Effectiveness of Jeryl Lynn-containing vaccine in Spanish children

Effectiveness and safety of a mumps containing vaccine in preventing laboratory-confirmed mumps cases from 2002 to 2017: A meta-analysis

Emerging evidence has figured that serum conversion rate of mumps is a crucial link of mumps disease. Nevertheless, a rising number of mumps outbreaks caused our attention and studies examining the serum conversion cases were conducted in small samples previously; this meta-analysis was conducted to assess the immunogenicity and safety of a mumps containing vaccine (MuCV) before 2019. We identified a total of 17 studies from the year of 2002-2017. In the case-control studies, the vaccine effectiveness (VE) of MuCV in preventing laboratory-confirmed mumps was 68% (odds risk: 0.32; 95% confidence interval [CI], 0.14-0.70) while in the cohort studies and randomised control trials, 58% (relative risk [RR]: 0.42; 95% CI, 0.26-0.69). Similar intervals of effectiveness rates were found during non-outbreak periods compared with outbreak periods (VE: 66%; RR: 0.34; 95% CI, 0.18-0.68 versus VE: 49%; RR: 0.51; 95% CI, 0.21-1.27). In addition, the MuCV group with two and three doses did not show enhanced laboratory-confirmed mumps than one dose (VE: 58%; RR: 0.42; 95% CI, 0.20-0.88 versus VE: 65%, RR: 0.35; 95% CI, 0.20-0.61) for the reason of the overlap of 95% CI. MuCV had comparable effectiveness comparing non-outbreak and outbreak period, one dose, and two or three doses. MuCV displayed acceptable adverse event profiles.

Vaccines for measles, mumps, rubella, and varicella in children

BACKGROUND

Measles, mumps, rubella, and varicella (chickenpox) are serious diseases that can lead to serious complications, 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. This is an update of a review published in 2005 and updated in 2012.

OBJECTIVES

To assess the effectiveness, safety, and long- and short-term adverse effects associated with the trivalent vaccine, containing measles, rubella, mumps strains (MMR), or concurrent administration of MMR vaccine and varicella vaccine (MMR+V), or tetravalent vaccine containing measles, rubella, mumps, and varicella strains (MMRV), given to children aged up to 15 years.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2019, Issue 5), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to 2 May 2019), Embase (1974 to 2 May 2019), the WHO International Clinical Trials Registry Platform (2 May 2019), and ClinicalTrials.gov (2 May 2019).

SELECTION CRITERIA

We included randomised controlled trials (RCTs), controlled clinical trials (CCTs), prospective and retrospective cohort studies (PCS/RCS), case-control studies (CCS), interrupted time-series (ITS) studies, case cross-over (CCO) studies, case-only ecological method (COEM) studies, self-controlled case series (SCCS) studies, person-time cohort (PTC) studies, and case-coverage design/screening methods (CCD/SM) studies, assessing any combined MMR or MMRV / MMR+V vaccine given in any dose, preparation or time schedule compared with no intervention or placebo, on healthy children up to 15 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the methodological quality of the included studies. We grouped studies for quantitative analysis according to study design, vaccine type (MMR, MMRV, MMR+V), virus strain, and study settings. Outcomes of interest were cases of measles, mumps, rubella, and varicella, and harms. Certainty of evidence of was rated using GRADE.

