Second Dose Of Measles Vaccine Research Articles

Efficacy of measles and rubella vaccination one year after the nationwide campaign in Shiraz, Iran

The World Health Organization target for measles elimination in the Eastern Mediterranean Region was established in 2010. In Iran, the national measles-rubella campaign, targeting individuals aged 5-25 years, was initiated in December 2003. To evaluate the impact of the campaign after one year, 909 serum samples were collected in Shiraz, southern Iran, from a population aged 6-26 years, divided into five groups according to age. IgG antibodies were tested using ELISA for the measles and rubella antibodies, and the plaque reduction neutralization test (PRNT; measles) was used for samples with equivocal results. Measles protective immunity reached 80.6%, 72.7%, 84.9%, and 87.5% and rubella immunity reached 91.0%, 99.6%, 99.6%, and 97.0% for the age groups 6-10, 11-15, 16-20, and 20-26 years, respectively. Seropositivity to the rubella virus in this population was high, especially in women of childbearing age (98.9%), thereby preventing congenital rubella infections. However for measles, it was significantly lower than the rate required to achieve >or=95% coverage for elimination. These data indicate that an increase in immunization coverage by supplementary administration of a second dose of measles vaccine is needed to interrupt the endemic transmission of the measles virus.

Extinction of the Human Leukocyte Antigen Homozygosity Effect After Two Doses of the Measles-Mumps-Rubella Vaccine

We have reported associations between human leukocyte antigen (HLA) homozygosity and low measles antibody levels after one dose of the measles, mumps, and rubella (MMR) vaccine. Here, we examined associations between HLA homozygosity and immune responses to MMR after two doses of vaccine. We examined associations between HLA homozygosity and measles antibody levels in a group of 178 children (cohort 1) as well as associations between homozygosity and antibody levels and lymphoproliferative responses to MMR in 346 children (cohort 2). In cohort 1, HLA homozygotes and heterozygotes had similar increases in measles antibody levels after a second dose of measles vaccine. In cohort 2, HLA homozygosity was not associated with measles immune measures after two doses of vaccine. Homozygosity at the DPB locus was associated with increased rubella antibody levels, and homozygosity at the class IA alleles was associated with lower mumps lymphoproliferative response. Homozygosity at increasing numbers of loci was also associated with lower mumps antibody levels and lymphoproliferative response. Therefore, two doses of the MMR vaccine appear to induce sufficient antibody levels and lymphoproliferative responses against measles and rubella, regardless of HLA homozygosity status. However, children who are HLA homozygous may be less protected against mumps compared with children who are heterozygous.

Emerging diseases: measles.

High vaccination coverage rates and the administration of a second dose of measles vaccine have resulted in a significant decline in the incidence of measles and neurologic diseases due to measles in many countries. However, intermittent outbreaks of measles still occur even in countries with excellent vaccination coverage, suggesting the existence of high rates of measles virus introduction from endemic regions and/or waning of vaccine-induced immunity. Strategies to sustain high levels of global immunity to measles virus by increasing vaccine coverage with routine and supplementary vaccination campaigns must be supported.

Measles elimination in Italy: projected impact of the National Elimination Plan

A mathematical model was used to evaluate the impact of the Italian Measles National Elimination Plan (NEP), and possible sources of failure in achieving its targets. The model considered two different estimates of force of infection, and the possible effect on measles transmission of the current Italian demographic situation, characterized by a below-replacement fertility. Results suggest that reaching all NEP targets will allow measles elimination to be achieved. In addition, the model suggests that achieving elimination by reaching a 95 % first-dose coverage appears unlikely; and that conducting catch-up activities, reaching high vaccination coverage, could interrupt virus circulation, but could not prevent the infection re-emerging before 2020. Also, the introduction of the second dose of measles vaccine seems necessary for achieving and maintaining elimination. Furthermore, current Italian demography appears to be favourable for reaching elimination.

Serological response to early measles vaccination.

