The association between intentional delay of vaccine administration and timely childhood vaccination coverage

OBJECTIVES

We evaluated the association between intentional delay of vaccine administration and timely vaccination coverage.

METHODS

We used data from 2,921 parents of 19- to 35-month-old children that included parents' reports of intentional delay of vaccine administration. Timely vaccination was defined as administration with > or = 4 doses of diphtheria, tetanus, and pertussis; > or = 3 doses of polio vaccine; > or = 1 dose of measles, mumps, and rubella vaccine; > or = 3 doses of Haemophilus influenzae type b vaccine; > or = 3 doses of hepatitis B vaccine; and > or = 1 dose of varicella vaccine by 19 months of age, as reported by vaccination providers.

RESULTS

In all, 21.8% of parents reported intentionally delaying vaccinations for their children. Among parents who intentionally delayed, 44.8% did so because of concerns about vaccine safety or efficacy and 36.1% delayed because of an ill child. Children whose parents intentionally delayed were significantly less likely to receive all vaccines by 19 months of age than children whose parents did not delay (35.4% vs. 60.1%, p < 0.05). Parents who intentionally delayed were significantly more likely to have heard or read unfavorable information about vaccines than parents who did not intentionally delay (87.6% vs. 71.9%, p < 0.05). Compared with parents who intentionally delayed only because their child was ill, parents who intentionally delayed only because of vaccine safety or efficacy concerns were significantly more likely to seek additional information about their decision from the Internet (11.4% vs. 1.1%, p < 0.05), and significantly less likely to seek information from a doctor (73.9% vs. 93.9%, p < 0.05).

CONCLUSIONS

Intentionally delayed vaccine doses are not uncommon. Children whose parents delay vaccinations may be at increased risk of not receiving all recommended vaccine doses by 19 months of age and are more vulnerable to vaccine-preventable diseases. Providers should consider strategies such as educational materials that address parents' vaccine safety and efficacy concerns to encourage timely vaccination.

Who gives pertussis to infants? Source of infection for laboratory confirmed cases less than 12 months of age during an epidemic, Sydney, 2009

An important approach to protecting infants against pertussis is to provide a booster vaccination to close contacts, however this strategy requires a good understanding of infection sources to be effective. The objective of this study was to identify the most important sources of transmission of pertussis infection to infants, regardless of hospitalisation status. Standardised interviews were conducted during routine follow-up calls with the parent or guardian of laboratory confirmed pertussis cases less than 12 months of age notified to 3 Sydney metropolitan public health units during a pertussis outbreak from January to May 2009. All contacts with a coughing illness or laboratory confirmed pertussis during the 3 weeks prior to onset of illness in the index case, were recorded. A source of infection could not be identified for 29 infants (31%) and a total of 86 known or suspected sources were identified for the other 66 infants. The most frequently identified sources were siblings (36%) and parents (24%), followed by other family members (21%), friends (13%), and settings outside the home such as medical centres (6%). Of 20 siblings aged 3 or 4 years, 16 (80%) were sources of infection, compared with 14 of the 44 (32%) other siblings less than 18 years of age. During this epidemic siblings were more important sources of infant infection than parents. Siblings aged 3 and 4 years of age were particularly important transmitters of pertussis infection to infants. Minimising pertussis infection in 3 and 4 year olds may be an important measure to prevent infant infection.

Reduced rate of side effects associated with separate administration of MMR and DTaP-Hib-IPV vaccinations

BACKGROUND

According to the Israeli immunization schedule, 1 year old babies should receive two concomitant vaccinations: MMR (measles-mumps-rubella), and DTap-Hib-IPV (diphtheria tetanus acellular pertussis-Haemophilus influenzae type b-poliomyelitis). However, about one-third of infants in Israel receive these vaccinations separately. Nurses at a primary care prevention clinic in Israel observed that the separate mode of vaccination is associated with a lower rate of side effects.

OBJECTIVES

To validate this observation and determine whether it represents an exception or the rule.

METHODS

A nested prospective follow-up study was conducted in a primary care clinic in Israel. The survey included 191 mothers and their offspring born during 2004/2005. The mothers were interviewed over the telephone 2 weeks after the day of vaccination.