MAIN RESULTS

We included 138 studies (23,480,668 participants). Fifty-one studies (10,248,159 children) assessed vaccine effectiveness and 87 studies (13,232,509 children) assessed the association between vaccines and a variety of harms. We included 74 new studies to this 2019 version of the review. Effectiveness Vaccine effectiveness in preventing measles was 95% after one dose (relative risk (RR) 0.05, 95% CI 0.02 to 0.13; 7 cohort studies; 12,039 children; moderate certainty evidence) and 96% after two doses (RR 0.04, 95% CI 0.01 to 0.28; 5 cohort studies; 21,604 children; moderate certainty evidence). The effectiveness in preventing cases among household contacts or preventing transmission to others the children were in contact with after one dose was 81% (RR 0.19, 95% CI 0.04 to 0.89; 3 cohort studies; 151 children; low certainty evidence), after two doses 85% (RR 0.15, 95% CI 0.03 to 0.75; 3 cohort studies; 378 children; low certainty evidence), and after three doses was 96% (RR 0.04, 95% CI 0.01 to 0.23; 2 cohort studies; 151 children; low certainty evidence). The effectiveness (at least one dose) in preventing measles after exposure (post-exposure prophylaxis) was 74% (RR 0.26, 95% CI 0.14 to 0.50; 2 cohort studies; 283 children; low certainty evidence). The effectiveness of Jeryl Lynn containing MMR vaccine in preventing mumps was 72% after one dose (RR 0.24, 95% CI 0.08 to 0.76; 6 cohort studies; 9915 children; moderate certainty evidence), 86% after two doses (RR 0.12, 95% CI 0.04 to 0.35; 5 cohort studies; 7792 children; moderate certainty evidence). Effectiveness in preventing cases among household contacts was 74% (RR 0.26, 95% CI 0.13 to 0.49; 3 cohort studies; 1036 children; moderate certainty evidence).  Vaccine effectiveness against rubella, using a vaccine with the BRD2 strain which is only used in China, is 89% (RR 0.11, 95% CI 0.03 to 0.42; 1 cohort study; 1621 children; moderate certainty evidence).  Vaccine effectiveness against varicella (any severity) after two doses in children aged 11 to 22 months is 95% in a 10 years follow-up (rate ratio (rr) 0.05, 95% CI 0.03 to 0.08; 1 RCT; 2279 children; high certainty evidence). Safety There is evidence supporting an association between aseptic meningitis and MMR vaccines containing Urabe and Leningrad-Zagreb mumps strains, but no evidence supporting this association for MMR vaccines containing Jeryl Lynn mumps strains (rr 1.30, 95% CI 0.66 to 2.56; low certainty evidence). The analyses provide evidence supporting an association between MMR/MMR+V/MMRV vaccines (Jeryl Lynn strain) and febrile seizures. Febrile seizures normally occur in 2% to 4% of healthy children at least once before the age of 5. The attributable risk febrile seizures vaccine-induced is estimated to be from 1 per 1700 to 1 per 1150 administered doses. The analyses provide evidence supporting an association between MMR vaccination and idiopathic thrombocytopaenic purpura (ITP). However, the risk of ITP after vaccination is smaller than after natural infection with these viruses. Natural infection of ITP occur in 5 cases per 100,000 (1 case per 20,000) per year. The attributable risk is estimated about 1 case of ITP per 40,000 administered MMR doses. There is no evidence of an association between MMR immunisation and encephalitis or encephalopathy (rate ratio 0.90, 95% CI 0.50 to 1.61; 2 observational studies; 1,071,088 children; low certainty evidence), and autistic spectrum disorders (rate ratio 0.93, 95% CI 0.85 to 1.01; 2 observational studies; 1,194,764 children; moderate certainty). There is insufficient evidence to determine the association between MMR immunisation and inflammatory bowel disease (odds ratio 1.42, 95% CI 0.93 to 2.16; 3 observational studies; 409 cases and 1416 controls; moderate certainty evidence). Additionally, there is no evidence supporting an association between MMR immunisation and cognitive delay, type 1 diabetes, asthma, dermatitis/eczema, hay fever, leukaemia, multiple sclerosis, gait disturbance, and bacterial or viral infections.  AUTHORS' CONCLUSIONS: Existing evidence on the safety and effectiveness of MMR/MMRV vaccines support their use for mass immunisation. Campaigns aimed at global eradication should assess epidemiological and socioeconomic situations of the countries as well as the capacity to achieve high vaccination coverage. More evidence is needed to assess whether the protective effect of MMR/MMRV could wane with time since immunisation.

Loss of protective immunity of two-dose mumps-containing vaccine over time: concerns with the new strategy of the mumps immunization program in China

Background: Currently, children aged 6-9 years have the highest incidence rate of mumps in China. Although China has introduced a two-dose schedule of measles-mumps-rubella vaccine into routine immunization (at 8 months and 18 months), the incidence rate of mumps in high-risk populations might not decrease due to waning immunity. Here we report a mumps outbreak supporting this hypothesis.Methods: The descriptive epidemiological method was used to summarize the overall characteristics of the course of the outbreak. We conducted a retrospective cohort study to evaluate the vaccine effectiveness (VE) of mumps-containing vaccine (MuCV).Results: A total of 78 cases were identified during the outbreak and the estimated vaccination coverage was 84.7%. Of 454 vaccinated students, 335 (73.8%) had received one-dose MuCV, 93 (20.5%) two-dose, and 26 (5.7%) three-dose. The VEs for both the one-dose (-17.0%, 95%CI: -120.3-38.2%) and two-dose groups (-10.0%, 95%CI: -138.0-48.8%) were not performed well, whereas the VE for the three-dose group was 100%. However, we found that the overall VE was 74.2% (95% CI: 9.7-92.6%) for students vaccinated within 5 years. We also observed that there was a broadly linear increase in mumps infection risk in both one-dose and two-dose group when the time since last dose vaccination was more than 5 years.Conclusions: The overall VE for both one-dose and two-dose MuCV was discouraging, but it appeared to be moderately effective within 5 years after vaccination. Further surveillance and seroepidemiological data are needed to understand the impact of the new vaccination strategy on mumps in China.

