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The Cochrane Database of Systematic... Feb 2012Mumps, measles and rubella (MMR) are serious diseases that can lead to potentially fatal illness, disability and death. However, public debate over the safety of the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Mumps, measles and rubella (MMR) are serious diseases that can lead to potentially fatal illness, disability and death. However, public debate over the safety of the trivalent MMR vaccine and the resultant drop in vaccination coverage in several countries persists, despite its almost universal use and accepted effectiveness.
OBJECTIVES
To assess the effectiveness and adverse effects associated with the MMR vaccine in children up to 15 years of age.
SEARCH METHODS
For this update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 2), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, PubMed (July 2004 to May week 2, 2011) and Embase.com (July 2004 to May 2011).
SELECTION CRITERIA
We used comparative prospective or retrospective trials assessing the effects of the MMR vaccine compared to placebo, do nothing or a combination of measles, mumps and rubella antigens on healthy individuals up to 15 years of age.
DATA COLLECTION AND ANALYSIS
Two review authors independently extracted data and assessed methodological quality of the included studies. One review author arbitrated in case of disagreement.
MAIN RESULTS
We included five randomised controlled trials (RCTs), one controlled clinical trial (CCT), 27 cohort studies, 17 case-control studies, five time-series trials, one case cross-over trial, two ecological studies, six self controlled case series studies involving in all about 14,700,000 children and assessing effectiveness and safety of MMR vaccine. Based on the available evidence, one MMR vaccine dose is at least 95% effective in preventing clinical measles and 92% effective in preventing secondary cases among household contacts.Effectiveness of at least one dose of MMR in preventing clinical mumps in children is estimated to be between 69% and 81% for the vaccine prepared with Jeryl Lynn mumps strain and between 70% and 75% for the vaccine containing the Urabe strain. Vaccination with MMR containing the Urabe strain has demonstrated to be 73% effective in preventing secondary mumps cases. Effectiveness of Jeryl Lynn containing MMR in preventing laboratory-confirmed mumps cases in children and adolescents was estimated to be between 64% to 66% for one dose and 83% to 88% for two vaccine doses. We did not identify any studies assessing the effectiveness of MMR in preventing rubella.The highest risk of association with aseptic meningitis was observed within the third week after immunisation with Urabe-containing MMR (risk ratio (RR) 14.28; 95% confidence interval (CI) from 7.93 to 25.71) and within the third (RR 22.5; 95% CI 11.8 to 42.9) or fifth (RR 15.6; 95% CI 10.3 to 24.2) weeks after immunisation with the vaccine prepared with the Leningrad-Zagreb strain. A significant risk of association with febrile seizures and MMR exposure during the two previous weeks (RR 1.10; 95% CI 1.05 to 1.15) was assessed in one large person-time cohort study involving 537,171 children aged between three months and five year of age. Increased risk of febrile seizure has also been observed in children aged between 12 to 23 months (relative incidence (RI) 4.09; 95% CI 3.1 to 5.33) and children aged 12 to 35 months (RI 5.68; 95% CI 2.31 to 13.97) within six to 11 days after exposure to MMR vaccine. An increased risk of thrombocytopenic purpura within six weeks after MMR immunisation in children aged 12 to 23 months was assessed in one case-control study (RR 6.3; 95% CI 1.3 to 30.1) and in one small self controlled case series (incidence rate ratio (IRR) 5.38; 95% CI 2.72 to 10.62). Increased risk of thrombocytopenic purpura within six weeks after MMR exposure was also assessed in one other case-control study involving 2311 children and adolescents between one month and 18 years (odds ratio (OR) 2.4; 95% CI 1.2 to 4.7). Exposure to the MMR vaccine was unlikely to be associated with autism, asthma, leukaemia, hay fever, type 1 diabetes, gait disturbance, Crohn's disease, demyelinating diseases, bacterial or viral infections.
AUTHORS' CONCLUSIONS
The design and reporting of safety outcomes in MMR vaccine studies, both pre- and post-marketing, are largely inadequate. The evidence of adverse events following immunisation with the MMR vaccine cannot be separated from its role in preventing the target diseases.
Topics: Adolescent; Age Factors; Autistic Disorder; Child; Child, Preschool; Clinical Trials as Topic; Crohn Disease; Epidemiologic Studies; Humans; Infant; Measles; Measles-Mumps-Rubella Vaccine; Mumps; Purpura, Thrombocytopenic; Rubella; Seizures, Febrile; Vaccines, Attenuated
PubMed: 22336803
DOI: 10.1002/14651858.CD004407.pub3 -
Revista Espanola de Enfermedades... Jan 2024Research on the immunogenicity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in patients with autoimmune hepatitis (AIH) has produced...
