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Rare 'breakthrough' COVID cases are causing alarm, confusion

Rare 'breakthrough' COVID cases are causing alarm, confusion

Reports of athletes, lawmakers and others getting the coronavirus despite vaccination may sound alarming but top health experts point to overwhelming evidence that the shots are doing exactly what they are supposed to: dramatically reducing severe illness and death.The best indicator: U.S. hospitalizations and deaths are nearly all among the unvaccinated, and real-world data from Britain and Israel support that protection against the worst cases remains strong. What scientists call “breakthrough” infections in people who are fully vaccinated make up a small fraction of cases.“When you hear about a breakthrough infection, that doesn’t necessarily mean the vaccine is failing,” Dr. Anthony Fauci, the U.S. government’s top infectious disease specialist, told a worried Senate panel this week. The shots are holding up, he said, even in the face of the highly contagious delta variant that is burning through unvaccinated communitiesHealth authorities have warned that even though the COVID-19 vaccines are incredibly effective — the Pfizer and Moderna ones about 95% against symptomatic infection in studies — they’re not perfect. No vaccine is.But it wasn’t until delta variant began spreading that the risk of breakthroughs started getting much public attention. The barrage of headlines is disconcerting for vaccinated people wondering how to balance getting back to normal with more exposure to unvaccinated strangers — especially if they have vulnerable family members, such as children too young to qualify for the shots.Sports fans are seeing daily reports about infected athletes, from the New York Yankees to the Summer Olympics. With the Games soon to start, Kara Eaker, a member of the U.S. women’s gymnastic team who said she was vaccinated, tested positive in a training camp just outside Tokyo. WNBA player Katie Lou Samuelson pulled out of the Olympics and the 3-on-3 basketball competition after testing positive despite being vaccinated.And politicians in the nation’s capital are being rattled by reports of breakthrough cases, including from a congressman, Florida Republican Vern Buchanan; some Texas Democratic lawmakers visiting Washington as a political protest; at least two people in the White House and several congressional staff members.White House press secretary Jen Psaki said Wednesday that with 2,000 people on the White House campus each day some breakthrough cases are inevitable, but that the administration will release information if doctors determine any staffer had close contact with the president, vice president or their spouses.One critical question about breakthrough cases is whether the person actually had symptoms, Dr. Francis Collins, director of the National Institutes of Health, told The Associated Press. “Or is this somebody just being sampled out of an abundance of caution because they had to go into some place like the Congress?” he added.Indeed, the U.S. Centers for Disease Control and Prevention has said for months that vaccinated people don’t even need to get tested after a virus exposure unless they develop symptoms. The agency cites limited evidence that they’re less likely to infect others than unvaccinated people who get an asymptomatic infection.But different places have different rules. In Britain, Prime Minister Boris Johnson — who survived COVID-19 early in the pandemic and now is fully vaccinated — began quarantining over the weekend after contact with someone experiencing mild symptoms from a breakthrough infection.And rigorous testing is required as thousands of athletes, coaches, officials and media — not all of whom are vaccinated — descend on Tokyo for the pandemic-delayed Olympics.While there’s not a specific count, it’s clear breakthrough infections are rare. As of July 12, the CDC had tallied 5,492 vaccinated people who were hospitalized or died and also tested positive for coronavirus — out of more than 159 million fully vaccinated Americans. CDC Director Dr. Rochelle Walensky has said 99.5% of all deaths from COVID-19 are in the unvaccinated.There isn’t a separate count of mild or asymptomatic breakthroughs, although CDC is tracking those through studies such as one that gives weekly virus tests to more than 5,000 essential workers, she told senators.Breakthroughs tend to be mild because a vaccinated person’s immune system doesn’t have to start from scratch to fight the coronavirus. Even if the virus sneaks past vaccine-spurred antibodies and starts replicating in your nose or throat, secondary defenses jump into action and usually, “the virus is stopped in its tracks within a few days,” said University of Pennsylvania immunologist Scott Hensley.There are caveats. The vaccines don’t work as well in people with severely weak immune systems, such as organ transplant recipients.And the government is watching closely for signs that breakthrough cases, especially serious ones, are rising, because that might signal the need for booster vaccinations.But meanwhile White House officials want to “normalize” the concept of breakthrough infections for the public, because they’re worried that these rare, inevitable events could play into the misinformation wars that have helped to keep millions from rolling up their sleeves.“The vaccines were developed to keep us out of those terrible institutions we call hospitals,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University. “We have to keep coming back to that.”———Associated Press Writers Jonathan Lemire and Zeke Miller contributed to this report.———The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

EXPLAINER: Are we going to need COVID-19 booster shots?

EXPLAINER: Are we going to need COVID-19 booster shots?

