Which coronavirus vaccine works for the youngest child?

Washington — Over the past decade, tens of millions of children and teens have received the Pfizer BioNTech vaccine, so the company’s main rival, Moderna, has been on the sidelines and its shots have been limited to adults.

However, Moderna may now be ready for a resurgence at a critical time in the country’s vaccination campaign. This week, the company plans to send federal authorities initial data on how effective the coronavirus vaccine is on the country’s youngest children.

About 18 million children under the age of five are the only Americans who are not yet eligible for vaccination. Although the acceptance of older children is slow, many parents are still worried about opportunities to protect babies, toddlers and preschoolers.

Moderna confronts Pfizer-BioNTech directly in search of an opportunity to vaccinate this group and hopes to discover what some scientists call the “Goldilocks” dose. Anxious side effects such as high fever.

Moderna chose a two-dose regimen that is one-quarter of the adult dose for children under 6 years of age. Pfizer will seek approval for a three-dose regimen for children under the age of five next month. The dose is 1/10. For those over 12 years old.

Moderna will also release data soon from clinical trials in the next age group (children 6-11 years).

Dr. Yvonne Maldonado, a professor of pediatric infectious diseases at Stanford University and a senior researcher at Stanford’s site for Pfizer’s pediatric vaccine trial, said new data from both Moderna and BioNTech in the coming weeks of their pediatric shots. He said it would provide important insights into effectiveness. She said researchers are closely watching whether higher doses of Moderna “provide a stronger immune response” than Pfizer’s shots elicited in young children.

A series of new studies that raise questions about how low doses of Pfizer protect elementary school children have been intriguing among federal scientists and vaccine experts for Moderna’s choice.

Dr. Ofer Levy, a pediatrician at Harvard Medical School and a member of the Food and Drug Administration’s independent vaccine advisory board, said Pfizer might have chosen a dose that was too low for people aged 5-11. He said he thought. A priority for maximizing safety. “

To date, Pfizer has been the only player to vaccinate young Americans, gaining vaccination approval for ages 12-15 in May last year and vaccination for ages 5-11 in October. did. Adult approval is also 16- and 17 years old.

Moderna sought permission to vaccinate teenagers last June, but the FDA was concerned about the risk of myocarditis, a condition associated with heart inflammation associated with both Moderna and Pfizer shots. Postponed review of the request.

Currently, more than 22 million people under the age of 18 are fully vaccinated with the Pfizer vaccine in the United States, but their intake has leveled off. For example, even if shots are provided, only about one in four children aged 5 to 11 years is fully vaccinated. More than 4 months in that group.

But as the country’s masks come off, more parents return to work, and the summer travel season approaches, the youngest children need to be protected.

Dr. Eric Rubin, an infectious disease expert and member of Harvard TH Chan School of Public Health, said, “Children are less effective in vaccines because fewer people actually get sick. There is no doubt about that. ” Of the Advisory Board to the Food and Drug Administration.

“But it will benefit some individuals,” he said. “It will save some lives.” According to the Centers for Disease Control and Prevention, 336 US children under the age of five have died in Covid since its inception. Pandemic.

We hope that the youngest children will be covered soon after regulators have pressured Pfizer-BioNTech to submit preliminary results for the three-dose study. The FDA wanted to launch a vaccination campaign with two doses while waiting for the final result of three times.

However, that effort broke down when new data from Pfizer, which contained more Omicron surges, convincingly showed that two doses did not adequately protect against symptomatic infections.

More detailed results from the Pfizer and Moderna tests are now available at about the same time. Both companies are still uncertain whether the vaccine is effective enough for the youngest age group, but both studies say they are safe.

“We are confident in our safety profile because we haven’t seen any disadvantages right now,” Dr. Paul Burton, Chief Medical Officer of Modana, said in an interview.

Pfizer spokeswoman Amy Rose states that after careful research, Pfizer-BioNTech has selected the “safest and most acceptable dose” for infants. Pfizer tests 10 micrograms for ages 5-11, one-third of adult and teenage doses, and 3 micrograms for children under 5 years.

Modelna proposes significantly higher doses than Pfizer in all three pediatric age groups: 100 micrograms for adults aged 12 to 17 years, 50 micrograms for children aged 6 to 11 years. Gram, 25 micrograms for children under 6 years old Check company data for all three age groups at the same time.

“We really stand behind these doses,” said Dr. Burton. Federal officials say that both Pfizer and Moderna vaccines have diminished in efficacy over time, but some adult studies suggest that Moderna protection lasts longer. “Dr. Burton said.

He said early results showed that a dose of 50 micrograms of Moderna stimulated a “strong immune response” in children aged 6 to 11 years. The higher the value, the higher the antibody level.

Dr. Philip Krause, who recently retired as the FDA’s senior vaccine regulator, said authorities spent a considerable amount of time last year worrying about the safety of Moderna’s vaccine for people under the age of 18, in some studies. The risk of myocarditis from injections has been shown to be high. Than Pfizer’s.

“The problem is always. Do you think the dose that provokes an immune response is likely to be defensive?” He said. “I couldn’t really test the incidence of myocarditis, but you ask,” What is the sacrifice of the immune response by reducing the dose, and do you think it is important? ” can do.

The CDC has recently been concerned about myocarditis and waits eight weeks between the first and second injections of Pfizer or Moderna in some people over the age of 12, especially boys and men aged 12 to 39 years. I recommended. The risk of developing side effects is highest.

Dr. Burton said myocarditis proved to be reassuring throughout the study, including recent UK data showing that myocarditis is extremely rare and usually mild in both Pfizer and Moderna recipients. ..

However, Dr. Walid F. Gerad, a drug safety expert at the University of Pittsburgh, said it is unclear whether higher doses of Moderna could increase the risk of myocarditis in young children. Regarding side effects, he and other experts said.

Moderna’s new impetus also arises after several studies have questioned the protection that double doses of Pfizer BioNTech’s vaccine provide to children aged 5 to 11 years. Researchers at the New York State Department of Health recently found that protection against double-dose infections was significantly diminished within a few weeks.

CDC researchers separately found that during the Omicron wave, the effectiveness of the two doses of Pfizer Shot for moderate forms of illness in children aged 5 to 11 years was significantly reduced. did.

Studies have sparked debate among vaccine experts as to whether stronger doses are better, or whether those children need a third dose. Booster shots are currently allowed for everyone over the age of 12. Pfizer expects results from a three-dose regimen study. Younger children next month.

Dr. Gerad said the dose for Pfizer between the ages of 5 and 11 could be too weak, but scientists were still uncertain. Given that they are now catching Covid and have a relatively low risk of getting sick.

Of all the questions, one thing is clear. Going back and forth between which vaccines are better for young children can discourage intake.

Allison M. Buttenheim, a behavioral health expert at the University of Pennsylvania, said people considering vaccination definitely felt comfortable. “Many people are uncomfortable with evolving science.”

About the author


Leave a Comment