Clinical trials of varicella vaccine in healthy adolescents and adults

Review Article: vaccination for patients with inflammatory bowel disease during the COVID-19 pandemic

BACKGROUND

Poor immune responses are frequently observed in patients with inflammatory bowel disease (IBD) receiving established vaccines; risk factors include immunosuppressants and active disease.

AIMS

To summarise available information regarding immune responses achieved in patients with IBD receiving established vaccines. Using this information, to identify risk factors in the IBD population related to poor vaccine-induced immunity that may be applicable to vaccines against COVID-19.

METHODS

We undertook a literature review on immunity to currently recommended vaccines for patients with IBD and to COVID-19 vaccines and summarised the relevant literature.

RESULTS

Patients with IBD have reduced immune responses following vaccination compared to the general population. Factors including the use of immunomodulators and anti-TNF agents reduce response rates. Patients with IBD should be vaccinated against COVID-19 at the earliest opportunity as recommended by International Advisory Committees, and vaccination should not be deferred because a patient is receiving immune-modifying therapies. Antibody titres to COVID-19 vaccines appear to be reduced in patients receiving anti-TNF therapy, especially in combination with immunomodulators after one vaccination. Therefore, we should optimise any established risk factors that could impact response to vaccination in patients with IBD before vaccination.

CONCLUSIONS

Ideally, patients with IBD should be vaccinated at the earliest opportunity against COVID-19. Patients should be in remission and, if possible, have their corticosteroid dose minimised before vaccination. Further research is required to determine the impact of different biologics on vaccine response to COVID-19 and the potential for booster vaccines or heterologous prime-boost vaccinations in the IBD population.

Canadian Association of Gastroenterology Clinical Practice Guideline for Immunizations in Patients With Inflammatory Bowel Disease (IBD)-Part 1: Live Vaccines

Background & Aims

Patients with inflammatory bowel disease (IBD) may be at increased risk of some vaccine-preventable diseases. The effectiveness and safety of vaccinations may be altered by immunosuppressive therapies or IBD itself. These recommendations, developed by the Canadian Association of Gastroenterology and endorsed by the American Gastroenterological Association, aim to provide guidance on immunizations in patients with inflammatory bowel disease. This publication focused on live vaccines.

Methods

Systematic reviews evaluating the efficacy, effectiveness, and safety of vaccines in patients with IBD, other immune-mediated inflammatory diseases, and the general population were performed. Critical outcomes included mortality, vaccine-preventable diseases, and serious adverse events. Immunogenicity was considered a surrogate outcome for vaccine efficacy. Certainty of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. Key questions were developed through an iterative process and voted on by a multidisciplinary panel. Recommendations were formulated using the Evidence-to-Decision framework. Strong recommendation means that most patients should receive the recommended course of action, whereas a conditional recommendation means that different choices will be appropriate for different patients.

Results

Three good practice statements included reviewing a patient’s vaccination status at diagnosis and at regular intervals, giving appropriate vaccinations as soon as possible, and not delaying urgently needed immunosuppressive therapy to provide vaccinations. There are 4 recommendations on the use of live vaccines. Measles, mumps, rubella vaccine is recommended for both adult and pediatric patients with IBD not on immunosuppressive therapy, but not for those using immunosuppressive medications (conditional). Varicella vaccine is recommended for pediatric patients with IBD not on immunosuppressive therapy, but not for those using immunosuppressive medications (conditional). For adults, recommendations are conditionally in favor of varicella vaccine for those not on immunosuppressive therapy, and against for those on therapy. No recommendation was made regarding the use of live vaccines in infants born to mothers using biologics because the desirable and undesirable effects were closely balanced and the evidence was insufficient.

Conclusions

Maintaining appropriate vaccination status in patients with IBD is critical to optimize patient outcomes. In general, live vaccines are recommended in patients not on immunosuppressive therapy, but not for those using immunosuppressive medications. Additional studies are needed to evaluate the safety and efficacy of live vaccines in patients on immunosuppressive therapy.

Canadian Association of Gastroenterology Clinical Practice Guideline for Immunizations in Patients With Inflammatory Bowel Disease (IBD)-Part 1: Live Vaccines

BACKGROUND & AIMS

Patients with inflammatory bowel disease (IBD) may be at increased risk of some vaccine-preventable diseases. The effectiveness and safety of vaccinations may be altered by immunosuppressive therapies or IBD itself. These recommendations developed by the Canadian Association of Gastroenterology and endorsed by the American Gastroenterological Association, aim to provide guidance on immunizations in adult and pediatric patients with IBD. This publication focused on live vaccines.

