[Summary of the multidisciplinary guideline 'Varicella']

The multidisciplinary guideline 'Varicella' provides guidelines for diagnosis, therapy, and prevention of chickenpox. At the first pregnancy check, patients should be questioned about previous chickenpox; in case of a negative or doubtful history varicella zoster virus (VZV) serology is indicated. VZV antibody determination is also indicated in patients considered for immunosuppressive therapy and for healthcare workers with a negative VZV history who are in contact with immunocompromised patients. Administration of VZV immunoglobulin within 96 hours following VZV contact can mitigate the infection in pregnant women and patients with T-cell deficiency. VZV immunoglobulin treatment should be considered for newborn infants of mothers who developed chickenpox in the period from five days before to two days after delivery. Antivirals can reduce the severity of infection and are safe during pregnancy. Varicella vaccine protects against chickenpox, but is contraindicated in immunocompromised patients and pregnant women.

[Herpes zoster and its prevention]

The mean herpes zoster incidence in Japan was 4.15/1,000 person-years and was 5.23-7.84/1,000 person-years among those 50 years old and older. One in three persons experiences herpes zoster before age 80, indicating how common it is. The Oka varicella vaccine was developed to prevent varicella in healthy and immunocompromized children and is now used to prevent varicella in 20 million people worldwide. Contact with varicella patients and Oka varicella vaccine are reported to augment varicella-zoster virus immunity in adults and the elderly. Oxman et al. have shown that Oka varicella vaccine prevents herpes zoster and postherpetic neuralgia (PHN) in the elderly. Oka varicella vaccine is approved to prevent herpes zoster and PHN in the elderly in USA and Europe. We review the relationship between varicella/Oka varicella vaccine and herpes zoster, the study by Oxman et al., and the need to introduce this new application of Oka varicella vaccine in Japan.

Immunogenicity and Reactogenicity of a Single Dose of Live Attenuated Varicella Vaccine and a Booster Dose of Measles–Mumps–Rubella Vaccine Given Concomitantly at 12 years of Age

Universal varicella-zoster virus (VZV) childhood vaccination is still debated, but adult chickenpox may be severe. It could be prevented by vaccination of seronegative adolescents. This study aimed to determine the feasibility of coadministration of a VZV vaccine and the measles-mumps-rubella (MMR) booster at 12 y of age. Guardians of 1231 12-y-old pupils where asked about the history of chickenpox in their children. 190 had no chickenpox history and 12 of 62 of them lacked VZV antibodies. Additional history-negative children were also recruited. 199 history-positive children received only MMR and 98 history-negative children received an MMR vaccine and a VZV vaccine. Serum samples were drawn before vaccination and after 8 weeks. Viral antibodies were measured by immunofluorescence (VZV) and enzyme-linked immunosorbent assays (VZV, MMR). All 184 history-positive children tested had VZV antibodies. 17/89 VZV-vaccinated and tested children (19%) lacked VZV antibodies before vaccination. 12 (71%) seroconverted after 1 dose. Cell-mediated immunity (CMI) against varicella was tested in 3/5 children who did not seroconvert after 1 dose of VZV vaccine. They seroconverted after a second dose and had measurable CMI. VZV vaccination did not affect the MMR response and there were no severe side-effects. A history of varicella infection, as reported by the guardian, is reliable, but a negative history was incorrect in 81% of the cases. This population of 12-y-old children may require 2 doses of VZV vaccine, at least when given simultaneously with the MMR vaccine.

Use of combination measles, mumps, rubella, and varicella vaccine: recommendations of the Advisory Committee on Immunization Practices (ACIP)