This study compares the persistence of measles IgG antibody in 239 children vaccinated at 6-8 months of age with 76 children vaccinated after 8 months of age. Among the children vaccinated prior to 9 months, 49 per cent of the children between 16 and 44 months and 33 per cent of children over 54 months had levels of measles IgG antibody conventionally considered protective. Among the children older than 48 months, 67 per cent of children vaccinated before 9 months and 13 per cent of children vaccinated after 8 months had antibody levels below the conventionally accepted protective levels of 0.2 IU/ml. Older children had lower antibody levels than younger children. Measles immunization before 9 months with the standard titer Edmonston-Zagreb vaccine has not provided a large proportion of under-five children with protective levels of measles IgG antibody. A significant proportion of children vaccinated at the currently recommended age also had suboptimal levels. It is difficult to protect the majority of the measles-susceptible population with a single dose regardless of the immunization schedule used. A second dose of measles vaccine may be necessary to increase the herd immunity.

Persistence of vaccine-induced antibody to measles 26-33 years after vaccination.

Because measles-specific antibody titer after vaccination is lower than after natural infection, there is concern that vaccinated persons may gradually lose protection from measles. To examine the persistence of vaccine-induced antibody, participants of a vaccine study in 1971, with documentation of antibody 1-7 years after vaccination, were followed up in 1997-1999 to determine the presence and titer of measles antibody. Of the 56 participants (77% were 2-dose recipients), all had antibodies detected by the plaque reduction neutralization (PRN) antibody assay an average of 26-33 years after the first or second dose of measles vaccine; 92% had a PRN titer considered protective (>1 : 120). Baseline hemagglutination inhibition antibody titer in 1971 strongly predicted follow-up PRN antibody titer (P<.001). Persistence of antibody in these primarily 2-dose recipients supports the current elimination strategy to achieve and sustain high population immunity with a 2-dose schedule.

Genotyping of measles virus in Canada: 1979-2002.

Genotyping is an important component of measles surveillance. In this study, we report the genotypes of 30 measles viruses from cases in Canada; 6 of these were collected between 1979 and 1996 and 24 were collected from 1997 through 2002. Many measles virus genotypes were found (C1, C2, D3, D4, D5, D6, D7, D8, E, and H1). These data indicate that the predominant measles virus genotypes detected from 1979 to 1997 in Canada are no longer commonly found. Since the implementation of a routine second dose of measles vaccine and catch-up campaigns in 1996-1997, the wide variety of measles virus genotypes found supports epidemiological data showing that importation of measles is the source of current measles cases in Canada.

Evolution of measles elimination strategies in the United States.

There have been 3 efforts to eliminate measles from the United States since the introduction of measles vaccine in 1963. To date, 10 major lessons have been learned from elimination efforts. First, elimination requires very high vaccination-coverage levels by age 2 years. Second, school immunization requirements ensure high coverage rates among schoolchildren. Third, a second dose of measles vaccine is needed to achieve satisfactory levels of immunity. Fourth, school immunization requirements can also ensure delivery of a second dose. Fifth, coverage assessment is crucial. Sixth, measles surveillance is critical for developing, evaluating, and refining elimination strategies. Seventh, surveillance requires laboratory backup to confirm a diagnosis. Eighth, tracking measles virus genotypes is critical to determining if an endemic strain is circulating. Ninth, once endemic transmission has been interrupted, internationally imported measles cases will continue and will cause small outbreaks. Tenth, collaborative efforts with other countries are essential to reduce imported measles cases.

Progress toward implementation of a second-dose measles immunization requirement for all schoolchildren in the United States.

In 1998, the Advisory Committee on Immunization Practices and the American Academy of Pediatrics recommended that states ensure that all children in grades kindergarten through 12 receive 2 doses of measles-mumps-rubella (MMR) vaccine by 2001. In 2000, the National Immunization Program surveyed states, the District of Columbia, and United States territories, commonwealths, and protectorates to assess progress toward this goal. Almost all respondents (53 [98%] of 54) reported a second-dose requirement for entry to elementary school, middle school, or both. By fall of 2001, most (82%) school-aged children in the United States were in grades requiring a second dose of measles vaccine. For 29 responding programs, the requirement did not yet affect all grades. By 2009, 52 of 54 responding programs will require a second dose for all grades. Although not all states have achieved coverage of all schoolchildren with 2 doses of MMR vaccine, most states are well on their way toward this goal.

