An epidemiological assessment towards elimination of rubella and congenital rubella syndrome in Singapore

ObjectiveIn line with regional and global goals for the elimination of rubella and congenital rubella syndrome (CRS), we reviewed the epidemiological situation in Singapore, based on surveillance reports on rubella and CRS, national immunization coverage and seroprevalence surveys. The aim of our review was to identify current gaps and steps taken to achieve the targets set by the World Health Organization (WHO) Western Pacific Regional Office (WPRO).MethodsEpidemiological data on clinical and laboratory-confirmed rubella cases, including CRS, notified to the Communicable Diseases Division, Ministry of Health, Singapore, from 2003 to 2013 were collated and analyzed. Vaccination coverage against rubella was obtained from the National Immunization Registry and School Health Services of the Health Promotion Board. The changing prevalence of rubella was determined from periodic serological surveys.FindingsThe incidence of indigenous rubella cases per million population decreased from 37.2 in 2008 to 7.6 in 2013 and there had been no indigenous case of CRS in 2012 and 2013. Therapeutic abortions performed due to rubella infections had become uncommon. The annual measles, mumps, and rubella (MMR) vaccination coverage in childhood population remained high ranging from 93% to 96%. The overall susceptibility to rubella in women aged 18–44 years had reduced significantly from 15.8% in 2004 to 11.0% in 2010. The prevalence of IgG antibody against rubella among Singapore children aged 1–17 years was maintained at 87.3% in 2008–2010.ConclusionAll available data indicated that Singapore has made good progress towards the elimination of rubella and CRS. It has attained the targets set by the WHO WPRO for 2015. In preparation for verification of rubella elimination, an enhanced surveillance system has been implemented to ensure that all reported cases are laboratory confirmed, and genotyping of rubella virus strains isolated is carried out to provide evidence for interruption of endemic transmission.     

Febrile seizures following measles and varicella vaccines in young children in Australia

BackgroundFebrile seizures (FS) are common in childhood with incidence peaking in the second year of life when measles and varicella-containing vaccines are administered. This study aimed to examine the vaccine-attributable risk of FS following separate administration of MMR and monovalent varicella vaccines (VV) prior to a planned change to MMRV as the second dose of measles-containing vaccine at 18 months of age.MethodsAll FS cases in children aged <5 years from 1st January 2012 to 30th April 2013 were identified from emergency department (ED) and inpatient databases at five Australian tertiary paediatric hospitals participating in PAEDS (Paediatric Active Enhanced Disease Surveillance). Immunization records were obtained from the Australian Childhood Immunization Register (ACIR). The relative incidence (RI) of FS following MMR dose 1 (MMR1) and VV in children aged 11–23 months was determined using the self-controlled case series (SCCS) method and used to calculate attributable risk.ResultsThere were 2013 FS episodes in 1761 children. The peak age at FS was 18 months. The risk of FS was significantly increased 5–12 days post receipt of MMR1 at 12 months (RI = 1.9 [95% CI: 1.3–2.9]), but not after VV at 18 months (RI = 0.6 [95% CI: 0.3–1.2]. The estimated excess annual number of FS post MMR1 was 24 per 100,000 vaccinated children aged 11–23 months (95% CI = 7–49 cases per 100,000) or 1 per 4167 doses.ConclusionsOur study detected the expected increased FS risk post MMR1 vaccine at 12 months, but monovalent varicella vaccine at age 18 months was not associated with increased risk of FS. This provides baseline data to assess the risk of FS post MMRV, introduced in Australia as the second dose of measles-containing vaccine at 18 months of age in July 2013.     

MMR vaccination status of children exempted from school-entry immunization mandates

BackgroundChild immunizations are one of the most successful public health interventions of the past century. Still, parental vaccine hesitancy is widespread and increasing. One manifestation of this are rising rates of nonmedical or “personal beliefs” exemptions (PBEs) from school-entry immunization mandates. Exemptions have been shown to be associated with increased risk of disease outbreak, but the strength of this association depends critically on the true vaccination status of exempted children, which has not been assessed.ObjectiveTo estimate the true measles-mumps-rubella (MMR) vaccination status of children with PBEs.MethodsWe use administrative data collected by the California Department of Public Health in 2009 and imputation to estimate the MMR vaccination status of children with PBEs under varying scenarios.ResultsResults from 2009 surveillance data indicate MMR1/MMR2 coverage of 18–47% among children with PBEs at typical schools and 11–34% among children with PBEs at schools with high PBE rates. Imputation scenarios point to much higher coverage (64–92% for MMR1 and 25–58% for MMR2 at typical schools; 49–90% for MMR1 and 16–63% for MMR2 at high PBE schools) but still below levels needed to maintain herd immunity against measles.ConclusionsThese coverage estimates suggest that prior analyses of the relative risk of measles associated with vaccine refusal underestimate that risk by an order of magnitude of 2–10 times.     