This report presents new recommendations adopted in June 2009 by CDC's Advisory Committee on Immunization Practices (ACIP) regarding use of the combination measles, mumps, rubella, and varicella vaccine (MMRV, ProQuad, Merck & Co., Inc.). MMRV vaccine was licensed in the United States in September 2005 and may be used instead of measles, mumps, rubella vaccine (MMR, M-M-RII, Merck & Co., Inc.) and varicella vaccine (VARIVAX, Merck & Co., Inc.) to implement the recommended 2-dose vaccine schedule for prevention of measles, mumps, rubella, and varicella among children aged 12 months-12 years. At the time of its licensure, use of MMRV vaccine was preferred for both the first and second doses over separate injections of equivalent component vaccines (MMR vaccine and varicella vaccine), which was consistent with ACIP's 2006 general recommendations on use of combination vaccines (CDC. General recommendations on immunization: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2006;55;[No. RR-15]). Since July 2007, supplies of MMRV vaccine have been temporarily unavailable as a result of manufacturing constraints unrelated to efficacy or safety. MMRV vaccine is expected to be available again in the United States in May 2010. In February 2008, on the basis of preliminary data from two studies conducted postlicensure that suggested an increased risk for febrile seizures 5-12 days after vaccination among children aged 12-23 months who had received the first dose of MMRV vaccine compared with children the same age who had received the first dose of MMR vaccine and varicella vaccine administered as separate injections at the same visit, ACIP issued updated recommendations regarding MMRV vaccine use (CDC. Update: recommendations from the Advisory Committee on Immunization Practices [ACIP] regarding administration of combination MMRV vaccine. MMWR 2008;57:258-60). These updated recommendations expressed no preference for use of MMRV vaccine over separate injections of equivalent component vaccines for both the first and second doses. The final results of the two postlicensure studies indicated that among children aged 12--23 months, one additional febrile seizure occurred 5-12 days after vaccination per 2,300-2,600 children who had received the first dose of MMRV vaccine compared with children who had received the first dose of MMR vaccine and varicella vaccine administered as separate injections at the same visit. Data from postlicensure studies do not suggest that children aged 4--6 years who received the second dose of MMRV vaccine had an increased risk for febrile seizures after vaccination compared with children the same age who received MMR vaccine and varicella vaccine administered as separate injections at the same visit. In June 2009, after consideration of the postlicensure data and other evidence, ACIP adopted new recommendations regarding use of MMRV vaccine for the first and second doses and identified a personal or family (i.e., sibling or parent) history of seizure as a precaution for use of MMRV vaccine. For the first dose of measles, mumps, rubella, and varicella vaccines at age 12--47 months, either MMR vaccine and varicella vaccine or MMRV vaccine may be used. Providers who are considering administering MMRV vaccine should discuss the benefits and risks of both vaccination options with the parents or caregivers. Unless the parent or caregiver expresses a preference for MMRV vaccine, CDC recommends that MMR vaccine and varicella vaccine should be administered for the first dose in this age group. For the second dose of measles, mumps, rubella, and varicella vaccines at any age (15 months-12 years) and for the first dose at age >or=48 months, use of MMRV vaccine generally is preferred over separate injections of its equivalent component vaccines (i.e., MMR vaccine and varicella vaccine). This recommendation is consistent with ACIP's 2009 provisional general recommendations regarding use of combination vaccines (available at http://www.cdc.gov/vaccines/recs/provisional/downloads/combo-vax-Aug2009-508.pdf), which state that use of a combination vaccine generally is preferred over its equivalent component vaccines.

[Chickenpox in Poland in 2008]

In 2008, 129.662 cases ofchickenpox were reported in Poland. The incidence 340.2 per 100,000 was lower compared to 2007 (420.2) and to the median incidence in 2002-2006 (370.7). Children 5-9 year old were the most affected age group - 3057.1 per 100 000. Of 129 662 cases, 800 (0.62%) were hospitalized and no deaths attributed to chickenpox were reported.

[Varicella-associated morbidity in children undergoing chemotherapy for acute lymphoblastic leukaemia]

INTRODUCTION

In children with cancer, varicella can be complicated by visceral dissemination with a risk of fatal outcome, especially in children with acute lymphoblastic leukaemia (ALL). Immunoprophylaxis and antiviral therapy have reduced the mortality, but the morbidity remains significant and is explored here in a cohort of children with ALL.

MATERIAL AND METHODS

Among 67 children diagnosed with ALL during 1992-2007, 22 were seronegative for varicella-zoster virus (VZV) at the time of diagnosis. Patient records were reviewed to describe varicella exposures, eruptions and vaccinations during chemotherapy (24-30 months) and the following six months of immune recovery.

RESULTS

Fifteen exposures were recognised in eight children and were managed with oral acyclovir prophylaxis; three resulted in clinical infection. Adoption of brief prophylaxis in the second week of incubation has not - so far - increased the infection rate (one in six versus two in nine). A further six varicella cases occurred without recognised exposure. All nine eruptions (in eight children) were uncomplicated but entailed hospitalisation days for intravenous therapy with acyclovir and loss of chemotherapy days. Seven children were VZV-vaccinated during maintenance chemotherapy; none developed varicella or zoster later in the course.

CONCLUSION

Despite protective isolation and prophylactic treatment, seronegative children with ALL have a high risk of varicella during or shortly after chemotherapy. We recommend that susceptible siblings should be vaccinated at the time of diagnosis and the child should receive vaccination once oral maintenance chemotherapy has been initiated.

[Safety and immunogenicity of lyophilized live attenuated domestic varicella vaccine]

OBJECTIVE

To evaluate the safety and immunogenicity of the lyophilized live attenuated domestic varicella vaccine of Oka strain in Zhejiang province.

METHODS

785 susceptible children aged 1-13 years, who had no history of VZV infection and had not been immunized, were observed. RESULTS The results showed that 2.29% children had adverse reactions after 30 mins of inoculation, 3.69% children had adverse reactions after 4 hours, 3.82% children had adverse reactions after 24 hours, 1.78% children had adverse reactions after 48 hours, 0.25% children had adverse reactions after 72 hours, no adverse reactions were observed after six weeks. There were 3.82% children had fever, The incidence rate of other adverse reactions such as swell and scleroma were low. The vaccine had high sero-converson rate.

CONCLUSION

The results showed that it has good safety and immunogenicity of the live attenuated domestic varicella vaccine.

[Case-control study on the relationship between varicella vaccine inoculation and varicella morbidity]

OBJECTIVE

To analyse and find out the influence of varicella vaccine inoculation to varicella morbidity.

METHODS

The case-control study was conducted. During October 1st 2006 to July 31st 2007, 193 varicella cases were identified, and 342 control subjects were matched.

