Evaluation of Live Attenuated Varicella Vaccine (Oka-RIT Strain) and Combined Varicella and MMR Vaccination in 13–17-Month-Old Children

ABSTRACT. The Oka-RIT strain of live attenuated varicella vaccine at dose levels 5300 PFU (high titre) and 2000 PFU (low titre) was tested in 13–17-month-old children; 50% of the children received the varicella vaccine alone, and the other 50 % received it together with a measles-mumps-rubella (MMR) vaccine. The high titre and low titre varicella vaccines induced 96% and 92% seroconversion rates, respectively. Following combined vaccination with MMR, the corresponding seroconversion rates for varicella were significantly lower at 85% and 72% respectively. Seroconversion rates to measles, mumps and rubella were not affected by the combination of varicella vaccine plus MMR vaccination. Single varicella vaccine at both titre levels was found safe, although 10% of the children had minor skin reactions, possibly attributable to the vaccine. Reactions typically associated with MMR vaccination did not significantly increase after the combined varicella plus MMR vaccination. This study confirmed that the Oka-RIT strain varicella vaccine is safe and immunogenic in healthy young children, but failed to find a totally satisfactory combination for a varicella-MMR vaccine.     

Time trends in pediatric Herpes zoster hospitalization rate after Varicella immunization

Herpes zoster (HZ) is an emerging concern for public health officials. The aim of this study was to determine whether universal Varicella immunization implemented in 2004 had an impact on HZ hospitalization in immunocompetent children in Greece. All HZ hospitalizations were recorded during the period 1999–2011. The overall attributable hospitalization rate was 13.89 cases/1000 hospital admissions (95%CI: 11.69–16.38 cases/1000 hospital admissions). HZ hospitalization rate remained unchanged during the study period. These data provide a basis for monitoring HZ hospitalization rate among children following universal toddler immunization.     

Herpes Zoster in a 2-Week-Old Premature Infant with Possible Congenital Varicella Encephalitis

ABSTRACT. This report concerns a case of neonatal herpes zoster associated with maternal gestational varicella. The child developed skin lesions at 18 days of age virologically confirmed to be varicella-zoster. The baby also had encephalitis and aspiration probably due to bulbar paralysis. Multiple small necrotic areas were found in the thalamus at post-mortem examination.     

Varicella in the fetus and newborn

Varicella (chickenpox) in pregnancy is unusual because most women of childbearing age are immune. It can, however, cause significant morbidity for the pregnant woman and in rare cases cause congenital varicella syndrome. The incidence of congenital varicella syndrome after maternal varicella during the first two trimesters is <1% across multiple cohort studies. Maternal infection in the third trimester is not associated with congenital varicella syndrome, but the infant may develop herpes zoster during the first one or two years. Maternal infection just before or after delivery presents a high risk for disseminated varicella in the infant. Serious infection can be prevented with passive antibody prophylaxis and antiviral therapy. Maternal herpes zoster does not result in adverse fetal or neonatal outcomes.     

Herpes zoster meningitis in immunocompetent children: Two case reports and a literature review

We encountered two cases of Herpes zoster (HZ) meningitis, a rarely occurring complication of HZ, in previously healthy children. One patient treated with i.v. acyclovir (ACV, 31 mg/kg/day) did not recover. His symptoms were relieved somewhat by increased ACV dosage, but it caused transient renal dysfunction. Another patient treated with i.v. ACV (30 mg/kg/day) recovered. Treatment for HZ meningitis in immunocompetent children has not been established. In a literature review, 80% of 20 patients were treated with the usual dose of ACV 15–30 mg/kg/day. The present cases suggest that a high dosage of ACV up to 60 mg/kg/day should be considered (while monitoring for side‐effects) unless symptoms improve. In the review, one of every three vaccine‐strain Varicella zoster virus (VZV) cases was severe, whereas the present cases resulted from wild type. Further investigations must examine different clinical characteristics of HZ meningitis caused by wild‐type and vaccine‐strain VZV.     

Short-Time and Low-Dose Intravenous Acyclovir Therapy in Varicella Zoster Infections with Malignant Disease in Children Receiving Combined Chemotherapy

The effects of low-dose and short-time acyclovir therapy in 14 children with malignant disease of ages 4-18 years who had developed varicella zoster virus infections while receiving aggressive chemo-J + radiotherapy are reported. Ten of them had chickenpox and 4 herpes zoster. Acyclovir 5 mg/kg was infused IV every 12 h in 9 patients and every 8 h in 5 patients for a median of 4 days' duration. We resumed the primary therapy when the patients' lesions had dried out and became crusted and new lesions had not reappeared. The period of initiation of the acyclovir therapy to the resumption of oncological treatment was 8.4 ± 2.7 days for chickenpox and 12.0 ± 3.4 days for herpes zoster patients. After restarting the oncological therapy, no adverse effects of acyclovir or complication of infection were observed. The efficiency of early, short-term, and relatively low dose acyclovir therapy is discussed and compared to the results in the relevant literature.     

