A new study, the first of its kind, provided support for guidelines suggesting that the capsular meningococcal B vaccine be given to children with three rare conditions that boost infection risk.
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For children with terminal chain complement deficiencies or who are undergoing treatment with eculizumab, “it is important that these patients are identified, receive education about sepsis management plans, and are prescribed prophylactic antibiotics according to local guidelines, along with vaccination, to provide every chance for them to be protected against this deadly disease,” the researchers wrote in Pediatrics.
While some countries suggest that the vaccine be given to all healthy infants, U.S. guidelines advise that the vaccine be given to preteenagers, teenagers, and adults who are considered at special risk. These include those with terminal chain complement deficiencies, who are believed to be up to 10,000 times more likely than healthy children to develop invasive meningococcal disease, and those who take eculizumab (Soliris). The risk groups recommended for vaccinations also include those with asplenia and splenic dysfunction, although their excess risk, if any, is unknown.
The new study of the capsular group meningococcal B vaccine, led by Federico Martinón-Torres, PhD, of the Hospital Clinico Universitario de Santiago de Compostela, Spain, adds to previous research that confirmed the effectiveness of vaccinating complement-deficient patients with capsular group A, C, W, and Y meningococcal vaccines.
For the open-label, phase 3b study, researchers in Italy, Spain, Poland, and Russia gave two doses of the vaccine 2 months apart to 239 children aged 2-17 years with an average age of 10 years. Nearly all were white, and 45% were female.
A total of 40 children had complement deficiency, 112 had asplenia or splenic dysfunction, and 87 children in the control group also received the vaccine.
Following vaccination, the percentages of children with exogenous complement serum bactericidal activity titers greater than or equal to 1:5 to the four test strains were similar in the healthy children and those with asplenia/splenic dysfunction. “It is reasonable to expect that this vaccine will be as effective in children with asplenia or splenic deficiency as in children in the control category,” the researchers wrote.
However, these levels were lower in the complement-deficient children, particularly in those with terminal chain complement deficiency and those who took eculizumab.
The proportions of children with exogenous complement serum bactericidal activity titers greater than or equal to 1:5 against the four test strains were 87% (H44/76), 95% (5/99), 68% (NZ98/254), and 73% (M10713) in complement-deficient children, compared with 98%, 99%, 83%, and 99%, respectively, in the healthy controls.
“Ongoing surveillance for vaccine failures is required to determine the significance of the trend to reduced immune response in children with terminal chain complement deficiencies or undergoing treatment with eculizumab,” the researchers wrote.