This literature marketed report as received from an other health professional refers to 2 patients of unknown age and gender. On an unknown date, the patients were vaccinated with VARIVAX (Merck) (manufacturer unknown). Two of the 7 vaccinated patients who had received one dose were hospitalized for varicella or varicella related complications. Characteristics of varicella-related hospitalizations in the mature VARIVAX (Merck) (manufacturer unknown) era, including the proportion vaccinated and the severity of disease, are not well described. The study describes the vaccination status, severity and reasons for hospitalization of the hospitalized varicella cases reported to the Department from 2003 to 2011, the period which includes the last 4 years of the mature one-dose program and the first 5 years after introduction of the routine two-dose program. A probable case of varicella was defined as an acute illness with diffuse (generalized) maculopapulovesicular rash without laboratory confirmation or an epidemiologic linkage to another probable or confirmed case. A confirmed case of varicella was defined as an acute illness with diffuse (generalized) maculopapulovesicular rash and either laboratory confirmation of varicella or epidemiologic linkage to another probable or confirmed case. A varicella-related hospitalization was defined as a probable or confirmed case of varicella that was hospitalized for at least 24 hours. Cases were categorized as being hospitalized for precautionary reasons if they had a chronic condition that resulted in the hospitalization without which they would otherwise not be hospitalized. Cases were categorized as hospitalized for varicella if they had severe varicella-related symptoms, such as fever or profuse rash, which required hospitalization. Cases were categorized as hospitalized for varicella-related complications if the disease resulted in a complication which required hospitalization. Reported varicella-related complications were categorized as: pulmonary (including pneumonia, respiratory failure, bronchiolitis), dermatologic (including secondary skin infections, cellulitis, impetigo), bacteremia/sepsis, dehydration, and neurologic (including encephalitis, cerebellar ataxia, meningitis, altered level of consciousness, seizures). Cases could have multiple complications. Chronic conditions where health conditions present before hospitalization and were categorized as: immunocompromised (including cancer, HIV/AIDS, previous organ transplant, autoimmune disorder), chronic renal failure, chronic lung disease, diabetes, and asthma. Cases could have multiple chronic conditions. Cases were categorized as vaccinated if they had documented proof (e.g., immunization record) of previous vaccination with at least one dose of varicella containing vaccine. Cases were considered as breakthrough varicella if they developed varicella 42 or more days after vaccination. Cases were classified as potentially preventable if they did not fall into one of the following categories: had documented proof of previous varicella disease, had been vaccinated with at least one dose of varicella containing vaccine, or were immunocompromised. Cases in pregnant women were considered as potentially preventable if they had not been previously vaccinated with at least one dose of varicella containing vaccine before pregnancy. A total of 158 hospitalized varicella cases were reported overall, of which 52.5% were potentially preventable and eligible for vaccination, 41.8% were not eligible for vaccination, and 5.7% were vaccinated. Most hospitalizations (72.2%) occurred among healthy persons, 54.4% occurred among persons >=20 years of age, and 3.8% of hospitalizations resulted in death. Data suggest that as many as half of the hospitalized varicella cases, including half of the deaths, may have been preventable given that they occurred in persons who were eligible for vaccination. More complete implementation of the routine varicella vaccination program could further reduce the disease burden of severe varicella. On unknown date, nine (5.7%) of the hospitalized varicella cases had been vaccinated against varicella; one (11.1%) was laboratory confirmed. All were children, of whom two were 1-4 years of age and seven were 11-14 years of age. Seven (77.8%) of the cases had received one dose and 2 (22.2%) had received two doses of VARIVAX (Merck) (manufacturer unknown) containing vaccine. Seven of the cases were considered breakthrough varicella and two developed a rash within 42 days of vaccination. Four of the vaccinated cases were immunocompromised; each had received one dose of VARIVAX (Merck) (manufacturer unknown) containing vaccine. 2 (28.6%) for varicella or varicella related complications (serious, hospitalisation). None of the hospitalized vaccinated cases resulted in death. Our descriptive data on hospitalized cases of varicella demonstrate that, as in the pre-vaccination era, most hospitalized cases of varicella continue to occur among previously healthy persons with no immunocompromising conditions. Our data suggest that as many as half of hospitalized varicella cases, including half of the deaths, may have been preventable given that they occurred in persons who were eligible for vaccination. More complete implementation of the routine VARIVAX (Merck) (manufacturer unknown) vaccination program could further reduce the disease burden of severe varicella. An estimated 15-20% of children may not respond to a single dose of VARIVAX (Merck) (manufacturer unknown). Whether these hospitalizations could have been prevented had these children received two doses of VARIVAX (Merck) (manufacturer unknown) prior to becoming immunocompromised is not known, but it highlights the importance of receiving vaccinations on schedule. The outcome of event was unknown. This is 1 of the several reports from the same literature article, others being 1409USA005096 and 1409USA008014. Additional information has been requested.