RESULTS

The rate of adverse effects in children who received the injections separately was significantly lower than among those who were vaccinated simultaneously (40% vs. 57%).

CONCLUSIONS

It may be necessary to reconsider the current vaccination policy regarding concomitant injections.

Levels of childhood vaccination coverage and the impact of maternal HIV status on child vaccination status in rural KwaZulu-Natal, South Africa*

OBJECTIVES

To analyse coverage of childhood vaccinations in a rural South African population and investigate whether maternal HIV status is associated with children's vaccination status.

METHODS

2 431 children with complete information, 12-23 months of age at some point during the period January 2005 through December 2006 and resident in the Africa Centre Demographic Surveillance Area at the time of their birth were investigated. We examined the relationship between maternal HIV status and child vaccination status for five vaccinations [Bacillus Calmette-Guérin (BCG), diphtheria-tetanus-pertussis (DTP3), poliomyelitis (polio3), hepatitis B (HepB3), and measles] in multiple logistic regressions, controlling for household wealth, maternal age, maternal education and distances to roads, fixed and mobile clinics.

RESULTS

Coverage of the five vaccinations ranged from 89.3% (95% CI 81.7-93.9) for BCG to 77.3% (67.1-83.6) for measles. Multivariably, maternal HIV-positive status was significantly associated with lower adjusted odds ratios (AOR) of child vaccination for all vaccines [(AOR) 0.60-0.74, all P < or = 0.036] except measles (0.75, P = 0.073), distance to mobile clinic was negatively associated with vaccination status (all P < or = 0.029), household wealth was positively (all P < or = 0.013) and distance to nearest road negatively (all P < or = 0.004) associated with vaccination status.

CONCLUSION

Positive maternal HIV status independently reduces children's probability to receive child vaccinations, which likely contributes to the morbidity and mortality differential between children of HIV-positive and HIV-negative mothers. As a means of increasing vaccination coverage, policy makers should consider increasing the number of mobile clinics in this and similar communities in rural Africa.

Updated recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding routine poliovirus vaccination

This report updates Advisory Committee on Immunization Practices (ACIP) recommendations for routine poliovirus vaccination. These updates aim to 1) emphasize the importance of the booster dose at age >/=4 years, 2) extend the minimum interval from dose 3 to dose 4 from 4 weeks to 6 months, 3) add a precaution for the use of minimum intervals in the first 6 months of life, and 4) clarify the poliovirus vaccination schedule when specific combination vaccines are used.

Coverage of recommended vaccines in children at 7-8 years of age in Flanders, Belgium

AIM

Evaluation of the coverage of primary diphtheria-tetanus-pertussis (DTP), poliomyelitis, hepatitis B (HBV) and measles-mumps-rubella (MMR) vaccine doses recommended before the age of 18 months in 7-year-old school children in Flanders, Belgium. Meningococcal serogroup C and DT-polio vaccines offered respectively as catch-up and booster vaccinations were also evaluated.

METHODS

Parents of 792 children born in Flanders in 1997 and selected by cluster sampling were interviewed at home in 2005. Vaccination data since infancy were collected retrospectively from vaccination documents and school health records.

RESULTS

Coverage rates were 88.0% for the first dose of MMR, and 72.0%, 84.2% and 91.4% for the recommended HBV, DTP and poliomyelitis primary vaccine doses, respectively. These rates included catch-up of missed infant MMR (4.9%) and HBV (6.4%) vaccinations. In addition, 88.3% of the target group received the DT-polio booster dose recommended at 6 years of age and 83.1% a meningococcal C vaccine dose. Preventive public health services as well as private physicians were involved to a varying extent. A lower socioeconomic status of the family was associated with a higher risk of nonvaccination.

CONCLUSION

Vaccinators in Flanders reach children relatively well during infancy and at school age, but catch-up of missed infant vaccine doses, especially MMR, should be optimized.