Measles and mumps vaccination as a model to investigate the developing immune system: passive and active immunity during the first year of life

Evaluations of neutralizing antibody responses in 6-, 9- and 12-month-old infants given measles or mumps vaccine indicated that 6-month-old infants had diminished humoral immune responses associated with passive antibody effects, but also had an intrinsic deficiency in antiviral antibody production, which was independent of passive antibody effects. In contrast, lower neutralizing antibody titers in 9-month-olds were related only to passive antibody effects. Measles and mumps-specific T-cell proliferation and interferon-gamma (IFNγ) production were induced by vaccination at 6, 9 or 12 months, regardless of passive neutralizing antibodies or age. These observations suggest a need to refine concepts about passive antibody interference and primary vaccine failure, taking into account the sensitization of antiviral T-cells, which occurs in the presence of passive antibodies and is observed in infants who do not develop active humoral immunity. A second dose of measles vaccine given at 12–15 months enhanced antiviral T-cell responses to measles in infants who were vaccinated at 6 or 9 months, and produced higher seroconversion rates. Since T-cell immunity is elicited under the cover of passive antibodies, the youngest infants benefit from the synergistic protection mediated by maternal antibodies and their own capacity to develop sensitized antiviral T-cells, which prime for subsequent exposures to the viral antigens. Conceptually, maternal immunization approaches with vaccines that can be given to women of child-bearing age before pregnancy, or that are safe for administration during pregnancy, should enhance passive antibody protection. Rather than being detrimental to infant adaptive immune responses, maternal vaccination can be coupled effectively with vaccine regimens that elicit priming of antiviral immune responses in infants during the first year of life.

Increased protections during a measles outbreak of children previously vaccinated with a second dose of measles-mumps-rubella vaccine.

In 1989 a second dose of measles vaccine was recommended for US children to prevent school outbreaks of measles. Coverage of school age children with a second dose remains incomplete, and data on the effectiveness of this recommendation are limited. We investigated a measles outbreak in Mesa County, CO, in December, 1994, and evaluated the efficacy of preoutbreak immunizations at an elementary school (School A) where many students had received two doses. All reported suspected cases of measles were investigated; cases that met a clinical case definition were tested by a measles IgM antibody assay. A confirmed case required laboratory confirmation or had to meet the clinical case definition and be epidemiologically linked to a confirmed case. Vaccination records of students at School A were reviewed. The effectiveness of one and two doses of measles vaccine was estimated using logistic regression. Sixty-two confirmed cases were reported, including 17 at School A. At School A the attack rate in unvaccinated children (7 of 16, 44%) was higher than in those with 1 dose (10 of 320, 3%) or 2 doses (0 of 289, 0%). Estimated vaccine effectiveness was 92% for 1 dose and 100% for 2 doses. Two doses were better than one dose in decreasing the likelihood of acquiring measles (P = 0.003). The lower attack rate among two dose recipients provides evidence that a two dose strategy can help prevent measles in schools. Administering the second dose at elementary school entry can help prevent the persistence of susceptible cohorts of children and is likely to be important in sustaining elimination of indigenous transmission of measles in the United States.

Timing and effectiveness of requirements for a second dose of measles vaccine.

Previous measles elimination goals have failed in the United States despite high coverage of schoolchildren with a single dose of measles vaccine. Since 1989 advisory groups have recommended that schoolchildren receive a second dose of measles vaccine as part of a revised strategy to eliminate measles from the US. States have responded by phasing in requirements for a second dose of measles vaccine at school entry for various age groups at primary school entrance, secondary school entrance or both. The purpose of this analysis was to evaluate the effectiveness of the requirements for a second dose of measles vaccine and to determine whether a primary or secondary school entrance requirement was more effective in lowering measles incidence. Using national surveillance data we examined the influence of state requirements for the second dose of measles vaccine on measles incidence from 1993 through 1995. Overall measles incidence was lower in states that had a requirement for a second dose of measles vaccine at either primary school entrance [relative risk (RR) = 0.35; 95% confidence interval, 0.25 to 0.49] or secondary school entrance (RR = 0.38; 95% confidence interval 0.29 to 0.50), compared with states without a second dose requirement. Incidence was lowest in states that required a second dose of measles vaccine at both primary and secondary school entrance (RR = 0.22; 95% confidence interval, 0.13 to 0.37). Our findings demonstrate that a requirement for a second dose of measles vaccine at either primary or secondary school entrance is effective in lowering measles incidence, with a greater reduction occurring in states where the second dose is required for both age groups.