Antibodies to measles,mumps, and rubella virus in Thai children after two-dose vaccination at 9 months and 2.5 years: A longitudinal study

IntroductionThailand changed the schedule of childhood measles–mumps–rubella (MMR) vaccination in 2014, moving the second dose from the age of 6 years to 2.5 years. There are currently no data on antibody responses to the MMR vaccine since this recommendation.Material and methodsWe investigated antibody responses in a cohort of children who received two doses of MMR vaccine at the ages of 9 months and 2.5 years that was originally established to evaluate antibody levels to Bordetella pertussis antigens (ClinicalTrials.gov no. NCT02408926). Infants were born to mothers who previously received tetanus–diphtheria–acellular pertussis vaccine at 27–36 weeks of gestation. Anti-measles, -mumps, and -rubella virus IgG levels were measured at birth (cord blood) and the ages of 2 and 7 months (before the first MMR vaccination); 18 and 24 months (9 and 15 months, respectively, after the first dose); and 36 months (6 months after the second dose) using commercially available enzyme-linked immunosorbent assay kits.ResultsAt 7 months of age, 96.2%, 99.6%, and 98.8% of infants had no protection against measles, mumps, and rubella, respectively. Levels of antibody against all three antigens increased significantly after the first but not the second dose. At 6 months after two-dose vaccination, 97.4%, 84.8%, and 78.7% of children remained seroprotected against measles, mumps, and rubella, respectively.ConclusionsMaternally derived antibodies to measles, mumps, and rubella virus disappeared by the age of 7 months in Thai children. Two-dose MMR vaccination at 9 months and 2.5 years of age induced robust immune responses against these viruses.     

Vaccine coverage and adherence to EPI schedules in eight resource poor settings in the MAL-ED cohort study

BackgroundLaunched in 1974, the Expanded Program on Immunization (EPI) is estimated to prevent two-three million deaths annually from polio, diphtheria, tuberculosis, pertussis, measles, and tetanus. Additional lives could be saved through better understanding what influences adherence to the EPI schedule in specific settings.MethodsThe Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) study followed cohorts in eight sites in South Asia, Africa, and South America and monitored vaccine receipt over the first two years of life for the children enrolled in the study. Vaccination histories were obtained monthly from vaccination cards, local clinic records and/or caregiver reports. Vaccination histories were compared against the prescribed EPI schedules for each country, and coverage rates were examined in relation to the timing of vaccination. The influence of socioeconomic factors on vaccine timing and coverage was also considered.ResultsCoverage rates for EPI vaccines varied between sites and by type of vaccine; overall, coverage was highest in the Nepal and Bangladesh sites and lowest in the Tanzania and Brazil sites. Bacillus Calmette-Guérin coverage was high across all sites, 87–100%, whereas measles vaccination rates ranged widely, 73–100%. Significant delays between the scheduled administration age and actual vaccination date were present in all sites, especially for measles vaccine where less than 40% were administered on schedule. A range of socioeconomic factors were significantly associated with vaccination status in study children but these results were largely site-specific.ConclusionsOur findings highlight the need to improve measles vaccination rates and reduce delayed vaccination to achieve EPI targets related to the establishment of herd immunity and reduction in disease transmission.     

