A new study published this week showed Pfizer's two-dose COVID-19 vaccine provided very little protection for children ages 5 to 11 during the omicron surge in New York.
The New York State Department of Health found that the effectiveness of the vaccine against COVID infection was just 12% in kids 5 to 11 during the surge. Protection against hospitalization was at 48%. The Pfizer vaccine was far more effective in children ages 12 to 17, the study showed.
The study has left some parents who got their young children vaccinated wondering if they did the right thing, and other parents whose children have yet to get the shot wondering if it's worth it.
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Two top Boston doctors shared their opinions on the recent study during NBC10 Boston's weekly "COVID Q&A" series Tuesday.
"I was disappointed to see the results for protection against infection," Boston Medical Center's Dr. Sabrina Assoumou said. "What they found was when you compare to 12- to 17-year-olds, their protection against infection after a month and a half was approximately 51%; 5 to 11 was only about 12%, which was disappointing because we would've liked to have had higher protection against infection."
The study also showed protection against hospitalization or severe disease for that same 5 to 11 group was 48%, compared to 73% for the 12 to 17 age group.
"What does that tell me? What is the good news?" Assoumou asked. "We have protection against severe disease and hospitalization, which is very important because during the omicron wave we've seen lots of hospitalization for kids. That's important. It tells me the vaccine is actually working. Unfortunately, against infection, it doesn't seem like its providing for 5- to 11-year-olds the protection we would want."
Assoumou, who has both a 3-year-old and a 6-year-old, said she is making sure her older child wears a high quality mask when she's at school, even though she is vaccinated.
"For that age group, we need a layered approach," she said.
As for why the Pfizer vaccine isn't working as well in younger kids, experts think it has to do with the lower dosage of the vaccine for the 5 to 11 age group. Kids in that age group were given two 10-microgram shots, while children aged 12 to 17 received 30-microgram shots.
"My hypothesis is because of the dose. Five to 11 is using a lower dose," Assoumou said.
"There are many possible explanations for what's going on," Brigham and Women's Hospital's Dr. Daniel Kuritzkes said. "The most likely issue is the one of dose. Pfizer is already lower than Moderna -- one-third the dose. They reduced the dose further in children largely because they were trying to balance the reactions you might get to the vaccine -- muscle ache, sore arm, fever -- versus how potent the vaccine might be."
"They went too low, in retrospect," he added. "They couldn't have known that. It is likely now they will go back and study higher doses, and we'll see how those do."
But overall, both doctors said they still think getting kids 5 to 11 vaccinated is the right thing to do, given the protection it provides against severe disease and hospitalization.
"There's a lot to unpack," Assoumou said. "To summarize, we do have some protection against severe disease -- that's really good. The vaccine is safe, it's effective, but we're a little disappointed about it's performance against infection."
"I still think 50% protection is better than no protection," Kuritzkes said. "It's also highly likely as the vaccines get fine tuned... kids who got the initial round of vaccine who end up getting boosted, then they'll be more fully protected. I don't think people who got vaccinated should feel they have somehow done something inappropriate for their children. There is still that 50% protection, and it's something that can be built on."