Antibodies to poliomyelitis virus in cord blood of neonates born to from mothers in contact or not in contact with the wild virus

Neutralizing antibodies to polioviruses in cord blood of neonates born from 64 mothers under age 20 and in 53 mothers aged 30 years and over were investigated in order to know and compare the transfer to newborns of antibodies to polioviruses produced by live oral vaccine mainly and those antibodies induced by natural contact with wild poliovirus strains. Total immunity for the two groups was higher than 80% for the three types of polioviruses, with only virus 3 showing an immunity below 80% (77.4%) in mothers aged 30 years and over. Average geometric titers though relatively low may be considered satisfactory. However, there is a statistically significant difference in titers to poliovirus type 2 (24.9) in mothers over age 30 years as compared to those found in mothers below age 20 years (10.8), for which we have found no explanation. It is not deemed necessary for the time being to take special prophylactic measures with these children given the occurrent epidemiologic status quo.     

Polio antibody outfit of newborns and infants born after 20 years of mass vaccination with live poliovaccine

Antibodies against type 1 and 2 poliovirus were tested in 250 infants and against type 3 poliovirus in 341 infants aged 0-13 months to compare the polio antibody outfit of newborns and infants born to three groups of mothers: (a) nonvaccinated, above 35 years of age; (b) vaccinated with attenuated poliovirus but having had chance of contact with wild poliovirus during childhood, age 22-35 years, and (c) vaccinated but not having had contact with wild poliovirus, below 22 years of age. Over 90% of newborns had specific neutralizing antibodies against all three poliovirus types. With increasing infant age the percentage of antibody-positive infants decreased: by age 9-11 months only 46%, 27% and 14% of infants displayed antibodies to polio-virus types 1, 2 and 3, respectively. Geometric mean titres decreased accordingly. Differences between infants born to mothers of the above three groups were nonsignificant: the results obtained suggest that future newborns will also possess satisfactory levels of antibodies acquired from mothers who have only had contact with attenuated vaccine poliovirus.     

Antibody status to poliomyelitis,measles, rubella,diphtheria and tetanus,Ontario, 1969-70: deficiencies discovered and remedies required.

A serologic survey was made in 15 health unit areas, testing some 5000 individuals in the age groups 4 to 6, 11 to 13, 15 to 17 and 23 to 45 years. Two types of serious deficiency were found. Only 65% of children 4 to 6 years old had antibodies to all three types of poliovirus, the antibodies being due almost entirely to immunization with Salk vaccine. Even in children who had had six or more doses only 74% had antibodies to the three types. The high percentage of students 11 to 13 and 15 to 17 years old with poliovirus antibodies can be attributed largely to natural infection and to Sabin vaccine in the mass campaign of 1962, as well as to Salk vaccine. In children who had received Sabin vaccine as well as Salk vaccine a very high level of immunity was found. The immunity of the school-age population will decline to an insufficient level unless Sabin vaccine is used after immunization with Salk vaccine. Of children 4 to 6 years old 18% had no diphtheria antitoxin and 6% had no tetanus antitoxin. Even in those who had had six or more doses of the antigens 5% had no diphtheria antitoxin and 1 to 2% had no tetanus antitoxin. This apparently refractory state is probably due to the use of unadsorbed toxoids, and it is clear that adsorbed toxoids should be used. In the adults, diphtheria antitoxin was found in only 55% and tetanus antitoxin in only 38%.     

Antibody state to poliovirus in first year university students, 1984.

Circulating antibodies to poliovirus were estimated in a group of 300 British and 84 foreign first year students who registered at the health centre of Nottingham University in 1984. Detectable antibodies to all three poliovirus serotypes were found in 212 (71%) of the British students but in only 47 (56%) of those from abroad. Most of the British students (280; 93%) had been born in 1965 or 1966, when uptake of poliomyelitis vaccine was declining. Immunisation histories showed that 10 British and 29 foreign students (3% and 35%) had no record of any immunisation; only five British and two foreign students, however, were negative for all three poliovirus serotypes. These findings provide evidence that a high proportion of British born people aged 18-29 have adequate circulating poliovirus antibodies despite incomplete immunisation schedules. Though this is reassuring, the absence of antibodies in some students and the lack of previous immunisation against poliomyelitis in 39 suggest that reinforcing doses of vaccine at the time of leaving school or beginning further education are still warranted, particularly for students from other countries. The findings also emphasise the need for accurate immunisation records.     

