U.S. regulators on Friday authorized the first COVID-19 shots for infants and preschoolers, paving the way for vaccinations to begin next week. The Food and Drug Administration’s action follows its advisory panel’s unanimous recommendation for the shots from Moderna and Pfizer. That means U.S. kids under 5 — roughly 18 million youngsters — are eligible for the shots. The nation’s vaccination campaign began about 1 1/2 years ago with older adults, the hardest hit during the coronavirus pandemic. There’s one step left: The Centers for Disease Control and Prevention recommends how to use vaccines. Its independent advisers began debating the two-dose Moderna and the three-dose Pfizer vaccines on Friday and will make its recommendation Saturday. A final signoff is expected soon after from CDC Director Dr. Rochelle Walensky. At a Senate hearing Thursday, Walensky said her staff was working over the Juneteenth federal holiday weekend “because we understand the urgency of this for American parents.” She said pediatric deaths from COVID-19 have been higher than what is generally seen from the flu each year. “So I actually think we need to protect young children, as well as protect everyone with the vaccine and especially protect elders,” she said. The FDA also authorized Moderna’s vaccines for school-aged children and teens; CDC’s review is next week. Pfizer’s shots had been the only option for those age groups. For weeks, the Biden administration has been preparing to roll out the vaccines for little kids, with states, tribes, community health centers and pharmacies preordering millions of doses. With FDA’s emergency use authorization, manufacturers can begin shipping vaccine across the country. The shots are expected to start early next week but it’s not clear how popular they will be. Without protection for their tots, some families had put off birthday parties, vacations and visits with grandparents. “Today is a day of huge relief for parents and families across America,” President Joe Biden said in a statement. While young children generally don’t get as sick from COVID-19 as older kids and adults, their hospitalizations surged during the omicron wave and FDA’s advisers determined that benefits from vaccination outweighed the minimal risks. Studies from Moderna and Pfizer showed side effects, including fever and fatigue, were mostly minor. White House COVID-19 coordinator Dr. Ashish Jha predicted the pace of vaccinations for kids under 5 to be far slower than it was for older populations and said the administration doesn’t have any internal targets for the pace of vaccinations. “At the end of the day, our goal is very clear: We want to get as many kids vaccinated as possible,” Jha told The Associated Press. In testing, the littlest children developed high levels of virus-fighting antibodies, comparable to what is seen in young adults, the FDA said. Moderna’s vaccine was about 40% to 50% effective at preventing infections but there were too few cases during Pfizer’s study to give a reliable, exact estimate of effectiveness, the agency said. “Both of these vaccines have been authorized with science and safety at the forefront of our minds,” Dr. Peter Marks, FDA’s vaccine chief, said at a news briefing. Marks said parents should feel comfortable with either vaccine, and should get their kids vaccinated as soon as possible, rather than waiting until fall, when a different virus variant might be circulating. He said adjustments in the vaccines would be made to account for that. “Whatever vaccine your health care provider, pediatrician has, that’s what I would give my child,” Marks said. The two brands use the same technology but there are differences. Pfizer’s vaccine for kids younger than 5 is one-tenth of the adult dose. Three shots are needed: the first two given three weeks apart and the last at least two months later. Moderna’s is two shots, each a quarter of its adult dose, given about four weeks apart for kids under 6. The FDA also authorized a third dose, at least a month after the second shot, for children who have immune conditions that make them more vulnerable to serious illness. Both vaccines are for children as young as 6 months. Moderna next plans to study its shots for babies as young as 3 months. Pfizer has not finalized plans for shots in younger infants. A dozen countries, including China, already vaccinate kids under 5, with other brands. Immediately upon hearing of the FDA’s decision, Dr. Toma Omofoye, a Houston radiologist, made appointments for her 4-year-old daughter and 3-year-old son. Without the shots, her family has missed out on family gatherings, indoor concerts, even trips to the grocery store, she said. During a recent pharmacy stop, Omofoye said her daughter stared and walked around like it was Disneyland, and thanked her. “My heart broke in that moment, which is why my heart is so elated now,” Omofoye said. But will other parents be as eager to get their youngest vaccinated? By some estimates, three-quarters of all U.S. children have already been infected. And only about 30% of children aged 5 to 11 have gotten vaccinated since Pfizer’s shots opened to them last November. The FDA officials acknowledged those low rates and said the government is committed to getting more older kids vaccinated and having better success with younger kids. “It’s a real tragedy, when you have something free with so few side effects that prevents deaths and hospitalization,” said FDA Commissioner Robert Califf. Roughly 440 children under age 5 have died from COVID-19, federal data show. Read: UNICEF finds Bangladesh as Covid-19 vaccine success story Dr. Beth Ebel of the University of Washington School of Medicine in Seattle, said the tot-sized vaccines would be especially welcomed by parents with children in day care where outbreaks can sideline parents from jobs, adding to financial strain. “A lot of people are going to be happy and a lot of grandparents are going to be happy, too, because we’ve missed those babies who grew up when you weren’t able to see them,” Ebel said.

