Measles morbidity among children inoculated against this infection

In the serological survey of 2009 children immunized against measles 285 children (14.2%) were found to be seronegative to this infection in the hemagglutination inhibition test with 4 hemagglutinating units of the antigen. Among 1724 immunized children showing positive response to vaccination and placed under dynamic observation for 11 years, 2 cases of measles were registered. At the same time, in the dynamic observation of 111 seronegative children 66 measles cases (59.5%) were registered during the above period, while among 169 children, also seronegative, but receiving booster immunization against measles, morbidity rate was only 1.2%. In some vaccinees the decrease of postvaccinal immunity to seronegative values was observed, but such decrease had no essential influence on the morbidity level among the vaccines. The increase of measles morbidity among schoolchildren immunized against this infection was due not to the decrease of their postvaccinal immunity, but to their concentration in schools and to their more intensive contacts with the sources of infection in comparison with children of preschool age.     

Immunological effectiveness of a booster inoculation against measles in children remaining seronegative after vaccination

Booster immunization against measles with a highly immunogenic vaccine leads to the development of prolonged postvaccinal immunity lasting at least 6-7 years (the term of observation) in the groups of children found to be seronegative after the titration of their blood sera with 1 hemagglutinating unit (HAU) of the antigen. The booster immunization of children in whose blood sera the minimal concentrations of antibodies can be determined in the presence of 1 HAU of the antigen (seronegative in the presence of 4 HAU) is less effective. The serological checks of immunized children entering preschool institutions and the primary grades at schools and the subsequent booster immunization of children found to be seronegative will lead to a further decrease in measles morbidity.     

Transplacental measles immunity in infants in the 1st year of life]

A total of 187 parturients (66 with a history of measles and 121 immunized with live measles vaccine, or LMV, in childhood) and their 187 newborn infants, as well as 195 children aged up to 1 year, were examined. Antimeasles antibodies in blood sera were detected in the hemagglutination inhibition test. In all mothers with a history of measles and in their newborn infants antimeasles antibodies in different titers were detected. In mothers, formerly immunized with LMV, antimeasles antibodies were absent in 5.8% and in their newborn infants, in 6.6% of the examinees. Among children aged up to 1 year, born of formerly immunized mothers, more rapid disappearance of passive antimeasles immunity was observed. In cases of contact with measles, the serological examinations of all children born of mothers immunized with LMV should be carried out in order to protect seronegative children by passive or active immunization.     

The duration and strength of postvaccinal measles immunity

A prolonged immunoepidemiological follow-up of a large group of children immunized against measles revealed a high epidemiological efficacy of a single vaccination. Cases of measles were registered only among those vaccinees in whose blood sera no specific hemagglutinins were detectable by titration with 4 hemagglutinating units of measles antigen prior to the disease. The study showed that groups of children seronegative with respect to measles appeared, as a rule, after unsatisfactory immunization and not due to loss of postvaccinal immunity with time. Properly immunized children in whom the formation of antimeasles antibodies had occurred in response to the injection of live measles vaccine retained postvaccinal immunity for more that 15 years (the term of observation).     

Measles: Winnipeg, 1973

There were 688 reported cases of measles in Winnipeg from January to June 1973. Seventy-three cases (10.6%) occurred among previously immunized children, 59% of whom had received their inoculations at less than 1 year of age. Seventy-five cases (10.9%) were severe enough to require admission to hospital, and 92% of these patients developed complications, most often pneumonia. Since 89.4% of the cases occurred among nonvaccinated children and another 6.3% were due to immunization at less than 1 year of age, the nonuse and misuse of measles vaccine appear to be the major causes of the present epidemic.     

The duration and intensity of measles immunity after a repeat inoculation against this infection

Controlled study lasting 6 years showed that booster immunization against measles was highly effective in children remaining seronegative, i. e. susceptible to this infection, after primary immunization: E = 97.5 +/- 0.12% (K = 35.7). Annual serological examination of children given booster immunization revealed that 87.6% of initially seronegative children retained specific antihemagglutinins for 5.5 years (the term of observation). The effectiveness of booster immunization against measles did not depend on the age when primary immunization had been made.     