Just because Pfizer wants to offer COVID-19 vaccine boosters doesn’t mean people will be lining up anytime soon — U.S. and international health authorities say that for now, the fully vaccinated seem well protected.Globally, experts are watching closely to determine if and when people might need another shot. At the same time, many suggest the priority for the time being should be vaccinations, noting that worrisome coronavirus mutants wouldn’t be popping up so fast if more of the U.S. and the rest of the world had gotten the initial round of shots.“If you want to stop hearing about the variant of the week,” said Jennifer Nuzzo, a Johns Hopkins University public health specialist, “we need to do more work to make sure all countries have more access to vaccines.”Here are some questions and answers about vaccine immunity and boosters.WHAT’S PROMPTING ALL THE BOOSTER DEBATE?U.S. health officials have long said that people one day might need a booster — after all, they do for many other vaccines. That’s why studies are underway to test different approaches: simple third doses, mix-and-match tests using a different brand for a third dose, or experimental boosters tweaked to better match different variants.But last week, Pfizer and its German partner BioNTech announced that in August, they plan to seek Food and Drug Administration authorization of a third dose because it could boost levels of virus-fighting antibodies, possibly helping ward off worrisome mutants.The companies haven’t publicly released data, and U.S. health officials issued a sharp response that boosters aren’t yet needed and that the government, not vaccine makers, will decide if and when that changes.The World Health Organization said Monday there is not enough evidence to show that third doses are needed. It said the scarce shots should be shared with poor countries instead of being used by rich countries as boosters.WHAT’S THE EVIDENCE THAT VACCINE PROTECTION REMAINS STRONG?An Associated Press analysis last month found nearly all COVID-19 deaths in the U.S. are occurring among the unvaccinated.In the last few weeks, infections and hospitalizations have begun rising as the highly contagious delta variant spreads. But the Centers for Disease Control and Prevention says the surges are driven by the least vaccinated parts of a country that has plenty of shots if people would only take them.No vaccine is perfect, meaning fully vaccinated people occasionally will get infected, but those so-called breakthrough cases usually are mild. Officials monitoring the need for boosters are watching closely for any jumps in serious breakthrough infections.So far the news is good: The people first in line for vaccines back in December and January don’t seem to be at higher risk for breakthrough infections than those vaccinated more recently, the CDC’s Dr. Jay Butler said Tuesday.IS THE BOOSTER QUESTION ALL ABOUT NEW VARIANTS?No, scientists also are watching to see how much vaccinated people’s overall immunity to the coronavirus wanes. That, too, could require a booster shot.Virus-fighting antibodies do gradually wane. That’s normal since the body doesn’t need to be on high alert forever.But antibodies aren’t its only defense. By the time those levels drop, the body has formed backups. They include memory B cells that, the next time you’re exposed, “explode, and they start dividing like mad” to make new antibodies, said University of Pennsylvania immunologist Scott Hensley.Another backup: T cells that kill virus-infected cells to help keep a breakthrough case from becoming severe.Lab studies signal antibodies aren’t as potent against the delta variant as they are against some earlier versions of the coronavirus but are still protective. Specialists worry more about the prospect of future mutants that might escape today’s vaccines, something preventable only by cracking down on viral spread everywhere.HOW ARE OTHER COUNTRIES DOING AGAINST THE DELTA VARIANT?Real-world data from England, Scotland, Canada and Israel shows that the vaccines most widely used in Western countries continue to provide strong protection. Researchers in Britain found two doses of the Pfizer vaccine, for example, are 96% protective against hospitalization with the delta variant and 88% effective against symptomatic infection.Israel recently reported preliminary data suggesting protection against mild delta infection has dipped lower, to 64%. But protection against severe illness remained high.There’s less information about how well other vaccines hold up against the delta variant. Thailand announced this week that health workers who had received two doses of a Chinese vaccine would be given a booster shot made by AstraZeneca.COULD SOME PEOPLE NEED A BOOSTER BEFORE THE ENTIRE POPULATION?That’s possible. Israel just began dispensing third doses of the Pfizer vaccine to transplant recipients and other patients with weak immune systems. The reason: People who take certain immune-suppressing medications don’t react as strongly to any vaccinations — not just COVID-19 vaccines — as healthy people.France already had a similar third-dose policy for the immunocompromised. And even though it’s not authorized in the U.S., some transplant recipients seek out a third dose in hopes of more protection.It’s not yet proven if a third dose helps and, if so, who needs one and when. The first large study of the strategy is beginning in thousands of patients in Norway.———The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