Prevalence of antibody to poliovirus in England and Wales 1984-6.

Serum from 995 subjects aged 6 months to 99 years was screened at a dilution of 1/8 for neutralising antibodies to poliovirus. Of these samples, 975 (98%) contained antibody to at least one serotype, and 763 (77%) contained antibody to all three, an improvement since previous studies. Children aged 8 to 15, however, had a low prevalence of antibody to poliovirus type 3, with only four (40%) of those aged 12 protected. This finding is possibly due to the waning of antibodies induced by the type 3 component of oral poliovirus vaccine and emphasises the continued importance of a booster dose of vaccine for those leaving school.     

Evaluation of poliovirus antibody titers in orally vaccinated semi‐captive chimpanzees in Uganda

Background To understand immunological responses in chimpanzees vaccinated with live‐attenuated vaccine (oral polio vaccine; OPV), serum neutralizing antibodies against poliovirus types 1, 2, and 3 were investigated over time. Methods The neutralizing antibody titers against poliovirus types 1, 2, and 3 were determined by microneutralization test using 100 ID₅₀ of poliovirus types 1, 2, and 3 (Sabin strains). Results Neutralizing antibodies against poliovirus types 1, 2, and 3 were detected in 85.7%, 71.4%, and 65% of the serum from 42 chimpanzees tested 9 years post‐vaccination. The neutralizing antibody titers in chimpanzees were similar to the documented levels in human studies as an indicator of vaccine efficacy. Conclusions This study reveals persistence of neutralizing antibodies in chimpanzees for at least 9 years after vaccination with OPV. This first study in chimpanzees provides useful information for the evaluation of the success of vaccination with OPV in other captive apes.     

Immune status of children of immigrants to poliomyelitis.

Four ethnic groups of children from the Glasgow area--155 Asians, 85 Africans, 85 Chinese, and 93 Scots--were examined for neutralising to poliovirus types 1, 2, and 3. Only seven of the 418 children had no detectable antibody, and of these, four were aged less than 7 months; none had received polio vaccine. The best-protected children were the Chinese (93% with antibody to all three poliovirus types), followed by the African (81%), Scottish (78%), and Asian children (77%). We conclude that children of immigrants are no more vulnerable to poliovirus infection than their Scottish counterparts.     

The trend of acquired immunity with live poliovirus vaccine and the effect of revaccination: follow-up of vaccinees for ten years

The persistence of neutralizing antibody (NA) against three types of poliovirus acquired after two doses of trivalent live attenuated poliovirus vaccine (LPV) has been followed up for ten years in individual vaccinees. Sixty-seven children were bled once a year over a five year period following the primary vaccination. More than 80% of them retained NA against all three types of poliovirus. Thirty-two individuals whose NA titres were 1:16 or over for types 1 and 2 and 1:4 or over for type 3 at the fifth year were further followed up for a further five years and it was shown that during this period some of them had a naturally-acquired antibody rise, mostly against type 3 virus. At the sixth to eighth year after the primary vaccination, one further dose of the trivalent vaccine was administered to the children whose NA titres were down to 1:8 or less and the effect of booster vaccination on NA was followed. Other subjects were revaccinated with LPV and their fecal excretion of the vaccine virus was investigated. The results showed that a decrease in serum antibody level could be a good indicator of the local resistance of the alimentary tract and that reinfection could occur if serum NA had decreased to 1:8 or less, which allowed a virus excretion in the stools.     

Humoral imunity to pertussis in children with diabetes of type 1

To determine the state of humoral immunity to pertussis in children with insulin-dependent diabetes, IgG antibodies to pertussis toxin (PT) were determined in blood serum samples by means of EIA. In a group of children aged up to 6 years the highest percentage (100%) received the complete course of vaccination against pertussis with Russian adsorbed DPT vaccine, containing whole-cell pertussis monovaccine, while in a group over 6 years the complete vaccination course (3 vaccinations and 1 revaccination) had 53.4% of children. Pertussis morbidity was considerably higher in nonvaccinated subjects than in children with 4-fold vaccination (p < 0.001). The coefficient of association (Q) was 0.84. Children of all age groups were found to have low and average titers of antibodies to PT. The regressive analysis showed a decrease in antibodies in persons completely immunized against pertussis by the age of 6 years old. The presence of antibodies in nonimmunized persons showed that cases of pertussis or carrier state took place among the population. High titers of antibodies, indicative of recent cases of pertussis, were registered in all age groups, but high titers of antibodies were registered mostly in the group of children over 13 years old (p < 0.05), which confirmed an increase in pertussis morbidity in adolescents. Thus, vaccination against pertussis effectively protected children with diabetes of type 1, aged up to 6 years. For more prolonged protection the vaccination and revaccination of children aged over 4 years old is necessary.     