Epidemiological situation of measles in Japan and measures for its control

In 2007, measles outbreak occurred mainly among teen/twenties in Japan, and many high-school, universities and colleges were closed to reduce spread of measles. Some high school students became measles when they were in foreign countries where measles has been eliminated, visited as school excursion. Since introducing measles vaccine as routine immunization, number of measles has been reduced remarkably in Japan. However, we had measles outbreak in 2001, and total annual patients number were estimated 200-300 thausands mainly among young infants. The main reason was low immunization coverage of measles at 1 year old, and operation to give measles vaccine as "the gift for 1 year old birthday" has been introduced widely. Then immunization coverage at this age was increased up from 50-60% (2001) to 80-90% (2006) and total measles number was estimated less than 10,000 at 2005 and 2006, however, measles outbreak occurred this time among teen/twenties in 2007. The total number of adult measles (more than 15 y.o.) were higher than the number of them at 2001 outbreak. To discontinue outbreak and to eliminate measles, enhancement of measles control activities has been introduced in Japan. Two doses policy with measles and rubella (MR) vaccine at 1 y.o. and before elementary school has been introduced since 2006 and further, supplementary immunization with MR at 1st grade in junior high school and 3rd grade in high school for 5 years from 2008 will start to eliminate measles by 2012. Reporting system will be also changed from sentinels system to notify to all measles cases system. In this paper, present epidemiological situation on measles in Japan, measles elimination strategy in WPRO, and plan for measles elimination in Japan are described.     

The use of the cluster selection method for assessing the status of immunity to controlled infections (measles, diphtheria and tetanus)]

The use of the method of cluster selection in mass serological examination makes it possible to obtain statistically significant results with very low expenditures. The coincidence of the results on the number of seronegative children, obtained by the method of cluster selection, with the results of mass serological examination of all children aged 6-7 years in the district (children found to be seronegative to measles constituted 5.5% and 5.0% respectively) is indicative of the statistical significance of the method used in this investigation. The results obtained by the method of cluster selection indicate that the level of protection among the children of the district was high both with respect to measles (94.5 +/- 1.8%) and tetanus (96.5 +/- 1.7%); with respect to diphtheria, the immune stratum was found to be less (91.1 +/- 2.3%). These data may be helpful in working out scientifically substantiated administrative decisions contributing to an increase in the effectiveness of planned mass immunization.     

Studies on live rubella vaccine. VI. Seroepidemiological surveillance and immunization of adolescents in high school.

The rubella seroimmunity status of a total of 1,204 students aged 12 to 19 in a junior and a senior high school in Osaka district was surveyed. Among these, 487 students (40.5%) were found to be seronegative (less than 1 : 8) by the hemagglutination inhibition (HI) test. A total of 287 students were immunized with live rubella vaccine, Biken lot No.7233. This caused an increased titer in all except one of the 262 seronegative students, while among 25 students with an initial HI antibody titer of 1 : 8 it caused more than 4-fold increase in 20 and 2-fold increase in 5. The vaccine caused no clinical manifestations, such as fever, rash or arthralgia.     

A chimeric human-bovine parainfluenza virus type 3 expressing measles virus hemagglutinin is attenuated for replication but is still immunogenic in rhesus monkeys

The chimeric recombinant virus rHPIV3-N(B), a version of human parainfluenza virus type 3 (HPIV3) that is attenuated due to the presence of the bovine PIV3 nucleocapsid (N) protein open reading frame (ORF) in place of the HPIV3 ORF, was modified to encode the measles virus hemagglutinin (HA) inserted as an additional, supernumerary gene between the HPIV3 P and M genes. This recombinant, designated rHPIV3-N(B)HA, replicated like its attenuated rHPIV3-N(B) parent virus in vitro and in the upper and lower respiratory tracts of rhesus monkeys, indicating that the insertion of the measles virus HA did not further attenuate rHPIV3-N(B) in vitro or in vivo. Monkeys immunized with rHPIV3-N(B)HA developed a vigorous immune response to both measles virus and HPIV3, with serum antibody titers to both measles virus (neutralizing antibody) and HPIV3 (hemagglutination inhibiting antibody) of over 1:500. An attenuated HPIV3 expressing a major protective antigen of measles virus provides a method for immunization against measles by the intranasal route, a route that has been shown with HPIV3 and respiratory syncytial virus vaccines to be relatively refractory to the neutralizing and immunosuppressive effects of maternally derived virus-specific serum antibodies. It should now be possible to induce a protective immune response against measles virus in 6-month-old infants, an age group that in developing areas of the world is not responsive to the current measles virus vaccine.     

The immune status of children in foci of measles infection studied by an immunoenzyme method

Children immunized with live measles vaccine in the foci of measles infection varying in intensity (1-9 cases per focus) have been subjected by two methods: the hemagglutination inhibition (HAI) test and the enzyme immunoassay (EIA). As shown in this study, in most cases (98% of all blood serum samples) the correlation between the results of the HAI test and EIA is not high (r = 0.5), which is linked with the detection of a wider spectrum of antibodies in EIA. The percentage of seronegative children detected by these two methods was practically the same (4.05 and 4.4, respectively). The analysis of the results obtained in this study indicates that EIA is a more informative and sensitive method, which confirms the effectiveness of its use for the determination of the level of collective immunity.     

