The next wave of Covid-19 is coming, and in some parts of the United States, it’s already here. Are you ready? By Tara Parker-Pope and Knvul Sheikh for the New York Times.

The culprit this time is BA.2, a subvariant of the highly infectious Omicron variant. Nobody knows for sure how much havoc it will cause, but BA.2 has already led to a surge of cases in Europe and is now the dominant version of the coronavirus in the United States and around the world.

Researchers are tracking an uptick in cases in the United States, and they’ve detected a rise in the viral particles recovered from nearly 150 wastewater-surveillance sites. Because people can shed the coronavirus even if they never develop symptoms, pieces of the virus collected in wastewater can serve as advance warning several days before official case counts rise, said Bronwyn MacInnis, who directs pathogen genomic surveillance at the Broad Institute in Cambridge, Mass. Over the past two weeks, Dr. MacInnis’s group has seen a rapid increase in levels of the BA.2 subvariant in the Northeast.

“I don’t think we’re looking at a crazy lockdown scenario in this part of the world with BA.2,” Dr. MacInnis said. “But we can’t be sure that we won’t have another curveball from this virus in the future.”

American health officials have said they are hopeful that BA.2 won’t cause another major surge, in part because so many people were infected by the original Omicron wave this winter and most likely have at least some natural or vaccine immunity to protect them against severe illness and hospitalization.

But other variables could turn the BA.2 wave into a more damaging surge. One concern is that less than 70 percent of Americans over 65 have had a first booster shot, leaving a large group vulnerable, said Dr. Eric Topol, a professor of molecular medicine at Scripps Research in La Jolla, Calif. And for many people who got their booster shots in the fall, immune protection may be waning. Unvaccinated people who are counting on natural immunity from a previous infection by a different variant should know that BA.2 can easily sidestep those fading immune defenses.

And then there’s the question of whether pandemic fatigue will prevent some people from taking reasonable precautions, like wearing masks and social distancing, when Covid numbers start to rise in their area.

“We know how to manage it,” said Dr. Robert Wachter, a professor and the chair of the medicine department at the University of California, San Francisco. “But the big caveat will be that there are lots of parts of the country that will not go back into careful mode. It’s wishful thinking to believe we’re going to stay in a situation as good as we are in now.”

While the virus is unpredictable, there are clear ways to protect yourself. The plans you make now can lower your risk of exposure, minimize the disruption to the lives of your family and friends and help to assure you have access to treatments if you or someone you know becomes seriously ill.

Here’s what you can do to prepare.

Pay attention to Covid indicators in your community

Don’t wait for public health officials to issue warnings. Keep an eye on Covid-19 statistics for your county or region. An easy way to do this is to check the color-coded map from the Centers for Disease Control and Prevention that shows community levels of Covid-19 around the country. The map is mostly a welcoming green right now, which means there are relatively low rates of new cases and hospital admissions. But there is a growing number of yellow spots, showing medium risk, in Texas, the Northeast and other areas, and orange-colored hot spots are cropping up in Montana, the Dakotas and other states, indicating high rates of community spread.

As the map shifts to yellow and eventually orange in your area, it’s time to take extra precautions, including donning masks in public spaces and rethinking large indoor gatherings where you don’t know the vaccination status of others.

If you want even earlier warning of Covid trends, you can bookmark the C.D.C.’s wastewater data tracker map.

Another useful indicator is your community’s positive test rate. Experts advise taking more precautions as you see positive test rates start to rise above 5 percent. The Johns Hopkins coronavirus resource center shows daily U.S. and state-by-state testing trends.

Have high-quality masks on hand

Even if you’re not wearing a mask now, check your mask supply and make sure you have plenty of high-quality medical-style masks on hand. A limited number of free N95 respirator masks are available at pharmacies and community centers. Enter your ZIP code on the C.D.C.’s mask locator to find a participating distributor near you. If you want to buy additional masks, use our guide to find a reliable supply of N95, KN95 or KF94 masks and avoid counterfeits.

Since many communities have lifted mask mandates, when and how often you use a mask is probably going to be up to you.

“The mask needs to go on when you start seeing case numbers going back up,” said Linsey Marr, professor of civil and environmental engineering at Virginia Tech and one of the world’s leading experts on viral transmission.

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Dr. Marr said she knows people are tired of masks, but wearing one is only a minor inconvenience and is a proven way to lower your risk. “I’m not into fear mongering, but there’s still so much we don’t know about long Covid that I don’t want to get Covid, and I don’t want anyone else to, either,” she said.

And the more people who wear masks as cases start to rise, the sooner the next wave will be over.

