In The News: Vaccination, Prophylaxis Recommended for Children with Primary Immunodeficiencies

Healio reports on a presentation delivered at the AAAAI annual meeting that recommended routine inactive vaccinations and other prophylactic treatment for children with primary immunodeficiencies. According to the presenter, children should be evaluated for T-cell deficiency and to what degree using TREC assays. Then, affected children 2-18 years of age should receive two doses of pneumococcal polysaccharide vaccine, with the first coming at least eight weeks after the child’s first dose of pneumococcal conjugate vaccine and the second five years later.

(As new vaccines receive licensure, particularly for pneumococcus, new approaches will likely be needed – https://www.cdc.gov/vaccines/vpd/pneumo/hcp/who-when-to-vaccinate.html)

Furthermore, the presenter shared stratifying T-cell deficiency may help quantify diagnoses and with the risk for infections. At 12 months, children with 22q11.2 deletion syndrome should get live MMR vaccine and varicella vaccine if they have CD4 counts of 400 cells/mm³ or higher, CD8 counts of 200 cells/mm³ or higher and three doses of the tetanus IgG protective vaccine. Children with CD45RA⁺CD3⁺/4⁺ percentage higher than their CD45RO⁺CD3⁺/4⁺ percentage in their earliest assessment should receive those vaccines as well, should they meet all the criteria.

For children with abnormal T-cell counts, they recommend physicians consider confirming newborn TREC screening results or flow cytometry confirming RTEs. The latter can help confirm adequate thymic function and rule out causes of severe combined immunodeficiency. Children with complete athymia and common variable immunodeficiency in association with 22q11.2 deletion syndrome may require immunoglobulin replacement.

The presentation closed with recommendations to consider prophylactic antibiotics for children who have recurrent bacterial sinopulmonary infections. Patients with 22q11.2 deletion syndrome have lower rates of opportunistic infections except for congenital athymia compared with patients with HIV, meaning they can tolerate lower CD4 counts before they need prophylaxis for pneumocystis jirovecii pneumonia. With or without 22q11.2 deletion syndrome, prophylaxis for mycobacterium avium complex with azithromycin for patients with congenital athymia was recommended.

PIDS member Tanya Rogo commented on the presentation, “Vaccination is one of the key strategies to preventing infection in immunocompromised children, but it can be challenging for practitioners to discern which vaccines a patient should or should not get according to their medical condition. The CDC has a table of vaccines classified by medical indication that I have found to be very helpful in my own practice.”