BACKGROUND
Research on the immunogenicity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in patients with autoimmune hepatitis (AIH) has produced varied results, and the determinants of the immunological response remain largely elusive.
METHODS
A comprehensive search of three primary databases (PubMed, Embase, and Web of Science) yielded pertinent studies on the topic. The data extraction was a collaborative effort among three independent researchers, who subsequently reconvened to validate the key data that were collated. The primary outcomes were the magnitudes of humoral and cellular immune responses to the vaccines. The secondary outcomes were related to factors affecting the humoral immune response post-vaccination.
RESULT
Our systematic review incorporated eight studies, and the meta-analysis involved three. The average antibody response rates after one, two, and three doses of the SARS-CoV-2 vaccine were 86%, 82%, and 91%, respectively. Unexpectedly, the antibody concentrations of seropositive patients were markedly lower than those of their healthy counterparts. The cellular immune response rates after two and three vaccine doses were 74% and 56%, respectively. Treatment with mycophenolate mofetil and corticosteroids was associated with a notable decrease in seropositivity [pooled odds ratio (95% confidence interval): 2.62 (2.12-3.25) and 2.4 (1.51-3.82), respectively]. In contrast, azathioprine had no discernable impact on the humoral response.
CONCLUSION
In patients with AIH, the immune response to COVID-19 vaccination is attenuated. Specific immunosuppressive agents, such as steroids and MMF, have been found to reduce antibody responses. Recognizing these determinants is foundational to formulating individualized vaccination strategies for patients with AIH. Further research with an emphasis on post-vaccination cellular immunity will be essential to refine the vaccination approaches for this demographic.
PubMed: 38235657
DOI: 10.17235/reed.2024.10053/2023 -
Clinical Gastroenterology and... Jul 2022The serological responses after severe acute respiratory syndrome coronavirus 2 vaccination may be attenuated in immunocompromised individuals. The study aimed to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND AIMS
The serological responses after severe acute respiratory syndrome coronavirus 2 vaccination may be attenuated in immunocompromised individuals. The study aimed to systematically evaluate the seroconversion rates after complete vaccination for coronavirus disease 2019 (COVID-19) in patients with inflammatory bowel disease (IBD).
METHODS
Electronic databases were searched to identify studies reporting response to COVID-19 vaccination in IBD. Pooled seroconversion rates after complete vaccination were calculated. Subgroup analysis for vaccine types was also performed. Pooled seroconversion rates for various drugs or classes were also estimated. The pooled rates of breakthrough infections in vaccinated IBD patients were estimated. The pooled neutralization rates after complete vaccination were also estimated. The studies reporting durability of titers were systematically assessed.
RESULTS
A total of 46 studies were included. The pooled seroconversion rate for complete vaccination (31 studies, 9447 patients) was 0.96 (95% confidence interval [CI], 0.94-0.97; I = 90%). When compared with healthy control subjects, the pooled relative risk of seroconversion was lower (0.98; 95% CI, 0.98-0.99; I = 39%). The pooled seroconversion rates were statistically similar among various drug classes. The pooled positivity of neutralization assays (8 studies, 771 participants) was 0.80 (95% CI, 0.70-0.87; I = 82%). The pooled relative risk of breakthrough infections in vaccinated IBD patients was similar to vaccinated control subjects (0.60; 95% CI, 0.25-1.42; I = 79%). Most studies suggested that titers fall after 4 weeks of COVID-19 vaccination, and the decay was higher in patients on anti-tumor necrosis factor alone or combination with immunomodulators. An additional dose of COVID-19 vaccine elicited serological response in most nonresponders to complete vaccination.
CONCLUSIONS
Complete COVID-19 vaccination is associated with seroconversion in most patients with IBD. The decay in titers over time necessitates consideration of additional doses in these patients.
Topics: COVID-19; COVID-19 Vaccines; Humans; Immunocompromised Host; Inflammatory Bowel Diseases; Vaccination
PubMed: 35189387
DOI: 10.1016/j.cgh.2022.02.030 -
Frontiers in Veterinary Science 2022Despite the accessibility of several live attenuated vaccines for animals, currently, there is no licensed vaccine for brucellosis in human populations. Available and...