Sero-epidemiological study of measles after 15 years of compulsory vaccination in Alexandria, Egypt

Cases of measles among 165 vaccinated and unvaccinated children were studied and the level of measles antibody in 230 previously vaccinated children was determined. Associations between demographic factors and immunological response to vaccination were also investigated. Approximately 80% of the children with measles had been vaccinated;their cases had significantly lower rates of complication. Rural areas accounted for significantly higher numbers of unvaccinated cases. Vaccination status did not correspond to place of exposure, duration of prodrome or accuracy of preliminary diagnosis. The seropositivity rate among vaccinated children was 86.1% with no significant variation with age. We recommend a second dose of measles vaccine and maintaining high vaccine coverage

Antibody response to measles vaccination in Turkish children.

In recent years, there has been a remarkable increase in measles cases among preschool and secondary school children in Turkey, as in many other countries. The seroconversion and coverage rates of measles vaccine should therefore be evaluated in order to obtain data that could be used to determine the vaccination policy for Turkey. Measles immunity status was studied by an enzyme-linked immunosorbent (ELISA) test determining the anti-measles IgG antibody levels. Measles specific IgG antibodies were found to be positive in 77.88% of the entire study group of 800 children aged 11 months to 12 years, while 21.25% had negative sera. Seven (0.87%) subjects had borderline results. The results of this study indicate the need to administer a second dose of measles vaccine, preferably at 18 months of age concomitant with other vaccines. This vaccination policy, together with an increase in the extent of immunization coverage, may help to achieve the World Health Organization's (WHO) target of the complete eradication of measles.

Writer; Measles in college

Almost 80 percent of young adults, including college students, are not aware they might be at risk for contracting measles, according to a December 1995 Gallup poll. More than half the students polled said they had not received the recommended second dose of measles vaccine. Students in post-secondary institutions are considered at greater risk for contracting measles because they often live in close quarters, increasing chances for spreading the highly contagious virus, reports the U.S. Centers for Disease Control and Prevention9s Advisory Committee for Immunization Practices.

Protecting adolescent girls against tetanus

An estimated 8 million infants and 2 million children and adults may die from tetanus during the 1990s despite efforts by the World Health Organization (WHO) to eliminate it by 1995. Vaccination to prevent postabortal and maternal tetanus has been neglected. The immunization of preschool children and of pregnant women has omitted adolescent girls, who are therefore at risk. Data collected on 1101 cases of maternal tetanus in developing countries between 1958 and 1990 indicated that 27% were attributed to postabortal and 67% to postpartum sepsis. In southeastern Nigeria where abortion rates are high, a high proportion of girls were also seronegative for tetanus antibodies. Many unvaccinated pregnant women cite the lack of money for obtaining vaccination when obtaining prenatal services. The WHO is promoting vaccination of women of reproductive age by screening their tetanus toxoid status, but adolescents are poorly covered because they are not regular attenders. Expressly targeting girls would be feasible, as it would require 5 injections providing protection for life. Even 4 injections may protect for 20 years if delivered at the end of primary school. Thus a school health service delivering tetanus vaccination may improve the vaccination of adolescent girls. This could be combined with distribution of vitamin A and antihelminthics whereby the response to the vaccine could be improved significantly. In addition, it has also been suggested that a late dose of an acellular pertussis vaccine and a second dose of measles vaccine given in adolescence would reduce the pool of susceptible girls, just as girls have been targeted for rubella vaccination. Implementation of tetanus vaccination would require local schools vaccination days, immunization cards, high potency primary vaccination, and tetanus boosters free of charge with a system to monitor antibody responses.