RESULTS

1. The proportion of nonvaccinated in case group was higher than that of control group (odds ratio 1.49, 95% confidence interval 0.99-2.24, P=0.043). 2. The morbidity to the people who received one dose varicella vaccine was obviously higher than that of people who reiceived more than 2 dose (odds ratio 3.04, 95% confidence interval 1.25-7.72, P=0.007). 3. Significant differences were not observed between the domestic vaccine and the impoted vaccine (odds ratio 1.38, 95% confidence interval 0.53-3.71 P=0.483). 4. Clinical symptom of the vaccine was lighter than that of the unvaccinated, and rash was not typical.

CONCLUSION

1. Inoculation varicella vaccine was effective measures to prevent varicella. 2. The risk to get varicella of one-dose vaccinated was higher than that of more than 2-dose vaccinated. 3. The effectiveness of domestic varicella vaccine was as high as impoted vaccine. 4. The clinical symptom of varicella would be alleviated if the person had vaccinated.

[Epidemiological characteristic of Varicella and Varicella-Zoster virus genotype in Minhang District of Shanghai]

OBJECTIVE

To describe the epidemiological characteristic of varicella, and to find out the genotype of the prevalent Varicella-Zoster Virus (VZV) in Minhang, Shanghai. Analysis was carried out during Nov. 2007 to Apr 2008.

METHODS

The data collected from the National Diseases Reporting Management System (NDRS) and Provincial Disease Surveillance Point System (DSP). Samples from herpes of patients were also collected to isolate VZV in Vero and Vero-E6 cell lines, then to detected if cytopathic effect (CPE) by PCR, and finally to identify the genotype by sequence analysis.

RESULTS

29 outbreaks of 271 cases occurred in Minhang during Nov. 2007 to Apr. 2008, and attack rate was 0.42% in average. Among the cases, 37 (13.65%) had vaccinated before getting varicella. Most cases occurred in November and December, and clustered in some areas with population migrant frequently. 2 VZV strains were isolated and identified as genotype J.

CONCLUSION

The prevalence of varicella in Minhang was serious. The varicella prevention and control among schools and kindergartens should be strengthened by propaganda and vaccination.

[Effectiveness on post-exposure vaccination of varicella and its influencing factors in elementary schools in Beijing]

OBJECTIVE

To evaluate the effectiveness of post-exposure varicella vaccination in elementary schools in Beijing and to explore its influencing factors.

METHODS

From May to July 2007, varicella cases from 49 elementary schools in 4 districts in Beijing were observed prospectively. The study included 7882 children who were from the same classrooms, same floor or same bungalow areas with the varicella cases. Vaccination status, history on varicella and onset of rashes were collected to calculate the secondary attack rate among those children under observation and then the effectiveness of vaccine was calculated.

RESULTS

The protection rate on post-exposure vaccination among children under observation was 85.26%. The rates were higher when the 1st case had received varicella vaccine before the onset, vaccines were administered soon after the exposure or there were less varicella cases occurred in the schools. For children in the same class, same floor or bungalow with varicella cases before post-exposure vaccination, the average rates of protection by vaccination were 84.26% and 87.06%, respectively. When the 1st case had received varicella vaccine prior to the onset, the post-exposure protection rates reached 92.09% and 93.06%, respectively, higher than that of the case when the 1st case had received no vaccination. When the administration of vaccine right after the occurrence of first varicella case, the rates of the effectiveness of vaccine were 83.09% and 93.02%, both of which were higher than that of vaccine administered after the occurrence of 2 or 3 cases. When the vaccine administration of vaccination combined with the isolation of the already infected cases or within 5 days after the onset of the 1st case, the vaccine effectiveness could reach 86.60% and 92.73%, both were higher than otherwise. However, in those schools that bungalows were used as classrooms but without bus, canteen from school or student lodgings, it seemed that post exposure vaccination was more effective in preventing varicella from occurring.

CONCLUSION

Varicella vaccination after exposure in elementary schools in Beijing was effective in prevention and control of the disease. Immediate administration together with the isolation of cases could maximize the effectiveness of the vaccine.

[Study on epidemiological effect of the freeze-dried attenuated live varicella vaccine]

OBJECTIVE

To evaluate the safety and epidemiological effect of the Freeze-dried Live attenuated varicella vaccine.

METHODS

A random, double-blind control clinical trial was adopted.

RESULTS

In the observation period, the incidence of varicella was 0.8 per thousand in the experimental group and 8.7 per thousand in control group. There was a significant difference (B.P=0.000017). Vaccine effectiveness (VE(%)) was 90.8%, the lower limit of 95%CI was 88.7%.

CONCLUSION

The varicella vaccine produced by Changchun keygen biological products co., Ltd. was safe and effective.