Effectiveness of measles immunoprophylaxis and the criteria for assessing its possible elimination

The study of measles morbidity in Donetsk Province in 1960-1984 and the study of antimeasles immunity in different groups of the population have shown that the problem of the liquidation of measles cannot be solved by immunizing the population in a single administration of the vaccine. To enhance the effectiveness of the immunoprophylaxis of measles and its influence on the epidemic process, a number of problems must be solved with the aim to improve the quality of the vaccine, especially its thermal stability, to establish the possibility of shifting the beginning of immunization from 15-17 months to 12 months of age, to increase the coverage of children with immunization against measles by decreasing the number of groundless exemptions from immunization and by immunizing children in risk groups according to individual schedules and dosage, to carry out selectively the booster immunization of persons who have lost their postvaccinal immunity, as revealed by laboratory test, or in whom such loss may be supposed, to introduce the objective method (indirect hemagglutination test) for controlling the state of immunity among different groups of the population into laboratory practice at sanitary and epidemiological stations. As to the possibility of the liquidation of measles, the statement of this problem is correct, but for its solution a complex of additional prophylactic and epidemic-control measures should be taken.     

Study of combined vaccination against yellow fever and measles in infants from six to nine months

A study has been carried out in the Ivory Coast to assess the efficacy of a combined vaccine against yellow fever and measles relative to that of each vaccine administered separately. Healthy children aged six to nine months were recruited and divided into two age groups: less than seven months (group I) and more than eight months (group II). In each group, they were randomly assigned to receive either yellow fever vaccine only (A), measles vaccine only (B), or the combined vaccine (C). The serological responses to measles and yellow fever were assessed in 219 initially seronegative children 45 days after immunization. More than 90% of the children developed yellow fever haemagglutination inhibiting antibodies. Neither age nor combination with measles vaccine influenced the responses to yellow fever vaccine. Measles haemagglutinational inhibiting antibodies were found in 97% of the children and the seroconversion rate was influenced neither by age nor by combination with yellow fever vaccine. Younger infants had lower titres of measles antibody. No particular adverse reactions were notified during the follow up. This study shows that combined yellow fever and measles vaccines are immunogenic in infants from the age of six months. Controlling yellow fever in endemic areas and the prevention of measles in young infants may greatly benefit by this combination.     

Vaccination against measles, mumps and rubella (MMR): a comparison between the antibody responses at the ages of 18 months and 12 years and between different methods of antibody titration

In connection with the introduction of the trivalent vaccine against measles, mumps and rubella at 18 months and 12 years of age, an evaluation of the seroconversion and booster effects in the two age-groups was carried out. This also comprised different laboratory-test methods appropriate for follow-up studies after large-scale, vaccination studies. The measles, mumps and rubella antibodies were measured by the haemolysis-in-gel (HIG) method. Measles antibodies were also measured by the haemagglutination-inhibition (HI) test. Borderline values or samples negative to measles or mumps were also tested by the serum-neutralization (SN) test. All but four of 150 18-month-old children lacked antibodies against measles by the HI test and one of these by the HIG method. Against mumps, 99% were seronegative in the HIG test and 97% in the SN test and two against rubella prior to vaccination. Among 247 schoolchildren, 60 (24%) lacked antibodies in the HI test and 28 (11%) of these also in the HIG test. Sixty-six schoolchildren (25%) were negative to mumps and 45% to rubella prior to vaccination. The seroconversion rate for the 18-month-old children was 96% against measles, 93% against mumps and 99% against rubella. The figure for the schoolchildren was 82% against measles, 80% against mumps and 100% against rubella. On comparing the titre levels in seroconverting children, the measles-antibody levels were found to be lower among older children, compared with younger, while the opposite was true for rubella.(ABSTRACT TRUNCATED AT 250 WORDS)     

Antidiphtheria immunity in children after immunization with adsorbed DPT vaccine and ADPT-M toxoid

Antidiphtheria immunity in children aged 3-15 years was evaluated, depending on their age, the vaccinal preparation chosen for immunization and the immunization schedule. Adsorbed DPT vaccine was shown to have a higher immunological activity in comparison with adsorbed DT toxoid with reduced antigen content. The relationship between the tension of antidiphtheria antitoxic immunity in children and the possibility of the formation of the clinical forms of diphtheria with different severity in the patients was established. Children aged 4-6 years were considered to be a group of high risk in diphtheria morbidity, as it was among the children of this group that toxic and subtoxic forms of diphtheria were most often registered (44.9 +/- 7.1% of the examinees); in addition, a high proportion of children seronegative to this infection (26,3 +/- 2.2%) was observed in this group.     