Seroprevalence of Antibodies to Measles, Mumps, and Rubella among Thai Population: Evaluation of Measles/MMR Immunization Programme

Stored serum specimens, from four regions of Thailand, of healthy children attending well baby clinics and of healthy people with acute illnesses visiting outpatient clinics were randomly sampled and tested for IgG antibody to measles, mumps, and rubella (MMR). The immunity patterns of rubella and mumps fitted well with the history of rubella and MMR vaccination, seroprotective rates being over 85% among those aged over seven years. A high proportion of younger children acquired the infection before the age of vaccination. MMR vaccination should preferably be given to children at an earlier age. For measles, 73% seroprotective rates among children, aged 8-14 years, who should have received two doses of measles/MMR vaccine, were lower than expected. This finding was consistent with the age-group reported in outbreaks of measles in Thailand. The apparent ineffectiveness (in relation to measles) of MMR immunization of 1^st grade students warrants further studies.Key words: Antibodies, Immunization, Measles, Measles vaccine, Mumps, MMR vaccine, Rubella, Seroepidemiologic studies, Seroprevalence, Vaccination, Thailand     

Immunogenicity and efficacy of one dose measles-mumps-rubella (MMR) vaccine at twelve months of age as compared to monovalent measles vaccination at nine months followed by MMR revaccination at fifteen months of age

BACKGROUND AND METHODS: measles is a common cause of morbidity and mortality in developing countries. Although the measles-mumps-rubella vaccine (MMR) is currently in use in developed countries, monovalent measles vaccine (MV) is routinely recommended by World Health Organization (WHO) at 9 months of age in Turkey, as in many other developing countries. In this study, 442 Turkish children received MV at 9 months of age and were revaccinated with MMR vaccine at 15 months of age. In the second group 495 children received MMR at 12 months of age with no earlier measles vaccination. Antibodies were measured before the first vaccination and 6 weeks after the MMR. All children had been followed for occurrence of measles infection for 60 months. Two vaccination schedules were compared for immunogenicity and protection rates. CONCLUSIONS: seroconversion and clinical protection rates were significantly higher in children who received only MMR at 12 months of age than in children revaccinated at 15 months of age. Seroconversion rate for measles was 69.9% in children who received MMR at 12 months of age and 90.3% in children revaccinated at 15 months of age (P=0.0003). While there was no measles case in children who were revaccinated, 12 (2.7%) children in the first group acquired measles during the follow-up period. Vaccination at 12 months of age appeared to be better than the current national standard. The late elimination of maternal antibodies and the inhibitory effect of a weak antibody response after the first dose of vaccine at 9 months may explain the better immunogenicity and efficacy of the MMR vaccine given at 12 months of age.     

The impact of Australia's measles control programme over the past decade

We reviewed measles surveillance data for 1993-2002 to determine the impact of Australia's measles control initiatives. The introduction of a second dose of measles-mumps-rubella (MMR) vaccine for 10- to 16-year-olds in 1993 was followed by marked reductions in measles notifications and hospitalizations, especially in the targeted age group. Further rate reductions were achieved following the Measles Control Campaign (MCC) in 1998, which involved a catch-up campaign for primary-school-aged children and lowering the age for the second dose of MMR vaccine to 4 years. Since the MCC, outbreaks have continued to occur, but most had a source case who was infected overseas, which suggests that indigenous transmission has been interrupted. In addition, a greater proportion of cases have been in adults although infants aged < 5 years still had the highest rates. In conclusion, Australia is making good progress towards measles elimination. However, as in other countries, this progress can be sustained only by maintaining high vaccination coverage with the routine childhood vaccination schedule.     

Timeliness of childhood vaccination in the Federated States of Micronesia

BackgroundVaccination coverage is typically measured as the proportion of individuals who have received recommended vaccine doses by the date of assessment. This approach does not provide information about receipt of vaccines by the recommended age, which is critical for ensuring optimal protection from vaccine-preventable diseases (VPDs).ObjectiveTo assess vaccination timeliness in the Federated States of Micronesia (FSM), and the projected impact of suboptimal vaccination in the event of an outbreak.MethodsTimeliness of the 4^th dose of diphtheria, tetanus, and acellular pertussis vaccine (DTaP) and 1^st dose of measles, mumps, and rubella vaccine (MMR) among children 24–35 months was assessed in FSM. Both doses are defined as on time if administered from 361 through 395 days in age. Timeliness was calculated by one-way frequency analysis, and dose delays, measured in months after recommended age, were described using inverse Kaplan-Meier analysis. A time-series susceptible-exposed-infected-recovery (TSEIR) model simulated measles outbreaks in populations with on time and late vaccination.ResultsTotal coverage for the 4^th dose of DTaP ranged from 36.6% to 98.8%, and for the 1^st dose of MMR ranged from 80.9% to 100.0% across FSM states. On time coverage for the 4^th dose of DTaP ranged from 3.2% to 52.3%, and for the 1^st dose of MMR ranged from 21.1% to 66.9%. Maximum and median dose delays beyond the recommended age varied by state. TSEIR models predicted 10.8–13.7% increases in measles cases during an outbreak based on these delays.ConclusionsIn each of the FSM states, a substantial proportion of children received DTaP and MMR doses outside the recommended timeframe. Children who receive vaccinations later than recommended remain susceptible to VPDs during the period they remain unvaccinated, which may have a substantial impact on health systems during an outbreak. Immunization programs should consider vaccination timeliness in addition to coverage as a measure of susceptibility to VPDs in young children.     

