Correlations between measles, mumps, and rubella serum antibody levels in Olmsted County school children

Measles, rubella, mumps and Toxoplasma gondii antibodies in saliva of vaccinated students of schools and universities in São Paulo City, Brazil

Introduction

Vaccines are well-established public health interventions with major impact on the prevalence of infectious diseases, but outbreaks are occurring frequently due to primary and secondary failures, despite high coverage. Surveillance of efficacy and duration of induced immunity is a difficult task as it requires invasive blood sampling in children and teenagers. Saliva can be an acceptable alternative source of IgG to assess vaccine efficacy and toxoplasmosis incidence. We investigated IgG response for measles, mumps, rubella, and T. gondii in saliva samples of vaccinated young people.

Methods

Saliva was collected from 249 public schools students from São Paulo, Brazil, aged 7 to 13 years old, during an interactive exhibition on hygiene. We used S. aureus protein A solid phase capture assay for IgG reactive to biotinylated purified proteins. Paired saliva and serum (47) were tested from young adults with serum evidence of T. gondii infection and from negative children less than 12 month old for standardization. Reproducibility was greater than 98% and sensitivity and specificity of the saliva assays were greater than 95%, as well as the concordance of paired saliva and serum samples.

Results

Saliva from high school students showed a prevalence of 8.5% (95% CI: 5.0–11.9%) for anti T. gondii IgG; 96.8% (94.6–99%) of anti-measles IgG; 59.1% (53–65%) of anti-rubella IgG, and 57.5% (51.3–63.6%) of anti-mumps IgG.

Discussion

The prevalence of antibodies against mumps and rubella after 6–8 years of vaccination was lower than against measles among students. The findings of this study demonstrate the feasibility of saliva sampling for follow-up of vaccine immune status in teenagers. This useful approach allows for IgG detection for vaccine control or epidemiological studies.

Systematic Review of Measles and Rubella Serology Studies

Serological tests provide information about individual immunity from historical infection or immunization. Cross-sectional serological studies provide data about the age- and sex-specific immunity levels for individuals in the studied population, and these data can provide a point of comparison for the results of transmission models. In the context of developing an integrated model for measles and rubella transmission, we reviewed the existing measles and rubella literature to identify the results of national serological studies that provided cross-sectional estimates of population immunity at the time of data collection. We systematically searched PubMed, the Science Citation Index, and references we identified from relevant articles published in English. We extracted serological data for comparison to transmission model outputs. For rubella, serological studies of women of child-bearing age provide information about the potential risks of infants born with congenital rubella syndrome. Serological studies also document the loss of maternal antibodies, which occurs at different rates for the different viruses and according to the nature of the induced immunity (i.e., infection or vaccine). The serological evidence remains limited for some areas, with studies from developed countries representing a disproportionate part of the evidence. The collection and review of serological evidence can help program managers identify immunity gaps in the population, which may help them better understand the characteristics of individuals within their populations who may participate in transmission and manage risks.

Humoral responses to independent vaccinations are correlated in healthy boosted adults

BACKGROUND

Roughly half of U.S. adults do not receive recommended booster vaccinations, but protective antibody levels are rarely measured in adults. Demographic factors, vaccination history, and responses to other vaccinations could help identify at-risk individuals. We sought to characterize rates of seroconversion and determine associations of humoral responses to multiple vaccinations in healthy adults.

METHODS

Humoral responses toward measles, mumps, tetanus toxoid, pertussis, hepatitis B surface antigen, and anthrax protective antigen were measured by ELISA in post-immunization samples from 1465 healthy U.S. military members. We examined the effects of demographic and clinical factors on immunization responses, as well as assessed correlations between vaccination responses.

RESULTS

Subsets of boosted adults did not have seroprotective levels of antibodies toward measles (10.4%), mumps (9.4%), pertussis (4.7%), hepatitis B (8.6%) or protective antigen (14.4%) detected. Half-lives of antibody responses were generally long (>30 years). Measles and mumps antibody levels were correlated (r=0.31, p<0.001), but not associated with select demographic features or vaccination history. Measles and mumps antibody levels also correlated with tetanus antibody response (r=0.11, p<0.001).