Close the gap for routine mumps vaccination in Japan

Mumps is a vaccine-preventable disease. Because the mumps vaccine can cause aseptic meningitis in rare cases, this vaccine is not routine in Japan. This has led to low vaccine coverage and severe disease burden in Japan. The present review summarizes mumps epidemiology and vaccination and discusses effective future strategies to mitigate the current disease burden of mumps in Japan. Although a recent study reported that mumps vaccine coverage rates are improving in Japan, current coverage rates are far below the optimal rate to suppress the ongoing epidemic, which has caused an average annual financial loss of 85 billion JPY between 2000 and 2016. Recent reports have demonstrated a much lower incidence of vaccine-induced aseptic meningitis in newly developed vaccines, especially when administered at 1 year of age. Cost-effectiveness studies suggest that routinization of the currently distributed domestic vaccine would be highly cost-effective. In addition, questionnaire surveillance data suggest that the majority of the Japanese population accepts the nominal risk of the vaccine when the proper information is provided. Finally, there are some successful programs in Japan that have attained high vaccine coverage rates with financial support from local governments. Taken together, these data suggest that the mumps vaccine should be immediately included in routine vaccines in Japan.

CDC Guidance for Use of a Third Dose of MMR Vaccine During Mumps Outbreaks

CONTEXT

In response to numerous mumps outbreaks reported throughout the United States in 2016 and 2017, the Advisory Committee on Immunization Practices (ACIP) recommended a third dose of measles, mumps, and rubella (MMR) vaccine for groups of persons determined by public health authorities to be at increased risk for acquiring mumps because of an outbreak.

OBJECTIVE

To provide guidance for health departments when implementing the ACIP recommendation.

DESIGN

Draft guidance was developed by Centers for Disease Control and Prevention subject matter experts based on technical consultations with health departments and review of published and unpublished data regarding mumps outbreaks. The guidance was finalized based on input from experts from the ACIP Mumps Work Group and local and state epidemiologists through the Council of State and Territorial Epidemiologists and the National Association of County and City Health Officials.

RESULTS

We developed guidance to assist public health authorities when determining which groups are at increased risk for acquiring mumps and should receive a third dose of MMR vaccine. During outbreaks, public health authorities identify groups of persons with known or likely close contact exposure to a mumps patient. Then, evidence of transmission and likelihood of transmission in a group's setting can be used to determine whether these groups are at increased risk. Additional epidemiologic and implementation factors may also be considered. All persons in the group at increased risk for acquiring mumps should receive a dose of MMR vaccine, including those with unknown vaccination status or those who have evidence of presumptive immunity other than documented 2 doses of MMR vaccine; no additional dose is recommended for persons who had received 3 or more doses before the outbreak.

CONCLUSION

This guidance provides a framework for public health authorities to use when considering a third dose of MMR in response to mumps outbreaks while maintaining flexibility to incorporate local factors related to individual outbreaks.

Vaccines for measles, mumps, rubella, and varicella in children

BACKGROUND

Measles, mumps, rubella, and varicella (chickenpox) are serious diseases that can lead to serious complications, 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. This is an update of a review published in 2005 and updated in 2012.

OBJECTIVES

To assess the effectiveness, safety, and long- and short-term adverse effects associated with the trivalent vaccine, containing measles, rubella, mumps strains (MMR), or concurrent administration of MMR vaccine and varicella vaccine (MMR+V), or tetravalent vaccine containing measles, rubella, mumps, and varicella strains (MMRV), given to children aged up to 15 years.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2019, Issue 5), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to 2 May 2019), Embase (1974 to 2 May 2019), the WHO International Clinical Trials Registry Platform (2 May 2019), and ClinicalTrials.gov (2 May 2019).

SELECTION CRITERIA

We included randomised controlled trials (RCTs), controlled clinical trials (CCTs), prospective and retrospective cohort studies (PCS/RCS), case-control studies (CCS), interrupted time-series (ITS) studies, case cross-over (CCO) studies, case-only ecological method (COEM) studies, self-controlled case series (SCCS) studies, person-time cohort (PTC) studies, and case-coverage design/screening methods (CCD/SM) studies, assessing any combined MMR or MMRV / MMR+V vaccine given in any dose, preparation or time schedule compared with no intervention or placebo, on healthy children up to 15 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the methodological quality of the included studies. We grouped studies for quantitative analysis according to study design, vaccine type (MMR, MMRV, MMR+V), virus strain, and study settings. Outcomes of interest were cases of measles, mumps, rubella, and varicella, and harms. Certainty of evidence of was rated using GRADE.