Varicella vaccination in Europe - taking the practical approach

Varicella is a common viral disease affecting almost the entire birth cohort. Although usually self-limiting, some cases of varicella can be serious, with 2 to 6% of cases attending a general practice resulting in complications. The hospitalisation rate for varicella in Europe ranges from 1.3 to 4.5 per 100,000 population/year and up to 10.1% of hospitalised patients report permanent or possible permanent sequelae (for example, scarring or ataxia). However, in many countries the epidemiology of varicella remains largely unknown or incomplete. In countries where routine childhood vaccination against varicella has been implemented, it has had a positive effect on disease prevention and control. Furthermore, mathematical models indicate that this intervention strategy may provide economic benefits for the individual and society. Despite this evidence and recommendations for varicella vaccination by official bodies such as the World Health Organization, and scientific experts in the field, the majority of European countries (with the exception of Germany and Greece) have delayed decisions on implementation of routine childhood varicella vaccination, choosing instead to vaccinate high-risk groups or not to vaccinate at all. In this paper, members of the Working Against Varicella in Europe group consider the practicalities of introducing routine childhood varicella vaccination in Europe, discussing the benefits and challenges of different vaccination options (vaccination vs. no vaccination, routine vaccination of infants vs. vaccination of susceptible adolescents or adults, two doses vs. one dose of varicella vaccine, monovalent varicella vaccines vs. tetravalent measles, mumps, rubella and varicella vaccines, as well as the optimal interval between two doses of measles, mumps, rubella and varicella vaccines). Assessment of the epidemiology of varicella in Europe and evidence for the effectiveness of varicella vaccination provides support for routine childhood programmes in Europe. Although European countries are faced with challenges or uncertainties that may have delayed implementation of a childhood vaccination programme, many of these concerns remain hypothetical and with new opportunities offered by combined measles, mumps, rubella and varicella vaccines, reassessment may be timely.

[Centralized immunization schedules and regional equity of access: an audit among Apulian healthcare workers]

The reform of the Vth Title of the Italian Constitution has given the Regions autonomous power over planning of their immunization programme and immunization calendar. This amendment has federalized Italy's vaccination system and, is justified by epidemiological evidence however casts doubt on its provision of equal rights to health care. The objective of this current study is to gain insight into the opinion of vaccine services officers in the Apulia region on federal immunization and the regional immunization programme. Research was conducted using an anonymous standardized questionnaire to which 302 vaccines services staff responded. 67.4% of respondents believe that the current federal vaccination programme should be maintained, whilst 20.2% believe that the current system should be eradicated and 12.4% believe it should be phased out gradually. The current apulian vaccination calendar provides free and active immunizations for all newborns for the pneumococcal, meningitis C, chickenpox and hepatitis A vaccines. The interviewees believe that the vaccinations provided in the regional immunization programme are very important (average importance out of 10 = 6.1/7). The positive response to the regional vaccination plan given by the health officers explains, at least in part, the conservative attitude tewards federal vaccination plans. It cannot be excluded that sacrificing regional autonomy over vaccination programmes might be considered by the vaccination officers as being responsible for the abandonment of the Region's long established immunization practices. The success of these practices is evident in the case of the Region's Hepatitis A immunization programme where the active provision of this vaccine has drastically reduced the endemicity of the illness in Apulia. These experiences of good practice should be adequately considered in before opting to phase out the current immunisation programme.

Seroprevalence of varicella-zoster virus in Polish population

A varicella zoster virus (VZV) is the first herpesvirus for which a vaccine was developed. Since 1999, the varicella vaccine is licensed in Poland and recommended for use in adults without history of a varicella infection, and in children and young adults with remission of acute leukemia. While serological data is essential to assess the appropriate vaccination programme, we conducted the first in Poland serosurvey on a representative group of Polish population aged 1-19. Serum samples were selected from a serum bank collected in 1995-2004 with a catchment area of the all geographical regions of Poland. A total of 1300 serum samples collected over 9 years (1995-1996, 1998-2004) were selected using a stratified sampling design (stratification by age). Samples were selected, consisting of 100 samples for each 1-year band of age groups 0-9 years, and 40 samples for each 1-year band of age groups 10-19 years. IgG serum antibodies specific to VZV were detected using an indirect enzyme immunoassay and the antibody level was expressed in international units per millilitre (mIU/ml) and was refered to the international standard for VZV immunoglobulin of 50 IU. The overall seroprevalence estimate, adjusted for sampling design for the age group 1-19 was 76.6% (95% CI: 74.6%-78.7%). Seroprevalence correlated closely with age (p<0.0001) and among 18 and 19 year olds reached 95% and 98% respectively. No association was found between gender, rural/urban areas and geographical regions of Poland. For samples collected over the 5 year period (2000-2004), evidence of overall differences in seropositivity over these years was not observed. In Poland VZV vaccination is provided only for a limited group of high risk patients. The possible updates in the immunization program are discussed and the results of the presented study can contribute valuable information to base the vaccination policy decisions.

