Safety and immunogenicity of varicella-zoster virus vaccine in pediatric liver and intestine transplant recipients

Primary varicella-zoster virus (VZV) infections following organ transplantation may cause significant morbidity. We examined the safety and immunogenicity of Varivax after transplantation as a potential prophylactic tool. Pediatric liver and intestine transplant recipients without history of chickenpox received one dose of Varivax. VZV humoral and cellular immunity were assessed before and > or =12 weeks after vaccination. Adverse events (AE) and management of exposure to wild type VZV were monitored. Sixteen VZV-naïve subjects, 13-76 months of age, at 257-2045 days after transplantation were immunized. Five children developed mild local AE of short duration. Four subjects developed fever and four developed non-injection site rashes, three of whom received acyclovir. Liver enzymes did not increase during the month after vaccination. Eighty-seven percent and 86% of children developed humoral and cellular immunity, respectively. There were five reported exposures to varicella in four children, none of which resulted in chickenpox. One subject received VZV-immunoglobulin and another subject with liver enzyme elevations after exposure received acyclovir; all remained asymptomatic. Varivax was safe and immunogenic in pediatric liver and intestine transplant recipients. Larger studies are needed to establish the efficacy and role of varicella vaccination after transplantation.

A tale of 2 alpha-herpesviruses: lessons for vaccinologists

Of the 8 known herpesviruses that affect human beings, we only have successful vaccines against varicella zoster virus. This brief review compares the pathogenesis of varicella zoster virus with that of the closely related alpha-herpesviruses herpes simplex virus 1 and 2, for which we have no satisfactory vaccines. The main objective of this review is to learn lessons from the success of varicella zoster virus vaccine that could be exploited for the development of successful vaccines against herpes simplex virus and perhaps against other herpes viruses.

Live virus immunization after orthotopic liver transplantation

Viral infection is a recognized and potentially serious complication in children following solid organ transplantation. The risks of viral infection are particularly important for infants who may not have completed standard childhood immunizations at the time of transplantation and are therefore at risk for otherwise preventable infections. The general practice of withholding live virus immunization from transplant recipients has been questioned and several small studies have looked at MMR and/or Varivax administration in children following transplantation. This retrospective study analyzes the response to primary MMR and varicella immunization in selected pediatric liver transplant recipients in the largest such study to date. Nineteen of 26 children (73%) developed serologic immunity for measles following MMR (although 18 required multiple doses). Similarly, varicella immunization resulted in seroconversion in 20 of 31 children (64.5%; seven required multiple doses). Only minor adverse effects reported in the general population were observed. Live virus immunization with MMR and Varivax was safe and immunogenic in this selected population of liver transplant recipients.

[Infectious disease]

Several articles published in 2005 offer new knowledge in infectious diseases treated by practitioners. This paper discusses viral (influenza) and bacterial (pneumococci and legionella) respiratory infections. Resistant staphylococci, different from healthcare-associated MRSA, are now found in community. The article assesses that epidemics of Norovirus infections are common during winter time. The screening for treatment of asymptomatic bacteriuria is not recommended. The possible development of a successful vaccine to prevent herpes zoster is finally reminded.

Varicella vaccination in Australia

Varicella zoster virus (VZV) causes both chickenpox and herpes zoster and is responsible for a significant disease burden, including hospitalizations and deaths, in Australian children and adults. Varicella vaccine has been available in Australia for 5 years; however, from November 2005, it will be funded for use in all susceptible children at 18 months and 10-13 years of age under the National Immunisation Program. Experience with universal varicella vaccination of children in the USA over the last 10 years has shown that the vaccine is safe and highly effective in reducing varicella-related disease. This review summarizes the epidemiology of VZV-related disease in Australia, the use of varicella vaccine and the international experience with vaccine efficacy and safety. The potential impact of varicella vaccination on the incidence of herpes zoster is also discussed.

[Immunisation against varicella]

Two vaccines against varicella are now being licensed in France, both deriving from the Oka strain. Seroconversion has been obtained in almost 100% of the cases after one dose in toddlers and children, and two doses in adolescents and adults. Efficacy has been mainly established from the US experience, where a universal immunisation programme of children aged > 12 months with a catch-up for susceptible adolescents and adults was begun in 1995. The incidence of varicella has decreased by about 85% over all age groups. The safety of the vaccine is good, and most adverse events are represented by fever, reactions at the injection site and varicella-like rashes. For the time being, France has adopted restrictive recommendations for the use of this vaccine because of uncertainties with respect to the duration of protection, a shift of the disease towards older age and the potential increase of the incidence of herpes-zoster.