MAIN RESULTS

We included 138 studies (23,480,668 participants). Fifty-one studies (10,248,159 children) assessed vaccine effectiveness and 87 studies (13,232,509 children) assessed the association between vaccines and a variety of harms. We included 74 new studies to this 2019 version of the review. Effectiveness Vaccine effectiveness in preventing measles was 95% after one dose (relative risk (RR) 0.05, 95% CI 0.02 to 0.13; 7 cohort studies; 12,039 children; moderate certainty evidence) and 96% after two doses (RR 0.04, 95% CI 0.01 to 0.28; 5 cohort studies; 21,604 children; moderate certainty evidence). The effectiveness in preventing cases among household contacts or preventing transmission to others the children were in contact with after one dose was 81% (RR 0.19, 95% CI 0.04 to 0.89; 3 cohort studies; 151 children; low certainty evidence), after two doses 85% (RR 0.15, 95% CI 0.03 to 0.75; 3 cohort studies; 378 children; low certainty evidence), and after three doses was 96% (RR 0.04, 95% CI 0.01 to 0.23; 2 cohort studies; 151 children; low certainty evidence). The effectiveness (at least one dose) in preventing measles after exposure (post-exposure prophylaxis) was 74% (RR 0.26, 95% CI 0.14 to 0.50; 2 cohort studies; 283 children; low certainty evidence). The effectiveness of Jeryl Lynn containing MMR vaccine in preventing mumps was 72% after one dose (RR 0.24, 95% CI 0.08 to 0.76; 6 cohort studies; 9915 children; moderate certainty evidence), 86% after two doses (RR 0.12, 95% CI 0.04 to 0.35; 5 cohort studies; 7792 children; moderate certainty evidence). Effectiveness in preventing cases among household contacts was 74% (RR 0.26, 95% CI 0.13 to 0.49; 3 cohort studies; 1036 children; moderate certainty evidence). Vaccine effectiveness against rubella is 89% (RR 0.11, 95% CI 0.03 to 0.42; 1 cohort study; 1621 children; moderate certainty evidence). Vaccine effectiveness against varicella (any severity) after two doses in children aged 11 to 22 months is 95% in a 10 years follow-up (rate ratio (rr) 0.05, 95% CI 0.03 to 0.08; 1 RCT; 2279 children; high certainty evidence). Safety There is evidence supporting an association between aseptic meningitis and MMR vaccines containing Urabe and Leningrad-Zagreb mumps strains, but no evidence supporting this association for MMR vaccines containing Jeryl Lynn mumps strains (rr 1.30, 95% CI 0.66 to 2.56; low certainty evidence). The analyses provide evidence supporting an association between MMR/MMR+V/MMRV vaccines (Jeryl Lynn strain) and febrile seizures. Febrile seizures normally occur in 2% to 4% of healthy children at least once before the age of 5. The attributable risk febrile seizures vaccine-induced is estimated to be from 1 per 1700 to 1 per 1150 administered doses. The analyses provide evidence supporting an association between MMR vaccination and idiopathic thrombocytopaenic purpura (ITP). However, the risk of ITP after vaccination is smaller than after natural infection with these viruses. Natural infection of ITP occur in 5 cases per 100,000 (1 case per 20,000) per year. The attributable risk is estimated about 1 case of ITP per 40,000 administered MMR doses. There is no evidence of an association between MMR immunisation and encephalitis or encephalopathy (rate ratio 0.90, 95% CI 0.50 to 1.61; 2 observational studies; 1,071,088 children; low certainty evidence), and autistic spectrum disorders (rate ratio 0.93, 95% CI 0.85 to 1.01; 2 observational studies; 1,194,764 children; moderate certainty). There is insufficient evidence to determine the association between MMR immunisation and inflammatory bowel disease (odds ratio 1.42, 95% CI 0.93 to 2.16; 3 observational studies; 409 cases and 1416 controls; moderate certainty evidence). Additionally, there is no evidence supporting an association between MMR immunisation and cognitive delay, type 1 diabetes, asthma, dermatitis/eczema, hay fever, leukaemia, multiple sclerosis, gait disturbance, and bacterial or viral infections.

AUTHORS' CONCLUSIONS

Existing evidence on the safety and effectiveness of MMR/MMRV vaccines support their use for mass immunisation. Campaigns aimed at global eradication should assess epidemiological and socioeconomic situations of the countries as well as the capacity to achieve high vaccination coverage. More evidence is needed to assess whether the protective effect of MMR/MMRV could wane with time since immunisation.

Assessing the Changes of Mumps Characteristics with Different Vaccination Strategies Using Surveillance Data: Importance to Introduce the 2-Dose Schedule in Quzhou of China

BACKGROUND

From 2005 to 2016, the prevention and control of mumps in China have undergone three stages of transition. These include the use of MuCV as a self-supported vaccine, the introduction of one-dose MMR to the Expanded Program on Immunization (EPI), and the administration of two-dose MuCV following supplementary immunization activities (SIAs) using MM. Here, using surveillance data, we assessed the epidemiology of mumps during the three stages.

METHODS

Children in Quzhou of China born from 2005 to 2016 and registered in the Zhejiang Provincial Immunization Information System (ZJIIS) were included. We analyzed the epidemic data and calculated incidence and MuCV coverage via birth cohorts.