Combined DTP-HBV-HIB vaccine versus separately administered DTP-HBV and HIB vaccines for primary prevention of diphtheria, tetanus, pertussis, hepatitis B and Haemophilus influenzae B (HIB)

BACKGROUND

Advantages to combining childhood vaccines include reducing the number of visits, injections and patient discomfort, increasing compliance, and optimizing prevention. The World Health Organization recommends that routine infant immunization programs include a vaccination against Haemophilus influenza type B (HIB) in the combined diphtheria, tetanus, pertussis (DTP)-hepatitis B (HBV) vaccination. The effectiveness and safety of the combined vaccine should be carefully and systematically assessed to ensure their acceptability by the community.

OBJECTIVES

To compare the effectiveness of combined DTP-HBV-HIB vaccine with DTP-HBV and HIB vaccinations.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 1) which contains the Acute Respiratory Infection Group's Specialized Register; MEDLINE (January 1966 to March 2009) and EMBASE (January 1990 to March 2009).

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials comparing vaccination with any combined DTP-HBV-HIB vaccine, with or without three types of inactivated poliovirus (IPV) or concomitant oral polio vaccine (OPV) in any dose, preparation or time schedule, compared with separate vaccines or placebo, administered to infants aged up to two years.

DATA COLLECTION AND ANALYSIS

Two review authors independently inspected references identified by the searches and evaluated them against the inclusion criteria, extracted data and assessed the methodological quality of included trials.

MAIN RESULTS

Meta-analysis was performed to pool the results of 18 studies. There were no data on clinical outcomes for the primary outcome and all studies used immunogenicity and reactogenicity (adverse events). In two immunological responses the combined vaccine achieved lower responses than the separate vaccines for HIB and HBV. Comparison found little heterogeneity. No significant differences in immunogenicity were found for pertussis, diphtheria, polio and tetanus. Serious adverse events were comparable. Minor adverse events were more common in children given the combined vaccine.

AUTHORS' CONCLUSIONS

We could not conclude that the immune responses elicited by the combined vaccine were different from, or equivalent to, the separate vaccines. Data for the primary outcome (prevention of disease) were lacking. There was significantly less immunological response for HIB and HBV, and more local reactions in the combined injections. However, these differences rely mostly on one study each. Studies did not use an intention-to-treat analysis and we were uncertain about the risk of bias in many of the studies. These results are therefore inconclusive. Studies addressing clinical end-points whenever possible, using correct methodology and a large enough sample size should be conducted.

Erythema multiforme minor following vaccination with paediatric vaccines

We present 2 cases of erythema multiforme following a combined tetanus and diphtheria revaccination and a combined diphtheria, tetanus, acellular pertussis inactivated polio and Haemophillus influenzae type B vaccine respectively, suggesting vaccines containing diphtheria and tetanus toxoids as a potential precipitating factor to erythema multiforme.

[Surveillance on antibody levels of diphtheria, pertusis and tetanus in health population in Shenzhen]

OBJECTIVE

To know the antibody levels of DDT and the immunization effect of DPT vaccine in health population in Shenzhen, and to provide theoretic basis for the immunization strategy of DPT.

METHODS

Antibody of pertusis was tested by agglutination tests, antibodies of diphtheria and tetanus were tested by IHA tests.

RESULTS

The antibody positive rate of diphtheria, pertusis and tetanus were 88.31%, 71.54% and 92.77% respectively. The protective rate were 87.38%, 64.15% and 37.23% respectively. The GMT of diphtheria, pertusis and tetanus were 0.2595, 0.5607 and 1:156.87 respectively.

CONCLUSION

The antibody levels of diphtheria, pertusis and tetanus decreased by age, we should carry out DT booster immunization in freshmen of middle school, colleges and adults.

FDA approval of expanded age indication for a tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine

On December 4, 2008, the Food and Drug Administration (FDA) approved an expanded age indication for the tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine (Tdap) Boostrix (GlaxoSmithKline Biologicals, Rixensart, Belgium). Boostrix is now licensed for use in persons aged 10-64 years as a single-dose booster immunization; the vaccine initially was licensed for persons aged 10-18 years. This announcement summarizes the indications for use of Boostrix. Complete recommendations of the Advisory Committee on Immunization Practices (ACIP) for Tdap vaccines have been described previously.

