8 Places You’re Still Most Likely To Catch Covid, Listed by Expert Doctors
Updated: Jul. 22, 2024
Doctors specializing in virus transmission recommend thinking twice before visiting areas where Covid-19 is known to spread the swiftest.
The pandemic may be behind us, but the future of Covid remains a question mark, according to infectious disease experts. For starters, Covid hasn’t yet settled into a seasonal pattern like the flu, says Shira Doron, MD, Chief Infection Control Officer for Tufts Medicine and Hospital Epidemiologist at Tufts Medical Center. “Will it have one winter peak like flu or a winter and summer peak like it has appeared to do so for the past few years?”
For instance, if Covid continues to circulate year-round, this could have implications for vaccine recommendations. In early 2024, the Centers for Disease Control and Prevention (CDC) updated its guidelines, advising people over age 65 to get their next dose of the vaccine.
Also, new Covid variants pop up faster than a more predictable virus like the flu—and this poses a challenge when it comes to vaccine development, according to Dr. Doron. Another question she says lingers in experts’ minds: Is it yet possible to predict what strain of the virus will be circulating in the coming year during the time of vaccine strain selection (currently done in June)?
For example, the flu vaccine was about 44% effective in preventing flu-related hospitalization in adults throughout the 2023-2024 season, says Hareesh Singam, MD, infectious disease specialist at Cleveland Clinic. “As per the Covid-19 vaccine, the estimated effectiveness was 42% earlier in the winter season and about 19% less later in the winter season.” This is because the more dominant JN.1 variant turned up late in the season.
One thing is certain—Covid is still highly contagious. So, while you don’t need to quarantine like it’s 2020, infectious disease experts insist you make smart decisions when going out and visiting places where infection rates remain the highest.
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What is the main way Covid-19 spreads?
Both Covid and the flu spread person-to-person via the respiratory route, explains Erica Johnson, MD, an internist at Johns Hopkins Bayview Medical Center in Baltimore and chair of the infectious disease board of the American Board of Internal Medicine. This means that “for both viruses, respiratory droplets and aerosols are generated when people who are infected cough or sneeze, or use their voice to talk or sing.”
Experts define droplets as larger and heavier, and they are best spread when people are within six feet of each other before they fall to the ground or surfaces, Dr. Johnson says. Aerosols are smaller and lighter, can remain suspended in the air for longer, and can travel distances through the air.
While the flu and Covid can spread via either route, “Covid is primarily transmitted through these smaller aerosols,” she says. Because these aerosols stay afloat in the air, they can circulate long distances within a space. That makes the virus much more easily transmissible.
For example, if someone infected with Covid has a high enough virus load in the respiratory tract, they can generate aerosols that linger in a room. If you enter that room and encounter the aerosols, you can get infected—even if you don’t have direct contact or even a conversation with the Covid-positive person who generated the aerosols in the first place.
This explains why Covid is considered much more infectious than the flu, says Jason E. Zucker, MD, infectious diseases specialist at NewYork-Presbyterian/Columbia University Irving Medical Center. “While exact estimates are hard to come by, some studies suggest it may be twice as infectious,” he says. The way Covid spreads in the air also makes the virus more likely to cause what have been called “super-spreader” events—highlighting how it can spread rapidly and extensively, he adds.
What’s more, there are small but important differences in how contagious you are with the flu versus Covid. Here’s how Dr. Zucker breaks it down:
- People with the flu are generally contagious for about one day before symptoms start, five to seven days from there or until symptoms resolve.
- People with Covid are generally contagious for two to three days before symptoms start and then remain contagious for five to seven days—but sometimes up to 10 days.
That’s why even as the CDC has relaxed its isolation recommendations and state and federal mask mandates have long been dropped, the agency still recommends masking up in higher-risk places (especially if there is a lot of Covid-19 active in your community).
