BRUSSELS — Bruised by major disruptions in supplies of the AstraZeneca and Johnson & Johnson vaccines, the European Union Wednesday announced it was putting trust and money into the Pfizer-BioNTech shot to salvage its vaccination rollout and secure doses for the future.
The pivot away from AstraZeneca, once a pillar of the E.U. inoculation program, comes after months of discord over delayed shipments and as the company battles worries over rare potential side effects of its shots.
In announcing the change in strategy, Ursula von der Leyen, president of the European Commission, said Pfizer had agreed to an early shipment of doses thatshe said should likely allow the bloc to reach its goal of inoculating 70 percent of adults by the end of the summer.
That goal was in jeopardy after AstraZeneca failed to deliver on expected doses in the first quarter of the year, then suffered fresh setbacks over potential side effects related to blood clots. The European vaccine campaign was dealt a further blow Tuesday when Johnson & Johnson said it would delay its own rollout in Europe because of similar concerns and after regulators paused its use in the United States.
supply disruptions from AstraZeneca in late January, and then with the emergence of the potential rare blood disorder that has battered the public’s confidence in vaccines and led to appointment cancellations.
“As we can see with the announcement by Johnson & Johnson yesterday, there are still many factors that can disrupt the planned delivery schedules of vaccines,” Ms. von der Leyen said Wednesday.
Ms. von der Leyen said the Pfizer doses under negotiation for the next two years would include potential booster shots to extend the immunity of people who have already been inoculated, as well as possible new shots or boosters targeting emerging variants that might prove resilient against existing vaccines.
The AstraZeneca and Johnson & Johnson vaccines performed well in clinical trials and the possible dangerous side effects have been rare. But trials of the Pfizer and Moderna shots shows that they were even more effective in preventing infection, and similar side effects have not emerged. Another mRNA vaccine, from CureVac, is in clinical trials.
On Wednesday, the European Medicines Agency, the bloc’s top drug regulator, said it was expediting its investigation of “very rare cases of unusual blood clots” in recipients of the Johnson & Johnson vaccine, and expected to issue a recommendation next week. While the evaluation is ongoing, the agency reiterated its view that the benefits of the vaccine outweigh the risks.
In a setback for AstraZeneca, Denmark on Wednesday became the first country to permanently stop the administration of the company’s vaccine, saying the potential side effects were significant enough to do so given that it had the pandemic under control and could rely on the Pfizer and Moderna inoculations.
With the fresh commitment by Pfizer to bring forward the delivery of 50 million doses originally slated for the end of the year, the company expects to deliver 250 million doses in total to the bloc by the end of June.
Ms. von der Leyen said more than 100 million people in the European Union had already received at least one vaccine dose, and 27 million had received both. The additional Pfizer vaccines, together with 35 million doses expected from Moderna over the next three months, and a more limited use of AstraZeneca doses already in the pipeline, should likely be enough to get the bloc to the coveted milestone of reaching 255 million people by September, E.U. officials said.
In stark contrast to the criticism of AstraZeneca’s handling of its E.U. dealings, Ms. von der Leyen praised Pfizer effusively, highlighting how important the company’s ability to respond quickly to help the European Union has been.
“I want to thank BioNTech/Pfizer; it has proven to be a reliable partner,” Ms. von der Leyen said. “It has delivered on its commitments, and it is responsive to our needs.”
Addressing another sore point, Ms. von der Leyen said that the future Pfizer doses would be produced in the European Union.
Ample exports from the factories within the bloc to the rest of the world have enabled countries like Mexico and Canada to launch their vaccination campaigns, but those exports have also been identified as one reason there weren’t enough vaccines to go around in Europe.
The United States and Britain, by contrast, held tight to the vaccines made in their countries, helping speed along their inoculation efforts.
The European Union will receive an extra 50 million doses this month of the coronavirus vaccine developed by Pfizer and BioNTech, the leader of the bloc’s executive arm said on Wednesday, a lift in its effort to meet inoculation targets in the face of difficulties with vaccines developed by AstraZeneca and Johnson & Johnson.