[Vaccination against chickenpox, shingles and rotavirus-infection]

The Dutch National Immunisation Programme (NIP) has been very successful over the past 50 years. In future, this programme shall not include all new vaccines. Such vaccines can, however, be individually administered. At present there are 3 vaccines available in the Netherlands that have not been included in the NIP to date: against varicella (chickenpox), herpes zoster (shingles) and rotavirus infections. These vaccines are safe and effective. Chickenpox is not always a harmless childhood disease. A chickenpox vaccine is now available as well as a combined vaccine against mumps, measles, rubella and chickenpox. Shingles (herpes zoster) is a common disease in the elderly people. For many patients it is a considerable burden with significant complications, mainly postherpetic neuralgia and herpes zoster ophthalmicus. Vaccination may be considered for people 60 years and older. Rotavirus is much more associated with severe symptoms of diarrhoea than other pathogens. More than 95% of children experience one or more episodes of rotavirus gastroenteritis before their 5th birthday. In the Netherlands about 3400 children are hospitalised each year for rehydration following rotavirus infection. The vaccine is given orally.

Anti-varicella-zoster vaccination in contacts of children receiving antineoplastic chemotherapy: a prospective pilot study

Varicella may be a severe infection in children with malignancy. Varicella vaccination is either not recommended for immunocompromised children or it requires temporary discontinuation of immunosuppression. We prospectively evaluated the feasibility of a varicella vaccination programme of household contacts of varicella-negative children receiving antineoplastic chemotherapy. From April 2004 to April 2005, 207 children were evaluated; in 49 (24 percent) the attending physicians collected no history about previous varicella and performed no serological evaluation before any transfusion. Among the 158 patients with complete history and/or a screening test, 51 (32 percent) were negative, with a total of 110 household contacts eligible for the study. Of these, 13 (12 percent) subjects resulted negative for varicella. In three of them vaccination was not performed due to parental refusal. This study demonstrates the difficulties in implementing a varicella vaccination programme targeting negative household contacts of immunocompromised children. The attitude of paediatric oncologists and parental refusal currently represent the main challenges against the complete success of this strategy in countries where VZV vaccination is not inserted in the general vaccination programme.

Impact of varicella vaccination on health care outcomes in Ontario, Canada: effect of a publicly funded program?

Varicella vaccines have been available for private purchase in Canada since 1998. Ontario introduced publicly funded varicella vaccination in 2004. We assessed the effects of private availability of varicella vaccines and subsequent implementation of a publicly funded vaccination program on varicella-related hospitalizations, emergency department (ED) use, and visits to physicians' offices in Ontario. Rates of hospitalizations, ED use, and office visits decreased 53% (95% CI, 48-58%), 43% (95% CI, 41-44%), and 45% (95% CI, 44-45%) after publicly funded vaccination, compared to only 9% (95% CI, 4-14%), 23% (95% CI, 22-24%), and 29% (95% CI, 28-29%) after private availability. Varicella vaccination is effective at reducing varicella-related health care use, with benefits extending beyond those who receive the vaccine. Publicly funded vaccination programs may be more effective than private vaccine availability.

Simultaneous vaccination of Chinese applicants for a United States immigrant visa

BACKGROUND

Simultaneous vaccination is still uncommon in China, and many Chinese people are quite concerned about the adverse reactions because few data regarding the adverse reactions of simultaneous vaccination in Chinese people have been reported. The objective of this study was to evaluate the safety of simultaneous vaccination and the frequency of adverse reactions following simultaneous vaccinations in Chinese applicants for a United States immigrant visa.

METHODS

We conducted a prospective observational study in 772 applicants receiving required vaccination in Guangdong International Travel Healthcare Center. The vaccines required for vaccination included diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP), adult formulation tetanus and diphtheria toxoids (Td), haemophilus influenzae type-b conjugate vaccine (Hib), oral polio vaccine (OPV), hepatitis B vaccine (HepB), combined measles mumps rubella vaccine (MMR), varicella vaccine (Var), and influenza vaccine (Inf), pneumococcal polysaccharide vaccine (PPV). Data on adverse reactions were collected by questionnaires.

RESULTS

Seven hundred and seventy-two participants have received a total of 2533 doses of different vaccines, and 49.6% of the participants reported adverse reactions within 7 days following vaccination, with 39.8%(307/772) local reactions and 20.2%(156/772) systemic reactions. There were no allergic reactions. Only one vaccinee visited hospital seeking treatment due to fever, and recovered well. The most frequent local reaction was pain at the injection site (260/772, 33.7%), especially in the case of PPV vaccination, 61.2% (63/103) vaccinees who received PPV complained of pain at the site of injection, while the most frequent systemic reaction was fever (84/772, 10.9%). Pain and fever were all temporary reactions and resolved within 72h. Logistic regression analysis found that females experienced adverse reactions more frequently than males [(local reactions: female:male=41.7%(187/448):37%(120/324), p=0.04; systemic reactions: female:male=23%(103/448):16.4%(53/324), p=0.026)]; vaccinees given PPV developed local reactions more frequently than those receiving the other vaccines. The number of vaccines has no significant influence on adverse reactions.

CONCLUSIONS

Simultaneous vaccination is feasible for Chinese applicants for a United States immigrant visa because the adverse reactions are mostly mild and temporary. Our data suggest that more Chinese people should be encouraged to receive simultaneous vaccination if the time is limited so as to reduce the risk of vaccine-preventable diseases.