RESULTS

The average incidence of mumps in 2005-2006, 2007-2010, and 2011-2016 was 51.57, 41.02, and 12.53 per 100,000 individuals, respectively. The highest incidence was in children aged 6-14 years from 2005-2016, of which the majority were school students (67.84%). Approximately 90% of the reported outbreaks occurred in school children (primary school/middle school). The seasonal characteristics of mumps were less obvious from 2011 to 2016. The coverage of one-dose MMR in the 2005 birth cohort was 71.38%. For the 2006-2010 birth cohort, the coverage of one-dose MuCV was 96.82% and the coverage of two-dose MuCV was 17.68%. The children born from 2011 to 2016 were only free vaccinated with MMR; the coverage of one-dose MuCV was 99.10%. The mumps incidence in the three birth cohorts significantly declined (X 2 = 805.90, P < 0.001 for trend). Except the children less than two years old, the mumps incidence for the children born from 2006 to 2010 was higher than that for the children born from 2011 to 2016.

CONCLUSION

The mumps incidence significantly declined following the introduction of one-dose MMR. The SIA using MM led to a rapid reduction of mumps cases. Therefore, we recommend a two-dose MuCV routine immunization schedule and improved vaccination coverage.

Current Status of Mumps Virus Infection: Epidemiology, Pathogenesis, and Vaccine

Mumps is an important childhood infectious disease caused by mumps virus (MuV). We reviewed the epidemiology, pathogenesis, and vaccine development of mumps. Previous studies were identified using the key words “mumps” and “epidemiology”, “pathogenesis” or “vaccine” in MEDLINE, PubMed, Embase, Web of Science, and Google Scholar. We excluded the articles that were not published in the English language, manuscripts without abstracts, and opinion articles from the review. The number of cases caused by MuV decreased steeply after the introduction of the mumps vaccine worldwide. In recent years, a global resurgence of mumps cases in developed countries and cases of aseptic meningitis caused by some mumps vaccine strains have renewed the importance of MuV infection worldwide. The performance of mumps vaccination has become an important issue for controlling mumps infections. Vaccine development and routine vaccination are still effective measures to globally reduce the incidence of mumps infections. During outbreaks, a third of MMR vaccine is recommended for groups of persons determined by public authorities.

Impact of the MMR vaccine on the incidence of mumps in the Community of Madrid and evaluation of the effectiveness of the Jeryl-Lynn strain. Years 1998-2016

INTRODUCTION

Mumps is characterised by parotid inflammation and fever and is preventable by vaccination with MMR vaccine. The objective of the study is to assess the impact and effectiveness of the vaccine.

MATERIAL AND METHODS

Cases notified to the Notifiable Disease System between 1998 and 2016 were used for the study. The vaccine effectiveness (VE) was calculated in cohorts vaccinated with two doses of Jeryl-Lynn, and the impact was calculated by comparing incidences by age and by Rubini (1995-1998) and Jeryl-Lynn (1999-2002) cohorts during the periods 1998-2004, 2005-2009 and 2010-2015. The incidences for age group and period were compared with the previous period and the incidences for cohorts were compared within a period with incidence ratios (IR) using Poisson models. The VE was estimated using the screening method using logistic regression models.

RESULTS

13,816 cases were reported. The incidence in 2005-2009 was higher than in 1998-2004 (IR: 1.46, 95% CI: 1.40-1.53), and it remained stable in 2010-2015 (IR: 0.99, 95% CI: 0.95-1.03). The average incidence rate of the Rubini cohort was 69.43 and the Jeryl-Lynn cohort was 32.24. The IR was 0.25 (95% CI: 0.22-0.29), 0.55 (95% CI: 0.49-0.61) and 0.88 (95% CI: 0.76-1.00) for each period respectively. 2,574 cases were included in the VE study. EV decreased over time reaching not significant values after seven years of follow-up (VE: 55%, 95% CI: 82 to -12%).

CONCLUSIONS

Parotiditis behavior is characterised by fluctuations, changes in presentation and a decrease in VE.

Mumps in the Vaccination Age: Global Epidemiology and the Situation in Germany

Vaccination against mumps virus (MuV) (mostly measles-mumps-rubella) is routinely performed in more than 120 countries and has resulted in a distinct decrease of mumps incidence. However, alteration of mumps epidemiology has been observed in several countries after implementation of the vaccine but is sparsely documented. Moreover, outbreaks have occurred after starting vaccination, even in highly vaccinated populations. In the former German Democratic Republic (DDR) mumps was a notifiable disease but vaccination against mumps was not implemented. In the five eastern German states forming the DDR until 1990, mumps was not notifiable until 2001. Except for the lack of reporting between 1990–2000, data from Eastern Germany allow analysis of mumps epidemiology after initiating the vaccination campaign. For the period from 2001 to 2016 the data show that the incidence of mumps dropped notably after initiating vaccines, and was accompanied by an increase of the median age of patients with mumps. In Eastern Germany, no outbreaks were noted, while several outbreaks occurred in Western Germany, possibly due to a lower vaccination rate. Further literature analysis revealed that outbreaks were facilitated by waning immunity and crowding. Nevertheless, although vaccination prevented infection, the course of illness, once infected, was sometimes more complicated. In comparison to non-vaccinated populations, high rates of complicated courses occurred and were marked by orchitis, due to higher age of mumps patients. Therefore, refusing vaccination against mumps increases the risk of severe courses when living in a vaccinated population.

