Safety of live attenuated influenza vaccine in mild to moderately immunocompromised children with cancer

Background

The safety of intranasal live-attenuated influenza vaccine (LAIV) in immunocompromised children with cancer is unknown. The objective of this study was to describe the safety and immunogenicity of LAIV in mild to moderately immunocompromised children with cancer.

Methods

We conducted a multicenter, randomized, double-blind study of LAIV versus placebo in children aged 5-17 years with cancer. LAIV (frozen formulation) or allantoic fluid/buffer was administered intranasally. Reactogenicity, adverse events, blood for immune assays, and nasal swabs for viral shedding were obtained during 5 visits over the first 42 days postvaccination; information concerning serious adverse events (SAEs) was collected for 180 days.

Results

20 subjects were enrolled (LAIV, n = 10; placebo, n = 10) with a mean age of 12.2 years. Ten subjects had hematologic malignancy (LAIV, n = 4; placebo, n = 6); 10 subjects had solid tumors (LAIV, n = 6; placebo, n = 4). One subject was excluded from immunogenicity analysis for not receiving a full dose of LAIV. LAIV resulted in an increased incidence of runny nose/nasal congestion occurring in all LAIV recipients; no related SAEs were observed. Four of 10 LAIV recipients shed vaccine virus, with none exceeding 7-10 days duration. LAIV demonstrated modest immunogenicity by hemagglutination inhibition (≥4 fold rise for any strain, 33%) and microneutralization assays (≥4 fold rise for any strain, 44%).

Conclusion

In this small pilot study conducted in mild to moderately immunocompromised children with cancer, runny nose/nasal congestion was increased in LAIV recipients, no related SAEs occurred, and prolonged viral shedding was not detected. Moderate immunogenicity was demonstrated in this small group of individuals. (ClinTrials.gov: NCT00112112).     

Fusarium meningoencephalitis in a child with acute leukemia

A 15-year-old boy with acute lymphoblastic leukemia (ALL) developed disseminated fusarium infection with meningoencephalitis following a contaminated skin wound. With antifungal therapy, the cutaneous lesions cleared but central nervous system (CNS) infection persisted causing a fibrosing meningitis and a brain granuloma. Fusaria are soil saprophytes that are more commonly associated with superficial eye and skin lesions, but may also cause severe systemic infections with CNS involvement in immuno-compromised patients. The organism may be confused with Aspergillus in tissue sections, and can only be diagnosed by culture.     

Reassembly of particles using the RNA from partially disassembled tobacco mosaic virus

Controlled alkaline disassembly of tobacco mosaic virus (TMV) results in the production of two populations of partially stripped virus. These particles have been designated PSV5 and 6 and are the two smallest particles produced during alkaline disassembly of TMV. The RNA from these particles was able to reassemble with TMV coat protein. The reassembled particles were resistant to ribonuclease treatment and sedimented upon sucrose density gradient centrifugation to the same position as authentic PSV5 and 6 particles.     

A cord blood transplant recipient with Mycobacterium mucogenicum central venous catheter infection after infusion of tap water

Mycobacterium mucogenicum is an unusual cause of central venous catheter and wound infections in immunocompromised persons. The organism is often found in drinking water and is resistant to many disinfectants. We report a cord blood transplant recipient who developed a central venous catheter infection after the patient herself had flushed her catheter with tap water. The infection was successfully treated by removal of the central venous catheter and administration of antimicrobial therapy.