The first COVID-19 shots for U.S. infants, toddlers and preschoolers moved a step closer Wednesday. The Food and Drug Administration’s vaccine advisers gave a thumbs-up to vaccines from Moderna and Pfizer for the littlest kids. The outside experts voted unanimously that the benefits of the shots outweigh any risks for children under 5 — that’s roughly 18 million youngsters. They are the last age group in the U.S. without access to COVID-19 vaccines and many parents have been anxious to protect their little children. If all the regulatory steps are cleared, shots should be available next week. Also read: Bangladesh number 1 recipient of COVID-19 vaccines under COVAX: UNICEF “This is a long-awaited vaccine,” said one panel member, Dr. Jay Portnoy of Children’s Hospital in Kansas City, Missouri. “There are so many parents who are absolutely desperate to get this vaccine and I think we owe it to them to give them a choice to have the vaccine if they want to.” Dr. Peter Marks, FDA’s vaccine chief, opened the meeting with data showing a “quite troubling surge” in young children’s hospitalizations during the omicron wave, and noted 442 children under 4 have died during the pandemic. That’s far fewer than adult deaths, but should not be dismissed in considering the need for vaccinating the youngest kids, he said. “Each child that’s lost essentially fractures a family,” Marks said. While endorsing the vaccines, some panel members said they believe chances are minimal for severe illness and death in young children. “Risks from vaccination are very low, but so are risks from COVID-19 for the youngest kids,” said Dr. Cody Meissner of Tufts University. Also read: Declare vaccines as global goods, Hasina urges World Health Assembly FDA reviewers said both brands appear to be safe and effective for children as young as 6 months old in analyses posted ahead of the all-day meeting. Side effects, including fever and fatigue, were generally minor in both, and less common than seen in adults. The two vaccines use the same technology but there are differences. In a call with reporters earlier this week, vaccine experts noted that the shots haven’t been tested against each other, so there’s no way to tell parents if one is superior. “You can’t compare the vaccines directly,” said Dr. Jesse Goodman of Georgetown University, a former FDA vaccine chief. If the FDA agrees with its advisers and authorizes the shots, there’s one more step. The Centers for Disease Control and Prevention will decide on a formal recommendation after its own advisers vote on Saturday. If the CDC signs off, shots could be available as soon as Monday or Tuesday at doctor’s offices, hospitals and pharmacies. Pfizer’s vaccine is for children 6 months through 4 years; Moderna’s vaccine is for 6 months through 5 years. Moderna’s shots are one-quarter the dose of the company’s adult shots. Two doses appeared strong enough to prevent severe illness but only about 40% to 50% effective at preventing milder infections. Moderna added a booster to its tests and expects to eventually offer one. Pfizer’s shots are just one-tenth its adult dose. Pfizer and partner BioNTech found that two shots didn’t provide enough protection in testing, so a third was added during the omicron wave. Pfizer’s submitted data found no safety concerns and suggested that three shots were 80% effective in preventing symptomatic coronavirus infections. But that was based on just 10 COVID-19 cases; the calculation could change as more cases occur in the company’s ongoing studies. Several advisers, noting that protection is low after two Pfizer doses, worried that some parents might end up skipping the third shot, or mistakenly thinking their kids are better protected between shots, leaving them vulnerable. Educating parents must be done “very very carefully so that they are not misled about what the vaccines actually provide,” said Dr. Archana Chatterjee of Rosalind Franklin University. The same FDA panel on Tuesday backed Moderna’s half-sized shots for ages 6 to 11 and full-sized doses for teens. If authorized by the FDA, it would be the second option for those age groups. Currently Pfizer