Shift within age-groups of mumps incidence, hospitalizations and severe complications in a highly vaccinated population. Spain, 1998-2014

The mumps vaccine (Jeryl-Lynn-strain) was introduced in Spain in 1981, and a vaccination policy which included a second dose was added in 1995. From 1992-1999, a Rubini-strain based vaccine was administered in many regions but later withdrawn due to lack of effectiveness. Despite high levels of vaccination coverage, epidemics have continued to appear. We characterized the three epidemic waves of mumps between 1998 and 2014, identifying major changes in susceptible populations using Poisson regression. For the period 1998-2003 (P1), the most affected group was from 1 to 4years old (y) [Incidence Rate (IR)=71.7 cases/100,000 population]; in the periods 2004-2009 (P2) and 2010-2014 (P3) IR ratio (IRR) increased among 15-24y (P2=1.46; P3=2.68) and 25-34y (P2=2.17; P3=4.05). Hospitalization rate (HR), complication rate (CR) and neurological complication rate (NR) among hospitalized subjects decreased across the epidemics, except for 25-34y which increased: HR ratio (HRR) (P2=2.18; P3=2.16), CRR (P3=2.48), NRR (P3=2.41). In Spain mumps incidence increased, while an overall decrease of hospitalizations and severe complications occurred across the epidemics. Cohorts born during periods of low vaccination coverage and those vaccinated with Rubini-strain were the most affected populations, leading to a shift in mumps cases from children to adolescents and young adults; this also reveals the waning immunity provided by the mumps vaccine. Despite not preventing all mumps cases, the vaccine appears to prevent serious forms of the disease.

Protective effect of vaccination against mumps complications, Czech Republic, 2007-2012

Background

In the Czech Republic, two-dose immunization against mumps achieves 98 % coverage. The routine reporting detects mumps cases, clinical complications, and hospital admissions in unvaccinated but also in vaccinated individuals. Using surveillance data of patients with mumps we assessed the effectiveness of mumps vaccination on mumps clinical complications and hospitalization need. We also investigated the effect of the time since immunization.

Methods

We analysed data on incident mumps cases reported to the Czech national surveillance system in 2007–2012. Using a logistic regression model with adjustment for age, sex, year of onset, and the administrative region, the association between vaccination and the most frequent mumps complications and hospitalization was evaluated. The adjusted odds ratios (ORa) for mumps complications were compared between the vaccinated and non-vaccinated groups, reflecting the vaccine effectiveness (VEa) computed as VEa = (1-ORa)×100. We estimated the risk of mumps complications by the time from vaccination.

Results

From total of 9663 mumps analysed cases 5600 (58 %) occurred in males. The mean age at the disease onset was 17.3, median 16 years. Ninety percent of the study patients had no complications, while 1.6 % developed meningitis, 0.2 % encephalitis, and 0.6 % pancreatitis. Mumps orchitis occurred in 659 (11.8 %) male cases. In total, 1192 (12.3 %) patients required hospitalization. Two doses of vaccine received by 81.8 % cases significantly reduced the risk of hospitalization: ORa 0.29 (95 % CI: 0.24, 0.35). Two doses showed statistically significant VEa 64 % (95 % CI: 46, 79) for meningitis, 93 % (95 % CI: 66, 98) for encephalitis in all cases, and 72 % (95 % CI: 64, 78) for orchitis in males. Vaccine effectiveness for orchitis declined from 81 to 74 % and 56 % in the most affected age groups 10–14, 15–19, and 20–24 years, respectively. Among 7850 two-dose recipients, the rate of complications rose from below 1 to 16 % in categories up to 6 years and 24 and more years after the second dose, respectively.

Conclusions

This study demonstrates a significant preventive effect of two-dose vaccination against mumps complications (orchitis, meningitis, or encephalitis) and hospitalization for mumps. The risk of complications increases with time interval from vaccination. Teenagers and young adults were the most affected age groups.

Mumps resurgence in Denmark

BACKGROUND

The past decade has witnessed a resurgence of parotitisvirus (mumps) in several countries where seemingly good mumps control otherwise had been achieved through vaccination. Recently detection of mumps has increased in Denmark.

OBJECTIVES

To describe the age-specific changes and time trends of parotitisvirus detection in Denmark over a 10 year period.

STUDY DESIGN

Retrospective cohort study based on national laboratory data for parotitisvirus typing surveillance and national epidemiology data for mumps reporting.

RESULTS

The parotitisvirus detection rate has increased almost 10 times during the past 10 years from an incidence <0.1 per 100,000 in 2003 to 0.96 per 100,000 in 2013. The age distribution has shifted from children to young adults, and most cases are unvaccinated (54%) or vaccinated once (41%). The increase is due mainly to the existence of cohorts with low MMR vaccine coverage.

CONCLUSION

Analysis of mumps surveillance data from Denmark documents that the incidence of mumps is increasing, and that the resurgence of parotitisvirus is primarily occurring among young Danish adults. Almost half of the infected clinical mumps cases had received the first dose of MMR.