Measles clinical presentation,hospitalization and vaccination status among children in a community-wide outbreak

BackgroundIn 2018–2019, a measles outbreak emerged in Israel (4158 notified cases). We aimed to evaluate the measles characteristics and the vaccination status among children during the outbreak.MethodsWe performed a cross-sectional study of measles cases in children under 18 years, residing in the Jerusalem district (2254 notified measles cases, June 2018-May 2019). The variables included: clinical symptoms (fever, rash, cough, coryza, conjunctivitis), hospitalizations and child’s vaccination status. The national measles vaccination schedule includes two vaccine doses (at ages 12 months and 6 years).ResultsChildren, under 18 years, comprised 79% (1782/2254) of the notified measles cases. The hospitalization rate was 6.6%. There was one fatality. The measles vaccination status was analyzed by age groups. Infants under 12 months (n = 425) were excluded. Children aged 1–5 years (n = 785) and 6–17 years (n = 572) were expected to receive 1 and 2 measles vaccine doses, respectively. Most (88%) children (1–17 years) were unvaccinated, 138 received 1 measles vaccine dose and 24 received 2 doses. Of children aged 1–5 years 106 (13.5%) received 1 vaccine dose and were compared to unvaccinated children. Vaccinated children showed lower rates of clinical symptoms and lower risk for hospitalization compared to unvaccinated children (Odds ratio: OR = 4.8, 95%CI 1.12–20.2). Vaccine effectiveness of 79% was estimated for one measles vaccine dose against hospitalization.ConclusionsData on vaccine effectiveness reflect how well vaccines protect children against infection and morbidity. We evaluated the real-world effectiveness of measles vaccine, in an outbreak setting, and showed reduced morbidity in once-vaccinated children.     

Progress and challenges in measles and rubella elimination in the WHO European Region

IntroductionDespite availability of safe and cost-effective vaccines to prevent it, measles remains one of the significant causes of death among children under five years of age globally. The World Health Organization (WHO) European Region has seen a drastic decline in measles and rubella cases in recent years, and a few of the once common measles genotypes are no longer detected. Buoyed by this success, all Member States of the Region reconfirmed their commitment in 2010 to eliminating measles and rubella, and made this a central objective of the European Vaccine Action Plan 2015–2020 (EVAP). Nevertheless, sporadic outbreaks continue, recently affecting primarily adolescents and young adults with no vaccination or an incomplete vaccination history. The European Regional Verification Commission for Measles and Rubella Elimination was established in 2011 to evaluate the status of measles and rubella elimination based on documentation submitted annually by each country’s national verification committee.DiscussionEach country’s commitment to eliminate measles and rubella is influenced by competing health priorities, and in some cases lack of capacity and resources. All countries need to improve case-base surveillance for both measles and rubella, ensure documentation of each outbreak and strengthen the link between epidemiology and laboratory data. Achieving high coverage with measles- and rubella-containing vaccines will require a multisectoral approach to address the root causes of lower uptake in identified communities including service delivery challenges or vaccine safety concerns caused by circulating myths about vaccination.ConclusionsThe WHO European Region has made steady progress towards eliminating measles and rubella and over half of the countries interrupted endemic transmission of both diseases by 2015. The programmatic challenges in disease surveillance, vaccination service delivery and communication in the remaining endemic countries should be addressed through periodic evaluation of the strategies by all stakeholders and exploring additional opportunities to accelerate the ongoing elimination activities.     