vaccine is their only choice. The nation’s vaccination campaign started in December 2020 with the rollout of adult vaccines from Pfizer and Moderna, with health care workers and nursing home residents first in line. Teens and school-age children were added last year. Moderna said in April that it is also seeking regulatory approval outside the U.S. for its little kid shots. According to the World Health Organization, 12 countries already vaccinate kids under 5, with other brands. In the U.S., it remains uncertain how many parents want their youngest vaccinated. By some estimates, three-quarters of all children have already been infected. And only about 29% of children aged 5 to 11 have been vaccinated since Pfizer’s shots opened to them last November, a rate far lower than public health authorities consider ideal. Dr. Nimmi Rajagopal, a family medicine physician at Cook County Health in Chicago, said she’s been preparing parents for months. “We have some that are hesitant, and some that are just raring to go,” she said.  

Most Americans should be given the Pfizer or Moderna vaccines instead of the Johnson & Johnson shot that can cause rare but serious blood clots, U.S. health officials said Thursday. The strange clotting problem has caused nine confirmed deaths after J&J vaccinations — while the Pfizer and Moderna vaccines don't come with that risk and also appear more effective, said advisers to the Centers for Disease Control and Prevention. The panel recommended the unusual move of giving preference to the Pfizer and Moderna vaccines, and late Thursday the CDC's director, Dr. Rochelle Walensky, accepted the panel's advice. Until now the U.S. has treated all three COVID-19 vaccines available to Americans as an equal choice, since large studies found they all offered strong protection and early supplies were limited. J&J's vaccine initially was welcomed as a single-dose option that could be especially important for hard-to-reach groups like homeless people who might not get the needed second dose of the Pfizer or Moderna options. Also read: Pfizer confirms COVID pill’s results, potency versus omicron But the CDC's advisers said during a meeting Thursday that it was time to recognize a lot has changed since vaccines began rolling out a year ago. More than 200 million Americans are considered fully vaccinated, including about 16 million who got the J&J shot. New data from unprecedented safety tracking of all those vaccinations persuaded the panel that while the blood clots linked to J&J's vaccine remain very rare, they're still occurring and not just in younger women as originally thought. In a unanimous vote, the advisers decided the safer Pfizer and Moderna vaccines are preferred. But they said the shot made by J&J's Janssen division still should be available if someone really wants it — or has a severe allergy to the other options. “I would not recommend the Janssen vaccine to my family members” but some patients may -- and should be able to -- choose that shot, said CDC adviser Dr. Beth Bell of the University of Washington. The clotting problems first came up last spring, with the J&J shot in the U.S. and with a similar vaccine made by AstraZeneca that is used in other countries. Eventually U.S. regulators decided the benefits of J&J's one-and-done vaccine outweighed what was considered a very rare risk — as long as recipients were warned. European regulators likewise continued to recommend AstraZeneca's two-dose vaccine although, because early reports were mostly in younger women, some countries issued age restrictions. COVID-19 causes deadly blood clots, too. But the vaccine-linked kind is different, believed to form because of a rogue immune reaction to the J&J and AstraZeneca vaccines because of how they're made. It forms in unusual places, such as veins that drain blood from the brain, and in patients who also develop abnormally low levels of the platelets that form clots. Symptoms of the unusual clots, dubbed “thrombosis with thrombocytopenia syndrome,” include severe headaches a week or two after the J&J vaccination — not right away — as well as abdominal pain and nausea. Also read: US