Mumps vaccine effectiveness and risk factors for disease in households during an outbreak in New York City

BACKGROUND AND OBJECTIVES

Mumps outbreaks have been reported among vaccinated populations, and declining mumps vaccine effectiveness (VE) has been suggested as one possible cause. During a large mumps outbreak in New York City, we assessed: (1) VE of measles-mumps-rubella vaccine (MMR) against mumps and (2) risk factors for acquiring mumps in households.

METHODS

Cases of mumps were investigated using standard methods. Additional information on disease and vaccination status of household contacts was collected. Case households completed follow-up phone interviews 78-198 days after initial investigation to ascertain additional cases. Mumps cases meeting the study case definition were included in the analysis. Risk factors for mumps were assessed, and VE was calculated using secondary household attack rates.

RESULTS

Three hundred and eleven households with 2176 residents were included in the analysis. The median age of residents was 13 years (range <1-85), and 462 (21.2%) residents met the study mumps case definition. Among 7-17 year olds, 89.7% received one or more doses of MMR vaccine, with 76.7% receiving two doses. Young adults aged 10-14 years (OR=2.4, CI=1.3-4.7) and 15-19 years (OR=2.5, CI=1.3-5.0) were at highest risk of mumps. The overall 2-dose VE for secondary contacts aged five and older was 86.3% (CI 63.3-94.9).

CONCLUSIONS

The two-dose effectiveness of MMR vaccine against mumps was 86.3%, consistent with other published mumps VE estimates. Many factors likely contributed to this outbreak. Suboptimal MMR coverage in the affected population combined with VE may not have conferred adequate immunity to prevent transmission and may have contributed to this outbreak. Achieving high MMR coverage remains the best available strategy for prevention of mumps outbreaks.

Effectiveness of one dose of mumps vaccine against clinically diagnosed mumps in Guangzhou, China, 2006-2012

Although mumps-containing vaccines were introduced in China in 1990s, mumps continues to be a public health concern due to the lack of decline in reported mumps cases. To assess the mumps vaccine effectiveness (VE) in Guangzhou, China, we performed a 1:1 matched case-control study. Among children in Guangzhou aged 8 mo to 12 y during 2006 to 2012, we matched one healthy child to each child with clinically diagnosed mumps. Cases with clinically diagnosed mumps were identified from surveillance sites system and healthy controls were randomly sampled from the Children's Expanded Programmed Immunization Administrative Computerized System in Guangzhou. Conditional logistic regression was used to calculate VE. We analyzed the vaccination information for 1983 mumps case subjects and 1983 matched controls and found that the overall VE for 1 dose of mumps vaccine, irrespective of the manufacture, was 53.6% (95% confidence interval [CI], 41.0-63.5%) to children aged 8 mo to 12 y. This post-marketing mumps VE study found that immunization with one dose of the mumps vaccine confers partial protection against mumps disease. Evaluation of the VE for the current mumps vaccines, introduction of a second dose of mumps vaccine, and assessment of modifications to childhood immunization schedules is essential.

Seroepidemiology of mumps in Europe (1996-2008): why do outbreaks occur in highly vaccinated populations?

Mumps outbreaks have recently been recorded in a number of highly vaccinated populations. We related seroprevalence, epidemiological and vaccination data from 18 European countries participating in The European Sero-Epidemiology Network (ESEN) to their risk of mumps outbreaks in order to inform vaccination strategies. Samples from national population serum banks were collected, tested for mumps IgG antibodies and standardized for international comparisons. A comparative analysis between countries was undertaken using age-specific mumps seroprevalence data and information on reported mumps incidence, vaccine strains, vaccination programmes and vaccine coverage 5-12 years after sera collection. Mean geometric mumps antibody titres were lower in mumps outbreak countries [odds ratio (OR) 0·09, 95% confidence interval (CI) 0·01-0·71)]. MMR1 vaccine coverage ⩾95% remained protective in a multivariable model (P < 0·001), as did an interval of 4-8 years between doses (OR 0·08, 95% CI 0·01-0·85). Preventing outbreaks and controlling mumps probably requires several elements, including high-coverage vaccination programmes with MMR vaccine with 4-8 years between doses.

Vaccines for measles, mumps and rubella in children

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.

Recent mumps outbreaks in vaccinated populations: no evidence of immune escape

Recently, numerous large-scale mumps outbreaks have occurred in vaccinated populations. Clinical isolates sequenced from these outbreaks have invariably been of genotypes distinct from those of vaccine viruses, raising concern that certain mumps virus strains may escape vaccine-induced immunity. To investigate this concern, sera obtained from children 6 weeks after receipt of measles, mumps, and rubella (MMR) vaccine were tested for the ability to neutralize a carefully selected group of genetically diverse mumps virus strains. Although the geometric mean neutralizing antibody titer of the sera was lower against some virus strains than others, all viruses were readily neutralized, arguing against immune escape.