INTRODUCTION
Despite the accessibility of several live attenuated vaccines for animals, currently, there is no licensed vaccine for brucellosis in human populations. Available and confirmed animal vaccines may be harmful and considered inappropriate for humans. Thus, human vaccines for brucellosis are required. We aimed to evaluate the effects of vaccines on mouse models and discuss the potential mechanisms of these vaccines for the design of the appropriate human vaccines.
MATERIALS AND METHODS
A systematic search was carried out in Web of Science, Embase, and PubMed/Medline databases. The following MeSH terms were applied: brucellosis, vaccine, , and vaccination. The original manuscripts describing the vaccines on mouse models were included. The review articles, editorials, correspondences, case reports, case series, duplicate publications, and articles with insufficient data were excluded.
RESULTS
Of the 163 full texts that were screened, 17 articles reached to inclusion criteria. Combining the results of these trials revealed a reduction in bacterial load and colonization rate of in the spleen, an increase in inflammatory markers, especially IFN-γ and IL-4, and the highest levels of antibody classes in vaccinated animals compared to animals challenged with various virulent strains of . The majority of studies found that different anti- vaccines induced a significant protective effect in animals challenged with strains. Additionally, mice were given the highest level of vaccine protection and significant clearance of strains when the immunization was delivered the IP (intraperitoneal) or IP-IN (intranasal) routes.
CONCLUSION
Brucella is responsible for half-million new cases globally annually, and the lack of a proper human vaccine poses the risk of brucellosis. A variety of vaccines are used to prevent brucellosis. Subunit vaccines and recombinant human vaccines have higher safety and protective properties. Although vaccination helps brucellosis control, it does not eradicate the disease. Thus, we recommend the following strategies. (a) establishment of a registration system; (b) close monitoring of slaughterhouses, markets, and herds; (c) training veterinarians; (d) legal protection of the consequences of non-compliance with preventive measures.
PubMed: 36118342
DOI: 10.3389/fvets.2022.903890 -
The Cochrane Database of Systematic... Jun 2014The prevention of varicella (chickenpox) using live attenuated varicella vaccines has been demonstrated both in randomised controlled trials (RCTs) and in... (Review)
Review
BACKGROUND
The prevention of varicella (chickenpox) using live attenuated varicella vaccines has been demonstrated both in randomised controlled trials (RCTs) and in population-based immunisation programmes in countries such as the United States and Australia. 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 METHODS
We searched CENTRAL (2014, Issue 1), MEDLINE (1966 to March week 1, 2014), EMBASE (January 1990 to March 2014) and LILACS (1982 to March 2014). We searched for unpublished trials registered on the clinicaltrials.gov and WHO ICTRP websites.
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 events following vaccination.
DATA COLLECTION AND ANALYSIS
Two review authors independently extracted and analysed data using Review Manager software.
MAIN RESULTS
We identified three trials involving 110 healthy children who were siblings of household contacts. The included trials varied in study quality, vaccine used, length of follow-up and outcomes measured and, as such, were not suitable for meta-analysis. We identified high or unclear risk of bias in two of the three included studies. Overall, 13 out of 56 vaccine recipients (23%) 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 fewer than 50 skin lesions). In the three trials, most participants received PEP within three days following exposure; too few participants were vaccinated four to five days post-exposure to ascertain the efficacy of vaccine given more than three days after exposure. No included trial 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. We identified no RCTs for adolescents or adults. Safety was not adequately addressed.
Topics: Adult; Chickenpox; Chickenpox Vaccine; Child; Herpesvirus 3, Human; Humans; Post-Exposure Prophylaxis; Randomized Controlled Trials as Topic; Vaccines, Attenuated
PubMed: 24954057
DOI: 10.1002/14651858.CD001833.pub3 -
Viruses May 2022Live-attenuated SARS-CoV-2 vaccines received relatively little attention during the COVID-19 pandemic. Despite this, several methods of obtaining attenuated...