CONCLUSIONS

Vaccination responses are predominantly robust and vaccine specific. However, a small but significant portion of the vaccinated adult population may not have quantitative seroprotective antibody to common vaccine-preventable infections.

Does rubella immunity predict measles immunity? A serosurvey of pregnant women

BACKGROUND

This study was undertaken to determine whether rubella immunity infers measles immunity in pregnant women.

METHODS

Stored serum samples were obtained from the Iowa State Hygienic Laboratory for evaluation of rubella and measles immunities with IgG enzyme-linked immunosorbent assay.

RESULTS

Nine hundred serum samples were obtained for testing. The average age of the women at the time of antepartum serum collection was 28 (range, 14 to 44) years. Measles and rubella immunity were 88% and 98%, respectively; there was no effect of immunity status by age identified. Eighty eight percent of those with rubella immunity were also measles immune. There was no association between paired rubella and measles immunity identified, P<.0001.

DISCUSSION

Known rubella immunity did not infer measles immunity in our population. Thus, we recommend that pregnant women exposed to measles be tested and appropriately treated if they are found to be nonimmune.

Measles virus-specific antibody levels in individuals in Argentina who received a one-dose vaccine

In spite of active measles virus (MV) vaccination strategies, reemergence continues to occur, impairing global eradication programs. The immune status against measles was evaluated in 350 vaccinated healthy Argentine children and teenagers who received a single dose of the MV Schwarz strain Lirugen vaccine (Aventis Pasteur). Sera were assessed for immunoglobulin G (IgG) antibodies by a commercial enzyme immunoassay (EIA) (Enzygnost; Behring), an in-house EIA, and neutralization EIA. Results obtained with these methods showed a marked decline in IgG level with increasing age. At 1 to 4 years of age, 84% of children had IgG antibodies above 200 mIU/ml, conventionally accepted as protective levels, whereas only 32% of older children and teenagers had antibody levels exceeding 200 mIU/ml. Moreover, the MV IgG content in the teenage group was significantly lower than the IgG antibody level of the group of younger children (P < 0.0001). In contrast, screening for IgG antibody levels to inactivated tetanus vaccine showed that, on average, 80% of this population was fully protected and that this high level of protection remained through the teenage years. This study suggests that within this population a considerable proportion of individuals had low measles antibody levels that may be insufficient to protect against reinfections or clinical disease.

Correlates of lymphoproliferative responses to measles, mumps, and rubella (MMR) virus vaccines following MMR-II vaccination in healthy children

Cell-mediated immunity (CMI) to measles, mumps, and rubella viral antigens plays a critical role in providing long-term protection against these infectious diseases. We examined CMI by measuring lymphoproliferative response induced in response to stimulation with the above three antigens following two doses of measles, mumps, and rubella-II (MMR-II) vaccine in a randomly selected, population-based cohort of healthy children. We determined if a correlative and predictive intraclass relationship exists between CMI to the three components of MMR-II. We detected positive lymphoproliferative responses to measles, mumps, and rubella vaccines. Mumps vaccine used as an antigen had the highest median stimulation index followed by measles and rubella vaccines. The overall intraclass correlation value for lymphoproliferative response to measles, mumps, and rubella using Pearson's correlation was 0.61 (95% confidence interval = 0.56, 0.66). We observed a significant pairwise association to individual vaccine components between subjects in the upper and lower 10th percentile of immune response. This study demonstrates recall CMI post-MMR-II vaccination with significant intraclass correlation among the CMI responses to the three vaccine components.