Vitamin A supplements are well tolerated with the pentavalent vaccine

The Expanded Programme on Immunisation provides an opportunity to deliver vitamin A supplements to young infants in order to improve their vitamin A status. However, concerns have been raised about the safety of administering high dose vitamin A supplements to infants less than 6 months of age in developing countries. A randomized controlled trial was carried out by the Kintampo Health Research Centre to assess the safety and immunogenicity of administering 15 mg retinol equivalent (RE)1 vitamin A alongside the pentavalent "diphtheria-polio-tetanus-Haemophilus influenzae b-hepatitis B vaccine" at 6, 10 and 14 weeks of age. All mothers received a post-partum supplement of 120 mg RE vitamin A as per national policy. Mothers of infants who had been vaccinated were visited 24 h after vaccination to assess the side effects of the vaccine. They were also interviewed about adverse events which may have occurred in the past 4 weeks since the child was vaccinated. There were significantly fewer reports of illnesses and fever in infants who had been given vitamin A compared to infants in the control group. The pentavalent vaccine was found to be tolerable when administered with vitamin A according to the WHO/EPI schedule for infant immunisation at 6, 10 and 14 weeks. There were few complaints made by the mothers of the children which were not thought to be related to giving vitamin A with the vaccines. There were six deaths in the trial, five in the intervention group and one in the control RR 4.65 (0.55-39.5), p = 0.12. Due to the high point estimate of 4.65, we wish to urge caution in administering high doses of vitamin A to young infants with the pentavalent vaccine at 6, 10 and 14 weeks of age.

Tracking progress towards universal childhood immunisation and the impact of global initiatives: a systematic analysis of three-dose diphtheria, tetanus, and pertussis immunisation coverage

BACKGROUND

Substantial resources have been invested in increasing childhood immunisation coverage through global initiatives such as the Universal Childhood Immunisation (UCI) campaign and the Global Alliance on Vaccines and Immunisations (GAVI). There are longstanding concerns that target-oriented and performance-oriented initiatives such as UCI and GAVI's immunisation services support (ISS) might encourage over-reporting. We estimated the coverage of three doses of diphtheria, tetanus, and pertussis vaccine (DTP3) based on surveys using all available data.

METHODS

We estimated DTP3 coverage by analysing unit record data from surveys and supplemented this with reported coverage from other surveys and administrative data. We used bidirectional distance-dependent regression to estimate trends in survey-based coverage in 193 countries during 1986-2006. We used standard time-series cross-sectional analysis to investigate any association in the difference between countries' official reports and survey-based coverage as the dependent variable and the presence of GAVI ISS as the independent variable, controlling for country and time effects.

FINDINGS

Crude coverage of DTP3 based on surveys increased from 59% (95% uncertainty interval 51-65) in 1986 to 65% (60-68) in 1990, 70% (65-74) in 2000, and 74% (70-77) in 2006. There were substantial differences between officially reported and survey-based coverage during UCI. GAVI ISS significantly increased the difference between officially reported coverage and survey coverage. Up to 2006, in 51 countries receiving GAVI ISS payments, 7.4 million (5.7 million to 9.2 million) additional children were immunised with DTP3 based on surveys compared with officially reported estimates of 13.9 million. On the basis of the number of additional children immunised from surveys at a rate of US$20 each, GAVI ISS payments are estimated at $150 million (115 million to 184 million) compared with actual disbursements of $290 million.

INTERPRETATION

Survey-based DTP3 immunisation coverage has improved more gradually and not to the level suggested by countries' official reports or WHO and UNICEF estimates. There is an urgent need for independent and contestable monitoring of health indicators in an era of global initiatives that are target-oriented and disburse funds based on performance.

Immunogenicity and safety of an indigenously developed DTPw hepatitis B combination vaccine in Indian infants

OBJECTIVE

To evaluate the safety and immunogenicity of an indigenous hepatitis B, diphtheria, tetanus and B. pertussis tetravalent vaccine (Shantetra) in comparison with Tritanrix HBTM in healthy Indian infants.