“Symptoms and duration of contagiousness can be prolonged, particularly in immunocompromised people,” Dr. Zucker adds. “Vaccination, most importantly, reduces the severity of illness.”
In which settings does Covid-19 spread most easily?
In general, Covid infection hot spots tend to be “indoor environments with limited fresh airflow, where large numbers of people gather for longer than 10 minutes of interactions, and where it is difficult to maintain physical distancing,” says Boris Lushniak, MD, Dean of the University of Maryland School of Public Health in College Park.
In a study published in Environmental Science & Technology, Zhe Peng, PhD, and other researchers at the University of Colorado at Boulder developed a mathematical model calculating the different factors that contribute to the level of risk for COVID-19 in different settings. These included:
- Viral factors: transmissibility and prevalence
- Human factors: mask use, movement, and conversation level
- Air-quality factors: room size, occupancy, and ventilation levels
Contrary to early pandemic concerns, 2023 research from the Journal of Infection and Public Health has shown that catching Covid from surfaces like a doorknob or countertop may be possible, but the risk is “exceedingly” low.
Using this data, researchers can now attribute specific risk levels to various scenarios and outline steps people can take to reduce their chances of catching Covid-19 in those higher-risk settings.
So, what are those high-risk settings? Infection remains highest in the places below.
1. Bars and restaurants
Regardless of the predominant Covid-19 variant in a given time period, bars and restaurants are, and always will be, hot spots for virus transmission. “These places are very risky because people don’t usually wear masks, and in bars, people tend to have close face-to-face conversations at short distances in an enclosed space with poor air quality,” says Dr. Peng.
2. Gyms and fitness centers
Many gyms and fitness centers are still Covid-19 hot spots, largely due to insufficient ventilation, large class sizes, and the intensity of workouts. “The most important risk factor at gyms is heavy exercise and breathing, as you can emit a lot more respiratory particles during intense exercise—even if you feel perfectly fine—which can then be inhaled by others,” Dr. Peng says.
Researchers were able to quantify it. People who work out strenuously expel 132 times more aerosol particles per minute than people at rest, according to a study in Proceedings of the National Academy of Sciences.
“Due to the sharp rise in aerosol emissions at high-intensity workloads above that initial benchmark, special protective measures are needed in case of a high risk of infections with serious consequences,” said study author Henning Wackerhage, PhD, a professor of exercise biology at the Technical University of Munich in Germany, in a news release. “Ideally, that kind of training would be moved outdoors. If that is not possible, testing should be done to ensure that no infected individuals are in the room.”
If you do decide to exercise indoors, choose your gym wisely, opting for a facility with a high-efficiency ventilation system, which helps curb the spread. Make sure the policies of both the gym and fitness classes align with your comfort level, Dr. Johnson advises. “If you are up to date on vaccines and you are not otherwise at high risk for severe Covid-19 and are comfortable with the idea that, if you do develop Covid-19, you may have symptoms, but they will likely be mild, you can take on more risks,” she says.
Of course, to really reduce your risk of contracting Covid-19, you’ll need to make some behavior changes. If the latest Covid strain is circulating in your community, consider maintaining a proper distance during workouts, and don’t feel like you have to go all out. “Risks are reduced by training at lower intensities and keeping sessions shorter,” Dr. Wackerhage said. “It might also be possible for fit, young athletes to wear masks while training.”
3. Places with high air pollution
A growing body of evidence suggests that air pollution may increase the risk of severe COVID-19 infection. Exposure to ground-level ozone, nitrogen dioxide (NO2) and other pollutants seems to increase the chances of people being hospitalized with COVID-19.
This may put people who live in big cities at an increased risk. “Particulate matter, ozone, and other gases cause inflammation, and when Covid-19 hits in a background of underlying inflammation, you are surely going to worsen it,” says Len Horovitz, MD, a pulmonology doctor with Lenox Hill Hospital in New York City.
