100 varieties alone, he says. Colds also result from coronaviruses (the Covid-causing SARS-CoV-2 isn’t the only one!), adenoviruses, respiratory syncytial viruses (RSV), and parainfluenza viruses. It’s hard to make a vaccine or medication that fights all or most of them although researchers are working on this kind of meta-vaccine.

It’s not like no one has tried. In the late ‘90s and early aughts, a now-defunct company, ViroPharma, developed an antiviral drug for common colds. Research suggested the drug, pleconaril, cut colds short by a day. In 2002, though, the FDA rejected the company’s application to approve the drug, citing safety concerns.

Fortunately, most colds are more of a nuisance than anything, says Dr. Eccles. They don’t usually infect your lungs to cause serious complications like pneumonia. But one, RSV, is particularly dangerous for babies and older people. Fortunately, RSV vaccines came out in 2023 and are now available to reduce RSV pneumonia risk in people over 60 or older than 50 with certain medical conditions. The drug companies behind the shots are also studying them in younger adults with hopes of expanding their use.

The path to RSV immunizations started soon after the virus was discovered in 1956, but it wasn’t easy. In the 1960s, research on an experimental vaccine stopped when too many kids in the study got sick. That shot contained an inactive form of the virus, but today’s version includes a protein found on the virus’s surface instead. It can’t infect you, but it makes your immune system build antibodies.

Influenza, a.k.a. the flu, is also more dangerous than a run-of-the-mill cold. It comes in multiple varieties, too. “Influenza is three different viruses in humans,” says Adolfo Garcia-Sastre, Ph.D., Professor of Microbiology and Director of the Global Health and Emerging Pathogens Institute of Icahn School of Medicine at Mount Sinai. “They are the H1s, the H3s, and influenza B.” Each has multiple relatives, and their genes mutate often to create new ones.

Compared to cold viruses, the flu is more likely to spur an outsized immune response and infiltrate your lungs. “If the virus is in the lungs replicating, you need to get immune cells into the lung to be able to eliminate the virus that is there,” says Garcia-Sastre. “But if a lot of immune cells get to the lung, it’s like flooding the lung, and that’s what pneumonia is about.” The immune cells can damage cells along your respiratory tract, leading to severe symptoms like wheezing and difficulty breathing. That’s when the flu turns dangerous, sometimes deadly.

Yearly flu shots can reduce that risk. Americans aged 18 to 64 who got last year’s flu shot were 45 percent less likely to seek emergency department or urgent care for the flu and 23 precent less likely to be hospitalized for it.

Most flu shots contain an antigen, or protein, from a mix of flu viruses selected based on what’s circulating. A nasal spray version contains a live but harmless version of the virus instead. Flu shot immunity lasts about eight months, and by next year, the shot will have a new set of variants to reflect the evolving viruses.

Like Covid-19 vaccines, flu vaccines are good at preventing life-threatening infections and less efficient at thwarting milder infections, say Garcia-Sastre. “The vaccine is mainly inducing immunity that protects the lungs, which is the area that, if the virus reaches the lungs, is going to give you more severe symptoms, like pneumonia,” says Garcia-Sastre. “But the vaccines don’t protect very well the upper respiratory mucosa, which is the area where the virus replicates and transmits without causing too many symptoms.”

The reason could be how the vaccines are delivered, he says. When you get a shot in the arm, antibodies start building in your bloodstream to reduce the circulation of the virus. Your lungs, the organs you most need to safeguard, are best protected because they receive more blood than your nose, mouth, and throat.

Antiviral medications oseltamivir and zanamivir can help you recover from flu faster, but only if you take them within 24 to 48 hours of symptoms. Otherwise, the cascade of inflammation that causes symptoms like congestion will be too far along to reverse. “These antivirals are like a fire extinguisher,” says Eccles. “If you can get them in early and dampen down the fire when it’s small, that’s great, but if the fire is spreading and getting through the roof of the house, it’s too late.”

The Quest for the Next Breakthrough

The Covid-19 pandemic renewed and reinvigorated the push to develop vaccines and antivirals for other viruses that can cause upper respiratory infections, says Dr. Kelly. “This is a really active area of research, and I do think we’re going to see a number of new products for respiratory viruses going forward,” he says.