Mumps in Poland in 2002

In 2002, 39,978 cases of mumps were reported in Poland. The incidence (104.6 per 100,000) was higher then in 2001 (43.3), which corresponds to a periodical increase of mumps incidence occurring in Poland every 3-4 years. This year's peak is much lower than the previous ones, which can be attributed to the growing vaccine coverage. Even though the mumps vaccine was not included into the national immunization program, the coverage in the 3-year old children reached in 2002 35.5%. Approximately 3.5% of cases were hospitalized (1400) and no mumps deaths were reported. Children 5-9 years old constituted the most affected age group (incidence 965.2 per 100,000). In Poland the MMR vaccine was recommended on voluntary basis in place of measles vaccine for children in their 2nd and 7th year of age. Immunization of 2-years old children is mandatory beginning in 2004.     

The 1991 measles epidemic in Israel.

INTRODUCTION AND METHODS. Prior to the institution of universal childhood vaccination against measles in Israel in 1967, large outbreaks occurred in epidemic cycles at intervals of 2-4 years. The mean annual incidence in the pre-vaccination period, 1950-66, was 470/100,000 per year. With the institution of routine measles vaccination, incidence rates fell, and since 1970 measles incidence has averaged less than one-tenth the pre-vaccination incidence rate, although epidemics occurred in 1975, 1982, 1984-85, and 1991. In this report, based upon cases of measles reported to and investigated by the Ministry of Health, we present an analysis of the 1991 measles epidemic, the measures taken to contain it, and an overview of the prospects for measles control in Israel in the future. RESULTS AND CONCLUSIONS. The 1991 measles epidemic, 1036 reported cases (incidence: 20.0/100,000), began in the south of the country among underimmunized Beduin children and spread to the Jewish population in the south and then to the rest of the country. The highest incidence was in children aged 12-23 months, followed by children less than 12 months of age and children aged 2-4 years. In the main, cases occurred in persons never immunized in the past, but in 37% of cases vaccine failure seems to have occurred. Control measures included mass vaccination of children in the south and lowering the age for routine measles vaccination nationwide to 12 months. Despite very substantial gains towards measles control in Israel, elimination of the disease is not a realistic goal, mainly because the transmission potential of the disease is too high and vaccine coverage and efficacy are not high enough. Trends in measles incidence over the last four decades allow a cautious optimism that measles containment can be achieved.     

Antibody persistence in children aged 6–7 years one year following booster immunization with two MMR vaccines applied by aerosol or by injection

ImportanceIn a previous study on booster vaccination, we reported that two aerosolized MMR vaccines were as safe and immunogenic as injectable vaccines containing the same antigens. We now present results of antibody persistence one year after immunization.ObjectiveTo assess the antibody persistence for measles, mumps, and rubella one year following booster immunization.MethodsWe performed clinical and serological follow-up of participants in a previous study of Mexican children aged 6–7 years, in which participants were randomized to four groups receiving, by aerosolized or by injection, the MMR SII vaccine (Serum Institute of India), or the MMR II (Merck Sharp & Dhome). We evaluated the antibody persistence by PRN test for measles and by ELISA for rubella and mumps. The occurrence of clinical events was evaluated via periodic visits of a nurse team to children’s schools and homes.ResultsOf the 260 initial participants, 241 completed one-year follow-up. There were only statistically significant differences in baseline seropositivity for mumps. One year after immunization, seropositivity in all groups was 100% for measles and rubella. The seropositivity rank for mumps was from 90.3% for the injected vaccine MMR II to 96.6% for vaccine MMR SII applied by aerosol; these differences were not statistically significant. With exception of the aerosolized vaccine MMR SII for the geometric mean titer (GMT) for measles, all study groups presented declination of GMT for the three viruses. The difference between the aerosolized vaccines MMR SII and MMR RII was statistically significant for mumps antibodies. Only mild clinical events were identified.ConclusionUnder conditions of no endemic transmission for measles and rubella, and of low circulation of mumps virus, school-aged children remained seropositive to the three viruses one year following booster immunization.The study was registered under CMN 2010-005 number at COFEPRIS (National Regulatory Authority).     