COVID vaccines still work against mutant, researchers find

COVID vaccines still work against mutant, researchers find

Pfizer is about to seek U.S. authorization for a third dose of its COVID-19 vaccine, saying Thursday that another shot within 12 months could dramatically boost immunity and maybe help ward off the latest worrisome coronavirus mutant.Research from multiple countries shows the Pfizer shot and other widely used COVID-19 vaccines offer strong protection against the highly contagious delta variant, which is spreading rapidly around the world and now accounts for most new U.S. infections.Two doses of most vaccines are critical to develop high levels of virus-fighting antibodies against all versions of the coronavirus, not just the delta variant — and most of the world still is desperate to get those initial protective doses as the pandemic continues to rage.But antibodies naturally wane over time, so studies also are underway to tell if and when boosters might be needed.On Thursday, Pfizer’s Dr. Mikael Dolsten told The Associated Press that early data from the company’s booster study suggests people’s antibody levels jump five- to 10-fold after a third dose, compared to their second dose months earlier.In August, Pfizer plans to ask the Food and Drug Administration for emergency authorization of a third dose, he said.Why might that matter for fighting the delta variant? Dolsten pointed to data from Britain and Israel showing the Pfizer vaccine “neutralizes the delta variant very well.” The assumption, he said, is that when antibodies drop low enough, the delta virus eventually could cause a mild infection before the immune system kicks back in.But FDA authorization would be just a first step — it wouldn’t automatically mean Americans get offered boosters, cautioned Dr. William Schaffner, a vaccine expert at Vanderbilt University Medical Center. Public health authorities would have to decide if they’re really needed, especially since millions of people have no protection.“The vaccines were designed to keep us out of the hospital” and continue to do so despite the more contagious delta variant, he said. Giving another dose would be “a huge effort while we are at the moment striving to get people the first dose.”Currently only about 48% of the U.S. population is fully vaccinated — and some parts of the country have far lower immunization rates, places where the delta variant is surging. On Thursday, Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said that’s leading to “two truths” — highly immunized swaths of America are getting back to normal while hospitalizations are rising in other places.“This rapid rise is troubling,” she said: A few weeks ago the delta variant accounted for just over a quarter of new U.S. cases, but it now accounts for just over 50% — and in some places, such as parts of the Midwest, as much as 80%.Also Thursday, researchers from France’s Pasteur Institute reported new evidence that full vaccination is critical.In laboratory tests, blood from several dozen people given their first dose of the Pfizer or AstraZeneca vaccines “barely inhibited” the delta variant, the team reported in the journal Nature. But weeks after getting their second dose, nearly all had what researchers deemed an immune boost strong enough to neutralize the delta variant — even if it was a little less potent than against earlier versions of the virus.The French researchers also tested unvaccinated people who had survived a bout of the coronavirus, and found their antibodies were four-fold less potent against the new mutant. But a single vaccine dose dramatically boosted their antibody levels — sparking cross-protection against the delta variant and two other mutants, the study found. That supports public health recommendations that COVID-19 survivors get vaccinated rather than relying on natural immunity.The lab experiments add to real-world data that the delta variant’s mutations aren’t evading the vaccines most widely used in Western countries, but underscore that it’s crucial to get more of the world immunized before the virus evolves even more.Researchers in Britain found two doses of the Pfizer vaccine, for example, are 96% protective against hospitalization with the delta variant and 88% effective against symptomatic infection. That finding was echoed last weekend by Canadian researchers, while a report from Israel suggested protection against mild delta infection may have dipped lower, to 64%.Whether the fully vaccinated still need to wear masks in places where the delta variant is surging is a growing question. In the U.S., the CDC maintains that fully vaccinated people don’t need to. Even before the delta variant came along, the vaccines weren’t perfect, but the best evidence suggests that if vaccinated people nonetheless get the coronavirus, they’ll have much milder cases.“Let me emphasize, if you were vaccinated, you have a very high degree of protection,” Dr. Anthony Fauci, the U.S. government’s top infectious disease expert, said Thursday.In the U.S., case rates have been rising for weeks and the rate of hospitalizations has started to tick up, rising 7% from the previous seven-day average, Walensky told reporters Thursday. However, deaths remain down on average, which some experts believe is at least partly due to high vaccination rates in people 65 and older — who are among the most susceptible to severe disease.———Associated Press writer Mike Stobbe contributed to this story.———The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Delta variant exploits low vaccine rates, easing of rules