Research shows that highly potent vaccine reduces the burden of herpes zoster and the incidence of postherpetic neuralgia in older adults

A live attenuated vaccine reduces the burden of herpes zoster (shingles) in older adults, according to the recently published results of a randomised, double-blind trial

Chickenpox vaccines: new drugs. A favourable risk-benefit balance in some situations

(1) Chickenpox is generally mild. Most severe cases of chickenpox occur in immunocompromised patients, adults, and pregnant women (and their foetuses). (2) Two live attenuated chickenpox vaccines derived from the same strain of varicella virus (Oka) are marketed in France, under the trade names Varilrix and Varivax. (3) They have not been adequately evaluated in immunocompromised children. (4) The impact of routine vaccination of women of child-bearing age on complications of chickenpox during pregnancy has not been studied. (5) Immunogenicity studies in several thousand immunocompetent children aged from 1 to 12 years show that the vaccine is almost always immunogenic after a single injection. Other comparative studies in adolescents and adults show that two injections are needed, at least two months apart. (6) A double-blind placebo-controlled trial including 513 immunocompetent children showed that Varilrix prevented 88% of cases of chickenpox after a median follow-up of 29 months, but no data on severe chickenpox were reported. A study that followed up 9202 children aged 1 to 12 years for more than 13 years showed that vaccination with Varivax failed to prevent chickenpox in 12.5% of cases and that 1.7% of these cases were severe. (7) Immunocompetent children vaccinated within three days after exposure to the virus are partially protected, according to one study of Varilrix (104 children) and two small studies of Varivax (10 and 42 children). There are no equivalent studies in adults. (8) Local adverse effects such as fever and rash are common in immunocompetent vaccinees. The rash is sometimes varicella-like and is due to infection by the vaccine strain. Pharmacovigilance studies of Varivax have shown no serious adverse effects. (9) Disseminated and/or persistent infection caused by the vaccine strain has been reported in immunocompromised patients. (10) Vaccination of immunocompetent subjects does not appear to result in a risk of chickenpox transmission to subsequent contacts. There seems to be no increase in the risk of herpes zoster in vaccinated children nor is there any firm evidence that chickenpox vaccination increases the incidence of herpes zoster in the general population. (11) Little information is available on vaccination during pregnancy. As a precaution, however, pregnant women should not be vaccinated. (12) Mass vaccination does not appear to be justified: chickenpox is generally mild during childhood, and several questions concerning the effects of the vaccine remain unanswered. (13) Chickenpox vaccination should be restricted to specific groups of non immune immunocompetent adults who are in a position to transmit chickenpox to immunodeficient contacts (e.g. health care personnel and kindergarten staff); adults who have been in contact with a case of chickenpox within the past three days; and children awaiting transplantation. The potential benefits and risks of vaccinating immunocompromised patients should be assessed on a case by case basis.

Incidence of herpes zoster, 1997-2002

We estimated age-specific herpes zoster (HZ) incidence rates in the Kaiser Permanente Northwest Health Plan (KPNW) during 1997-2002 and tested for secular trends and differences between residents of two states with different varicella vaccine coverage rates. The cumulative proportions of 2-year-olds vaccinated increased from 35% in 1997 to 85% in 2002 in Oregon, and from 25% in 1997 to 82% in 2002 in Washington. Age-specific HZ incidence rates in KPNW during 1997-2002 were compared with published rates in the Harvard Community Health Plan (HCHP) during 1990-1992. The overall HZ incidence rate in KPNW during 1997-2002 (369/100,000 person-years) was slightly higher than HCHP's 1990-1992 rate when adjusted for age differences. For children 6-14 years old, KPNW's rates (182 for females, 123 for males) were more than three times HCHP's rates (54 for females, 39 for males). This increase appears to be associated with increased exposure of children to oral corticosteroids. The percentage of KPNW children exposed to oral corticosteroids increased from 2.2% in 1991 to 3.6% in 2002. Oregon residents had slightly higher steroid exposure rates during 1997-2002 than Washington residents. There were significant increases in HZ incidence rates in Oregon and Washington during 1997-2002 among children aged 10-17 years, associated with increased exposure to oral steroids.

Successful Vaccination Against Varicella Zoster Virus Prior to Kidney Transplantation

BACKGROUND

In recent years we have observed a number of severe complications of primary varicella-zoster virus (VZV) infections after adult kidney transplantation. We questioned how many patients on the waiting list for kidney transplantation had not been protected against VZV and whether patients with renal insufficiency would be able to develop a specific immune response upon VZV vaccination.

METHODS

We examined the VZV antibody titer of 280 patients on the kidney transplant waiting list. Seronegative kidney transplant candidates were vaccinated twice with a live attenuated varicella vaccine at an interval of 6 weeks.

CONCLUSIONS

Approximately 3% of patients on the waiting list were seronegative for VZV. Vaccination induced no side effects and resulted in a positive serologic response in most patients.

[Rationale for vaccinations against chickenpox]

The article presents epidemiological situation of smallpox in them world and in Poland. On the basis of registered numbers of cases, as well as estimated numbers of complications problem of vaccination programs is analyzed. Strategy of general vaccination of children vs. Vaccination of risk groups is discussed.