Immunological effectiveness of a dried group-A meningococcal polysaccharide vaccine

The immunological effectiveness of dried group A meningococcal polysaccharide vaccine, developed at the Gabrichevsky Research Institute of Epidemiology and Microbiology, Moscow, for children aged 5-14 years was studied. The intensiveness of the immune response of children to 0.5 ml of the vaccine introduced in a single injection was evaluated by a rise in the level of agglutinating antibodies to group A meningococcal polysaccharide in the sera of the vaccinees 3-4 weeks after immunization with the following optimum doses: 25 micrograms for children aged 5-8 years, 50 micrograms for children aged 9-13 years and 75 micrograms for children aged 14 years and over. The vaccine was shown to be highly immunogenic. Antibodies to group A meningococcal polysaccharide were identified as IgM. These antibodies in a titer of 1:40 and higher could be detected in 90% of the vaccinated children in the younger age group, 7 months after immunization.     

Indicators of immunity in children vaccinated with live poliomyelitis vaccine]

Serological examination of 1057 children, residents of Leningrad, vaccinated with poliomyelitis vaccine at the appropriate calendar dates according to the scheme, showed the presence of antibodies to the polioviruses in 81.5-99.1% of the cases. There were more serologically negative children against the virus type III, and much less--against the virus type II. The value of the mean geometrical titres somewhat decreased with the advance of the children's age and the time lapse after the vaccination and revaccination. The greatest antibody titres determined were against the poliovirus type II, and the least--against type III. No antibodies against the viruses of types I and III were revealed in case of deficiency against the poliovirus type II. The number of children with the absence of antibodies against the poliovirus of all the types was insignificant.     

Excretion of live attenuated polioviruses in the faeces of orally vaccinated children. Comparison of two immunization schedules

The excretion of live, attenuated poliovirus vaccine strains was determined in the feces of Prague Infants home children given 10(5) PFU of type 1 and 2 and 2.10(5) PFU of type 3 vaccine in a routine annual mass campaign. The first two faeces specimens examined in each vaccinee prior to immunization were negative for the virus. A total of 476 stool specimens were collected from 37 children at weekly intervals for a period of 18 weeks. The presence of type 1 poliovirus in the faeces of children given monovalent type 1 vaccine was detectable for 9 weeks, with a maximum in first week, and the virus was isolated in 74.2% of vaccinees. The timing of bivalent type 2 and type 3 vaccine was 9 weeks after monovalent type 1 immunization. The excretion of these two types of poliovirus was found to persist for at least 6 weeks. Type 2 poliovirus was isolated in all vaccinees, type 3 in 70.4% of children. The highest percentage of children excreting type 2 poliovirus was recorded in the first week, the excretion of type 3 peaked three weeks after bivaccine administration. The excretion peaks were reached relatively early postvaccination, with type poliovirus reaching the highest titre per 1 g of faeces. After revaccination (one year later) with monovalent type 1 vaccine, the vaccine strain of type 1 poliovirus could be detected for 6 weeks and was present in the highest percentage of positive stool samples.(ABSTRACT TRUNCATED AT 250 WORDS)     

Seroprevalence of measles-, mumps- and rubella-specific IgG antibodies in german children and adolescents and predictors for seronegativity

We have undertaken a seroprevalence study with more than 13,000 children, who had been included in the German KIGGS survey, a representative sample of children and adolescents 0-17 years of age. The IgG titres against measles, mumps and rubella were determined in 1 to 17 year olds While 88.8% of the children were MMR-vaccinated at least once, 76.8% of children aged 1 to 17 years showed prevalence of antibodies to MMR. The highest seronegativity was seen with respect to mumps. Gender differences were most pronounced with regard to rubella IgG titres: girls aged 14 to 17 years were best protected, although seronegativity in 6.8% of this vulnerable group still shows the need of improvement. Search for predictors of missing seroprevalence identified young age to be the most important predictor. Children living in the former West and children born outside of Germany had a higher risk of lacking protection against measles and rubella, while children with a migration background but born in Germany were less often seronegative to measles antibodies than their German contemporaries. An association of seronegativity and early vaccination was seen for measles but not for mumps and rubella. A high maternal educational level was associated with seronegativity to measles and rubella. In vaccinated children, seronegativity was highest for mumps and lowest for rubella. For mumps, high differences were observed for seronegativity after one-dose and two-dose vaccination, respectively. Seronegativity increases as time since last vaccination passes thus indicating significant waning effects for all three components of MMR.     