Delta variant exploits low vaccine rates, easing of rules

The latest alarming coronavirus variant is exploiting low global vaccination rates and a rush to ease pandemic restrictions, adding new urgency to the drive to get more shots in arms and slow its supercharged spread.The vaccines most used in Western countries still appear to offer strong protection against the highly contagious delta variant, first identified in India and now spreading in more than 90 other countries.But the World Health Organization warned this week that the trifecta of easier-to-spread strains, insufficiently immunized populations and a drop in mask use and other public health measures before the virus is better contained will “delay the end of the pandemic.”The delta variant is positioned to take full advantage of those weaknesses.“Any suffering or death from COVID-19 is tragic. With vaccines available across the country, the suffering and loss we are now seeing is nearly entirely avoidable,” Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said Thursday in urging more Americans to roll up their sleeves ahead of the mutant’s spread.Amid concerns about the variant, parts of Europe have reinstated travel quarantines, several Australian cities are in outbreak-sparked lockdowns — and just as Japan readies for the Olympics, some visiting athletes are infected. The mutation is causing worry even in countries with relatively successful immunization campaigns that nonetheless haven’t reached enough people to snuff out the virus.For instance, the mutant has forced Britain, where nearly half the population is fully vaccinated, to postpone for a month its long-anticipated lifting of COVID-19 restrictions, as cases are doubling about every nine days.In the U.S., “we’re still vulnerable for these flare-ups and rebounds,” said Dr. Hilary Babcock of Washington University at St. Louis.The variants “are able to find any gaps in our protection,” she said, pointing to how hospital beds and intensive care units in Missouri’s least-vaccinated southwestern counties suddenly are filling — mostly with adults under 40 who never got the shots.With nearly half the U.S. population immunized, CDC’s Walensky said about 1,000 counties, mostly in the Midwest and Southeast, with vaccination rates below 30% “are our most vulnerable.”But the variant poses the most danger in countries where vaccinations are sparse. Africa is seeing cases rise faster than ever before, partially driven by the mutation, the WHO said Thursday, while areas in Bangladesh that border India are also seeing a variant-fueled surge. Fiji, which got through the first year of the pandemic without just two virus deaths, is now experiencing a significant outbreak blamed on the strain, and Afghanistan is desperately seeking oxygen supplies because of it.The delta variant remains far from the only version of the coronavirus that’s spreading — and you don’t want to catch any kind. Here’s what scientists know so far:EASIER SPREAD IS THE CHIEF THREATScientists believe the delta variant is about 50% more transmissible than other types. Researchers are just beginning to tease apart why. But there are early clues that some mutations may ease a key step in how the virus slips inside human cells, said Priyamvada Acharya, a structural biologist at the Duke Human Vaccine Institute.Still, it’s not clear if higher contagion is the whole reason the variant is spreading so quickly. In Britain, its rise followed a loosening of restrictions in May, when restaurants, gyms and other businesses reopened, and thousands of fans have attended sports events.IS IT MORE DANGEROUS?It’s harder to tell if the delta variant makes people sicker. British experts have said there are some preliminary signs it may increase hospitalization, but there’s no evidence it is more lethal.It fueled a devastating COVID-19 surge in India in February, and “this time around we had a lot more people who were very sick compared to before,” said Dr. Jacob John of Christian Medical College at Vellore. But he cautioned that the “explosion” of cases didn’t necessarily mean this version was more dangerous, as more cases usually mean more hospitalizations.THE BEST PROTECTION IS FULL VACCINATIONBritish researchers found two doses of either the Pfizer-BioNTech vaccine or the AstraZeneca one were only slightly less effective at blocking symptomatic illness from the delta variant than from earlier mutations — and importantly, remain hugely protective at preventing hospitalization.But there’s an important catch: Just one dose proved far less effective against the delta variant than against earlier versions of the virus. That has prompted Britain, which originally extended the gap between doses, to speed up second shots.There’s little information on whether the delta variant can escape other vaccines, such as ones developed in China or Russia.Experts say the Moderna vaccine, the same type as Pfizer’s, should be similarly protective. Johnson & Johnson still is studying how its one-dose vaccine fares against the variant. The company notes its shot does protect against a different worrisome mutant — the so-called beta variant that emerged in South Africa and is still considered the biggest challenge for today’s COVID-19 vaccines.WHAT ABOUT MASKS?The WHO has urged governments not to lift pandemic restrictions too quickly — including saying everyone, even the vaccinated, should continue to wear masks given that the delta variant spreads more easily and no vaccine is 100% effective.In the U.S., the CDC maintains it still is safe for the fully vaccinated to go mask-free. But there’s no way to know if maskless people really are vaccinated and local governments can set tighter guidelines. This week, with the delta variant spreading locally, health officials in Los Angeles County said they still recommend masks indoors in public places for everyone.If that’s confusing, consider that the more the virus is spreading in a particular area, the more risk even the vaccinated have of getting a mild or asymptomatic infection they could spread to someone not protected — such as children too young to qualify for the shots.In Missouri, fully vaccinated Babcock makes sure she has a mask to pop on quickly if she runs into a crowd: “I feel like my new normal is holding a mask in my hand, ready to put it on if I need it.”———Associated Press writers Maria Cheng in London and Aniruddha Ghosal in New Delhi contributed to this report.———The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.