Measles control in the United States: problems of the past and challenges for the future

Elimination of indigenous measles from the United States has been a public priority since 1978. To assess the progress made toward this goal, we review the epidemiology of measles from 1963 to the present. From the 1970s through early into the recent measles epidemic, the majority of measles cases were in highly vaccinated, school-age children. This was due primarily to a 1 to 5% primary measles-mumps-rubella vaccine failure rate and nonrandom mixing patterns among school-age populations. To eliminate susceptible individuals in the school-age populations, a second dose of measles vaccine is now recommended between 5 and 6 years or 11 and 12 years by both the Advisory Committee on Immunization Practices and the American Academy of Pediatrics. Later in the epidemic, measles cases surged among unimmunized preschool children, especially among the poor in inner-city areas. Immunization rates have been documented to be low among preschool populations because of missed opportunities to administer vaccines at all health visits and barriers to access to immunizations. To raise immunization rates, the age for the first measles-mumps-rubella immunization was lowered to 12 to 15 months of age, federal immunization funding has increased, and new standards for immunization delivery have been developed and promulgated.

Measles control in the United States: problems of the past and challenges for the future.

Elimination of indigenous measles from the United States has been a public priority since 1978. To assess the progress made toward this goal, we review the epidemiology of measles from 1963 to the present. From the 1970s through early into the recent measles epidemic, the majority of measles cases were in highly vaccinated, school-age children. This was due primarily to a 1 to 5% primary measles-mumps-rubella vaccine failure rate and nonrandom mixing patterns among school-age populations. To eliminate susceptible individuals in the school-age populations, a second dose of measles vaccine is now recommended between 5 and 6 years or 11 and 12 years by both the Advisory Committee on Immunization Practices and the American Academy of Pediatrics. Later in the epidemic, measles cases surged among unimmunized preschool children, especially among the poor in inner-city areas. Immunization rates have been documented to be low among preschool populations because of missed opportunities to administer vaccines at all health visits and barriers to access to immunizations. To raise immunization rates, the age for the first measles-mumps-rubella immunization was lowered to 12 to 15 months of age, federal immunization funding has increased, and new standards for immunization delivery have been developed and promulgated.

Immunity to measles in young adults in Israel.

The likelihood of an epidemic of measles in 1990-92 in Israel prompted us to study the immune status against measles in a random sample of 454 recruits aged 18-19 years in order to obtain data that might be used in determining vaccination policy. This cohort had received one dose of measles vaccine at 12 months of age. The measles immunity status was studied by determination of antibody values that were measured by means of an enzyme-linked immunosorbent (ELISA) IgG antibody test. Of the recruits, 84.6% were found to have positive sera for anti-measles IgG antibodies, while 13.7% had negative sera. Eight (1.7%) subjects had borderline results. The results of this study indicate the need to administer a second dose of measles vaccine at an older age in addition to the MMR (measles, mumps, rubella) vaccine that is now given in Israel at 12 months of age. This step will help achieve the World Health Organization's target of complete eradication of measles.

Boosting Effect of a Second Dose of Measles Vaccine Given to 12-year-old Children

In Sweden, a two-dose programme of vaccination against measles, mumps and rubella (MMR) was introduced in 1982 and the target groups were children aged 18 months and 12 years. In 1993 the first age group of 12-year-olds that were vaccinated with MMR at 18 months will appear. The majority of the 12-year-old vaccines for many years, however, had already been vaccinated against measles and the MMR measles component was thus a booster dose. As the benefit of a booster dose against measles has been questioned, this was studied in a group of 163 12-year-old children, 122 of whom had been vaccinated against measles as young children. Of the 41 unvaccinated children, 23 had a history of clinical measles. The mean neutralizing titre level of the earlier vaccinated children, prior to the booster, was lower than that of the naturally immune children (reciprocal titre level 8 versus 20). After the booster the corresponding titre levels were 13 and 23. Among the seronegative children receiving their first dose, this figure amounted to 14. A moderate rise in titre was seen in those with low prevaccination titres. As the antibody protection afforded by vaccination was slightly lower than that of natural infection, even after a booster, follow-up studies must be recommended to evaluate the long-term protection of both a single and a two-dose programme.