According to a large new set of data collected by health officials in New York State, the vaccine made by Pfizer-BioNTech is less effective in preventing coronaviruses in children than in older adolescents or adults.
The Pfizer vaccine is the only Covid shot authorized for that age group. The data collected during the Omicron surge suggest that it doesn't offer any protection against infections after a month after full immunization.
The vaccine's performance may be affected by the fact that older children and adults receive one-third of the vaccine dose.
The findings were posted online on Monday and come on the heels of clinical trial results which showed that the vaccine did not work well in young children who received a smaller dose.
The experts were worried that the news would discourage parents from immunizing their children. The vaccine was not protective against Omicron variant in adults.
The vaccine was developed in response to an earlier variant, so it is disappointing, but not entirely surprising, said Eli Rosenberg, deputy director for science at the New York State Department of Health.
He and other public health experts recommend the shot for children because of the protection against severe disease shown in the new data set.
We need to make sure we emphasize the doughnut and not the hole, according to a vaccine expert.
The study analyzed data from more than one million children who were fully vaccined between December 13, 2021, and January 31, 2022, the height of the Omicron surge.
The vaccine's effectiveness against hospitalization went down to 73 percent from 85 percent. The effectiveness of the younger children dropped. The estimates have wide margins of error because few children were hospitalized.
The numbers for protection from infections are more reliable. The vaccine's effectiveness against infections decreased in older children. It dropped to just 12 percent in the younger children.
Between ages 11 and 12 the numbers change a lot. The vaccine's effectiveness against infections was 67 percent in 12-year-olds, but just 11 percent in 11-year-olds.
The difference between the two age groups is striking, according to a immunologist at the Icahn School of Medicine at Mount Sinai.
The difference between the two ages is likely to be small, but children who were 11 received only 10 micrograms of vaccine, while children who were 12 got 30.
It would almost suggest that the dose that makes the difference is what matters.
More than 800 deaths have been linked to Covid-19 in children under 17 and more than 7,000 cases of multisystem inflammatory syndrome in children, a rare but serious condition associated with Covid. More children were hospitalized during the Omicron surge than at any other point.
The need to gather more information on the best dose, number and timing of shots for children is underscored by the findings. He said that they emphasize that vaccines are only one measure of protection from the virus.
The research was posted just days after the Centers for Disease Control and Prevention released new recommendations that would allow the majority of Americans to stop wearing masks.
The new data raises questions about the Biden administration's vaccine strategy. Only a small percentage of children have received two doses of the vaccine. The C.D.C has not yet recommended booster doses for this age group.
The vaccine hasn't been approved for children younger than 5. Scientific advisers to the Food and Drug Administration were scheduled to meet on Feb. 15 to evaluate two doses of the vaccine for the youngest children. The meeting was put off after Pfizer submitted additional data that suggested two doses were not as protective against the Omicron variant of the virus.
Dr. Rochelle P. Walensky was briefed on the findings in early February. F.D.A. leaders learned of the data at the same time. Federal officials and others familiar with their responses to the data said that it was important for it to be made public ahead of the F.D.A. expert meeting.
The data is consistent with a report from Britain that shows the effectiveness of the vaccine drops after two months. The C.D.C. is expected to release some of its data on the vaccine's effectiveness in younger children this week, according to people familiar with the agency's plans.
The vaccine has been available to young children in Israel since November.
Amy Rose, a spokeswoman for Pfizer, said that they continue to study and assess real-world data from the vaccine.
Dr. Philip Krause, who retired from the F.D.A. as a senior vaccine regulator, said assumptions about certain antibody levels being predictive of vaccine effectiveness should be reexamined.
He said that it weakens the argument for mandating that people get that lower dose.
As more evidence becomes available, experts revisit the vaccine interval and dosing. It may not be an option to give the children a higher dose of the vaccine because it may cause too many infections in young children.
Deepta Bhattacharya, an immunologist at the University of Arizona, said there are other ways to improve immunity in young children.
Pfizer and BioNTech are testing a third dose in children under 5, as well as in those aged 5 to 11, with the idea that an extra shot may significantly enhance immunity. The results of these trials are expected in a few weeks. Three doses of the vaccine were more protective against the Omicron variant than two, according to studies in adults.
Dr. Bhattacharya and his wife decided to give their children two doses instead of three because of studies suggesting that a longer gap between doses may improve protection. The C.D.C. encouraged people older than 12 to wait eight weeks between the first and second shots.
A vaccine that has a mix of several different versions is another option. Moderna and Johnson and Johnson are testing different versions of their vaccines.
The Delta variant differed from the next variant called Omicron. Training the body to recognize multiple versions of the virus would still offer a better chance of preventing infections with newer forms of the virus.
The newer vaccines that are authorized in the United States may work better for children. A vaccine made by Novavax is under review at the F.D.A., and the pharmaceutical companies are planning to submit their vaccine for evaluation soon.
Many parents want their children to be protected from the disease so that they don't spread it to vulnerable relatives, or they want them to stay in school so that they don't have long Covid, a poorly understood set of symptoms that can occur even after a mild infection. The vaccine's low effectiveness against infections doesn't help those concerns.
The vaccines provide more protection than we think, according to a vaccine data expert at the Fred Hutchinson Cancer Research Center in Seattle.
They may make it so that your kid who comes home with Covid won't have it for a long time, and they may have it for a shorter period of time.
The risk of severe outcomes increases with age, as the virus is here to stay. Paul Offit is the director of the Vaccine Education Center at Children's Hospital of Philadelphia and an adviser to the F.D.A.
He told parents that their children are going to need to be protected against this virus.
Sharon LaFraniere and Isabel Kershner were involved in the reporting.
All Rights Reserved © 2024