Order home Covid tests sooner rather than later

Each U.S. household is eligible for two sets of four home Covid tests free from the government; if you haven’t ordered them yet, get them now before the weather turns warm. The tests can be damaged by heat, and you don’t want yours sitting for hours in a mail truck on a hot day.

“Now is better than a month from now, especially for people in hot locations,” said Dr. Michael Mina, chief science officer for eMed, a company that verifies at-home test results. “Just take advantage of the program, get them and put them in your cupboard for when you need them.”

People with insurance can also be reimbursed for eight free tests a month. If you develop respiratory symptoms, have a fever or just feel unusually fatigued, use a test on the first day of symptoms. If symptoms persist and you still test negative at home a few days later, you may want to get a lab-based PCR test to be sure.

“If you can afford it, test when you think you have allergies, test when you think you have a cold,” said Kelly Hills, a bioethicist and risk expert and co-founder of the consulting firm Rogue Bioethics. “This is one of those things I think people need to get in the habit of setting aside money for because tests provide important data for making decisions.”

Get a booster (when you’re eligible)

Federal regulators have authorized a second booster shot for everyone 50 and older. The agency also authorized a second booster for people 12 and older with certain immune deficiencies.

While scientists are still debating the value of another booster, most say that people 65 and older and the immune compromised are likely to benefit. If you haven’t gotten your first booster shot, experts agree you should get one now. If you’ve recently had Covid, you most likely have as much natural protection as you’d get from a booster shot — at least for a while.

The protective antibodies from a vaccine or an infection tend to wane in four or five months. A well-timed booster shot tells the body to bump up its antibody defenses and helps other parts of the immune system — like B cells and T cells — become better at remembering how to fight the virus, said Theodora Hatziioannou, a virologist at Rockefeller University in New York City.

Get a pulse oximeter

A pulse oximeter is a small device that clips on your finger and measures your blood oxygen levels. When levels drop to 92 or lower, patients should see a doctor. Low oxygen can be a sign of Covid pneumonia and may raise your risk for serious complications from Covid-19. The devices can be less reliable for people with darker skin, so pay attention to downward trends as well as the number.

 

A study from South Africa found that the risk of dying from Covid-19 was about 50 percent lower among patients who had been instructed to monitor their oxygen saturation at home. You can find the devices for about $30 in pharmacies and online. (Researchers say the pulse oximetry reading on your Apple watch probably is less reliable than the fingertip device.)

Make a plan for antiviral drug treatment

Two oral antiviral therapies are available to treat Covid-19 in the United States, though they require a doctor’s prescription and are authorized only for people who may be at high risk of severe disease. One, called Paxlovid, developed by Pfizer, is taken as three pills twice a day for five days. It is available for high-risk patients 12 and older.

The second drug, called molnupiravir, was developed by Merck in partnership with Ridgeback Biotherapeutics. It is taken as four pills twice a day for five days, and is available for high-risk adults 18 and older.

For the pills to be most effective, you need to start taking them within five days of the start of your symptoms, so it’s important to have a plan for getting a prescription and knowing which pharmacy can fill it, said Kuldip Patel, the senior associate chief pharmacy officer at Duke University Hospital in North Carolina.

You can use the Covid-19 therapeutics locator to track local supply of the drugs and check with your doctor to make sure you can receive the medication should you fall ill. (Some doctors are still declining to prescribe the drugs.) You can also look up qualified pharmacy-based clinics near you, as well as community health centers and long-term care facilities that have an authorized medical provider so you can get tested and, if positive, receive antiviral medication on the spot.

People who are immune compromised should also talk to their doctor about Evusheld, an antiviral drug from AstraZeneca that can be given by injection to provide an additional layer of protection on top of vaccines.

Have backup plans for social events and travel

If you have plans for a graduation party, wedding or other large event, it’s a good idea to have an outdoor backup plan if your community’s case numbers spike. If you’re planning to travel, do a little advance research into clinics and pharmacies at your destination so you know whether you can get antiviral drugs if you catch Covid-19 on your trip. Make sure you have extra funds or plenty of room on your credit card in case you need to extend your trip to recover from Covid. (You still need proof of a negative Covid test for international travel.)

Health experts said planning for the next wave of Covid shouldn’t disrupt your life or prompt you to cancel travel plans or time with friends and family. In fact, being prepared for the unexpected will allow you to keep living your life as normally as possible.

“A lot of people feel it’s a terrible inconvenience and they are sick of it, and I understand that,” said Dr. Topol, of Scripps Research. “We’ve had a time out, and it’s been good. But people should be ready to gear up if need be.”