Live-attenuated SARS-CoV-2 vaccines received relatively little attention during the COVID-19 pandemic. Despite this, several methods of obtaining attenuated coronaviruses are known. In this systematic review, the strategies of coronavirus attenuation, which may potentially be applied to SARS-CoV-2, were identified. PubMed, Scopus, Web of Science and Embase databases were searched to identify relevant articles describing attenuating mutations tested in vivo. In case of coronaviruses other than SARS-CoV-2, sequence alignment was used to exclude attenuating mutations that cannot be applied to SARS-CoV-2. Potential immunogenicity, safety and efficacy of the attenuated SARS-CoV-2 vaccine were discussed based on animal studies data. A total of 27 attenuation strategies, used to create 101 different coronaviruses, have been described in 56 eligible articles. The disruption of the furin cleavage site in the SARS-CoV-2 spike protein was identified as the most promising strategy. The replacement of core sequences of transcriptional regulatory signals, which prevents recombination with wild-type viruses, also appears particularly advantageous. Other important attenuating mutations encompassed mostly the prevention of evasion of innate immunity. Sufficiently attenuated coronaviruses typically caused no meaningful disease in susceptible animals and protected them from challenges with virulent virus. This indicates that attenuated COVID-19 vaccines may be considered as a potential strategy to fight the threat posed by SARS-CoV-2.
Topics: Animals; COVID-19; COVID-19 Vaccines; Humans; SARS-CoV-2; Spike Glycoprotein, Coronavirus; Vaccine Development; Vaccines, Attenuated
PubMed: 35632736
DOI: 10.3390/v14050991 -
Croatian Medical Journal Apr 2013To assess the efficacy and effectiveness of seasonal influenza vaccines in healthy children up to the age of 18 years. (Meta-Analysis)
Meta-Analysis Review
AIM
To assess the efficacy and effectiveness of seasonal influenza vaccines in healthy children up to the age of 18 years.
METHODS
MedLine, EMBASE, CENTRAL, CINAHL, WHOLIS, LILACS, and Global Health were searched for randomized controlled trials and cohort and case-control studies investigating the efficacy or effectiveness of influenza vaccines in healthy children up to the age of 18 years. The studies were assessed for their quality and data on the outcomes of influenza-like illness, laboratory-confirmed influenza, and hospitalizations were extracted. Seven meta-analyses were performed for different vaccines and different study outcomes.
RESULTS
Vaccine efficacy for live vaccines, using random effects model, was as follows: (i) for similar antigen, using per-protocol analysis: 83.4% (78.3%-88.8%); (ii) for similar antigen, using intention to treat analysis: 82.5 (76.7%-88.6%); (iii) for any antigen, using per protocol analysis: 76.4% (68.7%-85.0%); (iv) for any antigen, using intention to treat analysis: 76.7% (68.8%-85.6%). Vaccine efficacy for inactivated vaccines, for similar antigen, using random effects model, was 67.3% (58.2%-77.9%). Vaccine effectiveness against influenza-like illness for live vaccines, using random effects model, was 31.4% (24.8%-39.6%) and using fixed-effect model 44.3% (42.6%-45.9%). Vaccine effectiveness against influenza-like illness for inactivated vaccines, using random effects model, was 32.5% (20.0%-52.9%) and using fixed-effect model 42.6% (38.3%-47.5%).
CONCLUSIONS
Influenza vaccines showed high efficacy in children, particularly live vaccines. Effectiveness was lower and the data on hospitalizations were very limited.
Topics: Adolescent; Child; Child, Preschool; Humans; Infant; Influenza Vaccines; Influenza, Human; Seasons; Treatment Outcome; Vaccines, Attenuated; Vaccines, Inactivated
PubMed: 23630141
DOI: 10.3325/cmj.2013.54.135 -
Frontiers in Psychiatry 2024The emergence of a new coronavirus strain caused the COVID-19 pandemic. While vaccines effectively control the infection, it's important to acknowledge the potential for...
BACKGROUND
The emergence of a new coronavirus strain caused the COVID-19 pandemic. While vaccines effectively control the infection, it's important to acknowledge the potential for side effects, including rare cases like psychosis, which may increase with the rising number of vaccinations.
OBJECTIVES
Our systematic review aimed to examine cases of new-onset psychosis following COVID-19 vaccination.
METHODS
We conducted a systematic review of case reports and case series on new-onset psychosis following COVID-19 vaccination from December 1st, 2019, to November 21st, 2023, using PubMed, MEDLINE, ClinicalKey, and ScienceDirect. Data extraction covered study and participant characteristics, comorbidities, COVID-19 vaccine details, and clinical features. The Joanna Briggs Institute quality assessment tools were employed for included studies, revealing no significant publication bias.
