Three studies released Friday offered more evidence that COVID-19 vaccines are standing up to the omicron variant, at least among people who received booster shots. They are the first large U.S. studies to look at vaccine protection against omicron, health officials said. The papers echo previous research — including studies in Germany, South Africa and the U.K. — indicating available vaccines are less effective against omicron than earlier versions of the coronavirus, but also that boosters doses rev up virus-fighting antibodies to increase the chance of avoiding symptomatic infection. The first study looked at hospitalizations and emergency room and urgent care center visits in 10 states, from August to this month. Read: Omicron cases rise to 55 in Bangladesh It found vaccine effectiveness was best after three doses of the Pfizer or Moderna vaccines in preventing COVID-19-associated emergency department and urgent care visits. Protection dropped from 94% during the delta wave to 82% during the omicron wave. Protection from just two doses was lower, especially if six months had passed since the second dose. Officials have stressed the goal of preventing not just infection but severe disease. On that count, some good news: A third dose was at least 90% effective at preventing hospitalizations for COVID-19, both during the delta and omicron periods, the study also found. The second study focused on COVID-19 case and death rates in 25 states from the beginning of April through Christmas. People who were boosted had the highest protection against coronavirus infection, both during the time delta was dominant and also when omicron was taking over. Those two articles were published online by the Centers for Disease Control and Prevention. The Journal of the American Medical Association published the third study, also led by CDC researchers. It looked at people who tested positive for COVID-19 from Dec. 10 to Jan. 1 at more than 4,600 testing sites across the U.S. Three shots of the Pfizer and Moderna vaccines were about 67% effective against omicron-related symptomatic disease compared with unvaccinated people. Two doses, however, offered no significant protection against omicron when measured several months after completion of the original series, the researchers found. “It really shows the importance of getting a booster dose,” said the CDC’s Emma Accorsi, one of the study’s authors. Read: Govt school in Chandpur charging students Tk 50 per jab of vaccine! Americans should get boosters if at least five months have passed since they completed their Pfizer or Moderna series, but millions who are eligible have not gotten them. “If you are eligible for a booster and you haven’t gotten it, you are not up to date and you need to get your booster,” CDC Director Dr. Rochelle Walensky said during a White House briefing Friday.

U.S. health officials may soon recommend COVID-19 booster shots for fully vaccinated Americans. A look at what we know about boosters and how they could help fight the coronavirus: WHY MIGHT WE NEED BOOSTERS? It’s common for protection from vaccines to decrease over time. A tetanus booster, for example, is recommended every 10 years. Read: US okays Covid booster dose for those with weak immune systems Researchers and health officials have been monitoring the real-world performance of the COVID-19 vaccines to see how long protection lasts among vaccinated people. The vaccines authorized in the U.S. continue to offer very strong protection against severe disease and death. But laboratory blood tests have suggested that antibodies — one of the immune system’s layers of protection — can wane over time. That doesn’t mean protection disappears, but it could mean protection is not as strong or that it could take longer for the body to fight back against an infection. The delta variant has complicated the question of when to give boosters because it is so much more contagious and much of the data gathered about vaccine performance is from before the delta variant was widely circulating. Delta is taking off at the same time that vaccine immunity might also be waning for the first people vaccinated. Israel is offering a booster to people over 50 who were vaccinated more than five months ago. France and Germany plan to offer boosters to some people in the fall. The European Medicines Agency said it too is reviewing data to see if booster shots are needed. WHEN WOULD THEY BE GIVEN? It depends on when you got your initial shots. One possibility is that health officials will recommend people get a booster roughly eight months after getting their second shot of the Pfizer or Moderna vaccine. Officials are continuing to collect information about the one-shot Johnson & Johnson vaccine, which was authorized for use in the U.S. in late February, to determine when to recommend boosters. Read:US to recommend COVID vaccine boosters at 8 months WHO WOULD GET THEM? The first people vaccinated in the United States would likely be first in line for boosters too. That means health care workers, nursing home residents and other older Americans, who were the first to be vaccinated once the shots were authorized last December. BOOSTER? THIRD SHOT? WHAT’S THE DIFFERENCE? Transplant recipients and other people with weakened immune systems may not have gotten enough protection from vaccines to begin with. They can now receive a third dose at least 28 days after their second shot as part of their initial series of shots needed for them to be fully vaccinated. For those with normal immune systems, boosters are given much later after full vaccination — not to establish protection, but to rev it up again. WHAT QUESTIONS REMAIN? Still unknown is whether people should get the same type of shot they got when first vaccinated. And the nation’s top health advisers will be looking for evidence about the safety of boosters and how well they protect against infection and severe disease. Read:Why might COVID-19 vaccine boosters be necessary? Global access to vaccines is also important to stem the pandemic and prevent the emergence of new variants. Booster shots could crimp already tight global vaccine supplies. WHAT ABOUT THE UNVACCINATED? Dr. Melanie Swift, who has been leading the vaccination program at Mayo Clinic in Rochester, Minnesota, says getting more shots into people who haven’t yet been vaccinated at all is “our best tool, not only to prevent hospitalization and mortality from the delta variant, but to stop transmission.” Every infection, she says, “gives the virus more chances to mutate into who knows what the next variant could be.” “People who took the vaccine the first time are likely to line up and get their booster,” Swift says. “But it’s not going to achieve our goals overall if all their unvaccinated neighbors are not vaccinated.”