METHODS

Systematic reviews evaluating the efficacy, effectiveness, and safety of vaccines in patients with IBD, other immune-mediated inflammatory diseases, and the general population were performed. Critical outcomes included mortality, vaccine-preventable diseases, and serious adverse events. Immunogenicity was considered a surrogate outcome for vaccine efficacy. Certainty of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. Key questions were developed through an iterative process and voted on by a multidisciplinary panel. Recommendations were formulated using the Evidence-to-Decision framework. Strong recommendation means that most patients should receive the recommended course of action, whereas a conditional recommendation means that different choices will be appropriate for different patients.

RESULTS

Three good practice statements included reviewing a patient's vaccination status at diagnosis and at regular intervals, giving appropriate vaccinations as soon as possible, and not delaying urgently needed immunosuppressive therapy to provide vaccinations. There are 4 recommendations on the use of live vaccines. Measles, mumps, rubella vaccine is recommended for both adult and pediatric patients with IBD not on immunosuppressive therapy, but not for those using immunosuppressive medications (conditional). Varicella vaccine is recommended for pediatric patients with IBD not on immunosuppressive therapy, but not for those using immunosuppressive medications (conditional). For adults, recommendations are conditionally in favor of varicella vaccine for those not on immunosuppressive therapy, and against for those on therapy. No recommendation was made regarding the use of live vaccines in infants born to mothers using biologics because the desirable and undesirable effects were closely balanced and the evidence was insufficient.

CONCLUSIONS

Maintaining appropriate vaccination status in patients with IBD is critical to optimize patient outcomes. In general, live vaccines are recommended in patients not on immunosuppressive therapy, but not for those using immunosuppressive medications. Additional studies are needed to evaluate the safety and efficacy of live vaccines in patients on immunosuppressive therapy.

A systematic review and meta-analysis of seroprevalence of varicella zoster virus: A nationwide population-based study

Varicella zoster virus (VZV) causes chicken pox as a primary infection following which it becomes latent in neurons. It may then reactivate to cause shingles (herpes zoster). Severity of lesions and VZV pathogenicity are depended on the host's immune response and variant in VZV Dr Athina Myrto ChioniIdentification of VZV seroprevalance rate in general population may lead to develop new health strategic managements such as vaccination. Therefore, we aimed to provide a systematic review of the seroprevalence of VZV infection among Iranian population and estimate age- and gender- specific prevalence of VZV. Keywords "seroprevalence"; "varicella zoster virus" and "Iran"; were searched in international electronic databases and also in national Persian databases. Twenty two pooled studies among 262 total studies containing (240 published articles; 18 dissertations; and 4 proceedings abstracts) from 1992 to 2014 with total sample size of 7867 individuals were included in the final review. Data was analyzed using random effect method. The heterogeneity was calculated using I-square statistics The overall IgG seroprevalence rate of VZV infection in general population of Iran was 78.50% (95% CI; 77.74%-79.25%). There was significant heterogeneity among the studies (P<0.0001; I²=99.4%). Furthermore, the relative risk of VZV infection is high in females (80.47%, 95% CI; 79.40%-81.54%) and older adults (95.30%, 95% CI; 94.11% -96.48%). Our results may represent a true background and estimation of VZV infection in Iran and generate the cost-benefits immunization program. Moreover, the ensuing data suggests further attention on disease seroprevalence in order to obtain efficient data for therapeutic intervention targeted against VZV.

Safety and immunogenicity of the live attenuated varicella vaccine following T replete or T cell-depleted related and unrelated allogeneic hematopoietic cell transplantation (alloHCT)