Assessment of the prophylactic effectiveness of an inactivated influenza vaccine by immunizing schoolchildren in the springtime

To evaluate the prophylactic effectiveness of influenza inactivated chromatographic vaccine, limited epidemiological observations were made on school children aged 11-14 years in Leningrad, in the autumn of 1981 and the spring of 1982. For immunization, made in a single administration, the vaccine composed of A (H3N2) + +A (H1N1) and containing 3.0-3.4 micrograms of hemagglutinin of each component per 0.2 ml of the preparation was used. Altogether 6928 schoolchildren were under observation; of these, 3686 children were immunized and 3242 children received placebo. The results of questioning and the analysis of morbidity rate among the schoolchildren, both immunized and receiving placebo, showed the safety and low reactogenicity of the vaccine irrespective of the time of the immunization campaign. The immunogenic potency of the preparation, as indicated by all observation results, proved to be higher in spring, than in autumn. The data thus obtained indicate that children immunized in spring were better protected and retained a higher level of protection within 12 months after immunization. The shift of the time of the immunization campaign from autumn to spring increased the immune layer in the groups of children by 16.5%. In 10 months after spring immunization the morbidity rate in influenza and acute respiratory diseases among the vaccinees was found to decrease 1.7 times.     

沪191麻疹疫苗免疫持久性和影响因素的评价

１９９１～１９９８年,我们对荆州区川店镇５０３名６～１５月龄儿童进行了现行沪１９１麻疹疫苗血清流行病学效果观察,结果表明,初次免疫后１个月麻疹ＩｇＧ抗体阳转率为９１６５％,ＧＭＴ为１∶２６６７４,达保护滴度者比例为４６５％。随着时间的推移,第４年上述指标迅速下降到４６８６％、１∶１２７４和１８５％,第６年时低至２９４３％、１∶４８９和１３６％。０２ｍｌ、０３ｍｌ和０５ｍｌ麻疹疫苗组的近期和远期效果是类似的,初免后１个月时ＩｇＧ滴度越高,其免疫持久性越好;初免月龄是影响麻苗免疫效果的主要原因,６月龄初免组的免疫效果明显低于≥８月龄组。结果提示麻苗８月龄初免是可行的。     

Advisability of carrying out mass prevention of infectious hepatitis with gamma globulin

In Vilnius 15,183 pupils in 20 schools were observed for two years; in October, 1966, gamma globulin prophylaxis of infectious hepatitis was carried out among all the pupils of these schools. 17.062 pupils in 27 schools, who received no gamma globulin, were used for control. At the end of the first year of observation morbidity rate among the immunized children was found to be considerably lower than among the school children of the control group. During the second year of observation morbidity rate among the children of the "old" immunized group increased 3.5-fold and did not significantly differ from morbidity rate among the children of the control group. The latter increased 1.8-fold. The authors have come to the conclusion that the effect of gamma globulin prophylaxis on the epidemic process depends on the method of such prophylaxis. The method of prophylaxis by introducing gamma globulin immunization with universal coverage, as the use of the former method is not followed by an increase in total morbidity (i.e. among both immunized and nonimmunized children) during the second year after immunization, which is observed after prophylaxis by universal immunization.     

Immunological structure of the population in a system of epidemiological surveillance of diphtheria

The characteristics of antitetanus and antidiphtheria immunity in children, adolescents and adults in Perm have been determined by means of the passive hemagglutination test, and the tendency towards the decrease of their immunity to diphtheria with the increase of their age has been established. The registered and actual coverage of children and adolescents by immunization is characterized on the basis of the presence of antibodies to the tetanus component of combined vaccines. A considerable proportion of persons at boarding schools and vocational technical schools has been found to be seronegative with respect to diphtheria. The seasonal dynamics of antitoxic immunity is presented.     

Total immunization of children against influenza decreases morbidity in a number of diseases among elderly persons during influenza epidemic

Immunization of children aged 3-6 years in kindergartens and school children aged 7-17 years against influenza with inactivated influenza vaccine was carried out in two districts of the Moscow region. The comparison of morbidity in influenza-like diseases among the immunized children with that among nonimmunized children in control districts revealed that the effectiveness of immunization was 60.9% in kindergartens and 68.8% in schools. The analysis of morbidity in a number of diseases among 158,451 elderly persons not immunized against influenza demonstrated that, in comparison with the control districts, in those districts where mass immunization of children was carried out morbidity in influenza-like diseases among elderly persons was 3.4 times lower and, out of other 10 diseases under study, morbidity in 8 diseases was 1.5-2.6 times lower. As indicated by the data obtained in this study, total anti-influenza immunization of children in organized groups not only essentially decreased influenza morbidity among children, but also greatly decreased morbidity in influenza and a number of diseases, appearing as complications of influenza infection, among nonimmunized elderly persons during influenza epidemic.