RESULTS
A total of 21 articles described 24 cases of new-onset psychotic symptoms following COVID-19 vaccination. Of these cases, 54.2% were female, with a mean age of 33.71 ± 12.02 years. Psychiatric events were potentially induced by the mRNA BNT162b2 vaccine in 33.3% of cases, and psychotic symptoms appeared in 25% following the viral vector ChAdOx1 nCoV-19 vaccine. The mean onset time was 5.75 ± 8.14 days, mostly reported after the first or second dose. The duration of psychotic symptoms ranged between 1 and 2 months with a mean of 52.48 ± 60.07 days. Blood test abnormalities were noted in 50% of cases, mainly mild to moderate leukocytosis and elevated C-reactive protein. Magnetic resonance imaging results were abnormal in 20.8%, often showing fluid-attenuated inversion recovery hyperintensity in the white matter. Treatment included atypical antipsychotics in 83.3% of cases, typical antipsychotics in 37.5%, benzodiazepines in 50%, 20.8% received steroids, and 25% were prescribed antiepileptic medications. Overall, 50% of patients achieved full recovery.
CONCLUSION
Studies on psychiatric side effects post-COVID-19 vaccination are limited, and making conclusions on vaccine advantages or disadvantages is challenging. Vaccination is generally safe, but data suggest a potential link between young age, mRNA, and viral vector vaccines with new-onset psychosis within 7 days post-vaccination. Collecting data on vaccine-related psychiatric effects is crucial for prevention, and an algorithm for monitoring and treating mental health reactions post-vaccination is necessary for comprehensive management.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023446270.
PubMed: 38680784
DOI: 10.3389/fpsyt.2024.1360338 -
BMJ (Clinical Research Ed.) Apr 2014To describe the potential benefits and harms of zanamivir. (Review)
Review
OBJECTIVES
To describe the potential benefits and harms of zanamivir.
DESIGN
Systematic review of clinical study reports of randomised placebo controlled trials and regulatory information
DATA SOURCES
Clinical study reports, trial registries, electronic databases, regulatory archives, and correspondence with manufacturers.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Randomised placebo controlled trials in adults and children who had confirmed or suspected exposure to natural influenza.
MAIN OUTCOME MEASURES
Time to first alleviation of symptoms, influenza outcomes and complications, admissions to hospital, and adverse events in the intention to treat (ITT) population.
RESULTS
We included 28 trials in stage 1 (judgment of appropriate study design) and 26 in stage 2 (formal analysis). For treatment of adults, zanamivir reduced the time to first alleviation of symptoms of influenza-like illness by 0.60 days (95% confidence interval 0.39 to 0.81, P<0.001, I(2)=9%), which equates to an average 14.4 hours' reduction, or a 10% reduction in mean duration of symptoms from 6.6 days to 6.0 days. Time to first alleviation of symptoms was shorter in all participants when any relief drugs were allowed compared with no use. Zanamivir did not reduce the risk of self reported investigator mediated pneumonia (risk difference 0.17%, -0.73% to 0.70%) or radiologically confirmed pneumonia (-0.06%, -6.56% to 2.11%) in adults. The effect on pneumonia in children was also not significant (0.56%, -1.64% to 1.04%). There was no significant effect on otitis media or sinusitis in both adults and children, with only a small effect noted for bronchitis in adults (1.80%, 0.65% to 2.80%), but not in children. There were no data to assess effects on admissions in adults and children. Zanamivir tended to be well tolerated. In zanamivir prophylaxis studies, symptomatic influenza in individuals was significantly reduced (1.98%, (0.98% to 2.54%); reducing event rates from 3.26% to 1.27%, which means 51 people need to be treated to prevent one influenza case (95% confidence interval, 40 to 103). In contrast, the prophylaxis effect on asymptomatic influenza cases was not significant in individuals (risk difference 0.14%, -1.10% to 1.10%) or in households (1.32%, -2.20% to 3.84%). In households treated prophylactically there was an effect on symptomatic influenza (14.84%, 12.18% to 16.55%), but this was based on only two small studies including 824 participants. Prophylaxis in adults reduced unverified pneumonia (0.32%, 0.09% to 0.41%; NNTB (number needed to treat to benefit) 311, 244 to 1086) but had no effect on pneumonia in children or on bronchitis or sinusitis in adults or children (risk difference 0.32%, 0.09% to 0.41%; NNTB 311, 244 to 1086).