Measuring the timeliness of childhood vaccinations: Using cohort data and routine health records to evaluate quality of immunisation services

BackgroundTo achieve full benefits of vaccination programmes, high uptake and timely receipt of vaccinations are required.ObjectivesTo examine uptake and timeliness of infant and pre-school booster vaccines using cohort study data linked to health records.MethodsWe included 1782 children, born between 2000 and 2001, participating in the Millennium Cohort Study and resident in Wales, whose parents gave consent for linkage to National Community Child Health Database records at the age seven year contact. We examined age at receipt, timeliness of vaccination (early, on-time, delayed, or never), and intervals between vaccine doses, based on the recommended schedule for children at that time, of the following vaccines: primary (diphtheria, tetanus, pertussis (DTP), polio, Meningococcal C (Men C), Haemophilus influenzae type b (Hib)); first dose of measles, mumps and rubella (MMR); and pre-school childhood vaccinations (DTP, polio, MMR). We compared parental report with child health recorded MMR vaccination status at age three years.ResultsWhile 94% of children received the first dose of primary vaccines early or on time, this was lower for subsequent doses (82%, 65% and 88% for second and third doses and pre-school booster respectively). Median intervals between doses exceeded the recommended schedule for all but the first dose with marked variation between children. There was high concordance (97%) between parental reported and child health recorded MMR status.ConclusionsRoutine immunisation records provide useful information on timely receipt of vaccines and can be used to assess the quality of childhood vaccination programmes. Parental report of MMR vaccine status is reliable.     

Measles–mumps–rubella vaccination and respiratory syncytial virus-associated hospital contact

BackgroundThe live measles vaccine has been associated with lower non-measles mortality and admissions in low-income countries. The live measles–mumps–rubella vaccine has also been associated with lower rate of admissions with any type of infection in Danish children; the association was strongest for admissions with lower respiratory infections.ObjectiveTo examine whether measles, mumps, and rubella (MMR) vaccination was associated with reduced rate of hospital contact related to respiratory syncytial virus (RSV) in a high-income country.MethodsNationwide cohort study of laboratory-confirmed RSV hospital contacts at age 14–23 months in all children born in Denmark 1997–2002 who had already received the vaccine against diphtheria, tetanus, pertussis (acellular), polio, and Haemophilus influenzae type b (DTaP-IPV-Hib) at the recommended ages of 3, 5, and 12 months.ResultsThe study included 888 RSV hospital contacts in 128,588 person years of follow up (rate 6.8/1000 person years). Having MMR as the most recent vaccine was associated with a reduced rate of RSV hospital contacts compared with having DTaP-IPV-Hib as the most recent vaccine (Incidence rate ratio (IRR), 0.75; 95% confidence interval (CI), 0.63–0.89). After adjustment for potential confounders including exact age in days the IRR was 0.78 (95% CI, 0.66–0.93). The adjusted IRR was 0.74 (95% CI, 0.60–0.92) in males and 0.84 (95% CI, 0.66–1.06) in females (P Interaction, 0.42). There was no association in the first month after MMR vaccination (adjusted IRR, 0.97; 95% CI, 0.76–1.24) but the adjusted IRR was 0.70 (95% CI, 0.58–0.85) from one month after MMR vaccination.ConclusionsMMR vaccination was associated with reduced rate of hospital contacts related to laboratory-confirmed RSV infection. Further research on the association between MMR vaccination and other unrelated pathogens are warranted.     

Immune non-interference and safety study of Vi-DT typhoid conjugate vaccine with a measles,mumps and rubella containing vaccine in 9–15 months old Nepalese infants

BackgroundTyphoid fever is a common disease in developing countries especially in the Indian subcontinent and Africa. The available typhoid conjugate vaccines (TCV) have been found to be highly immunogenic in infants and children less than 2 years of age. Many countries are planning to adopt TCV in their routine EPI programs around 9 months of age when measles containing vaccines are given. Therefore, Vi-DT TCV was tested in 9–15 months aged healthy infants in Nepal to demonstrate non-interference with a measles containing vaccine.MethodsThis was a randomized, open label, phase III study to assess the immune non-interference, safety, and reactogenicity of Vi-DT typhoid conjugate vaccine when given concomitantly with measles, mumps and rubella (MMR) vaccine. A total of 360 participants aged 9–15 months were enrolled and randomized equally into Vi-DT + MMR (180 participants) or MMR alone (180 participants) group and were evaluated for immunogenicity and safety 28 days post vaccination.ResultsUsing the immunogenicity set, difference between proportions (95% CI) of the Vi-DT + MMR group vs MMR alone group were ?2.73% (-8.85, 3.38), ?3.19% (-11.25, 4.88) and 2.91% (-3.36, 9.18) for sero-positivity rate of anti-measles, anti-mumps and anti- rubella, respectively. Only the lower bound of the range in difference of the proportions for sero-positivity rate of anti-mumps did not satisfy the non-inferiority criteria as it was above the ?10% limit, which may not be of clinical significance. These results were confirmed in the per protocol set. There were no safety concerns reported from the study and both Vi-DT + MMR and MMR alone groups were comparable in terms of solicited and unsolicited adverse events .ConclusionsResults indicated that there is non-interference of MMR vaccine with Vi-DT and Vi-DT conjugate vaccine could be considered as an addition to the EPI schedule among children at risk of contracting typhoid.     

