Originally Published: 18 AUG 23 07:27 ET

Updated: 18 AUG 23 08:42 ET

By Brenda Goodman, CNN

(CNN) — Last year’s respiratory virus season in the US was a bad one.

After two years of extraordinarily light flu seasons, which infectious disease experts attributed to Covid-19 pandemic precautions like social distancing and masking, influenza came roaring back, hitting early and hard.

Then respiratory syncytial virus, or RSV, which had been showing up at odd times during the year, surged to new heights over the winter months. It was one of the worst RSV seasons many doctors said they could remember.

On top of all that, there was an increase in Covid-19 cases, which almost seemed old hat after three years of wave after wave. The bivalent Covid-19 booster arrived just in time to defend against the BA.5 subvariant, but only 17% of Americans wound up getting the updated vaccine, according to the US Centers for Disease Control and Prevention.

There were packed hospitals. Packed urgent cares. Drug shortages for common cold and fever meds. Endless sick days for kids, then more sick days for parents. Sick days for everyone.

The good news is that we probably won’t have a repeat of that terrible season in the months ahead. Experts predict that illnesses like RSV and the flu, which are both at very low levels now, will settle back into their seasonal patterns this year.

Covid-19 cases could have a winter surge, but many experts don’t expect it to reach the heights of recent years unless the coronavirus throws us a wild card in the form of a new variant. Earlier this year, experts who study the evolution of the virus predicted that there was a 10% to 20% chance of that happening within the next two years.

And there’s more good news: There are new tools to help protect the most vulnerable, in the form of vaccines and antibodies. Some of these are now available, with other expected to arrive in the weeks ahead.

“We have three respiratory viruses that we think will be the major players for wintertime colds: Covid, flu and RSV. And for the first time in human history, we have vaccinations against all three of them,” said Dr. Buddy Creech, a pediatric infectious disease specialist at Vanderbilt University. However, he noted, “A shot is only so good if it gets into your shoulder.”

Experts say there will be major challenges ahead to make sure everyone who needs these vaccines has access to them and feels comfortable getting them.

The government is no longer purchasing Covid-19 vaccines for all, which means that cost will be passed on to insurers and potentially to patients themselves. Some of the questions about who will pay for the shots and their administration can’t be answered until the latest version of the vaccine is approved by the US Food and Drug Administration and recommended by the US Centers for Disease Control and Prevention.

The delivery system for getting vaccines to adults is lacking, too.

“We still don’t have a robust system in place for adult immunization advocacy and delivery and how to expand beyond the existing pharmacy chains and hospitals,” said Dr. Peter Hotez, co-director of the Texas Children’s Hospital Center for Vaccine Development. “This is especially true in rural and low-income areas.

“This, and the fact that antivaccine activism has increased during the Covid pandemic, means that uptake of the three adult vaccines this fall … is likely to be low,” Hotez said.

Here’s what experts are predicting as we look ahead to another respiratory virus season.

Covid-19

Covid-19 cases are getting an end-of-summer bump as people travel and seek indoor refuge from the record-breaking heat.

“That tends to allow us to share germs with each other. And that’s certainly happening with Covid. And as I look around, friends and family and colleagues, there’s a lot of disease going on right now,” Creech said.

Covid-19 hospitalizations have been on the rise since early July, according to data from the CDC. In the first week of August, more than 10,000 people were hospitalized with Covid-19. That’s a 60% increase over the course of a month, including a 14% bump in the most recent week.

Rates are now at levels last seen in April, but this isn’t like the waves of the past. Weekly Covid-19 hospitalizations are still about a quarter of what they were at this time last year and lower than they were for about 90% of the pandemic.

Updated Covid-19 vaccines, which are designed to boost antibodies against the recombinant XBB strain and its offshoots, are on the way. But they aren’t expected to be available for another month or so.

“The challenge, of course, is that our new boosters would help that. But they’re not going to be available, probably, until mid- to late September. So we’re going to have to endure that surge,” Creech said.

Paxlovid and other antivirals like molnupiravir are available to help prevent severe disease in people who may be at risk, but they’re underused for older patients, said Dr. Carlos Del Rio, an infectious disease specialist at Emory University.

Often, the drugs aren’t prescribed because people don’t initially look sick enough to need them.

“And the issue is, if you’re over the age of 60, you need to take it so you don’t get sick,” Del Rio said, which is why it’s still smart to take a Covid-19 test any time you have respiratory symptoms.

“If you are over the age of 60, I will say, be sure that you get tested promptly and you get started on antiviral medications like Paxlovid right away, so you can actually also decrease your risk.”

Dr. William Schaffner, an infectious disease expert at Vanderbilt, said he expects that the summer increase in Covid-19 cases will abate a bit before going up again.

“Nothing like the past winters that we’ve had, but we anticipate that along with the other to respiratory viruses, Covid-19 will have an increase again this winter,” he said.

That’s why it will be a good idea to get the updated Covid-19 vaccines when they become available.