[Priorix Tetra: a new combined vaccine against measles, rubella, mumps and varicella]

Varicella is an infectious disease caused by a virus of the herpes virus family (VZV) affecting predominantly the pediatric age. Varicella is considered a mild disease, but in some cases, mainly in immunocompromised subjects, it can evolve towards complicated cases, even fatal. In immunocompetent subjects, however, serious complications can also arise, such as cutaneous bacterial superinfections, pneumonia, conjunctivitis or corneal infections and central nervous system (CNS) complications. The rate of hospitalization, even in developed countries, is high. Due to the epidemiological relevance of varicella, the availability of a live, attenuated, safe and effective vaccine, has prompted an international debate on the opportunity of extensive infant varicella vaccination, that could be overcome by the introduction of the combined tetravalent vaccines against measles, mumps, rubella and varicella (MMRV). Priorix Tetra, a new quadrivalent MMRV vaccine produced by GlaxoSmithKline, has demonstrated high immunogenicity, comparable to that of the separate vaccines (Priorix and Varilrix) in addition to a favorable tolerability and safety profile. This review summarizes the epidemiology of measles, mumps, rubella and varicella in Italy, encompassing the rationale for the introduction of varicella vaccination and describes the immunological, clinical and safety profile of Priorix Tetra.

[Incorporation of varicella-zoster virus vaccination in childhood immunization schedules]

Varicella is a highly infectious disease caused by the varicella-zoster virus (VZV). Usually chickenpox is a self-limiting and relatively mild disease of childhood, although it is frequently more severe with significant complications, and less often, is responsible for case fatalities. Varicella disease is more severe and its complications are more frequent and severe amongst high risk groups (neonates, pregnant women and immunocompromised patients). After the initial infection, the VZV remains dormant in dorsal root ganglia and may reactivate with declining cellular immunity to cause herpes zoster, particularly in the elderly and immunocompromised. Varicella vaccine is an effective preventive tool for decreasing the burden attributable to the disease and its complications. The incorporation of VZV vaccination in childhood immunization schedules was restricted until recently. Nowadays, many countries implement it. A few years ago, the Israeli Ministry of Health recommended adding the vaccine to the childhood immunization schedule. This was not enacted because of budgetary constraints. This is due in September this year, together with an additional dose of pertussis vaccine for pupils in 8th grade. During the next few years there are plans for other new vaccines, that are being incorporated in the routine vaccination programs in developed countries, also to be added to the Israeli childhood immunization schedule: the conjugated pneumococcal vaccine, the vaccine against the rotavirus and the HPV vaccine.

Vaccines for post-exposure prophylaxis against varicella (chickenpox) in children and adults

BACKGROUND

Live attenuated varicella vaccines for the prevention of varicella (chickenpox) has been demonstrated both in randomised controlled trials (RCTs) and in population-based immunisation programmes in countries such as the United States. However, many countries do not routinely immunise children against varicella, and exposures continue to occur. Although the disease is often mild, complications such as secondary bacterial infection, pneumonitis and encephalitis occur in about 1% of cases, usually leading to hospitalisation. The use of varicella vaccine in persons who have recently been exposed to the varicella zoster virus has been studied as a form of post-exposure prophylaxis (PEP).

OBJECTIVES

To assess the efficacy and safety of vaccines for use as PEP for the prevention of varicella in children and adults.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2008, Issue 1); MEDLINE (1966 to February 2008); and EMBASE (January 1990 to February 2008).

SELECTION CRITERIA

RCTs and quasi-RCTs of varicella vaccine for PEP compared with placebo or no intervention. The outcome measures were efficacy in prevention of clinical cases and/or laboratory-confirmed clinical cases and adverse effects following vaccination.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and analysed data using Review Manager software.

MAIN RESULTS

Three studies involving 110 healthy children who were siblings of household contacts were identified as suitable for inclusion. The studies varied in quality, study design, vaccine used, and outcomes measured and, as such, were not suitable for meta-analysis. Overall, 13 out of 56 vaccine recipients (18%) developed varicella compared with 42 out of 54 placebo (or no vaccine) recipients (78%). Of the vaccine recipients who developed varicella, the majority only had mild disease (with less than 50 skin lesions). In the three studies, most subjects received PEP within three days following exposure; too few subjects were vaccinated four to five days post exposure to ascertain the efficacy of vaccine given more than three days after exposure. No included studies reported on adverse events following immunisation.

AUTHORS' CONCLUSIONS

These small trials suggest varicella vaccine administered within three days to children following household contact with a varicella case reduces infection rates and severity of cases. No RCTs for adolescents or adults were identified. However safety was not adequately addressed.

[Best practices in prevention public health]

It describes the ten best practices implemented by the Department for Prevention dell'AUSL 7 of Ragusa in Sicily, with particular reference to the draft coverage against chickenpox vaccine made in two cohorts: new born to 15 months of age (80%) and adolescents at 12 years of age (50%).

[Safety and efficacy of varicella vaccine in healthy children--one year follow-up]

BACKGROUND AND AIMS

to assess the safety and efficacy of varicella virus vaccine after administration of one dose.

MATERIAL AND METHODS

106 healthy children (59 girls, 47 boys), with no history of varicella, were vaccinated between March and April 2004. The subjects were aged 9 months to 12 years (median 47 months). Antibody concentrations were determined twice: after 46 days (test 1) and after 13 months (test 2). The concentration of IgG-antibody against VZV was measured using the ELISA IgG Test kit (Genzyme Virotech, Germany).

