A doubling of COVID-19 cases in the past two weeks suggests the USA has entered a fourth wave of the pandemic.
No one knows what the next month or two will bring, but the example of the United Kingdom suggests the infection rate could get high, while hospitalizations and deaths stay relatively low.
Instead of the virus raging through entire communities, it is likely to target the unvaccinated, including children, and if rates are high enough, the most vulnerable of the vaccinated – the elderly and the immunocompromised.
“Since the majority of our population is now immune, it’s unlikely that we’re going to return to the massive nationwide waves we saw back in January,” David Dowdy, an infectious disease epidemiologist with the Hopkins Bloomberg School of Public Health, said Wednesday in a webinar with media.
But major outbreaks can still occur, particularly in areas with low vaccination rates.
“We’re going to be living in two pandemic worlds, the world that’s vaccinated and the world that’s unvaccinated,” said Dr. Luis Ostrosky, chief of infectious diseases at UTHealth and an infectious disease specialist at Memorial Hermann-Texas Medical Center in Houston.
The three vaccines authorized for use in the USA, from Moderna, Pfizer-BioNTech and Johnson & Johnson, have all been shown to be highly effective against variants of the virus, including delta, which accounts for most of the cases in the nation.
More than 99% of those currently hospitalized with COVID-19 are unvaccinated. Ostrosky said virtually all his patients are unvaccinated and all regret not getting the shots.
COVID-19 may not be as deadly in this new wave, because older people are largely vaccinated and younger people are less likely to die from an infection, said Ravina Kullar, an infectious disease specialist and epidemiologist and adjunct faculty member at UCLA Medical Center.
But the delta variant is substantially more contagious than previous ones, though it’s unclear whether it makes people any sicker than previous variants.
“The concern about delta is well placed,” said Dr. Yonatan Grad, an infectious disease specialist at the Harvard T.H. Chan School of Public Health. “We’re certainly seeing that this wave is something to contend with and not to take lightly.”
COVID-19 rates are rising again
In the U.K., which has roughly the same rate of vaccinations as the USA, the seven-day average number of infections is back to where it was Jan. 20, when the country was just a few weeks past its peak.
Hospitalizations hover around 500 a day compared with 4,500 at their January height, and deaths remain far lower – 26 reported across the country Tuesday compared with the peak of more than 1,300 on Jan. 19.
In the USA, infections have more than doubled since the week of June 22. Total cases have risen in 48 states, and deaths are also beginning to climb. Still, the infection rates are 90% below what they were at the January peak.
There’s still another spike expected this fall. The coronavirus that causes COVID-19 is probably a seasonal virus, which means people are more vulnerable to it, just like the flu, in the fall and winter. No one knows when that start date will be, Grad said.
About 80% of those over 65 are fully vaccinated in the USA, so younger people represent a higher percentage of those falling ill. Although children under 12 are unlikely to get a severe case of COVID-19, they are unable to get vaccinated, so they remain vulnerable to the delta variant.
“By virtue of kids not having the opportunity to be vaccinated at the same level as adults, I think they are going to experience a disproportionate burden of infection and sickness from the delta variant,” Dowdy said.
The vaccines are good but not perfect. People who get infected with COVID-19 after vaccination, even if their infection is so mild they don’t notice, could be contagious, though probably less than those who aren’t vaccinated, Grad said.
Three Yankee pitchers – all of whom had been vaccinated – tested positive for the coronavirus Thursday, forcing the postponement of their first game after the All-Star break.
Those who get mild disease after vaccination could suffer symptoms of so-called long-haul COVID, said Priya Duggal, an epidemiologist at Johns Hopkins, who was on the call with Dowdy.
People who have caught COVID-19 are likely to be protected against reinfection for at least a year, according to a study published last month in the journal Nature. Researchers found that getting vaccinated after infection boosted by 50-fold the activity of neutralizing antibodies needed to repel the virus and prevented infection with variants.
“There are still unknowns about the extent and duration of protection from natural infection and how well there’s protection against new variants,” Grad said. “Even people who have had COVID-19 are still advised to get vaccinated.”
Although the vaccines appear effective against variants, if the virus spirals out of control anywhere in the world, new variants can arise that could challenge immunity, Dowdy said.
“As long as the virus is circulating, mutating in other countries, it’s going to be a threat to us, too,” he said.
What can be done?
To reverse the increase in infections, what’s needed “is really injecting a sense of urgency into the equation,” Ostrosky said, recommending that people get vaccinated and resume wearing masks indoors when in public.
“If we don’t act now, we’re just going to be in the same situation we were in a year ago with closures, with disruptions, with deaths,” he said. “It’s very discouraging.”
Ostrosky said he thinks there are two types of people still declining vaccination: those greatly misinformed and those who need more reassurance that they are not going to be harmed by the shots, which have been given to more than 185 million people in the USA. “Access is really not the issue right now, it’s more reluctance,” he said.
Unfortunately, he said, the people who are most reluctant to get vaccinated are also those most reluctant to wear masks.
Thursday, Los Angeles County announced it would reinstitute a mask mandate for indoor public spaces.
Kullar said she wishes the Centers for Disease Control and Prevention had waited longer before saying masks are unnecessary for the fully vaccinated. Instead of providing an incentive to get vaccinated, the CDC’s move encouraged everyone, including the unvaccinated, to take off their masks, she said. “It confused the public even more.”
She said people should continue wearing masks indoors in public places until at least 70% of those in their community or county are vaccinated, “and if you’re immunosuppressed, I wouldn’t remove your mask.”
Outdoors remains safe, she said, particularly if people keep their distance from others.
The most important thing in the battle against COVID-19, Ostrosky said, is for people to get vaccinated.
“We can do this,” he said. “We have no time to waste.”
Contact Karen Weintraub at kweintraub@usatoday.com.
Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.