There are limited studies assessing the live attenuated varicella vaccine following allogeneic hematopoietic cell transplantation (alloHCT). Because of the morbidity of varicella acquired after childhood, we immunized and retrospectively analyzed the safety and immunogenicity of this vaccine in 46 varicella zoster virus (VZV) seronegative patients <20 years old at HCT who achieved a CD4 cell count ≥200/μL, were off immunosuppression, and responded to ≥1 post-HCT vaccines. Two vaccinated patients lacking follow-up titers were excluded from analysis. Stem cells were derived from an HLA-matched sibling (n = 18) or an alternative (HLA mismatched related or unrelated) donor (n = 26). Median time to vaccination was 4 years. Sixty-four percent of patients seroconverted following 1 immunization. There was no significant difference in response between recipients of a matched related or alternative donor graft (P = .2) or between those given a T cell-depleted or T-replete alternative donor graft (P = .27). Three of 44 patients developed a self-limited varicella-like rash within 2.5 weeks of immunization. With a median follow-up of 29.1 (range: 6.9-167.1) months, there were no subsequent cases of varicella-like rashes. No patient developed shingles. This study suggests that this vaccine is safe and immunogenic when given according to preset clinical and immunologic milestones, warranting larger prospective studies in patients ≥24 months following HCT as outlined in current post-HCT vaccine guidelines.

Varicella complications: Is it time to consider a routine varicella vaccination?

Background/Aim. Varicella is a common and benign disease of childhood. Complications are rare, but in some patients, even without risk factors, severe, life threatening complications could be seen. The aim of this study was to establish the type and frequency of varicella complications among hospitalized patients over an 8-year period. Methods. This retrospective analysis included medical charts of the patients hospitalized in the Infectious Disease Clinic, Belgrade, Serbia, from 2001-2008 (4.85% of all registered patients with varicella in Belgrade, 2001-2008). Among hospitalised patients dermografic characteristics were analyzed: hospitalisation lenght, presence and type of complications, presence of immunocompromising conditions and outcome of the disease. The diagnosis of varicella was made on clinical grounds, and in persons > 40 years, with negative epidemiological data of contacts, serological confirmation (ELISA VZV IgM/IgG BioRad?) and avidity of IgG antibodies were done to exclude the possibility of disseminated herpes zoster. Results. A total of 474 patient were hospitalized over an 8-year period. The age of patients was from 5 months to 75 years (mean 22.4 ? 16.1, median 23.5 years). The majority of patients were adults (n = 279; 58.9%) and 195 (41.1%) patients were ? 15 years old. Complications were found in 321/474 (67.7%) patients. The registered complications were: varicella pneumonia (n = 198; 41.38%), bacterial skin infections (n = 40; 8.4%), cerebelitis (n = 28; 5.9%), bacterial respiratory infection (n = 21; 4.4%), viral meningitis (n = 10; 2.31%), encephalitis (n = 9; 1.9%), thrombocytopenia (n = 2; 0.4%); 11 (2.3%) patients had more than one complication, among them were sepsis, myopericarditis and retinal hemorrhages. When complications were analyzed according to the age, there were no statistical significance, but when type of complication was analyzed statistical significance was found (p < 0.05). In adults, pneumonia was the most common complication: 173/279 (62%), followed by skin infections (2.9%), bacterial respiratory infections (2,2%), and more than one complication (2.3%). Pneumonia was more common in adults than in children (7 : 1). In children skin infections were the most common complications (16.4%), followed by cerebelitis (13.3%), viral pneumonia (12.8%), bacterial respiratory infections (7.7%), encephalitis (3.6%), and more than one complication (4.1%). Neuroinfections were more common in children than in adults (6:1), as well as bacterial skin infections (4 : 1). Two patients died (0,4%). Conclusion. There was no difference in the incidence of varicella complication in children and adults, but the type of complication differed. In children the most common complications were skin and neurological infections, while in adults it was varicella pneumonia. These data provide a baseline for estimating the burden of varicella in Belgrade and support the inclusion of varicella vaccine in childhood immunisation program in Serbia.

Occupational risk of infection by varicella zoster virus in Belgian healthcare workers: a seroprevalence study

OBJECTIVES

To assess the prevalence of varicella zoster virus (VZV) antibodies in Flemish (Belgian) healthcare workers, to investigate the association between seronegativity and selected variables, and to assess the reliability of recall about disease as a predictor of immunity.

METHODS

A seroprevalence study of VZV antibodies (IgG) was conducted among a systematic sample of 4923 employees in various professional groups, employed in 22 hospitals in Flanders and Brussels (Belgium). Information about sex, age, department, job, and years of employment, the country of origin, and history of varicella was obtained. The presence of VZV antibodies was investigated with the enzyme linked immunosorbent assay (ELISA), Enzygnost anti VZV / IgG (Dade Behring, Marburg, Germany). Statistical analysis was performed by calculating prevalences and prevalence ratios (PRs) and their 95% confidence intervals (95% CIs). Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) of the recalled history were determined.

