Vulnerable adolescents 12 to 17 years old should get COVID-19 booster shots, NACI says

Adolescents 12 to 17 years old who are especially vulnerable to COVID-19 should get booster shots, the National Advisory Committee on Immunization (NACI) said in updated guidance issued Friday.

That includes those who have underlying medical conditions that put them at risk for severe COVID-19 illness, those who live in congregate settings such as shelters, group homes or correctional facilities and those who are disproportionately affected by COVID-19 because of their race or marginalization.

According to NACI’s recommendation, underlying medical conditions that should qualify adolescents to receive a booster shot include:

• Cancer that is being actively treated.
• Chronic kidney disease.
• Chronic lung diseases, including uncontrolled asthma.
• Cystic fibrosis.
• Neurodevelopmental and other chronic neurological conditions including epilepsy and cerebrovascular disease.
• Diabetes.
• Down syndrome.
• Congenital heart disease or other chronic heart diseases, including pulmonary hypertension.
• Chronic liver disease.
• Obesity.
• Pregnancy.
• Sickle cell disease or thalassemia.
• Substance use disorders.
• Immunocompromised state, including primary immune deficiency, solid organ or haematopoietic stem cell transplant, HIV infection, or immunosuppressive therapy.
• Adolescents deemed medically fragile or have medically complex needs.

The latest recommendation makes many more adolescents eligible for additional doses of coronavirus vaccine.

“Canadian adolescents 12 to 17 years of age are facing record-high incidence rates of COVID-19 during this new wave, driven in large part by Omicron,” NACI said in its updated guidance. 

The advisory committee had already recommended that adolescents 12 to 17 years of age who are moderately to severely immunocompromised should get third doses as part of their standard COVID immunization series, because they may not mount an adequate immune response with two doses.   

Adolescents 12 and older get the same vaccine doses as adults. The Pfizer-BioNTech vaccine is preferred over Moderna for children and adolescents, NACI said, because “there are currently no data” on the use of Moderna booster doses in that age group. 

Although it is continuing to monitor data about waning immunity, NACI said, it is not recommending booster shots for the general population of 12- to 17-year-olds “at this time,” but will update its guidance “as required.”

Booster shots for all adolescents 12 and older have been approved in the U.S.  

No evidence boosters needed yet for all teens, experts say

Dr. Fatima Kakkar, a pediatric infectious diseases specialist at CHU Sainte-Justine in Montreal, welcomed Friday’s booster guidance.   

“It’s not a blanket recommendation that all 12- to 17-year-olds need a booster,” she said. “For most adolescents overall, we still know that two-dose [vaccine] regimen is very effective against severe disease.” 

In addition to COVID-19 itself, one of the worries for children and teens is multisystem inflammatory syndrome in children (MIS-C), a rare but serious condition that can happen after infection with coronavirus, Kakkar said.  

The pediatric patients she said she ends up seeing in hospital with COVID-19 or MIS-C generally fall into three categories: unvaccinated; immunocompromised; or suffering from multiple underlying medical conditions. 

Although there isn’t yet a lot of specific data on adolescents and COVID-19 immunity, healthy kids and teens generally mount stronger immune responses after vaccination than adults, said Dawn Bowdish, a professor at the McMaster Immunology Research Centre in Hamilton.  

“The very few studies we have suggest that children’s responses last a lot longer than adults. Where even, sort of, healthy middle-aged people might have waning immunity by six months, kids seem to be able to keep that immune response for 12 months or greater,” Bowdish said. 

Immunocompromised children ages 5-11 

Earlier on Friday, Chief Public Health Officer of Canada Dr. Theresa Tam said children ages five to 11 who are moderately to severely immunocompromised should get a third dose of COVID-19 vaccine — emphasizing NACI guidance that had been published on Tuesday. 

The third dose given to children should be the Pfizer-BioNTech mRNA vaccine, the committee said, noting it should be given four to eight weeks after the second dose. 

According to NACI guidance, children and teens are considered immunocompromised if they have one of the following conditions:

• Active treatment for solid tumour or hematologic malignancies.
• Receipt of solid-organ transplant and taking immunosuppressive therapy.
• Receipt of chimeric antigen receptor (CAR)-T-cell therapy or stem cell transplant (within two years of transplantation or taking immunosuppression therapy).
• Moderate to severe primary immunodeficiency with associated humoral and/or cell-mediated immunodeficiency or immune dysregulation.
• Treatment of HIV with immunosuppressive therapies.

NACI emphasizes recommendation that children be vaccinated 

NACI’s guidance also “strengthened” its previous recommendation that all children ages five to 11 be vaccinated with two pediatric doses of the Pfizer-BioNTech vaccine. The pediatric dose is one-third (10 micrograms) the size of the 30-microgram dose given to adolescents 12 and older and to adults. 

“Children five to 11 years of age continue to remain at low risk of severe COVID-19 outcomes, including from the Omicron variant; however, the number of children experiencing severe disease or requiring hospitalization is increasing due to [a] large number of children becoming infected with SARS-CoV-2 during this wave of the pandemic,” the updated NACI guidance said.