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.     

Intestinal trypsin can significantly modify antigenic properties of polioviruses: implications for the use of inactivated poliovirus vaccine.

It was recently reported that the intestinal protease trypsin cleaves in vitro the VP1 protein of type 3 poliovirus at antigenic site 1 (J. P. Icenogle, P. D. Minor, M. Ferguson, and J. M. Hogle, J. Virol. 60:297-301, 1986). We found that incubation of purified or crude type 3 poliovirus preparations with specimens of human intestinal fluid brings about a similar change in the virion structure. Sera from children immunized solely with the regular inactivated poliovirus vaccine (IPV) neutralized trypsin-cleaved Sabin 3 virus poorly, if at all, despite moderate levels of antibodies to the corresponding intact virus. Sera containing very high titers of the intact virus also neutralized the trypsin-cleaved virus but at a relatively weaker capacity. Most sera from older persons who may have been exposed to a natural poliovirus infection before the introduction of the poliovirus vaccines as well as sera from children infected with type 3 poliovirus during the recent outbreak in Finland were able to neutralize the trypsin-cleaved type 3 polioviruses. Serum specimens collected 1 month after a single dose of live poliovirus vaccine from children previously immunized with IPV were able to neutralize the trypsin-cleaved virus as well. During natural infection and after live poliovirus vaccine administration polioviruses are exposed to proteolytic enzymes in the gut. Our results may offer an alternative explanation for the relatively weak mucosal immunity obtained with IPV. Improvement of IPV preparations by incorporation of trypsin-treated type 3 polioviruses in the vaccine should be studied.     

Protection against hepatitis B by the Butang recombinant vaccine in newborn children in South Brazil

The prevention of hepatitis B by vaccination is one of the most efficient tools to avoid the transmission of the virus. This study evaluated the immunogenicity of the national vaccine Butang in children born in Campo Mour?o City, state of Paraná, Brazil, aged 7 to 12 months, by determining the anti-HBsAg antibodies levels after completion of the National Immunization Program Protocol for hepatitis B. All 70 children evaluated by the MEIA method (immune-enzymatic micro particles) showed seroconversion to the Butang vaccine. Nine children (12.9%) presented a low response, with anti-HBs titers between 11 and 100 mUI/ml; 39 children (55.7%) showed a good response to the vaccine, with titers between 101 and 1000 mUI/ml; and 22 children (31.4%) showed antibodies titers higher than 1000 mUI/ml. The mean titer of the anti-HBs antibody titers was 1408.1 +/- 2870.26 mUI/ml (15.7 to 19560.0 m UI/ml). The levels of antibodies produced by the prematurely-born children were not statistically different from those found in the newborns. Fifty-five children were also evaluated through the ELFA method (ELISA with a final detection in fluorescence), which presented similar results. The results obtained in our study corroborated the effectiveness of the national vaccine Butang in newborn children of Campo Mour?o City, Paraná, even if they were premature.     

The Incidence of Japanese Encephalitis in Taiwan—A Population-Based Study

Background

A mass Japanese encephalitis (JE) vaccination program targeting children was launched in Taiwan in 1968, and the number of pediatric JE cases substantially decreased thereafter. The aim of this study was to elucidate the long-term trend of JE incidence, and to investigate the age-specific seroprevalence of JE-neutralizing antibodies.

Methodology/Principal Findings

A total of 2,948 laboratory-confirmed JE cases that occurred between 1966 and 2012 were analyzed using a mandatory notification system managed by the Centers for Disease Control, Taiwan. A total of 6,594 randomly-sampled serum specimens obtained in a nationwide population-based survey in 2002 were analyzed to estimate the seroprevalence of JE-neutralizing antibodies in the general population. The average annual JE incidence rate of the group aged 30 years and older was 0.167 cases per 100,000 people between 2001 and 2012, which was higher than the 0.052 cases per 100,000 people among those aged under 30 years. These seroepidemiological findings indicate that the cohort born between 1963 and 1975, who generally received two or three doses of the vaccine and were administered the last booster dose more than 20 years ago, exhibited the lowest positive rate of JE-neutralizing antibodies (54%). The highest and second highest antibody rates were observed, respectively, in the oldest unvaccinated cohort (86%) and in the youngest cohort born between 1981 and 1986, who received four doses 10–15 years ago (74%).