[Study of a population-wide epidemic outbreak of mumps virus G1 in Jerez de la Frontera (Spain)]

OBJECTIVES

To characterize the mumps outbreak, assess the effectiveness of vaccines and discuss prevention and control measures.

DESIGN

Observational cross-sectional study of cases by person, place, and time.

LOCATION

City Jerez de la Frontera and 8 Primary Care centres.

PARTICIPANTS

A total of 116 cases of mumps were reported throughout seven months, with the last case in June 2008.

MEASUREMENTS

MAIN OUTCOMES

age, sex, place of study or work, symptoms start date, clinical description, complications, and genotype of virus isolation, history and vaccination compositions. Calculation of total vaccine effectiveness. Active case finding and contact studies were performed on the families, work places and leisure areas.

RESULTS

The mean age of the cases was 16.24 years(SD 10.6). The majority (68.96%) of the cases were children at school and 31.03% arose from family and work areas. Mumps vaccine coverage rates were above 90%. The complete vaccine effectiveness (2 doses); for those under 20 years-old it was: 99.84% (95% CI=99.77 - 99.89), being lower in schools with the highest attack rate, immunised with current vaccine from Jeryl Lynn strain: 71.01% (95% CI=55.85 80.97). Two doses of this strain were used in 13.79% of the cases. Susceptible populations were vaccinated at the start of the outbreak: 11,381 doses used in schools and 93 outside schools.

CONCLUSIONS

An outbreak of mumps virus G 1 population with high rates of mumps vaccine coverage, with areas with low vaccine effectiveness with current vaccine. Mass vaccination of population has contributed to the resolution of the outbreak.

Persistence of antibodies in 4-8 year old Austrian children after vaccination with hexavalent DTaP-HBV-IPV/Hib and MMR vaccines

To determine the proficiency of the Austrian childhood vaccination schedule to induce long lasting seroprotection against vaccine preventable diseases a seroepidemiological study in 348 children between four and eight years of age was conducted. Antibodies against diphtheria, tetanus, pertussis, hepatitis B, measles, mumps and rubella antigens were assessed in children, who had been vaccinated with hexavalent DTaP-HBV-IPV/Hib vaccines at three, four, five months and in the second year of life and/or MMR vaccines in the second year of life at least once, but mostly twice. High seroprotection rates (SPRs) were detected for tetanus (96%) and measles (90%). SPRs regarding diphtheria and mumps were 81% and 72%, respectively. Rubella-SPRs were 68% in females and 58% in males. Hepatitis B-antibody levels ≥10 mIU/mL were present in 52%; antibodies against pertussis were detected in 27% of the children. SPRs for measles and rubella depended on the interval since last vaccination; mumps-antibodies were significantly lower after one MMR-vaccination only. Antibodies against diphtheria, tetanus and pertussis depended on the interval since last vaccination while HBs-antibodies did not. The low levels of antibodies 1-7 years after vaccination against pertussis, rubella and mumps after only one vaccination should be considered when recommending new vaccination schedules.

Assessment of mumps virus-specific antibodies by different serological assays: which test correlates best with mumps immunity?

Mumps is one of the vaccine-preventable childhood diseases and it has not yet been eradicated in Germany. This raises the question as to whether the available mumps vaccines are effective enough to prevent mumps and which antibody test system allows the authentic assigning of mumps-specific immunity. In an attempt to answer this question, we analysed 227 sera samples from medical students of the University Hospital Frankfurt/Main, Germany, using different test systems: indirect immune fluorescence, neutralisation assay, routine ELISA and newly developed immunoassays, which contain the mumps nucleoprotein and the wild-type strain Enders ATCC VR106, respectively. Mumps vaccination coverage of the screened collective amounted to 75.1%, which differs notably from the detected mumps-specific seropositivity rates in the literature (range 53.3% to 82.4%). In contrast, a small group of unvaccinated students had much higher seropositivity rates. Of course, assigned vaccination coverage and calculated seropositivity rates are not effective enough to interrupt the transmission of the mumps virus. The often-occurring mumps outbreaks, some in highly vaccinated populations, may not always demonstrate vaccine failure. The investigation of newly developed test systems and the occurrence of different mumps virus genotypes should also be considered.

Mumps vaccine effectiveness in highly immunized populations

The aim of the study was to investigate effectiveness of mumps MMR component in communities with high MMR coverage. Outbreak-related cases of mumps born between 1995 and 2005 notified to Navarre and Catalonia public health services during the period 2005-2007 were studied. Vaccine effectiveness (VE) and their 95%CI were calculated using the screening method. Of 47 confirmed, 85.1% immunized with at least one dose (1MMR) and 44.9% with two (2MMR). Estimated VE was 85.4% (95%CI: 67.3-93.4) for 1MMR and 88.5% (95%CI: 78.1-93.9) for 2MMR. High 2MMR coverage, improved confirmation techniques and further VE studies with all confirmed cases are needed to prevent further outbreaks.