expands Pfizer COVID boosters, opens extra dose to age 16 While it’s still very rare, the Food and Drug Administration told health care providers this week that more cases have occurred after J&J vaccinations since the spring. They occur most in women ages 30 to 49 -- about once for every 100,000 doses administered, the FDA said. Overall, the government has confirmed 54 clot cases— 37 in women and 17 in men, and nine deaths that included two men, the CDC's Dr. Isaac See said Thursday. He said two additional deaths are suspected. The CDC decides how vaccines should be used in the U.S., and its advisers called the continuing deaths troubling. In comparing the pros and cons of all the vaccines, the panelists agreed that side effects from the Pfizer and Moderna vaccines weren't as serious — and that supplies now are plentiful. Nor is J&J still considered a one-and-done vaccine, several advisers noted. The single-dose option didn't prove quite as protective as two doses of the Pfizer and Moderna vaccines. Plus, with extra-contagious virus mutants now spreading, booster doses now are recommended. For J&J recipients, a booster is recommended at least two months after vaccination. U.S. health officials had previously OK’d mixing vaccines for booster shots. Several countries, including Canada, already have policies that give preference to the Pfizer and Moderna vaccines. But J&J told the committee its vaccine still offers strong protection and is a critical option especially in parts of the world without plentiful vaccine supplies or for people who don't want a two-dose shot. While blood clots are rare, “unfortunately cases of COVID-19 are not,” J&J’s Dr. Penny Heaton said. The U.S. is fortunate in its vaccine availability and Thursday's action shouldn't discourage use of J&J's vaccine in places around the world where it's needed, said CDC adviser Dr. Matthew Daley of Kaiser Permanente Colorado. The FDA also warned this week that another dose of the J&J vaccine shouldn't be given to anyone who developed a clot following either a J&J or AstraZeneca shot. The committee also heard some of the first data on reported side effects of Pfizer vaccinations in younger children. Early last month, the CDC recommended a two-dose series for that age group, and more than 7 million doses have been given so far. But few problems have been reported. Of the 80 reported cases of serious side effects, about 10 involved a form of inflammation that has been seen in male teens and young adults.

Vaccine makers are racing to update their COVID-19 shots against the newest coronavirus threat even before it’s clear a change is needed, just in case. Experts doubt today’s shots will become useless but say it’s critical to see how fast companies could produce a reformulated dose and prove it works -- because whatever happens with omicron, this newest mutant won’t be the last. Omicron “is pulling the fire alarm. Whether it turns out to be a false alarm, it would be really good to know if we can actually do this -- get a new vaccine rolled out and be ready,” said immunologist E. John Wherry of the University of Pennsylvania. It’s too soon to know how vaccines will hold up against omicron. The first hints this week were mixed: Preliminary lab tests suggest two Pfizer doses may not prevent an omicron infection but they could protect against severe illness. And a booster shot may rev up immunity enough to do both. Better answers are expected in the coming weeks and regulators in the U.S. and other countries are keeping a close watch. The World Health Organization has appointed an independent scientific panel to advise on whether the shots need reformulating because of omicron or any other mutant. But authorities haven’t laid out what would trigger such a drastic step: If vaccine immunity against serious illness drops, or if a new mutant merely spreads faster? “This is not trivial,” BioNTech CEO Ugur Sahin, Pfizer’s vaccine partner, said shortly before omicron’s discovery. A company could apply to market a new formula “but what happens if another company makes another proposal with another variant? We don’t have an agreed strategy.” Read:COVID cases