One effort is the quest to make flu vaccines even better. “People are working and trying to improve vaccines by tweaking the way the vaccines are delivered , the ways the antigen is delivered in the vaccine, that may result in longer immunity,” says Garcia-Sastre.

The ultimate win would be a universal flu shot that fends off every flu virus at once. That might require a rethink about the proteins incorporated into the shot. Flu shots contain hemagglutinin, a protein on the surface of flu viruses that binds to receptors in human cells. Your body builds antibodies that bind to hemagglutinin so it can’t find your cells’ receptors.

“The problem is that the hemagglutinin changes with time, and therefore the previous antibodies, they would not be able to bind new hemagglutinins of new variants, and then the virus escapes this immunity that has been generated by previous vaccination or previous infection,” says Garcia-Sastre.

If someone could incorporate a less finicky antigen shared by a broad range of flu viruses into a vaccine, they could, in theory, protect against more flu types.

“There are some approaches that have been investigated, even for universal flu vaccines, but they are still at early stages of clinical development, so it’s unclear yet whether they are going to be successful or not,” says Garcia-Sastre.

For example, researchers at the University of California-Riverside are developing an mRNA vaccine (like a Covid-19 shot) aimed at all flu viruses. Researchers at Oxford University are trying to target parts of the virus that don’t mutate often to offer hardier flu protection, but that treatment is years away.

How to Fight Colds and Flu Today

Schedule a flu shot.

You might still catch the flu, but you will reduce your risk of getting seriously sick. “We see the same thing with flu every year–there are healthy adults, unvaccinated in particular, who are dying of flu,” says Kelly. Local pharmacies make it easy to get shots at your convenience.

Buy hand sanitizer by the gallon.

The rhinoviruses behind many colds can spread through contact with contaminated surfaces like doorknobs and elevator buttons, says Kelly. Wash your hands often and stock up on hand sanitizer. Kelly keeps a tiny bottle of hand sanitizer in his pocket and buys it by the jug to stash around his house so it’s always within reach.

Cover up.

Eccles recommends keeping your nose warm with a scarf, balaclava, or a mask when you go outside. “You’re more susceptible to infection if you have a cold nose,” he says. Cold and flu viruses replicate faster in your schnozz, at about 90 degrees fahrenheit than at your core body temperature closer (closer to 98.) Warm drinks can help relieve a cough and sore throat.

Try pain relievers.

An over-the-counter anti-inflammatory like acetaminophen, ibuprofen, or aspirin can help relieve headaches, muscle pains, sore throat, and fever. Ask your doctor or pharmacist about interactions with other meds you take.

Use nasal spray.

To unclog a blocked nose, try a nasal decongestant spray. “You’re delivering the medication in high concentration, just where it’s needed,” says Eccles. Don’t use it for more than three days, or you risk rebound symptoms. When Eccles is sick, he also uses iota-carrageenan nasal spray, available in Europe and Asia but not approved yet in the U.S. It contains negatively charged molecules extracted from red algae that attract and trap positively charged viral particles surfing along in your mucus reducing symptoms.

Use what Covid-19 taught you.

Maintain that famous six-foot distance from others and consider wearing a mask when bugs are going around or if you feel sniffly. “Over time, we, individually and as a society, have sort of progressively been thinking less and using those measures less to protect ourselves, which is part of the reason why we’ve seen some pretty significant activity of viruses other than Covid,” says Dr. Kelly.

Go to bed early.

Sleep restores your immune system for the next challenge. “We are all coming into contact with these viruses really frequently, whether it be kids bringing them home from daycare or being out in the community, so if your immune system is just in a better state to respond to that virus, that could potentially prevent you from being from getting sick from the virus,” says Dr. Kelly.

Be smart about supplements.

Zinc supplements don’t prevent colds but can shorten symptoms by about two days, suggests a recent study review from the Cochrane Library. Research on other supplements people take for colds, like vitamin C, vitamin D, and probiotics, is mixed. Rather than popping a high-dose capsule, eat more foods with these nutrients, says Kelly. Think oranges and strawberries, salmon and tuna, and yogurt and kimchi.

Read more stories in this special package that looks at the latest breakthroughs for common health issues.