If you have asthma, emphysema, or COPD, avoid going out on smoggy days. “If you are at high risk for severe Covid-19 due to underlying conditions, consider masking outdoors on days when pollution is high,” he says.
How can you tell when the pollution level is up? AirNow tracks air quality. Type in your ZIP code, city or state to find out where your community stands.
4. Planes, trains, and cruises
Simply put, large-scale studies repeatedly show that masks effectively reduce your risk of infection—especially in places with poor ventilation and close quarters for extended periods of time, like an airplane or train. (That’s why masking up is one of those air travel rules you should know about.)
After some scary stories of Covid-19 on cruise ships at the start of the pandemic, the industry is picking up again. The CDC monitored cases on cruises for two years under the Covid-19 Program for Cruise Ships, which required participating cruise lines to report the vaccination status classification for each cruise. The organization has since ended the program, leaving individual cruise lines to manage infection risks.
How to cruise safely
“These days, there is so much immunity that most people do not get very sick from Covid,” Dr. Doron says. “So the choice to take precautions is up to the individual.” She adds that it’s important to consider how high-risk you are for developing serious complications from Covid (such as if you have a chronic disease) to guide what precautionary steps to take.
For example, if you’re heading out to venture the high seas, it’s a good idea for everyone to be up-to-date on their Covid-19 vaccination and boosters. And if you’re concerned about your personal risk status, wear a mask when onboard—particularly in crowded, indoor areas—and spend as much time outdoors as possible.
5. Crowded beaches and pools
When considering a day by the water, the key word is “crowded.” On one hand, beaches and pools allow for more airflow than indoor environments. However, experts believe that viral particles can still travel from an infected person to others nearby, especially in places where people linger for hours at a time.
“Risk depends on how crowded these places are,” Dr. Peng says. “When you are on the beach, you tend to stay put, and even if you are infectious, you are not exhaling vigorously. Try to maintain social distance, and [if you can do that] you can remain maskless at the beach or pool since the risk is much less than it is in any indoor place.”
Public pools may also be more problematic than people realize, Dr Horovitz says. “When you are swimming, you are often breathing heavily, and your risk of catching COVID-19 depends on how close you are to someone who is not vaccinated,” he explains.
6. Sporting events, festivals, and religious services
Experts believe that outdoor sporting arenas are safer than indoor ones, yet the risks are evident; fans yell, chant, sing, sit close together, travel from outside the area and share food and personal items like noisemakers with others—all actions that can spread Covid-19, Dr. Peng notes.
The same can be said about places of religious worship where singing and praying are performed. “It all depends on how big the theater or venue is,” he says. “If it is very big and people can practice social distancing and wear masks, the risk of catching Covid-19 is reduced.”
However, watching a movie in a theater may be lower risk. “Most people sit there quietly, as opposed to a religious service, where people may speak loudly or sing,” Dr. Peng says.
Each place will have different rules, so don’t hesitate to ask about the property’s cleaning and disinfection protocols, says Dr. Lushniak. “All this is about your personal and your family’s health.”
7. Indoor social gatherings
Gathering with unvaccinated friends and family who do not live with you does carry risk, especially if you’re indoors. Because Covid-19 is spread through tiny droplets in the air, simply being in close contact with a contagious person could increase your risk of infection, even if the person doesn’t show symptoms.
“If there is one or more infectious persons at the indoor gathering, the risk of Covid-19 spreading is high,” says Dr. Peng. Testing before the event helps, though. “If you can make sure everyone is really negative, you can gather without masks,” he says.
Spacing tables and chairs six feet apart, planning social-distance-friendly activities, wearing face masks, and washing hands frequently can further help protect guests from infection. “If windows are open and there is a cross breeze, the event is safer, but it’s not always practical to open doors and windows,” Dr. Peng adds. (It’s unlikely that indoor air conditioning will increase the spread of the virus.)