spike even as US hits 200M vaccine milestone It’s a tough decision — and the virus moves faster than science. Just this fall the U.S. government’s vaccine advisers wondered why boosters weren’t retooled to target the extra-contagious delta variant — only to have the next scary mutant, omicron, be neither a delta descendent nor a very close cousin. If vaccines do need tweaking, there’s still another question: Should there be a separate omicron booster or a combination shot? And if it’s a combo, should it target the original strain along with omicron, or the currently dominant delta variant plus omicron? Here’s what we know. COMPANIES AREN’T STARTING FROM SCRATCH COVID-19 vaccines work by triggering production of antibodies that recognize and attack the spike protein that coats the coronavirus, and many are made with new technology flexible enough for easy updating. The Pfizer and Moderna vaccines are fastest to tweak, made with genetic instructions that tell the body to make harmless copies of the spike protein — and that messenger RNA can be swapped to match new mutations. Pfizer expects to have an omicron-specific candidate ready for the Food and Drug Administration to consider in March, with some initial batches ready to ship around the same time, chief scientific officer Dr. Mikael Dolsten told The Associated Press. Moderna is predicting 60 to 90 days to have an omicron-specific candidate ready for testing. Other manufacturers that make COVID-19 vaccines using different technology, including Johnson & Johnson, also are pursuing possible updates. Pfizer and Moderna already have successfully brewed experimental doses to match delta and another variant named beta, shots that haven’t been needed but offered valuable practice. NOT CLEAR IF TWEAKS ARE NEEDED So far, the original vaccines have offered at least some cross-protection against prior variants. Even if immunity against omicron isn’t as good, Dr. Anthony Fauci, the top U.S. infectious disease expert, hopes the big antibody jump triggered by booster doses will compensate. Pfizer's preliminary lab testing, released Wednesday, hint that might be the case but antibodies aren’t the only layer of defense. Vaccines also spur T cells that can prevent serious illness if someone does get infected, and Pfizer's first tests showed, as expected, those don't seem to be affected by omicron. Also, memory cells that can create new and somewhat different antibodies form with each dose. "You're really training your immune system not just to deal better with existing variants, but it actually prepares a broader repertoire to deal with new variants,” Dolsten said. How aggressive a mutant is also plays a role in whether to reformulate the vaccine. Omicron appears to spread easily but early reports from South African scientists hint that it might cause milder infections than previous variants. Read: Scientist behind UK vaccine says next pandemic may be worse HOW TO TELL IF UPDATES WORK The FDA has said companies won’t need massive studies of tweaked vaccines but small ones to measure if people given the updated shot have immune responses comparable to the original, highly effective shots. Wherry doesn't expect data from volunteers testing experimental omicron-targeted shots until at least February. WHAT ABOUT COMBINATION SHOTS? Flu vaccines protect against three or four different strains of influenza in one shot. If a vaccine tweak is needed for omicron, authorities will have to decide to whether to make a separate omicron booster or add it to the original vaccine -- or maybe even follow the flu model and try another combination. There’s some evidence that a COVID-19 combo shot could work. In a small Moderna study, a so-called bivalent booster containing the original vaccine and a beta-specific dose caused a bigger antibody jump than either an original Moderna booster or its experimental beta-specific shot. And scientists already are working on next-generation vaccines that target parts of the virus less prone to mutate. Omicron brings “another important wake-up call,” Wherry said -- not just to vaccinate the world but create more versatile options to get that job done.