Susceptibility of medical students to vaccine-preventable viral diseases: a serological study

As a measure for the prevention and control of nosocomial infections in medical school students, we examined the students' titers of antibodies to measles, rubella, varicella, and mumps viruses to determine whether vaccination was required. We also analyzed and discussed correlations among antibody titers to the viruses. Subjects were 363 Juntendo University students, ranging from freshmen to seniors. EIA was used to measure IgG antibody titers. Eight subjects (2.2%) had negative titers for measles, 36 (9.9%) for rubella, 8 (2.2%) for varicella, and 10 (2.7%) for mumps. Seronegative subjects were vaccinated against each virus and high seroconversion rates were obtained: 100% for measles and rubella, 67% for varicella, and 89% for mumps. In addition, we used Pearson's test to search for correlations among the antibody titers for each virus. A weak correlation was observed among antibody titers for measles, rubella, and mumps but not for varicella. These results suggest that MMR vaccine might be effective in people with low levels of antibody to measles, rubella, and mumps.

Study of the immune response engendered by differents combined measles, mumps and rubella (MMR) vaccines in an area of Andalusia (Spain)

The objective of the study is to evaluate and compare the degree of serological protection conferred by the three components of two MMR vaccines: "Vac triple MSD" (Aventis Pasteur MSD) and "Triviraten" (Berna), and to study the effects of a second dose of "Priorix" (Glaxo SmithKline), in an unprotected population. In March 2001, this study was conducted in a sample of 86 children aged 3 and 4 years, in two Basic Health Zones of Cádiz (Spain). Mumps, measles and rubella antibody titers were evaluated by IgG enzyme linked immunosorbent assay (ELISA). All the children showing lack of response were revaccinated with the vaccine "Priorix" of GSK; in 12 of these children (all vaccinated previously with "Triviraten"), studies confirmed the existence of seroconversion utilizing the same methodology. The most outstanding finding has been the low percentage of children vaccinated with "Triviraten" possessing protective titers (>1:500) against mumps (14.3%) compared with those vaccinated with "Vac triple MSD" (81.1%, P<0.000001); geometric mean values (GMT) of 164 and 1631, respectively, were obtained. Significant differences, and in the same direction, were also found in respect of measles (83.7 and 100%, and GMT of 889 and 5076), although not so striking. However, all the children studied did have protective titres (>16UI/ml) of antibodies against rubella. Of the 12 children studied who had not responded with protective titers of anti-mumps antibodies, eight children (66.7%) showed seroconversion with "Priorix", and only one child (25%) presented seroconversion in the response to measles. We have thus proved that the "Rubini" strain provides insufficient protection against mumps in our child population. We have also found that the "Edmonston-Zagreb" strain confers less protection against measles than the "Enders" strain, although the "Schwarz" strain, after revaccination of the children who had failed with the "Edmonston-Zagreb" strain, did not achieve a satisfactory seroconversion, either.

Immunogenicity of second dose measles-mumps-rubella (MMR) vaccine and implications for serosurveillance

Measles and mumps, but not rubella, outbreaks have been reported amongst populations highly vaccinated with a single dose of measles-mumps-rubella (MMR) vaccine. Repeated experience has shown that a two-dose regime of measles vaccine is required to eliminate measles. This paper reports the effect of the first and second MMR doses on specific antibody levels in a variety of populations.2-4 years after receiving a first dose of MMR vaccine at age 12-18 months, it was found that a large proportion of pre-school children had measles (19.5%) and mumps (23.4%) IgG antibody below the putative level of protection. Only a small proportion (4.6%) had rubella antibody below the putative protective level. A total of 41% had negative or equivocal levels to one or more antigens. The proportion measles antibody negative (but not rubella or mumps) was significantly higher in children vaccinated at 12 months of age than at 13-17 months. There was no evidence for correlation of seropositivity to each antigen, other than that produced by a small excess of children (1%) negative to all three antigens. After a second dose of MMR, the proportion negative to one or more antigens dropped to <4%. Examination of national serosurveillance data, found that following an MR vaccine campaign in cohorts that previously received MMR, both measles and rubella antibody levels were initially boosted but declined to pre-vaccination levels within 3 years. Our study supports the policy of administering a second dose of MMR vaccine to all children. However, continued monitoring of long-term population protection will be required and this study suggests that in highly vaccinated populations, total measles (and rubella) IgG antibody levels may not be an accurate reflection of protection. Further studies including qualitative measures, such as avidity, in different populations are merited and may contribute to the understanding of MMR population protection.