The 27-nation bloc has also entered negotiations with Pfizer over the supply of 1.8 billion new vaccine doses — including booster shots to prolong immunity and new vaccines to tackle emerging variants — in 2022 and 2023, said Ursula von der Leyen, the president of the European Commission, its executive arm.
With these two announcements, the European Union embarked on a hard pivot to mRNA vaccines such as Pfizer’s, staking its coronavirus response on them, a day after Johnson & Johnson suspended the rollout of its vaccine in the European Union and as the bloc continued to suffer the fallout from restrictions on the AstraZeneca vaccine, after reports of extremely rare but serious potential side effects from both.
In another setback for AstraZeneca, Denmark on Wednesday became the first country to permanently stop the administration of the vaccine developed by the British-Swedish drugmaker. Denmark has heavily relied on Pfizer’s vaccine and has approved two others — Moderna’s, and Johnson & Johnson’s.
suffering blow after blow, first with major supply disruptions from AstraZeneca, and then as it has sought to respond to the reports of potential rare side effects.
Ms. von der Leyen’s announcements on Wednesday were significant in two ways.
Pfizer’s commitment to bring forward the delivery of the 50 million doses, which were originally slated for the end of the year, means the company will deliver a total of 250 million doses to the bloc by the end of June. Ms. von der Leyen said 100 million people in the European Union had already been inoculated.
But it also signaled that the bloc would seek to peg its strategy to tackle variants and the need for boosters in the medium term on mRNA vaccines, a newer technology being used by Pfizer and Moderna, moving away from vaccines based on other approaches like those from AstraZeneca and Johnson & Johnson.
“We need to focus now on technologies that have proven their worth: mRNA vaccines are a clear case in point,” Ms. von der Leyen said.
A senior Chinese official said that the country’s vaccines may need to be administered in greater doses or in concert with other shots because of their low overall effectiveness.
The comments on Saturday by Gao Fu, the director of China’s disease control center, suggest that China and more than 60 countries that have approved Chinese vaccines could need to adjust their distribution programs. The widespread distribution of Chinese vaccines means that any changes could potentially affect hundreds of millions of people or more.
Possible steps to boost effectiveness of Chinese vaccines include changing the amount of vaccine given, the number of shots, the time between shots or the type of vaccines given, Mr. Gao said.
He also praised the possibilities offered by messenger RNA. That technology is used in the Moderna and Pfizer-BioNTech vaccines but not in any of the vaccines thus far approved in China.
said in January that the efficacy rate for the CoronaVac vaccine from the Beijing-based company Sinovac was just over 50 percent. By comparison, Moderna and Pfizer-BioNTech were found to be 90 percent effective in real world conditions, researchers said last month.
Last month the distributor in the United Arab Emirates of vaccines from China’s Sinopharm said it was offering a third dose in addition to the standard two-dose regimen for a “very small number” of people who were “not really responsive” to the vaccine.
On Feb. 22, Mom texted that she and Dad had booked a March 11 appointment to get their first shots, followed by second doses in April. A day later, she reported that Dad hadn’t pressed the button to confirm the appointment on the online booking system and had lost the slots.
The next week, they texted again: They had walked to a private clinic that was dispensing Sinovac shots. After a short wait, they received the vaccine. On April 2, they told us that they had gotten their second dose of Sinovac and were feeling fine. Mom groused that even though they had an appointment, they “still need to wait for half an hour.”
Our responses were more enthusiastic.
“Great news,” I wrote.
“Yay!” Pui-Ying texted, followed by celebratory emojis.
“Congrats!” Pui Ling said.
Pui-Ying had moved with her family to Malawi in 2016 to work as a doctor and conduct clinical research on children’s health. Resources at the Queen Elizabeth Central Hospital, where she works, were limited. When Madonna’s charity helped finance the construction of a new children’s wing at the hospital, which opened in 2017, it was big news.