Conclusion/Significance

Over the past decade, the main age group of the confirmed JE cases in Taiwan shifted from young children to adults over 30 years of age. People who were born between 1963 and 1975 exhibited the lowest seroprevalence of JE-neutralizing antibodies. Thus, the key issue for JE control in Taiwan is to reduce adult JE cases through a cost-effective analysis of various immunization strategies.     

Protective efficacy of a whole cell pertussis vaccine

A trial of the efficacy of a plain whole cell pertussis vaccine was conducted in Sweden. In this non-blinded trial 525 infants aged 2 months who were born on days with an even number received three doses of vaccine one month apart and 615 infants of the same age who were born on days with an odd number were enrolled as controls. During the 18 months of follow up there were 55 cases of pertussis. The attack rate was 1·5% (8/525) among the vaccinated children and 7·6% (47/615) among the unvaccinated children (p<0·001). The estimated efficacy of the vaccine was 80% (95% confidence interval 58 to 90).The estimated efficacy of pertussis vaccine was similar to that observed in British trials over 30 years ago.     

Cleavage of VP1 and modification of antigenic site 1 of type 2 polioviruses by intestinal trypsin.

We have exposed 22 independent type 2 poliovirus isolates to human intestinal fluid and purified trypsin. In all cases the virus retained its infectivity, while polyacrylamide gel electrophoresis of viral proteins showed disappearance of the VP1 bands. Concomitantly, the viruses became resistant to antigenic site 1-specific monoclonal antibodies, indicating that the cleavage took place at the antigenic site 1. Sera from persons immunized solely with the inactivated poliovirus vaccine (IPV) neutralized intact type 2 polioviruses more readily than the corresponding trypsin-cleaved virus preparations. The ratio between the neutralization indices for the intact and trypsin-cleaved type 2 polioviruses was not significantly changed by a dose of trivalent oral poliovirus vaccine given to children previously immunized with IPV. These results indicate that while the antigenic site 1 of type 2 poliovirus is immunogenic in humans when IPV is used, the relative role of this antigenic site in human immunity appears to be less critical than that in the case of type 3 polioviruses. Before we obtained these results, only antigenic site 1 had been shown to be immunogenic in type 2 polioviruses.     

Seroprotection against serogroup C meningococcal disease in adolescents in the United Kingdom: observational study

Objective To determine the persistence of bactericidal antibody titres following immunisation with serogroup C meningococcal glycoconjugate vaccine at age 6-15 years in order to examine changes in persistence of antibodies with age.Design Observational study.Setting Secondary and tertiary educational institutions in the United Kingdom.Participants Healthy adolescents aged 11-20 years previously immunised between 6 and 15 years of age with one of the three serogroup C meningococcal vaccines.Intervention Serum obtained by venepuncture.Main outcome measures Percentage of participants with (rabbit complement) serum bactericidal antibody titres of at least 1:8; geometric mean titres of serogroup C meningococcal serum bactericidal antibody.Results Five years after immunisation, 84.1% (95% confidence interval 81.6% to 86.3%) of 987 participants had a bactericidal antibody titre of at least 1:8. Geometric mean titres of bactericidal antibody were significantly lower in 11-13 year olds (147, 95% confidence interval 115 to 188) than in 14-16 year olds (300, 237 to 380) and 17-20 year olds (360, 252 to 515) (P<0.0001 for both comparisons). Within these age bands, no significant difference in geometric mean titres of bactericidal antibody between recipients of the different serogroup C meningococcal vaccines was seen. More than 70% of participants had received a vaccine from one manufacturer; in this cohort, geometric mean titres were higher in those immunised at aged 10 years or above than in those immunised before the age of 10.Conclusions Higher concentrations of bactericidal antibody are seen five years after immunisation with serogroup C meningococcal vaccine at age 10 years or above than in younger age groups, possibly owing to immunological maturation. This provides support for adolescent immunisation programmes to generate sustained protection against serogroup C meningococcal disease not only for the vaccine recipients but also, through the maintenance of herd immunity, for younger children.