07/23/2021 3:43 PM
The New York Times International Weekly
Updated 07/23/2021 3:43 PM
A wedding in Oklahoma in which 15 vaccinated guests became infected with the coronavirus.
Raucous 4th of July celebrations spread the virus from Provincetown, Massachusetts, to dozens of locations across the country.
spreads across the country, reports of so-called advanced infections in vaccinated people have become increasingly frequent, including, most recently, when at least six Texas Democrats and an aide to the president House of Representatives
A man receives the COVID-19 vaccine from Pfizer at a vaccination center in southern France.
AP Photo / Nicolas Garriga.
The highly contagious variant, combined with the near absence of preventive restrictions, is driving a rapid increase in cases in all states, and in hospitalizations in almost all of them.
Today, it accounts for about
83% of diagnosed infections
in the United States.
But as worrying as the trend may sound, infections in vaccinated people remain
experts say, and those that cause serious illness, hospitalization, or death even more so.
More than 97% of people hospitalized for COVID-19 are not vaccinated.
"The message remains that if you are vaccinated, you are protected," said Dr. Celine Gounder, an infectious disease specialist at Bellevue Hospital Center in New York.
"You are not going to end up with a serious illness, hospitalization or death."
Reports of progress in infections should not be interpreted as not working vaccines, Dr.
the Biden administration's chief adviser on pandemics
, said Thursday
"By no means does it mean that it is a failed vaccine," he said.
"The success of the vaccine is based on the prevention of the disease."
Even so, vaccinated people can contract infections, the vast majority asymptomatic or mild.
This may come as a surprise to vaccinated Americans, who often assume they are
against the virus.
And advances in infections raise the unresolved possibility that vaccinated people could
spread the virus.
Given the proliferation of the virus in much of the country, some scientists say that the time has come for vaccinated people to consider the
use of masks indoors
and in crowded spaces such as the subway, shopping centers or concert halls, a recommendation This goes beyond the current guidelines of the Centers for Disease Control and Prevention, which only recommend the use of masks for
The agency does not plan to change its guidelines unless there is a significant change in science, said a federal official who spoke on condition of anonymity because he was not authorized to speak on the matter.
The agency's guidelines already give local leaders the ability to adjust their policies based on transmission rates in their communities, he added.
Citing the rise of the delta variant, health officials in several California jurisdictions are already urging that it be masked indoors again;
Los Angeles County is demanding it.
"Seat belts reduce risk, but we still have to drive carefully," said Dr. Scott Dryden-Peterson, an infectious disease physician and public health researcher at Brigham & Women's Hospital in Boston.
"We are still
trying to figure out
what 'safe driving' is in the delta era, and what we should do."
The uncertainty about the delta is partly due to its
from previous versions of the coronavirus.
Although its mode of transmission is the same - it is inhaled, usually in closed spaces - delta is believed to be about
twice as contagious
Significantly, early data suggest that people infected with the delta variant may carry a number of viruses roughly
1,000 times greater
than those infected with the parent virus.
Although this does not seem to mean that they are getting sicker, it is likely that they are
more contagious and for a longer time.
The dose also matters: A vaccinated person exposed to a low dose of the coronavirus may never become infected, or not noticeably.
A vaccinated person exposed to extremely high viral loads of the delta variant is
to have their immune defenses overcome.
The problem is compounded as community transmission rates increase, because exposures in dose and number will increase.
Vaccination rates in the country have stagnated, with less than half of Americans fully immunized, giving the virus
plenty of room to spread.
Unvaccinated people "are not, for the most part, taking precautions, and that's what is driving everyone," said Dr. Eric J. Rubin, infectious disease physician and editor-in-chief of the
New England Journal of Medicine.
"We are all susceptible to any behavior in this epidemic."
Gounder compared the protection vaccines offer to a golf umbrella that keeps people dry in a storm.
"But if you're out in a hurricane, you're still going to get wet," he said.
"That is the situation that the delta variant has created, in which there is still a
lot of community dispersion
For the average vaccinated person, a breakthrough infection is likely to be inconsequential, causing few or no symptoms.
But scientists worry that a few vaccinated people who become infected could develop a long-term COVID, a
of symptoms that persists after the active infection has resolved.
Much has been made of the delta's ability to bypass immune defenses.