Staffing was tight even before the coronavirus, Pui-Ying said. When the pandemic came, the hospital decided on a one-week-on, one-week-off routine to reduce staff exposure to Covid-19 while ensuring that enough medical professionals would be working at all times. Masks, gloves and other protective equipment were scarce.
In pediatrics, Pui-Ying and her colleagues set up a “respiratory zone” for children with Covid-19. It was essentially a two-room ward, with about a dozen beds in the main room. The second room, which was an isolation unit, had space for four children.
Pfizer and BioNTech requested on Friday that the Food and Drug Administration expand the emergency use authorization for their coronavirus vaccine to permit its use in children ages 12 to 15. If approved, it could allow young adolescents to start getting vaccinated before going back to school in the fall.
The companies plan to request similar authorizations from health agencies around the world in the coming days, they said in a joint statement.
“These submissions represent a critical step in Pfizer’s and BioNTech’s ongoing efforts to support governments in broadening global vaccination efforts,” the statement said. Clinical trial results found the vaccine highly effective in that age group, the companies said last month.
The Pfizer-BioNTech vaccine is currently approved for use via emergency authorization in people 16 and older. Granting approval for its use in the younger age group would also speed the country’s efforts to reach herd immunity, which will depend on vaccinating children.
More than 2,000 young adolescents participated in a Phase 3 trial of the vaccine. Among those who received the vaccine, none developed symptomatic coronavirus infections or exhibited serious side effects, the companies said last month. The vaccinated 12- to 15-year-olds also produced higher levels of antibodies, on average, than older adolescents and young adults did.
The trial results have not yet been published in a scientific journal.
She grew up in Hungary, daughter of a butcher. She decided she wanted to be a scientist, although she had never met one. She moved to the United States in her 20s, but for decades never found a permanent position, instead clinging to the fringes of academia.
Now Katalin Kariko, 66, known to colleagues as Kati, has emerged as one of the heroes of Covid-19 vaccine development. Her work, with her close collaborator, Dr. Drew Weissman of the University of Pennsylvania, laid the foundation for the stunningly successful vaccines made by Pfizer-BioNTech and Moderna.
For her entire career, Dr. Kariko has focused on messenger RNA, or mRNA — the genetic script that carries DNA instructions to each cell’s protein-making machinery. She was convinced mRNA could be used to instruct cells to make their own medicines, including vaccines.
But for many years her career at the University of Pennsylvania was fragile. She migrated from lab to lab, relying on one senior scientist after another to take her in. She never made more than $60,000 a year.
was published, in Immunity, it got little attention.
Dr. Weissman and Dr. Kariko then showed they could induce an animal — a monkey — to make a protein they had selected. In this case, they injected monkeys with mRNA for erythropoietin, a protein that stimulates the body to make red blood cells. The animals’ red blood cell counts soared.
25 years of work by multiple scientists, including Pieter Cullis of the University of British Columbia.
Scientists also needed to isolate the virus’s spike protein from the bounty of genetic data provided by Chinese researchers. Dr. Barney Graham, of the National Institutes of Health, and Jason McClellan, of the University of Texas at Austin, solved that problem in short order.
Testing the quickly designed vaccines required a monumental effort by companies and the National Institutes of Health. But Dr. Kariko had no doubts.
On Nov. 8, the first results of the Pfizer-BioNTech study came in, showing that the mRNA vaccine offered powerful immunity to the new virus. Dr. Kariko turned to her husband. “Oh, it works,” she said. “I thought so.”
To celebrate, she ate an entire box of Goobers chocolate-covered peanuts. By herself.
Dr. Weissman celebrated with his family, ordering takeout dinner from an Italian restaurant, “with wine,” he said. Deep down, he was awed.
“My dream was always that we develop something in the lab that helps people,” Dr. Weissman said. “I’ve satisfied my life’s dream.”