More than a dozen states will open vaccine eligibility to all adults this week in a major expansion of COVID-19 shots for tens of millions of Americans amid a worrisome increase in virus cases and concerns about balancing supply and demand for the vaccines. Meanwhile, the director of the Centers for Disease Control and Prevention said Monday that she had a recurring feeling of "impending doom" about a potential fourth wave of infections after cases in the U.S. rose 10% over the last week. She pleaded with Americans not to relax preventative practices such as social distancing and mask-wearing. Also read: AstraZeneca: US data shows vaccine effective for all adults “Just please hold on a little while longer," Dr. Rochelle Walensky said during a White House briefing. Several Northeastern states and Michigan have seen the biggest increases, with some reporting hundreds or thousands more new cases per day than they were two weeks ago. A new study by the CDC concluded that the Pfizer and Moderna vaccines were 90% effective after two doses, a finding that Walensky said should offer hope. States opening eligibility to anyone ages 16 and older on Monday included Texas, Oklahoma, Louisiana, Ohio, North Dakota and Kansas. The rapid expansion has fueled concerns that the number of eager vaccine seekers will far outstrip the available supply of shots, frustrating millions of newly eligible people who have waited since late last year for a chance to get an injection. Other officials have put their faith in a promised glut of vaccines and instead turned their attention to the next challenge: pressing as many people as possible to get the shots so the nation can achieve herd immunity at the earliest opportunity. Vaccination rates in Texas have lagged behind much of the U.S., and although state officials put at least part of the blame on delays in data reporting, they also acknowledged that appointment slots are going unfilled. Demand "has definitely decreased over the past couple of weeks,” said Imelda Garcia, head of the state’s expert vaccine allocation panel. Texas is supposed to receive more than 1 million new doses this week. On Monday, the state launched a new online vaccine scheduler and phone number, taking a bigger role in efforts that had largely been done at the local level. In Kansas, where some local health officials have said they are also struggling to find people to vaccinate, an additional 400,000 people are now eligible for shots. Democratic Gov. Laura Kelly has been criticized by Republicans for a slow, disorganized vaccine rollout, and she faced more criticism Friday when she announced the plan to expand eligibility. One Republican lawmaker said people with chronic medical conditions could be left behind. Louisiana Gov. John Bel Edwards has said the state will soon have enough shots for everyone who wants one and that the challenge now is to make sure people want to get vaccinated. Some counties in Illinois are being allowed to expand eligibility to all this week if they find doses are going unused. But in Chicago, the vaccine will not be available to everyone until at least May 1 because the city does not have enough shots on hand. On Tuesday, Minnesota opens eligibility, followed by Indiana and South Carolina on Wednesday, Connecticut and Montana on Thursday, and New Hampshire and Colorado on Friday. In New York, Gov. Andrew Cuomo announced that residents over 30 will be eligible for vaccinations starting Tuesday, and everyone over 16 can sign up starting April 6. Connecticut officials said “priority access” will be given to people with high medical risks or developmental disabilities once everyone 16 and up is eligible. That could include some hospitals organizing dedicated clinics or reserving appointment slots for people with those conditions, officials said. Arizona opened up eligibility to all adults last week, but it has since been dealing with an unintended consequence: Interest in volunteering at four state-run vaccination sites plummeted almost immediately. Since February, thousands of volunteer shifts filled up within an hour. Now many remain vacant, said Rhonda Oliver, CEO of HandsOn Greater Phoenix, a nonprofit handling online volunteer recruitment. “People saw it as a way to get the vaccine sooner,” Oliver said. “We anticipated a drop-off, but we just didn’t expect it to go off a cliff in a matter of 24 to 48 hours like this.” On Wednesday, the first day of the new eligibility, only 70 of the scheduled 145 volunteers appeared at State Farm Stadium in Glendale, and dozens of people either withdrew earlier or did not show up. Oliver said that put an unfair burden on volunteers who did show up and could not take breaks. The shortage of volunteers should not affect wait times for those with appointments, Oliver said. HandsOn Greater Phoenix is hoping to lessen the hemorrhaging by reaching out to large companies and community groups looking for service activities. The group also is encouraging friends or family members who have been