Age: 1.0
Sex: M
Vaccine: VARCEL
Symptoms: Varicella virus test positive, Varicella zoster virus infection
Clinical narrative: This literature marketed report was received from a healthcare professional via published literature article regarding an 18 month old male patient. The patient's vaccinated against Varicella-zoster virus (VZV) to prevent chickenpox can suffer rare complications, including vaccine related zoster (shingles). The vaccine was effective in preventing chickenpox and substantially reducing morbidity, but could also lead to shingles just as natural infection with wild-type VZV. Among VZV vaccine recipients, shingles has been reported but was uncommon. Estimates propose a frequency of 0.18 cases per 1000 vaccine patient-years. One study found the incidence of zoster (from both vaccine-strain and wild-type) to be approximately 48 cases per 100,000 person-years in vaccinated children, and 230 cases per 100,000 person-years in unvaccinated children (from wild-type only). Among those vaccinated in a later study, not all  zoster occurrences were shown to be caused by the vaccine-strain VZV, as some were caused by wild-type VZV. This suggests vaccines may become infected with wild-type virus, display minimal clinical manifestations and develop shingles. Clinical characteristics of vaccine-related zoster among children are similar to those of wild-type zoster and VZV vaccine used to prevent chickenpox considerably reduces morbidity from wild-type VZV infection. However, the vaccine strain establishes neuronal latency, hence reactivation of vaccine virus in and transmission from healthy and immunocompromised individuals could be possible. Consequently, vaccinated patients with subsequent zoster should be considered contagious warranting appropriate barrier precautions as both vaccine-strain and wild-type VZV may cause zoster. Considering the vast number of vaccines administered worldwide, short term side effects of vaccination are relatively uncommon and late onset reactions such as Zoster are even rarer. The authors reported one such complication, vaccine related herpes zoster dermatitis in an 18 month old patient who was born at term after a normal pregnancy and otherwise healthy. On an unknown date (reported as at 12 months age), the patient received vaccination with varicella virus vaccine live (Oka/Merck) (manufacturer unknown) (dose, strength, route, frequency, lot # and expiration date unknown. The patient presented with a painful rash lasting for two days and upon examination, a zosteriform skin eruption was present at dermatomes L2, L3, L4 on the left. The eruption was erythematous, patchy, and studded with vesicles. The child was afebrile with no other dermatologic findings. A vesicle was unroofed and swapped for VZV polymerase chain reaction (PCR). The patient was prescribed with acyclovir and the lesions had healed after two weeks. The child's mother was pregnant who also had a history of chicken pox did not develop infection over the following 8 weeks. There was no family history of compromised immunity. Subsequently VZV was detected in the patient's specimen by PCR. As the patient's mother was pregnant and the patient had many unvaccinated contacts at daycare, a strain specific differentiation was performed and the VZV was identified as the Oka vaccine strain. The outcome of herpes zoster dermatitis was reported as recovered. The reporter considered herpes zoster dermatitis to be related to varicella virus vaccine live (Oka/Merck) (manufacturer unknown). Additional information has been requested.