Dr. Kariko and Dr. Weissman were vaccinated on Dec. 18 at the University of Pennsylvania. Their inoculations turned into a press event, and as the cameras flashed, she began to feel uncharacteristically overwhelmed.
A senior administrator told the doctors and nurses rolling up their sleeves for shots that the scientists whose research made the vaccine possible were present, and they all clapped. Dr. Kariko wept.
Things could have gone so differently, for the scientists and for the world, Dr. Langer said. “There are probably many people like her who failed,” he said.
LONDON — For months, European countries have seesawed between craving and rebuffing AstraZeneca’s vaccine, with the shot’s fortunes rising and falling on spats over supply and on questions over the efficacy of the vaccine itself.
But few concerns have proved as disruptive to the rollout of the world’s workhorse vaccine in Europe as reports of very rare blood clots in some recipients. Many countries responded by halting the shot’s use, only to start giving it again after an all-clear from regulators at the European Medicines Agency, and then stopped inoculations a second time in certain age groups after doctors became more concerned about the clots.
On Tuesday, those concerns were reinforced yet again when a top vaccines official at the European Medicines Agency said that the vaccine was linked to extremely rare, though sometimes fatal, blood clots in a small number of recipients. It was the first indication from an international regulatory body that the clots may be a real, if very unusual, side effect of the shot.
Regulators now appear to be considering issuing their first formal warnings about the potential side effects — not only in continental Europe, which has long been wary of the shot for political and scientific reasons, but also in Britain, the birthplace of the AstraZeneca vaccine and long its biggest champion, where new data have sown concerns as well.
speedy inoculation program,have also insisted that the vaccine’s benefits far outweighed the risks. They and the company cited a lack of evidence in Britain that the clotting events were any more common than would be expected among people who had never been given AstraZeneca’s vaccine.
But the evidence changed last week when Britain reported 30 cases of the rare blood clots, 25 more than previously. This week, a prominent scientific adviser to the British government said there was “increasing evidence” of the clots being associated with the vaccine.
regulators reported 30 cases of the rare blood clots combined with low platelets among 18 million people given the AstraZeneca vaccine. That translated to roughly one case in 600,000 recipients of the vaccine.
European countries’ divergent approaches to the vaccine stem from a number of factors, including the supply of vaccines and severity of the pandemic. Marco Cavaleri, the official at the European Medicines Agency who spoke about the link between the vaccine and blood clots, said on Tuesday that those factors would likely continue to dictate how countries used the shot.
Beyond those factors, countries also took very different approaches to managing risk, scientists said. Countries that have continued using the shot were more focused on securing the overall health of their citizens. Others were more preoccupied with minimizing the risk to any single person.
“The attitude here is more, ‘Get me out of the pandemic,’” said Penny Ward, a visiting professor in pharmaceutical medicine at King’s College London, referring to the British approach. In continental Europe, she said, “There seems to be a much higher emphasis on individual safety in the population.”
Adriano Mannino, a philosopher at the University of Munich and director of the Solon Center for Policy Innovation in Germany, said that the collective benefits of the vaccine dominated thinking in Britain, while Germans were more concerned with the risk of an injection going wrong in individual cases. That reflected, partly, Germany’s history with the Nazis, who conducted lethal experiments on people.
“In many areas where law has to regulate ethically delicate and potentially dangerous things,” he said, “the German state has tended to go for tough restrictions.”
Nevertheless, Germans over 60 — the age group still being given AstraZeneca’s vaccine — flooded hotlines to book appointments and stood in line for hours in recent days as eligibility restrictions for their age group were relaxed.
In the northeastern city of Wismar, several hundred people waited for up to five hours on Tuesday in a driving wind and mix of rain and snow to receive the shot.
“I wish there had been better weather,” Kerstin Weiss, the head of the district authority in the northeastern region, told public broadcaster NDR. “But honestly, this is a sign that people are willing to be vaccinated with AstraZeneca.”