vaccinated to volunteer together. Many other states are still limited by a continued lack of supply. California officials said the state can administer 3 million shots a week now, and Democratic Gov. Gavin Newsom has predicted that maximum capacity will climb to 4 million by the end of April. But supplies have limited the effort so far to 1.8 million shots per week, a figure that is expected to increase to 2.5 million per week in the first half of April and then 3 million by the end of April, when everybody 16 and older will be offered the vaccine. Santa Clara County has been told it will get 58,000 doses this week, health officer Dr. Marty Fenstersheib said, but the state will begin allowing about 400,000 more people between 50 and 64 in the county to sign up as of Thursday, in addition to the current backlog. “We don’t have the vaccine, and we are concerned,” Fenstersheib said. Among the methods officials are employing to reach underserved communities are vans used as mobile clinics that travel to hard-hit neighborhoods and provide on-the-spot vaccinations. In California, mobile clinics are helping vaccinate farmworkers who may not have transportation to larger vaccination sites or cannot navigate the state’s online portal. Los Angeles also plans to have 10 mobile vaccination teams. Also read: Shots in little arms: COVID-19 vaccine testing turns to kids Colorado Gov. Jared Polis said Monday that four mobile bus clinics will distribute vaccines to underserved communities. While demand has dropped off in some communities, it’s as brisk as ever in others, and sign-up hassles continue. Lena Lawson, a 37-year-old technology consultant in Phoenix, tried to book a vaccine appointment since the new eligibility rules started. Working from home, she was able to periodically refresh appointment websites but had no luck for three days. She happened to be up at 2 a.m. Sunday and finally got a slot at a Walgreens on Tuesday. “I was pretty surprised. Oh, my God, I got an appointment. I’m good,” Lawson said. The effort was smoother for University of Utah professor Bill Johnson. He said he was bracing for a time-consuming and confusing experience but instead found it remarkably easy. “We had to make the appointment online and got in two days later,” said Johnson, 59, who got his first shot at the convention center in Salt Lake City. “It took us 10 minutes to drive there, and they jabbed us two minutes after we arrived.”Mar 30 (AP/UNB)-More than a dozen states will open vaccine eligibility to all adults this week in a major expansion of COVID-19 shots for tens of millions of Americans amid a worrisome increase in virus cases and concerns about balancing supply and demand for the vaccines. Meanwhile, the director of the Centers for Disease Control and Prevention said Monday that she had a recurring feeling of "impending doom" about a potential fourth wave of infections after cases in the U.S. rose 10% over the last week. She pleaded with Americans not to relax preventative practices such as social distancing and mask-wearing. “Just please hold on a little while longer," Dr. Rochelle Walensky said during a White House briefing. Several Northeastern states and Michigan have seen the biggest increases, with some reporting hundreds or thousands more new cases per day than they were two weeks ago. A new study by the CDC concluded that the Pfizer and Moderna vaccines were 90% effective after two doses, a finding that Walensky said should offer hope. States opening eligibility to anyone ages 16 and older on Monday included Texas, Oklahoma, Louisiana, Ohio, North Dakota and Kansas. The rapid expansion has fueled concerns that the number of eager vaccine seekers will far outstrip the available supply of shots, frustrating millions of newly eligible people who have waited since late last year for a chance to get an injection. Other officials have put their faith in a promised glut of vaccines and instead turned their attention to the next challenge: pressing as many people as possible to get the shots so the nation can achieve herd immunity at the earliest opportunity. Vaccination rates in Texas have lagged behind much of the U.S., and although state officials put at least part of the blame on delays in data reporting, they also acknowledged that appointment slots are going unfilled. Demand "has definitely decreased over the past couple of weeks,” said Imelda Garcia, head of the state’s expert vaccine allocation panel. Texas is supposed to receive more than 1 million new doses this week. On Monday, the state launched a new online vaccine scheduler and phone number, taking a bigger role in efforts that had largely been done at the local level. In Kansas, where some local health officials have said they are also struggling to find people to vaccinate, an additional 400,000 people are now eligible for shots. Democratic Gov. Laura Kelly has been criticized by Republicans for a slow, disorganized vaccine rollout, and she faced more criticism Friday when she announced the plan to