After struggling for months to persuade Americans to get the COVID-19 vaccine, U.S. health officials could soon face a fresh challenge: talking vaccinated people into getting booster shots to gain longer-lasting protection as the delta variant sends infections soaring again. As early as this week, U.S. health authorities are expected to recommend an extra dose of the vaccine for all Americans eight months after they get their second shot, according to two people who spoke to The Associated Press on condition of anonymity to discuss internal deliberations. That means the biggest vaccination drive in U.S. history is about to get even more extensive. The move is being driven by both the highly contagious variant and preliminary evidence that the vaccine’s protective effect starts dropping within months. The new urgency from U.S. officials reflects how quickly the variant has knocked the country back on its heels. On July Fourth, President Joe Biden proclaimed that the nation was declaring its independence from the virus. But since then, infections, hospitalizations and deaths have increased nationwide, overloading emergency rooms across parts of the South and West. READ: US okays Covid booster dose for those with weak immune systems When Pfizer announced plans in July to apply for approval for boosters, U.S. officials shot back that it was too early to know whether they were needed. Experts worried that a new campaign calling for boosters would muddle the continuing campaign to win over the tens of millions of Americans who are skeptical or hesitant to get their first shots. “We have to really make sure that while we’re spending a lot of time and effort on third doses that we don’t undermine our campaign for first vaccinations,” Lawrence Gostin, a public health specialist at Georgetown University, said Tuesday. “That’s truly the existential crisis in the United States.” Calling for third doses could discourage people who had been skeptical of the shot’s effectiveness in the first place, Gostin warned. Booster shots would only begin to be administered widely once the Food and Drug Administration formally approves the vaccines, which are being dispensed for now under what is known as emergency use authorization. Full approval of the Pfizer shot is expected in the coming weeks. Last week, U.S. health officials recommended boosters for some people with weakened immune systems, such as cancer patients and organ transplant recipients. The director of the National Institutes of Health, Dr. Francis Collins, said Sunday the U.S. could decide in the next couple of weeks whether to offer booster shots this fall to other Americans as well. Among the first to receive them could be health care workers, nursing home residents and other older Americans, who were some of the first to be vaccinated once the shots were authorized last December. More than 198 million Americans have received at least one dose of a COVID-19 vaccine, or 70% of those who are eligible, according to the Centers for Disease Control and Prevention. Just under 60% of Americans 12 and older are fully vaccinated. The vaccination drive has been slower than the Biden administration had hoped for. At the same time, the variant is spreading aggressively through unvaccinated communities and also causing an increasing number of “breakthrough infections” of fully inoculated people. Studies show the vaccine remains highly protective against severe COVID-19, but results from Israel released last month suggest its effect wanes. Its effectiveness against symptomatic infection peaked at 96% two months after study participants got their second dose. Four months later, it was down to 90%. By six months, it was about 84%. Israel, which exclusively administered the Pfizer shot, has been offering a booster to people over 50 to control its delta surge. Researchers are still trying to understand to what extent the breakthrough infections are due to waning immunity or vulnerability to the delta variant. On Tuesday, European medical regulators said they are talking with vaccine developers about the need for boosters but haven’t made any decisions. On Monday, Pfizer and its partner BioNTech announced they submitted data to the FDA to support authorizing a booster shot for the general public. Pfizer said a small study showed people who received a third dose had higher levels of antibodies against several versions of the coronavirus, including the delta variant. The company is working on a larger study. READ: Why might COVID-19 vaccine boosters be necessary? Americans who received the earliest doses of Pfizer’s vaccine — mainly health care workers and nursing home residents — are approaching the eight-month mark from when they received their second dose. “There is a concern that the vaccine may start to wane in its effectiveness,” the NIH’s Collins said. “And delta is a nasty one for us to try to deal with. The combination of those two means we may need boosters, maybe beginning first with health care providers, as well as people in nursing homes, and then gradually moving forward” with others. He said because the variant only started hitting the country hard in July, the next couple of weeks of case data will help the U.S. make a decision. The Pfizer and Moderna vaccines are administered in two doses. Officials are continuing to collect information as well about the one-shot Johnson & Johnson vaccine, which was only approved in the U.S. in late February, to determine when to recommend boosters. The White House has said that even though the U.S. has begun sharing more than 110 million vaccine doses with the rest of the world, the nation has enough to deliver boosters to Americans. Global health officials, including the World Health Organization, have called on wealthier and more-vaccinated countries to hold off on booster shots to ensure the supply of first doses for people in poor corners of the world. Gostin said the Biden administration’s plans to recommend boosters for all Americans are “a slap in the face” to other nations that haven’t yet been able to vaccinate their most vulnerable people. “It’s tone-deaf to the rest of the world that can’t even get any doses,” he said.