Benjamin Mueller reported from London and Melissa Eddy from Berlin. Monika Pronczuk and Emma Bubola contributed reporting.
Walgreens’s system currently allows people to rebook their second-dose appointment, but they can do so only the day before the appointment.
“I’m not happy about it,” Ms. DeTurris Poust said. “It gives me one extra week of not being protected, so it means there’s one more week that I’m worried about catching it from someone, or giving it to someone.”
Some public health experts said they were not concerned that Walgreens has been scheduling doses with a four-week gap.
“It’s a week difference. Everybody’s going to need to put it in their contexts and their risk factors, but I think this is a very reasonable approach” from Walgreens, said Dr. Katherine Poehling, a pediatrician at Wake Forest School of Medicine who sits on the C.D.C. advisory panel that recommended that Pfizer doses be given roughly three weeks apart.
But other experts said they were troubled.
“It is not the role of a private, for-profit company to make public health decisions that should be determined by guidelines issued by a public health authority,” said Lawrence Gostin, a global health law professor at Georgetown University.
Dima Qato, a pharmacist and associate professor at the University of Southern California School of Pharmacy, said she was concerned about how the public perceives inconsistent messages about spacing doses of the same vaccine.
“As we’re trying to build trust in this pandemic, I think this may push us back,” Dr. Qato said.
Walgreens is not the only vaccine provider that has been giving second shots slightly later than recommended. Others around the country have been doing so for months, especially in the early days of the rollout when vaccine supply was constrained and sites had little clarity about which vaccines and how many doses they would be receiving in subsequent weeks, said Tinglong Dai, who studies health care operations at Johns Hopkins University.
For weeks, the mood in much of the United States has been buoyant. Cases, hospitalizations and deaths from the coronavirus have fallen steeply from their highs, and millions of people are being newly vaccinated every day. Restaurants, shops and schools have reopened. Some states, like Texas and Florida, have abandoned precautions altogether.
In measurable ways, Americans are winning the war against the coronavirus. Powerful vaccines and an accelerating rollout all but guarantee an eventual return to normalcy — to backyard barbecues, summer camps and sleepovers.
But it is increasingly clear that the next few months will be painful. So-called variants are spreading, carrying mutations that make the coronavirus both more contagious and in some cases more deadly.
Even as vaccines were authorized late last year, illuminating a path to the pandemic’s end, variants were trouncing Britain, South Africa and Brazil. New variants have continued to pop up — in California one week, in New York and Oregon the next. As they take root, these new versions of the coronavirus threaten to postpone an end to the pandemic.
rising exponentially in the United States.
Limited genetic testing has turned up more than 12,500 cases, many in Florida and Michigan. As of March 13, the variant accounted for about 27 percent of new cases nationwide, up from just 1 percent in early February.
pledged a “down payment” of $200 million to ramp up surveillance, an infusion intended to make it possible to analyze 25,000 patient samples each week for virus variants. It’s an ambitious goal: The country was sequencing just a few hundred samples each week in December, then scaling up to about 9,000 per week as of March 27.
Until recently, B.1.1.7’s rise was camouflaged by falling rates of infection over all, lulling Americans into a false sense of security and leading to prematurely relaxed restrictions, researchers say.
“The best way to think about B.1.1.7 and other variants is to treat them as separate epidemics,” said Sebastian Funk, a professor of infectious disease dynamics at the London School of Hygiene and Tropical Medicine. “We’re really kind of obscuring the view by adding them all up to give an overall number of cases.”
Other variants identified in South Africa and Brazil, as well as some virus versions first seen in the United States, have been slower to spread. But they, too, are worrisome, because they contain a mutation that diminishes the vaccines’ effectiveness. Just this week, an outbreak of P.1, the variant that crushed Brazil, forced a shutdown of the Whistler Blackcomb ski resort in British Columbia.
as fast as possible.