Varicella zoster virus vaccination policies and surveillance strategies in Europe

The incorporation of varicella zoster virus (ZVV) vaccination in childhood immunisation schedules is becoming an increasingly common option in Europe. The current study forms part of the European Sero-Epidemiology Network 2 (ESEN2) organisational analysis for VZV and describes current passive immunisation policies, as well as current and proposed active immunisation strategies, and existing surveillance systems for diseases caused by the varicella zoster virus in ESEN countries. A questionnaire was compiled and distributed to 23 participating countries. A VZV vaccine is currently licensed in 14 of the 20 participating ESEN countries. Germany is the only country to have incorporated VZV vaccination into its routine childhood immunisation programme. Three further countries currently recommend vaccination of children against VZV and five countries are also considering introducing routine immunisation against VZV for children. However, of the eight countries with or considering introducing childhood VZV immunisation, only six have case-based mandatory notification of varicella, and only two countries have primary care surveillance data available for herpes zoster.

Comparison of varicella history with presence of varicella antibody in refugees

OBJECTIVE

To compare history of varicella with presence of varicella antibody in refugees and to determine the number of unnecessary doses of varicella vaccine administered to refugee children > or =7 years of age.

METHODS

Cross-sectional study of refugees > or =7 years of age evaluated between July 2000 and October 2002 by the Refugee Health Assessment Program at Boston Medical Center. We recorded age, sex, region of origin, varicella history, and results of serologic testing for presence of varicella antibodies.

RESULTS

Eighty-eight percent of individuals with a positive history of clinical varicella had varicella antibody; 65% of those with negative history had varicella antibody. The positive predictive value of a history of clinical varicella was 88%. The negative predictive value of a negative history was 39%.

CONCLUSION

History of varicella was not a reliable predictor of presence or absence of varicella antibody in refugees. Strategies to protect individuals with negative histories of clinical varicella include immediate immunization or serotesting followed by immunization of susceptible individuals. Relying on positive histories of clinical varicella may leave some individuals susceptible to varicella and impede efforts to eliminate varicella in the US.

[Varicella-zoster virus infections]

The primary infection with varicella-zoster virus (VZV) is manifest clinically as varicella. It is a common very contagious disease, normally appearing in childhood. VZV is a ubiquitous virus with a high prevalence. Clinically it is characterized by pleomorphic skin lesions. Normally antiviral therapy is necessary only in severe cases, in adults or in immunosuppressed patients. Herpes zoster, also caused by (VZV), is a neurodermal disease representing the endogenous relapse of the primary varicella infection. Herpes zoster is characterized by lesions concentrated in the innervation region of a cranial or spinal nerve. One of the most feared manifestations of herpes zoster is pain. Several antiviral drugs are approved and many studies have shown that antiviral therapy, started early in the course of disease, can significantly reduce risk and duration of postherpetic neuralgia in elderly patients. Therefore, antiviral therapy in combination with an adequate pain management should be given to all elderly patients as soon as herpes zoster is diagnosed.

An economic evaluation of varicella vaccination in Italian adolescents

An economic evaluation was performed to assess five varicella vaccination scenarios targeted to 11-year-old Italian adolescents. The scenarios were: "compulsory vaccination" of all adolescents, recommended vaccination of susceptible adolescents on the basis of an "anamnestic screening", a "blood test" or a combination of both ("both tests") and vaccination of adolescents in the private sector, at the parents' charge ("private vaccination"). Probabilities and unit costs were taken from published sources and experts opinion. The accuracy of the anamnestic screening (81.6% sensitivity and 87.3% specificity) was derived from a separate descriptive study among 344 Italian adolescents. The costs and benefits of each scenario were simulated using a Markov model and cost-effectiveness, budget-impact and cost-benefit analyses were conducted. Of all considered scenarios, "both tests" and "anamnestic screening" were the most appealing options with an estimated net direct cost of 5058 and 8929 per life-year gained (compared to no vaccination) versus 14,693-42,842 for the other scenarios. These two scenarios further resulted in substantial net savings for society (over 600,000 per cohort, BCR: 2.17). The need for a serological confirmation was highly dependent on the sensitivity of the anamnestic screening, which is believed to increase once such a program is launched. For practical considerations, "anamnestic screening" seems to be the most convenient option.

Papillomviruserkrankungen

Papillomaviruses are prevalent throughout the world. They can cause warts or papillomas. Some papillomaviruses are also involved in the pathogenesis of malignant tumors. Cutaneous and anogenital warts are the most frequent viral disease of the skin. The incidence of verrucae vulgaris and condylomata is estimated to be 7-10% in the European population and 1% in the American population. HPV infections can be verified by clinical examination, cytology and histology, detection of antibodies, molecular techniques and directly via viral structures. Antibodies against HPV are considered markers for prolonged infection and cumulatively high expression of viral particles since they persist with low titers years after a lesion has resolved. Sensitivity only reaches 50-60% even in HPV DNA-positive patients. Serodiagnosis does not appear to be appropriate for routine practice. No virustatic treatment exists. Depending on wart-specific factors, compliance of the patient, and experience of the attending therapist, all ablative, chemodestructive or novel immuno modulatory procedures are comparable. However, there are enormous differences in price and effort required for treatment, which should be considered when choosing the method.