RESULTS

The prevalence of VZV seropositivity in Flemish healthcare workers was 98.5% (95% CI 98.1 to 98.8). Seronegativity was significantly associated with age and job, increasing with both older and younger age. The prevalence of seronegative workers was significantly less in nursing staff than non-nursing staff. There was no significant difference for sex and years of employment. The PPV and NPV of recalled history were 98.9% and 3.4%. Sensitivity and specificity were 83% and 38.9%.

CONCLUSION

The prevalence of VZV seropositivity was very high in this sample of Flemish healthcare workers. Because of this low overall susceptibility, VZV infection seems not to be an important occupational risk among healthcare workers in Flanders. The increasing seronegativity above the age of 45 is possibly due to a loss of detectable antibodies. A positive history of varicella was a good predictor of immunity, but a negative history had no value as a predictor of susceptibility in adults.

Three year seroepidemiological study of varicella-zoster virus in São Paulo, Brazil

A serosurvey of varicella has been carried out in children attending the public school network of São Paulo city, Brazil, from 1992 to 1994. This study was performed in order to establish the age related prevalence of antibodies against varicella-zoster virus (VZV) and its age specific transmission dynamics pattern in these children. Among 2500 schools in the city of São Paulo public network, 304 were randomly selected; 7 children of a given age (ranging from 1 to 15 years) were randomly selected in each school, and blood samples were obtained by fingerprick into filter paper. Blood eluates were analyzed for the presence of antibodies to VZV by ELISA. Proportion of seropositivity were calculated for each age group. Samples consisted of 1768 individuals in 1992, 1758 in 1993, and 1817 in 1994, resulting in 5343 eluates. A high proportion of seropositive children from 1 to 3 years of age was observed, ascending until 10 years of age and reaching a plateau around 90% afterwards. VZV transmission in this community was similar along the three years of the study. In children attending public schools in the city of São Paulo, contact with VZV occurs in early childhood. If immunization against VZV is considered it should be introduced as soon as possible.

Seroprevalence of varicella antibodies among new house officers

STUDY OBJECTIVE

Varicella, an illness common to children, can occur in nonimmune adults, often causing serious morbidity and mortality. House officers without protective titers to varicella are at risk of contracting the disease and may spread it to the patients they serve. They are also subject to significant losses in work time and wages. Accordingly, in August 1996, the Centers for Disease Control and Prevention recommended vaccinating nonimmune health care providers with the varicella vaccine. We also sought to document the seroprevalence of varicella antibodies among new house officers and to determine the association of self-reported history of infection with varicella antibody levels.

METHODS

This study was conducted at a university-affiliated teaching hospital. Serology testing was performed on house officers beginning their residencies in July 1997. Subjects provided information regarding demographics, medical history, previous varicella exposure, and previous administration of varicella vaccine. Serum was tested using the FIAX test kit, (Biowhitaker, Walkersville, MD).

RESULTS

One hundred fifty-four house officers participated. The mean age was 30 (range, 24 to 50+/-SD 5.5 years). History of varicella infection was given by 119 (77%) of the 154 subjects, whereas 15 (10%) reported no history of infection, and 20 (13%) were uncertain. Ten (7%) of the participants had received varicella vaccine previously. Overall, 6 (4%) had nonprotective titers to varicella. Of the 119 house officers who reported a history of varicella, only 2 (1.7%) had nonprotective titers, and 4 (27%) who reported no history of varicella infection had nonprotective titers. Of the 10 house officers who had previously received varicella vaccine, 1 (10%) had nonprotective titers.

CONCLUSION

Although most house officers had protective titers, a reported history of varicella or the administration of varicella vaccine did not assure the presence of protective titers. House officers should be tested for varicella immunity regardless of a history of previous infection or the administration of varicella vaccine.

Frontiers of occupational health. New vaccines, new prophylactic regimens, and management of the HIV-infected worker

New prophylactic or treatment options are available for a number of infectious diseases that may be transmitted in the health care setting. Infectious diseases that can now be prevented by vaccination of the employee include hepatitis A, pertussis, hepatitis B, and primary varicella. New prophylactic or treatment regimens are available for Neisseria meningitidis, Streptococcus pyogenes, and Bordetella pertussis; treatment of multidrug-resistant tuberculosis is also discussed. Finally, management of the HIV-infected health care worker is reviewed.