Infections are rising again, driven to an uncertain degree by B.1.1.7 and other variants. Earlier this week, Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, pleaded with Americans to continue to practice masking and social distancing, saying she felt a sense of “impending doom.”
60 percent more contagious and 67 percent more deadly than the original form of the virus, according to the most recent estimates.
The variant is no different from the original in how it spreads, but infected people seem to carry more of the virus and for longer, said Katrina Lythgoe, an evolutionary biologist at the University of Oxford. “You’re more infectious for more days,” she said.
So contagious is B.1.1.7 that Britain succeeded in driving down infections only after nearly three months of strict stay-at-home orders, plus an aggressive vaccination program. Even so, cases fell much more slowly than they did during a similar lockdown in March and April.
three-quarters of new infections, some hospitals have had to move coronavirus patients to Belgium to free up beds. Roughly as many people are dying each day from Covid-19 in Europe as were this time a year ago.
For too long, government officials disregarded the threat. “Case plateaus can hide the emergence of new variants,” said Carl Pearson, a research fellow at the London School of Hygiene and Tropical Medicine. “And the higher those plateaus are, the worse the problem is.”
In the United States, coronavirus infections began a rapid decline in January, soon prompting many state leaders to reopen businesses and ease restrictions. But scientists repeatedly warned that the drop would not last. After the rate bottomed out at about 55,000 cases and 1,500 deaths per day in mid-March, some states — notably Michigan — began seeing an uptick.
Since then, the national numbers have steadily risen. As of Saturday, the daily count was up to nearly 69,000, and the weekly average was 19 percent higher than the figure two weeks earlier.
Pfizer-BioNTech and Moderna vaccines seem to be slightly less effective against B.1.351, the variant identified in South Africa. That variant contains the Eek mutation, which seems to enable the virus to partly sidestep the body’s immune response. The vaccines made by Johnson & Johnson, AstraZeneca and Novavax were even less potent against B.1.351.
“I think for the next year or two, E484K will be the most concerning” mutation, said Jesse Bloom, an evolutionary biologist at the Fred Hutchinson Cancer Research Center in Seattle.
The mutation slightly alters the so-called spike protein sitting on the surface of the coronavirus, making it just a bit harder for antibodies to latch on and destroy the invader.
The good news is that the virus seems to have just a few survival tricks in its bag, and that makes it easier for scientists to find and block those defenses. “I’m feeling pretty good about the fact that there aren’t that many choices,” said Michel Nussenzweig, an immunologist at Rockefeller University in New York.
The Eek mutation seems to be the virus’s primary defense against the immune system. Researchers in South Africa recently reported that a new vaccine directed against B.1.351 ought to fend off all other variants, as well.
Pfizer, BioNTech and Moderna already are testing newly designed booster shots against B.1.351 that should work against any variants known to blunt the immune response.
Instead of a new vaccine against variants, however, it may be just as effective for Americans to receive a third dose of the Pfizer-BioNtech or Moderna vaccines in six months to a year, said Dr. Anthony S. Fauci, head of the National Institute of Allergy and Infectious Diseases.
That would keep antibody levels high in each recipient, overwhelming any variant — a more practical strategy than making a specialized vaccine for each new variant that emerges, he said.
“My only concern about chasing all the variants is that you’d almost be playing Whac-A-Mole, you know, because they’ll keep coming up and keep coming up,” Dr. Fauci said.
In one form or another, the new coronavirus is here to stay, many scientists believe. Multiple variants may be circulating in the country at the same time, as is the case for common cold coronaviruses and influenza. Keeping them at bay may require an annual shot, like the flu vaccine.
The best way to deter the emergence of dangerous variants is to keep cases down now and to immunize the vast majority of the world — not just the United States — as quickly as possible. If significant pockets of the globe remain unprotected, the virus will continue to evolve in dangerous new ways.
“This might be something that we have to deal with for a long time,” said Rosalind Eggo, an epidemiologist at London School of Hygiene and Tropical Medicine.