RESULTS

no local and/or general symptoms were observed after vaccination. Effectiveness of vaccination was 98.1%. Two vaccinated children with borderline values (antibody concentrations were 9-11 VE) developed a mild form of varicella 13 months after vaccination. Protective levels of antibody concentrations were found in 95 out of 106 children (89.6%) 46 days after vaccination and in 72 out of 104 children (69.2%) 13 months after vaccination. The mean antibody concentration 46 days after vaccination (test 1) was 21.3VE (6.7-43.8 VE), and 13 months after vaccination (test 2) was 17.2VE (4.9-38.4) i.e. significantly lower (p<0.001). In both tests no significant statistical differences were noted between the post-vaccination concentrations in girls (VE1-20.6 and VE2-22.2) and boys ( VE2-17.3 and VE2-17.0). Neither the subjects' age nor sex at the time of vaccination correlated with the decreased antibody concentrations 13 months after vaccination. In 27.4% of children statistically significant lowering of antibody concentration was detected 13 months after vaccination (lp < 0.0001).

CONCLUSIONS

the varicella vaccine (Varilrix) was found to be safe and its effectiveness was 98.1% after 13 months. Only in 2 children mild clinical sings of varicella occurred. However, because of a statistically significant lowering of antibody concentration 13 months after the vaccination, a two dose regimen of varicella vaccination should be recommended.

Update: recommendations from the Advisory Committee on Immunization Practices (ACIP) regarding administration of combination MMRV vaccine

On February 27, 2008, new information was presented to the Advisory Committee on Immunization Practices (ACIP) regarding the risk for febrile seizures among children aged 12-23 months after administration of the combination measles, mumps, rubella, and varicella (MMRV) vaccine (ProQuad, Merck & Co., Inc., Whitehouse Station, New Jersey). This report summarizes current knowledge regarding the risk for febrile seizures after MMRV vaccination and presents updated ACIP recommendations that were issued after presentation of the new information. These updated recommendations remove ACIP's previous preference for administering combination MMRV vaccine over separate injections of equivalent component vaccines (i.e., measles, mumps, and rubella [MMR] vaccine and varicella vaccine).

Another injection?

A national vaccination programme against chickenpox has been recommended by researchers, but its implementation may be difficult.

Varicella surveillance and policy in the United States and Minnesota

An estimated 82.7% of Minnesota children 19 months to 35 months of age were vaccinated against varicella in 2006 as a result of accepted national recommendations, provider education, and vaccination mandates. Despite the wide-ranging acceptance of vaccination, outbreaks of varicella continue to occur in schools and childcare centers, even those with a high percentage of vaccinated children. As a result, national recommendations have been modified to include a universal second dose of vaccine. Starting in September 2008, students entering kindergarten or 7th grade in Minnesota will be required to provide documentation of having had 2 doses of varicella vaccine, a history of the disease, or legal exemption.

[Combined vaccine against measles, mumps, rubella and varicella and recommendations for varicella immunization in Italy?]

In Italy, the whole population is affected by chickenpox especially in infancy with an important burden of disease. Vaccination is recommended for susceptible adolescents and adults, but the offer is different in different regions. The availability of a combined vaccine against measles, mumps, rubella and varicella could allow an easier introduction of VZV prophylaxis in infants immunization schedules without increasing the number of injections and of accesses to Health Services.

Solid organ transplantation and response to vaccination

Although early vaccination is recommended in candidates for solid organ transplantation (SOT), consensual protocols do not yet exist. We applied an SOT vaccination protocol in the Hospital Clinic of Barcelona (Spain). Serology was performed before and after vaccination and compliance with the vaccination schedule was analysed during the period 2003-2004. Two hundred and thirty seven patients (72.9% male; mean age 56.31 years, range 19-72) were included. A total of 74.5% of subjects susceptible to hepatitis B virus infection responded to hepatitis B vaccination. Most patients were protected against hepatitis A, varicella, measles, rubella and mumps. The vaccine protocol was implemented satisfactorily and the administration of two courses of hepatitis B vaccine was shown to be effective.

Combination vaccine use and vaccination quality in a managed care population

OBJECTIVE

To evaluate the impact of a pentavalent combination vaccine on childhood immunization coverage rates and timeliness within a managed care organization.

STUDY DESIGN

Retrospective matched-cohort analysis of encounter data from administrative claims and a state immunization registry.

METHODS

Children were stratified into 2 demographically matched cohorts (combination and reference), based on receipt of the DTaP/HepB/IPV combination vaccine. Children were followed until 24 months of age, and coverage rates and on-time rates were assessed. Outcomes were measured for the HEDIS Combination 2 vaccine series (4 doses of diphtheria/tetanus/pertussis, 3 doses of polio, 1 dose of measles/mumps/rubella, 3 doses of Haemophilus influenzae type b, 3 doses of hepatitis B, and 1 dose of varicella) and each vaccine series individually.