A general measles vaccination campaign in urban Guinea-Bissau: Comparing child mortality among participants and non-participants

BackgroundMeasles vaccination campaigns targeting children aged 9–59 months are conducted every three years in Guinea-Bissau. Studies have demonstrated beneficial non-specific effects of measles vaccine. We compared mortality one year after the December 2012 measles vaccination campaign in Bissau city for children who received campaign measles vaccine with children who did not receive campaign measles vaccine.MethodsField workers from Bandim Health Project registered all children living in the Bandim Health Project’s study area who received measles vaccination at the campaign posts. Children not seen during the campaign were visited at home and campaign participation status was assessed. We compared mortality rates of participants vs. non-participants in Cox regression models.Results5633 children aged 9–59 months (85%) received campaign measles vaccination and 1006 (15%) did not. During the subsequent year 16 children died. Adjusted for background factors, the hazard ratio (HR) comparing measles vaccinated versus unvaccinated was 0.28 (95% CI: 0.10–0.77). The benefit was larger for girls (HR: 0.17 (0.05–0.59)) and for children who had received routine measles vaccine before the campaign (HR: 0.15 (0.04–0.63)).ConclusionsWe found indications of strong beneficial non-specific effects of receiving measles vaccine during the 2012 campaign, especially for girls and children with previous routine measles vaccination. Measles vaccination campaigns may be an effective way of improving child survival.     

Measles control in Maputo, Mozambique, using a single dose of Schwarz vaccine at age 9 months.

In Maputo city, immunization is available at government health facilities, all contacts being used to vaccinate children. Door-to-door mobilization is conducted to identify eligible children and refer them for immunization. Card-documented measles vaccine coverage, estimated by community surveys, rose from 48% in 1982 to 86% in 1986 and 92% in 1992. The median age at measles vaccination was 10.2 months in 1986 and 9.2 months in 1992. The reported measles incidence rates per 100,000 population fell by 92% from 569 in 1977-78 (pre-vaccination) to 44 in 1990-92, and the reported inpatient measles mortality fell from 19.8 to 0.7 per 100,000. Among children whose age at measles onset was known, the proportion of reported measles cases in children under 9 months of age fell from 2162 (20.3% of 10,636 cases) in 1982-85 to 1695 (17.8% of 9501 cases) in 1986-92. The proportion of cases in children aged > or = 5 years increased from 15.2% to 32.8% in the corresponding periods. The global goals for measles control can be achieved by a single dose of Schwarz vaccine at 9 months of age.     

Measles imported by returning U.S. travelers aged 6-23 months, 2001-2011

In the first 2 months of 2011, CDC received reports of seven imported measles cases among returning U.S. travelers aged 6-23 months; four required hospitalization. Young children are at greater risk for severe measles, death, or sequelae such as subacute sclerosing panencephalitis. Although all seven children had been eligible for vaccination before travel, none had received measles, mumps, and rubella (MMR) vaccine, the only measles-containing vaccine currently available in the United States. To characterize imported measles cases reported in the first 2 months of 2011 in U.S. travelers aged 6-23 months and compare them with cases in recent years, CDC analyzed data from the National Notifiable Diseases Surveillance System (NNDSS) for the period January 2001-February 2011. The results of that analysis indicated that, during January-February 2011, a total of 13 imported cases were reported in U.S. residents, including the seven children aged 6-23 months. During 2001-2010, a total of 159 imported cases were reported in U.S. residents, including 47 (range: 3-8 per year) in children aged 6-23 months (three of whom had been vaccinated before travel). Because measles remains endemic in much of the world, international travelers should be up-to-date on vaccinations. In accordance with the Advisory Committee for Immunization Practices (ACIP) recommendations, U.S. children who travel or live abroad should be vaccinated at an earlier age than those living in the United States because of the greater risk for exposure to measles outside the United States, and particularly outside the Americas.