Still, she added, “Even if it changes again, which it is very likely to do, we are in a better, much stronger position than a year ago to deal with it.”
The Pfizer-BioNTech coronavirus vaccine is extremely effective in adolescents 12 to 15 years old, perhaps even more so than in adults, the companies reported on Wednesday. No infections were found among children who received the vaccine in a recent clinical trial, the drug makers said; the children produced strong antibody responses and experienced no serious side effects.
The findings, if they hold up, may speed a return to normalcy for millions of American families. Depending on regulatory approval, vaccinations could begin before the start of the next academic year for middle school and high school students, and for elementary school children not long after.
The companies announced the results in a news release that did not include detailed data from the trial, which has not yet been peer-reviewed nor published in a scientific journal. Still, the news drew praise and excitement from experts.
“Oh my god, I’m so happy to see this — this is amazing,” said Akiko Iwasaki, an immunologist at Yale University. If the vaccines’s performance in adults was A-plus, the results in children were “A-plus-plus.”
had left her with sense of “impending doom,” while President Biden called on state and local officials to reinstate mask mandates.
Vaccination efforts are accelerating throughout the nation. As of Tuesday, 29 percent of adults had received at least one dose of a coronavirus vaccine, and 16 percent had been fully inoculated, according to the C.D.C.
But the country cannot hope to reach herd immunity — the point at which immunity becomes so widespread that the coronavirus slows its crawl through the population — without also inoculating the youngest Americans, some experts say. Children under 18 account for about 23 percent of the population in the United States.
“The sooner that we can get vaccines into as many people as possible, regardless of their age, the sooner we will be able to really feel like we’re ending this pandemic for good,” said Angela Rasmussen, a virologist affiliated with Georgetown University in Washington.
Data from Israel suggest that vaccinating adults alone can significantly decrease the number of cases, but “long term, to hit the herd immunity threshold, we will have to vaccinate children,” she said.
children ages 5 to 11 just last week. Company scientists plan to start testing the vaccine next week in even younger children, ages 2 to 5, followed by trials in children ages 6 months to 2 years.
testing its vaccine in children. Results from a trial in adolescents ages 12 to 17 are expected in the next few weeks and in children 6 months to 12 years old in the second half of this year.
AstraZeneca started testing its vaccine in children 6 months and older last month, and Johnson & Johnson has said it will wait for results from trials in older children before testing its vaccine in children under 12.
Some parents have said they are reluctant to immunize their children because the risk posed by the virus is low. Children make up fewer than 1 percent of deaths from Covid-19, but about 2 percent of children who get the illness require hospital care.
The new results may not sway all of those parents, but they may reassure parents who have been wary of the vaccines, said Jennifer Nuzzo, an epidemiologist at the Johns Hopkins Center for Health Security.
“While I don’t think we have to wait until children are vaccinated to fully reopen schools, being able to vaccinate children may help some families feel safer about returning to school,” she said.
Pfizer and BioNTech plan to request from the Food and Drug Administration an amendment to the emergency use authorization for their vaccine, in hopes of beginning immunizations of older children before the start of the next school year. The companies also are planning to submit their data for peer review and publication in a scientific journal.
They will monitor the participants for two years after the second dose to assess the vaccine’s long-term safety and efficacy. Side effects of vaccines are usually apparent within the first six weeks, said Dr. Kristin Oliver, a pediatrician and vaccine expert at Mount Sinai Hospital in New York. “Still, it’s good to know that safety monitoring is going to continue,” she said.
The C.D.C. recommends that people avoid getting other vaccines for two weeks before and after receiving the two doses of the coronavirus vaccine.
But children receive more vaccines in the few weeks before the school year than at any other time, Dr. Oliver noted, so pediatricians and parents should aim to get those other immunizations done earlier than usual.
The coronavirus vaccines should ideally be given by pediatricians who have deep experience in immunizing children, Dr. Oliver added. “Now is the time to start planning how that rollout is going to take place in this age group,” she said.