CONCLUSIONS
Based on a full assessment of all trials conducted, zanamivir reduces the time to symptomatic improvement in adults (but not in children) with influenza-like illness by just over half a day, although this effect might be attenuated by symptom relief medication. Zanamivir also reduces the proportion of patients with laboratory confirmed symptomatic influenza. We found no evidence that zanamivir reduces the risk of complications of influenza, particularly pneumonia, or the risk of hospital admission or death. Its harmful effects were minor (except for bronchospasm), perhaps because of low bioavailability.
Topics: Adult; Antiviral Agents; Child; Humans; Influenza, Human; Randomized Controlled Trials as Topic; Treatment Outcome; Zanamivir
PubMed: 24811412
DOI: 10.1136/bmj.g2547 -
Vaccine Mar 2017Live vaccines are generally contraindicated on immunosuppressive therapy due to safety concerns. However, data are limited to corroborate this practice. (Review)
Review
Safety of live vaccinations on immunosuppressive therapy in patients with immune-mediated inflammatory diseases, solid organ transplantation or after bone-marrow transplantation - A systematic review of randomized trials, observational studies and case reports.
BACKGROUND
Live vaccines are generally contraindicated on immunosuppressive therapy due to safety concerns. However, data are limited to corroborate this practice.
OBJECTIVES
To estimate the safety of live vaccinations in patients with immune-mediated inflammatory diseases (IMID) or solid organ transplantation (SOT) on immunosuppressive treatment and in patients after bone-marrow transplantation (BMT).
DATA SOURCES
A search was conducted in electronic databases (Cochrane, Pubmed, Embase) and additional literature was identified by targeted searches.
ELIGIBILITY CRITERIA
Randomized trials, observational studies and case reports.
POPULATION
Patients with IMID or SOT on immunosuppressive treatment and BMT patients <2years after transplantation.
INTERVENTION/VACCINATIONS LOOKED AT
Live vaccinations: mumps, measles, rubella (MMR), yellow fever (YF), varicella vaccine (VV), herpes zoster (HZ), oral typhoid, oral polio, rotavirus, Bacillus Calmette-Guérin (BCG), smallpox.
DATA EXTRACTION
One author performed the data extraction using predefined data fields. It was cross-checked by two other authors.
RESULTS
7305 articles were identified and 64 articles were included: 40 on IMID, 16 on SOT and 8 on BMT patients. In most studies, the administration of live vaccines was safe. However, some serious vaccine-related adverse events occurred. 32 participants developed an infection with the vaccine strain; in most cases the infection was mild. However, in two patients fatal infections were reported: a patient with RA/SLE overlap who started MTX/dexamethasone treatment four days after the YFV developed a yellow fever vaccine-associated viscerotropic disease (YEL-AVD) and died. The particular vaccine lot was found to be associated with a more than 20 times risk of YEL-AVD. One infant whose mother was under infliximab treatment during pregnancy received the BCG vaccine at the age of three months and developed disseminated BCG infection and died. An immunogenicity assessment was performed in 43 studies. In most cases the patients developed satisfactory seroprotection rates. In the IMID group, YFV and VV demonstrated high seroconversion rates. MTX and tumor necrosis factor inhibitory therapy appeared to reduce immune responses to VV and HZ vaccine, but not to MMR and YF-revaccination. Seroconversion in SOT and BMT patients showed mostly higher rates for rubella than for measles, mumps and varicella.
LIMITATIONS
Risk of bias was high in the majority of studies since 39 of them were observational and 17 were case series/case reports. Only eight studies were randomized trials. BMT patient numbers included in this review were low.
CONCLUSIONS
Although live vaccinations were safe and sufficiently immunogenic in most studies, some serious reactions and vaccine-related infections were reported in immunosuppressed IMID and SOT patients. Apart from mild vaccine-related infections MMR and VV vaccines were safe when administered less than two years after BMT.
IMPLICATIONS OF KEY FINDINGS
Until further data are available, live vaccinations under most immunosuppressive treatments should only be administered after a careful risk benefit assessment of medications and dosages.
FUNDING
None.
Topics: Bone Marrow Transplantation; Chickenpox; Chickenpox Vaccine; Female; Humans; Immune System Diseases; Immunosuppressive Agents; Infant; Inflammation; Male; Measles; Measles-Mumps-Rubella Vaccine; Mumps; Observational Studies as Topic; Organ Transplantation; Pregnancy; Randomized Controlled Trials as Topic; Rubella; Vaccination; Vaccines, Attenuated; Vaccines, Combined; Yellow Fever; Yellow Fever Vaccine
PubMed: 28162821
DOI: 10.1016/j.vaccine.2017.01.048