Persistently High Antibody Titers and Deficient Specific Cellular Immunity to Varicella-Zoster Virus in a Retarded Patient after Varicella Infection

We report on a 19 month old female who has been retarded developmentally after a severe varicella infection contracted from her mother 4 months after delivery. Her titer of varicella-zoster virus (VZV) IgG antibody has been remarkably high for 4 years after the infection. Natural killer activity and the specific cellular immunity to VZV, as tested by delayed type hypersensitivity skin test and lymphocyte-proliferation assay, were impaired. She had an improvement of ataxia and then progressed developmentally after administration of an anti-viral agent. Administration of oral corticosteroids and methylprednisolone transiently decreased titers of VZV antibody and, contrary to previous reports, returned natural killer activity to normal levels. We suggest that this case may be a persistent VZV infection similar to congenital cytomegalovirus infection due to selective defects in cellular immunity including NK cells. Whether this specific deficient cellular immunity is genetically determined or secondary to the viral infection is speculative. This is the first known report of such a case.     

Simultaneous Administration of HB Recombinant Vaccine with Diphtheria and Tetanus Toxoid and Oral Polio Vaccine: a Pilot Study

An extensive vaccination program to be used in highly endemic areas is the main strategy against the spreading of hepatitis B. The purpose of this study was the evaluation of the immune response to the recombinant HB vaccine administered singly or at the same time as other compulsory vaccines anti-diphtheria, anti-tetanus and oral anti-polio. Evidence was found of the serological efficacy both of HB vaccine and compulsory vaccines with a percentage of seroconversion of 100%. However, the infants who received HB vaccine at birth and at the age of 1 month had titers of antiHBs higher than the infants who received HB vaccine at birth and at 3 months. No difference in antibody levels of compulsory vaccines was observed among the study groups and the controls who received only compulsory vaccines. Our results suggest that HB vaccination must be encouraged and pursued in all newborns.     

Live vaccines after pediatric solid organ transplant: Proceedings of a consensus meeting, 2018

Growing evidence suggests receipt of live‐attenuated viral vaccines after solid organ transplant (SOT) has occurred and is safe and needed due to lapses in herd immunity. A 2‐day consortium of experts in infectious diseases, transplantation, vaccinology, and immunology was held with the objective to review evidence and create expert recommendations for clinicians when considering live viral vaccines post‐SOT. For consideration of VV and MMR post‐transplant, evidence exists only for kidney and liver transplant recipients. For MMR vaccine post‐SOT, consider vaccination during outbreak or travel to endemic risk areas. Patients who have received antiproliferative agents (eg. mycophenolate mofetil), T cell–depleting agents, or rituximab; or have persistently elevated EBV viral loads, or are in a state of functional tolerance, should be vaccinated with caution and have a more in‐depth evaluation to define benefit of vaccination and net state of immune suppression prior to considering vaccination. MMR and/or VV (not combined MMRV) is considered to be safe in patients who are clinically well, are greater than 1 year after liver or kidney transplant and 2 months after acute rejection episode, can be closely monitored, and meet specific criteria of “low‐level” immune suppression as defined in the document.     

Specific Antibodies to Poliovirus Type I in Breastmilk of Unvaccinated Mothers before and Seven Years after Start of Community-Wide Vaccination of Their Infants with Live, Oral Poliovirus Vaccine

ABSTRACT. Secretory IgA (SIgA) antibodies against poliovirus type 1 were determined using the ELISA method in breastmilk samples obtained each month from 100 young, healthy, unvaccinated mothers living in urban slum areas of Lahore, Pakistan. The study covered two different groups, one in 1980–1981 and the other in 1987, before and seven years after a nation-wide expanded programme of childhood immunization (EPI) had started. The SIgA titres did not change neither with duration of lactation nor with time after vaccination in the infants of the mothers studied. The seasonal breastmilk IgA antibody titres to poliovirus type 1 corresponded to the epidemiological conditions existing both before (1980–81) and after general vaccination coverage with live, oral poliovirus vaccine (OPV) had reached 80% of the infant population (1987). Neutralization titres did not seem to correlate well with ELISA titres although colostrum samples had high levels of neutralizing antibodies. The wide variation between high (> 10 000) and low (<500) individual breastmilk IgA antibody titres observed during various seasons could be of consequence for the breast-fed baby. Colostrum, which was also found to have significant neutralization capacity, might interfere with the OPV now often given on the day of birth.     

Follow-up of the Antibody Response to Measles Vaccine in a Rural Area of Guinea-Bissau

ABSTRACT. One hundred and fourty-four children who either were already immune or had been successfully immunized against measles were reexamined after 16 months. All still had circulating Elisa antibodies at a clearly detectable level. Titres were higher in the group of children stated to have had measles prior to the immunization. None of the children had measles after immunization. Boostering by the wild virus may have occurred, whereas no evidence of a booster effect from the vaccine was found. About one third of the children were underweight. Plasmodium falciparum parasitaemia rate, and also its seasonality, varied with the location of the child's homestead. Even children exposed to mesoendemic P. falciparum malaria and moderate malnutrition can be successfully immunized with a conventional live attenuated measles vaccine from 8 months of age, which probably results in a lasting protection.