Air filters can also help catch viruses circulating in the air before they reach your nose and mouth. PM2.5 particles, such as pollen, dust mites, aerosols, mold, bacteria, and viruses, are roughly 3% of the diameter of a piece of human hair and can be easily inhaled, causing or worsening existing allergies and respiratory diseases. High-efficiency particulate air (HEPA) filters can remove at least 99.97% of particles that are 0.3 microns in diameter from the air.
Research in Otolaryngology-Head and Neck Surgery showed that portable HEPA filters can catch COVID-19 particles in the air much more quickly and effectively than non-HEPA filters. These can also help with indoor air pollution.
8. Outdoor social gatherings
Most respiratory viruses thrive in cold, dry weather—but a January 2024 study published in npj Viruses suggests that the Covid virus may spread just as easily in warmer, humid conditions. This could explain, in part, why Covid cases pop up all summer long when viruses like the flu and the common cold more or less disappear.
Remember: Dr. Zucker says that Covid is more likely to trigger “super-spreading events” than the flu as well. This occurs when one highly contagious person winds up infecting many others at a single event, whether it’s a large concert or a small family gathering.
Though super-spreader events are more likely to occur in crowded, indoor spaces, Covid’s year-long seasonality and high transmission rate mean that any outdoor event where you’re in close contact with other people can still present a risk of infection.
How to travel safely
Dr. Johnson says that traveling is OK as long as you do so within your comfort zone. “If you are at high risk for severe Covid-19, due to your age or underlying health status, or traveling with or visiting someone who is, a road trip is safer than taking a plane, train or cruise,” she says.
Here are some other activities that put you at less of a risk for Covid-19 than crowded vacations in tight quarters:
- Visit one of the best RV parks in your state.
- Plan a camping trip with your closest (vaccinated) family.
- Gather a few friends and explore a national park.
Here’s How Long Before Travel & Parties You Need to Get Your Vaccines, Says Research
How to protect yourself from Covid-19 in 2024-25
Predicting the next COVID-19 surge is a tall order. Yet another question on experts’ minds, according to Dr. Doron: “What is the chance we could experience another ‘Omicron-like event’ where the virus mutates so much that the population doesn’t have enough built-up immunity to withstand a surge in cases of severe disease?”
While researchers are working on an AI tool that can help predict the next variant wave, that’s not a widespread public health reality right now. That’s why it pays to be vigilant about your Covid-19-reduction practices—especially if your summer vacation plans involve close quarters with other people.
“I recommend wearing masks on airplanes because you are really packed in—you don’t know if the people sitting near you are infectious, and ventilation isn’t ideal,” says Dr. Peng. Even better: Wear a mask whenever you’re indoors with a group of people, whether that’s on a cruise, at the gym, or elsewhere.
What about Covid-19 testing around your travel plans? “There are no longer special recommendations for Covid,” Dr. Doron explains. She says that if you are at high risk for complications of respiratory viruses, it’s a good idea to test at the first sign of symptoms since the treatments (such as Paxlovid) work best when given early. “If you are not high-risk, you generally do not need to test anymore, even with symptoms.”
However, there’s one big exception: “If you are having symptoms or are concerned about the fact that you will be around a vulnerable friend or family member, consider home testing,” Dr. Johnson adds.
And don’t forget to wash your hands. As far as Covid-19 avoidance tips go, it’s an oldie but a goodie.
What to do if you’ve been exposed to Covid-19
If you’re feeling sick or have been exposed to Covid-19 in the past 14 days, it’s best to skip social gatherings completely and test yourself to confirm your Covid-19 status. That’s true regardless of your vaccination status since breakthrough infections can occur among fully vaccinated and boosted people.
If you test positive, the CDC has recently dropped its five-day isolation guidelines. The updated 2024 recommendations mirror those of other respiratory viruses: you should stay away from others while sick but can resume normal activities once symptoms improve and you’ve been fever-free for at least 24 hours. However, for the next five days, use precautions in public, such as hand-washing, physical distancing, and masking.
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