RESULTS

Children in the combination cohort were significantly more likely to be fully vaccinated for the HEDIS Combination 2 series by 2 years of age and to be vaccinated within the recommended age ranges. In the combination cohort 86.9% (752/865) of patients were fully covered compared with only 74.1% (641/865) of the reference cohort (P <.001). In the combination cohort 45.2% (391/865) of patients received vaccinations on time versus 37.5% (324/865) of the reference cohort, P = .001.

CONCLUSIONS

Receipt of DTaP/HepB/IPV was associated with improved coverage and age-appropriate immunization in a managed care population.

Universal mass vaccination against varicella in Germany using an MMRV combination vaccine with a two-dose schedule: an economic analysis

Former economic analyses have shown that universal mass vaccination of infants against varicella using a one-dose schedule is cost-saving in Germany. In July 2006, an MMRV combination vaccine has been approved in Germany which shall be given in a two-dose schedule. We re-analysed our former analysis with the EVITA model in order to prove whether our former conclusion that universal mass vaccination against varicella is cost-saving is still valid when using a two-dose schedule vaccine. Indeed we found that universal mass vaccination of infants against varicella with a two-dose vaccine is cost-saving from societal as well as from health care perspective.

Safety and Immunogenicity of Early Vaccination with Two Doses of Tetravalent Measles-Mumps-Rubella-Varicella (MMRV) Vaccine in Healthy Children from 9 Months of Age

BACKGROUND

This open, randomized, controlled study [208136/018] assessed the safety and immunogenicity of early vaccination with an experimental tetravalent measles-mumps-rubella-varicella (MMRV) vaccine (GlaxoSmithKline Biologicals) compared to concomitant administration of separate licensed MMR (Priorix) and varicella (Varilrix) vaccines (MMR+V).

METHODS

Vaccines were administered as a two-dose course in healthy children at 9 and 12 months of age (N = 153 in the MMRV group and N = 146 in the MMR+V group).

RESULTS

The incidence of fever of any intensity (axillary temperature > or = 37.5 degrees C) during the 15 days of follow-up post-dose 1 was higher in the MMRV group than in the MMR+V group (48.3% vs 25.7%, respectively) but was low in both groups post-dose 2 (20.3% and 22.1%, respectively). The incidence of fever > 39.0 degrees C and the incidence of solicited local symptoms (pain, redness, swelling) were low ( < or = 5.3% and < or = 13.7%, respectively) in the two groups after each vaccine dose. Seroconversion rates were similar in the two groups for all vaccine antigens after each vaccine dose and were > or = 99.2% for each antigen post-dose 2. Anti-measles GMT was higher in the MMRV group than in the MMR+V group after the first vaccine dose. After the second dose, slight to moderate increases in measles, mumps and rubella antibody titers and a substantial increase in varicella antibody titer were seen in both groups, leading to higher GMTs in the MMRV group compared with the MMR+V group for measles, mumps and varicella. Anti-rubella antibody GMTs were similar in the two groups post-dose 2.

CONCLUSION

Early vaccination with two doses of this experimental MMRV vaccine at 9 and 12 months of age was well-tolerated and at least as immunogenic as two doses of separate licensed MMR and varicella vaccines.

Immunogenicity and safety of a tetravalent measles-mumps-rubella-varicella vaccine co-administered with a booster dose of a combined diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus-Haemophilus influenzae type b conjugate vaccine in healthy children aged 12-23 months

This study was undertaken to assess the co-administration of an experimental measles-mumps-rubella-varicella vaccine (MMRV, GlaxoSmithKline Biologicals) with a combined diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus-Haemophilus influenzae type b conjugate (DTPa-HBV-IPV/Hib) vaccine in healthy children. Healthy children aged 12-23 months (N = 451) were randomised to one of three parallel groups to receive one dose of MMRV vaccine co-administered with a booster dose of DTPa-HBV-IPV/Hib vaccine (co-administration group), or one dose of MMRV vaccine alone (MMRV group), or a booster dose of DTPa-HBV-IPV/Hib vaccine alone (DTPa-HBV-IPV/Hib group). No differences in seroconversion rates for measles (>95%), mumps (>80%), rubella (>99%) and varicella (>98%) were seen between the co-administration group and the MMRV group. No differences in geometric mean titres (GMTs) were observed between the two groups with the exception of anti-measles titres, which were observed to be higher in the MMRV group than in the co-administration group (4,419.2 vs. 3,441.8 mIU/ml respectively). Immune response to the booster dose of DTPa-HBV-IPV/Hib vaccine was observed to be similar in the co-administration group and the DTPa-HBV-IPV/Hib group. Co-administration of the MMRV vaccine with a booster dose of DTPa-HBV-IPV/Hib vaccine was well-tolerated and did not exacerbate the reactogenicity profile of either vaccine. In summary, GlaxoSmithKline Biologicals' experimental MMRV vaccine was immunogenic and well-tolerated when administered with a booster dose of DTPa-HBV-IPV/Hib vaccine during the second year of life. The ability to co-administer the MMRV vaccine at the same time as other routine childhood immunisation vaccines could increase compliance with varicella vaccination in countries where this vaccine is already recommended and may facilitate implementation of varicella vaccination elsewhere.