Varicella Vaccine Safe for Rheumatic Patients
By Nancy Walsh, Staff Writer, MedPage Today
Published: July 19, 2010
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner Earn CME/CE credit
for reading medical news
* Explain to interested patients that immunosuppression, whether from disease or drug treatment, can result in severe infection with varicella if exposure occurs.
* Also tell them that two doses of the vaccine are likely to be needed for full protection.
Varicella vaccine appears to be safe and relatively immunogenic for use in children with rheumatic diseases being treated with immunosuppressive drugs, a small prospective study has found.
Positive varicella-zoster virus IgG titers were detected in 10 of 20 previously seronegative patients with juvenile idiopathic arthritis, dermatomyositis, scleroderma, or vasculitis and in 13 of 18 healthy matched controls (P=0.2) four to six weeks after immunization, according to Gecilmara Salviato Pileggi, MD, of the University of SÃ£o Paulo in Brazil.
During the three months following receipt of the vaccine, no overt varicella episodes or severe adverse reactions were seen among children who seroconverted, the researchers reported in the July Arthritis Care & Research.
Children with altered immune systems, such as can occur with the use of antirheumatic drugs, are at increased risk of severe disease should they be exposed to varicella, and there have been case reports of affected patients having serious and even fatal infections.
But evidence has been lacking on the safety of live vaccines in children with rheumatic diseases receiving immunosuppressive therapy, so Pileggi and colleagues conducted an open-label study that included 25 patients whose median age was 7.2 years. All patients received a single dose of varicella vaccine.
All participants were receiving methotrexate, at a mean dosage of 16.4 mg/m2/week, and 13 also were receiving prednisone in doses of 0.1 to 0.7 mg/kg/day.
Among the total cohort of 25 patients, five had equivocal pre-immunization virus titers and were excluded from the vaccine response analysis.
Low-grade fever lasting a single day was seen in one patient and one control, and three patients had mild varicella-like rashes during the first two weeks.
During a median follow-up period of 32 months, 16 patients reported exposure to wild varicella zoster virus, with eight of the exposures involving a household or classmate contact.
Two of those eight, both of whom were nonresponders to the vaccine, developed chickenpox, with one having a severe case complicated by pneumonia and probable macrophage activation syndrome.
That patient was receiving anti-tumor necrosis factor therapy at the time of the exposure, the investigators noted.
Vaccination was not associated with worsening of the underlying disease, and, in fact, among the subgroup of 17 patients with juvenile idiopathic arthritis, a significant improvement was seen in the number of joints with active arthritis in the three months following vaccination, decreasing from a mean of 3.2 (95% CI 1.4 to 5) to 1.8 (95% CI 0.8 to 2.8, P=0.009).
The investigators noted that the overall seroconversion rate to the vaccine was lower in this study than was seen in an earlier large study, where response rates exceeded 90%.
However, a more recent study found rates of seroconversion of 76% after one dose of the vaccine, and the Advisory Committee on Immunization Practices recommends the use of two doses in healthy children.
An editorial accompanying the study concurred.
"Based on the results of the current study, if a decision was made to immunize children with rheumatic diseases against varicella, a two-dose regimen would be preferable," wrote Robert W. Frenck, MD, of Cincinnati Children's Hospital and Jane F. Seward, MBBS, of the Centers for Disease Control and Prevention in Atlanta.
"Of note, in countries using varicella vaccine (one- or two-dose policy) in their universal childhood immunization program, most children will receive varicella vaccine before developing juvenile rheumatic diseases," the editorialists pointed out.
A limitation of the study was the small number of patients from a single center, and multicenter studies with larger numbers of patients are clearly needed to more fully estimate responsiveness to the vaccine in children with rheumatic diseases, Pileggi and colleagues noted.
"More research in this field is necessary for the development of specific immunization guidelines for patients with rheumatic and other autoimmune diseases receiving treatment with immunosuppressive agents who are still susceptible to preventable infectious disease," they concluded.
The lead author's work was supported by the University of SÃ£o Paulo, and another author was supported by the Conselho Nacional de Desenvolvimento CientÃfico e TechnolÃ³gico.
Editorialist Frenck has received consultant and speaking fees from the Data Safety Monitoring Boards of Novartis Vaccines.
Primary source: Arthritis Care & Research
Pileggi G, et al "Safety and immunogenicity of varicella vaccine in patients with juvenile rheumatic diseases receiving methotrexate and corticosteroids" Arthritis Care Res 2010; 62: 1034-1039.
Additional source: Arthritis Care & Research
Frenck R, Seward J "Varicella vaccine safety and immunogenicity in patients with juvenile rheumatic diseases receiving methotrexate and corticosteroids" Arthritis Care Res 2010; 62: 903-906.
Technical & specific medical articles covering many areas Kawasaki-related
1 post • Page 1 of 1