expand eligibility. One Republican lawmaker said people with chronic medical conditions could be left behind. Louisiana Gov. John Bel Edwards has said the state will soon have enough shots for everyone who wants one and that the challenge now is to make sure people want to get vaccinated. Some counties in Illinois are being allowed to expand eligibility to all this week if they find doses are going unused. But in Chicago, the vaccine will not be available to everyone until at least May 1 because the city does not have enough shots on hand. On Tuesday, Minnesota opens eligibility, followed by Indiana and South Carolina on Wednesday, Connecticut and Montana on Thursday, and New Hampshire and Colorado on Friday. In New York, Gov. Andrew Cuomo announced that residents over 30 will be eligible for vaccinations starting Tuesday, and everyone over 16 can sign up starting April 6. Connecticut officials said “priority access” will be given to people with high medical risks or developmental disabilities once everyone 16 and up is eligible. That could include some hospitals organizing dedicated clinics or reserving appointment slots for people with those conditions, officials said. Arizona opened up eligibility to all adults last week, but it has since been dealing with an unintended consequence: Interest in volunteering at four state-run vaccination sites plummeted almost immediately. Since February, thousands of volunteer shifts filled up within an hour. Now many remain vacant, said Rhonda Oliver, CEO of HandsOn Greater Phoenix, a nonprofit handling online volunteer recruitment. “People saw it as a way to get the vaccine sooner,” Oliver said. “We anticipated a drop-off, but we just didn’t expect it to go off a cliff in a matter of 24 to 48 hours like this.” On Wednesday, the first day of the new eligibility, only 70 of the scheduled 145 volunteers appeared at State Farm Stadium in Glendale, and dozens of people either withdrew earlier or did not show up. Oliver said that put an unfair burden on volunteers who did show up and could not take breaks. The shortage of volunteers should not affect wait times for those with appointments, Oliver said. HandsOn Greater Phoenix is hoping to lessen the hemorrhaging by reaching out to large companies and community groups looking for service activities. The group also is encouraging friends or family members who have been vaccinated to volunteer together. Many other states are still limited by a continued lack of supply. California officials said the state can administer 3 million shots a week now, and Democratic Gov. Gavin Newsom has predicted that maximum capacity will climb to 4 million by the end of April. But supplies have limited the effort so far to 1.8 million shots per week, a figure that is expected to increase to 2.5 million per week in the first half of April and then 3 million by the end of April, when everybody 16 and older will be offered the vaccine. Santa Clara County has been told it will get 58,000 doses this week, health officer Dr. Marty Fenstersheib said, but the state will begin allowing about 400,000 more people between 50 and 64 in the county to sign up as of Thursday, in addition to the current backlog. “We don’t have the vaccine, and we are concerned,” Fenstersheib said. Among the methods officials are employing to reach underserved communities are vans used as mobile clinics that travel to hard-hit neighborhoods and provide on-the-spot vaccinations. In California, mobile clinics are helping vaccinate farmworkers who may not have transportation to larger vaccination sites or cannot navigate the state’s online portal. Los Angeles also plans to have 10 mobile vaccination teams. Colorado Gov. Jared Polis said Monday that four mobile bus clinics will distribute vaccines to underserved communities. Also read: S. Korea approves AstraZeneca COVID-19 vaccine for all adults While demand has dropped off in some communities, it’s as brisk as ever in others, and sign-up hassles continue. Lena Lawson, a 37-year-old technology consultant in Phoenix, tried to book a vaccine appointment since the new eligibility rules started. Working from home, she was able to periodically refresh appointment websites but had no luck for three days. She happened to be up at 2 a.m. Sunday and finally got a slot at a Walgreens on Tuesday. “I was pretty surprised. Oh, my God, I got an appointment. I’m good,” Lawson said. The effort was smoother for University of Utah professor Bill Johnson. He said he was bracing for a time-consuming and confusing experience but instead found it remarkably easy. “We had to make the appointment online and got in two days later,” said Johnson, 59, who got his first shot at the convention center in Salt Lake City. “It took us 10 minutes to drive there, and they jabbed us two minutes after we arrived.”

The makers of COVID-19 vaccines are figuring out how to tweak their recipes against worrisome virus mutations — and regulators are looking to flu as a blueprint if and when the shots need an update.