In fact, all existing vaccines appear capable of preventing severe disease and death from the variant (although questions have been raised lately about the
Johnson & Johnston
In laboratory studies, delta has been shown to be a milder threat than
, the variant first identified in
Whether a vaccinated person becomes infected may depend on the level of antibodies after vaccination, the strength of those antibodies against the variant, and whether the level of antibodies in the person's blood has decreased since immunization.
In either case, the immune defenses prepared by vaccines should recognize the virus shortly after infection and
before major damage occurs.
"That's what explains why people get infected and why people don't get seriously ill," said Michel C. Nussenzweig, an immunologist at Rockefeller University in New York.
"It is almost inevitable, unless people are given very frequent reinforcements."
There is little evidence beyond anecdotal reports to indicate whether delta variant infections are more common or more likely to spread to other people.
The CDC has recorded about 5,500 hospitalizations and deaths in vaccinated people, but is not tracking milder infections.
Additional data is being obtained from the COVID-19 Sports and Society Task Force, a coalition of professional sports leagues that is working closely with the CDC.
The group's sports teams are testing more than 10,000 people at least daily and sequencing all infections, according to Dr. Robby Sikka, a physician who worked with the NBA's Minnesota Timberwolves.
League infections appear to be more common with the delta variant than with the
variant, the variant first identified in
Predictably, vaccines significantly reduce the severity and duration of illness, and players are back in less than two weeks after being infected, compared to nearly three weeks prior to the pandemic.
But while sick, gamers carry
very high amounts of the virus for seven to 10 days
, compared to two to three days for those infected with alpha, Sikka said.
Infected players are required to remain in quarantine, so the project has not been able to track whether they spread the virus to others, but they likely do, he added.
"If they are returned to society at will, I think there will be contagion from vaccinated individuals," he added.
"They don't even recognize that they have COVID because they think they are vaccinated."
Elyse Freitas was surprised to find that 15 vaccinated people became infected at her wedding.
Freitas, 34, a biologist at the University of Oklahoma, said she had been very cautious during the pandemic, and had already postponed her wedding once.
But after much deliberation, he held the wedding indoors on July 10.
Based on the symptoms, Freitas believes that the initial contagion occurred at a bachelorette party two days before the wedding, when a dozen vaccinated people went to bars in downtown Oklahoma City without masks;
seven of them subsequently tested positive.
Eventually, 17 wedding guests became infected, almost all with mild symptoms.
"In hindsight, I should have paid more attention to vaccination rates in Oklahoma and the emergence of the delta variant and adjusted my plans accordingly," he added.
"We have to remain vigilant and careful."
An outbreak in Provincetown, Massachusetts illustrates how quickly a group can grow, given the right conditions.
During its famous 4th of July celebrations, the small town played host to more than
, who danced and mingled at crowded bars and house parties.
This year, the crowd was much larger than usual, says Adam Hunt, 55, an advertising executive who has lived in Provincetown part-time for about 20 years.
But bars and clubs didn't open until they were allowed to, Hunt noted: "We thought we were doing the right thing. We thought we were okay."
Hunt was not infected with the virus, but several of his vaccinated friends who had flown in from as far away as Hawaii and Alabama tested positive upon his return.
In all, the group has grown to at least 256 cases - including 66 visitors from other states - about two-thirds in vaccinated people, according to Steve Katsurinis, president of the Provincetown Board of Health.
"I didn't expect vaccinated people to test positive at the rate they were doing," Katsurinis said.
Provincetown has acted swiftly to contain the outbreak, reinstating the requirement to wear masks and intensifying testing.
250 tests are being carried out a day, compared to eight before July 1, Katsurinis said.
Health authorities should also help the public understand that vaccines do what they are supposed to do:
keep people from getting seriously ill,
said Kristen Panthagani, a geneticist at Baylor College of Medicine who runs a blog to explain complex scientific concepts.
The news often cites the percentage of hospitalized people who are vaccinated as a measure of the effectiveness of vaccines, but that number is easy to misinterpret, he warned.
The proportion of vaccinated people who fall ill will increase over time as the vaccinated population increases and fewer people overall are hospitalized for COVID-19, he said.
And as more people get vaccinated, reports of late-breaking infections will also increase.
"The efficacy of vaccines is not 100%, it never is," he said.
"Nor should we expect COVID vaccines to be perfect. It is too high an expectation."
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c.2021 The New York Times Company
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