Live attenuated vaccines in patients receiving immunosuppressive agents

Area of Science:

• Immunology
• Vaccinology
• Infectious Diseases

Background:

• Patients on immunosuppressive agents face increased risks of severe infectious diseases.
• Current guidelines in Japan and other countries contraindicate live attenuated vaccines for these patients.
• There is a high need for effective infectious disease prevention in immunocompromised individuals.

Purpose of the Study:

• To evaluate the safety and effectiveness of live attenuated vaccines in patients receiving immunosuppressive therapy.
• To review existing evidence on live attenuated vaccine use in immunocompromised populations.
• To identify potential immunological criteria for safe vaccination.

Main Methods:

• Systematic review of 25 reports detailing 2,091 vaccinations in patients on immunosuppressants.
• Analysis of infection rates and complications associated with live attenuated vaccines.
• Prospective study at the National Center for Child Health and Development assessing safety and serological effectiveness under specific immunological conditions (e.g., CD4 count ≥ 500/mm³, PHA SI ≥ 101.6, IgG ≥ 300 mg/dL).

Main Results:

• A low rate of vaccine virus infection (1.1%, 23/2091 patients) was observed, primarily with varicella virus (21 patients).
• No life-threatening complications were reported in the reviewed cases.
• The prospective study confirmed serological effectiveness and safety under defined immunological criteria.

Conclusions:

• The evidence suggests that live attenuated vaccines can be administered to patients on immunosuppressants, even under specific immunological conditions.
• Further research is required to gather more evidence and define precise immunological criteria for safe use.
• Package inserts and guidelines may require revision based on accumulating evidence regarding live attenuated vaccine use in immunocompromised patients.