Drugmaker Moderna announced Thursday that preliminary data from human clinical trials shows that its updated Covid-19 vaccine “showed a significant boost in neutralizing antibodies against EG.5 and FL.1.5.1 variants,” two XBB offshoots that are increasing in the US. The company didn’t provide any specifics on its early results.

Of course, all bets are off if the United States sees another variant like Omicron, which took off just after Thanksgiving in 2021.

On Thursday, the World Health Organization said it was keeping a close eye on BA.2.86, a new highly mutated distant cousin of the BA.2 subvariant. WHO has added it to a list of seven “variants under monitoring,” a designation that encourages reporting of the variant and requires WHO scientists to assess its risks.

Compared with BA.2, the new variant has 33 amino acid changes to its spike, according to Dr. Jesse Bloom, who studies viral evolution at the Fred Hutchinson Cancer Center in Seattle.

“This makes it an evolutionary jump comparable in size to that which originally gave rise to Omicron,” Bloom posted on his lab’s website Wednesday.

Four sequences of the virus have been found in three countries: Israel, Denmark and the United States.

The four sequences come from four infections, but scientists worry that they could represent many more because genomic monitoring of the virus has dropped off worldwide.

The CDC said it was also working to learn more about the new variant.

“Scientists are working now to understand more about the newly identified lineage in these four cases, and we will share more information as it becomes available,” CDC spokesperson Kathleen Conley said Thursday.

Flu

If flu returns to a more normal pattern this year, cases will start to rise in November and peak after the New Year, Schaffner said.

The US might get some hints about what the flu season might look like from watching trends in Australia, which is now coming out its own flu season.

There, cases started to rise early “and then kind of stayed level,” said Dr. Jennifer Nayak, a pediatric infectious disease specialist at the University of Rochester Medical Center in New York. “We may see flu peak earlier similar to what they saw in Australia. It’s hard to know.”

This year’s flu vaccine has an updated H1N1 strain to more closely match the flu viruses that were emerging at the end of last season. So far, it seems to be a good match for the circulating viruses.

Returning to a typical seasonal pattern doesn’t mean it will necessarily be an easy year. The CDC estimates that the flu caused between 140,000 and 710,000 hospitalizations annually between 2010 and 2020. The agency also says the flu kills between 12,000 and 52,000 Americans each year.

The CDC recommends that everyone over 6 months of age get an annual flu vaccine. But the challenge will be getting people to take the shot, which doctors recommend doing in September and October so your protection will last through the entire season.

The vaccine fatigue that’s cut into uptake rates for the bivalent Covid-19 vaccine also seemed to creep into flu vaccinations rates last year.

“Last year, we didn’t immunize as many people against flu as we normally do. And of course, we would like to improve that very substantially,” Schaffner said.

As with Covid, experts say it makes sense to test for the flu if you get sick, since there are antiviral medications that may make the illness shorter and less severe, but they work only if taken early in the infection.

RSV

RSV attacks the lungs, causing congestion, cough, sneezing and sometimes a fever. In older children and healthy adults, RSV is usually a mild infection. But newborns can run into trouble because it causes their tiny lungs to fill with mucus that they have trouble clearing. Some need hospital care to keep their airways open and extra oxygen to get them through the worst of the infection.

RSV is the leading cause of hospitalization for infants under a year of age, but babies aren’t the only group vulnerable to this virus.

This year, infectious disease experts expect RSV to return to a more normal seasonal pattern, which means cases should begin to rise in October, peaking in late December to mid-February.

During a typical year, RSV hospitalizes 80,000 children under age 5 and twice as many people over the age of 65, according to CDC estimates.

Those numbers could come down considerably this year thanks to a new antibody shot for babies called Beyfortus and RSV vaccines from Pfizer and GSK for people 60 and older. In clinical trials, all three cut the risk of severe disease and hospitalization by 75% or more, on average.

The CDC not only recommended Beyfortus for babies, it also added the shot to the Vaccines for Children program, which provides immunizations to children who might not otherwise get them due to cost.

The CDC’s recommendation also means the shot should be covered under Affordable Care Act rules that require health plans to cover certain preventive services with no cost-sharing for patients, but it may take some time for that coverage to kick in, so parents should check with their insurance provider to see if the shot — which will wholesale for $495 a dose — will be covered.

Another RSV vaccine — designed to protect newborns by delivering a shot to mothers late in their pregnancy — is also under consideration by the US Food and Drug Administration.

Trials of the RSV vaccine for older adults, who were followed for two years, found that protection from a single dose carried into the second virus season.

“What that means is, you don’t have to wait to get that vaccine. You can get it this afternoon, as soon as it becomes available, if you would like to get a start on this trifecta of vaccines,” Schaffner said.

Both GSK and Pfizer confirmed Thursday that their RSV vaccines for seniors are now in pharmacies nationwide.

“You could start with RSV vaccine just as soon as you’d like, because the protection is going to go through this season and maybe even into the next season. So the timing is not important,” Schaffner added.