DESIGN

Multicentric, randomized, single blind intention-to-treat study with 12-18 weeks of follow up period.

SETTING

5 out patient departments at tertiary care referral centers across India.

PARTICIPANTS

151 infants were randomized in a 2:1 ratio to recruit 101 in the Shantetra and 50 in the Tritanrix HBTM groups respectively. A total of 136 subjects completed the study. No patients were withdrawn from the study due to any adverse effects.

INTERVENTIONS

Recruited subjects were randomized to receive three doses of either of the two DTPw-Hepatitis B combination vaccines as per the EPI schedule.

MAIN OUTCOME MEASURES

Monitoring the humoral immune response (seroconversion rates) induced by each antigenic component three to six weeks after the last dose of vaccine in both the groups.

RESULTS

Seroprotective immune response was observed in 98.9% subjects for diphtheria, tetanus and hepatitis B components in the Shantetra group as compared to 95.5% subjects in the Tritanrix HB group. Anti pertussis antibody response was seen in 89% and 91.1% in the Shantetra and Tritanrix HB groups, respectively. The commonly observed adverse events in both the groups were, pain at injection site, mild fever and transient crying.

CONCLUSION

The safety and immunogenicity of indigenously developed DTPwHepatitis B combination vaccine was demonstrated in the present study.

Poor immune responses to a birth dose of diphtheria, tetanus, and acellular pertussis vaccine

OBJECTIVES

To evaluate the safety and immunogenicity of an additional birth dose of diphtheria, tetanus, and acellular pertussis vaccine (DTaP).

STUDY DESIGN

Fifty infants between 2 to 14 days of age were randomly assigned to receive either DTaP and hepatitis B vaccines (experimental) or hepatitis B alone (control) at birth. At 2, 4, 6, and 17 months of age, DTaP and routine vaccines were administered to both groups. Safety data were collected after each dose, and sera were obtained at birth, 6, 7, 17, and 18 months. Immune responses to pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae were measured by enzyme-linked immunosorbent assay; responses to other vaccines were assessed.

RESULTS

No differences were seen between the 2 groups in either local or systemic reactions; all vaccines were well tolerated. Compared with the control group, infants in the experimental group demonstrated significantly lower geometric mean antibody concentrations for pertussis toxin and pertactin 6, 7, and 18 months, for fimbrae at 6, 7, 17, and 18 months, and for FHA at 18 months, and lower geometric mean antibody concentrations for diphtheria at 7 months. Immune responses to all other vaccine antigens were comparable.

CONCLUSION

Administration of an additional dose of DTaP at birth was safe but was associated with a significantly lower response to diphtheria and 3 of 4 pertussis antigens compared with controls.

Immunogenicity and reactogenicity of DTPa-HBV-IPV/Hib vaccine as primary and booster vaccination in low-birth-weight premature infants

AIM

To assess suitability of a combined DTPa-HBV-IPV/Hib vaccine (Infanrix hexa) for immunization of low-birth-weight (<2.0 kg) preterm infants, with particular focus on the hepatitis B response.

METHODS

Open-label study in 170 preterm infants receiving primary vaccination at 2, 4 and 6 months of age and booster vaccination at 18-24 months. Enrollment and analysis were stratified in two groups: infants with birth weight between 1.5 kg and 2.0 kg (low birth weight: LBW), infants with BW <1.5 kg (very low birth weight: VLBW).

RESULTS

One month after the three dose primary vaccination, 93.7% and 94.9% of infants in VLBW and LBW groups, respectively, had anti-HBs antibody concentrations > or = 10 mIU/mL. High seroprotection and response rates (92.4-100%) to all vaccine antigens were observed. Those were reinforced (>98%) by booster vaccination for all antigens except for HBs in VLBW children: only 88.7% of those had anti-HBs antibody concentrations > or = 10 mIU/mL, compared with 96.5% of LBW children (difference statistically not significant). The vaccine was well tolerated in both groups of infants.

CONCLUSION

Preterm infants will benefit by the administration of a primary and booster vaccination with DTPa-HBV-IPV/Hib vaccine.

[Combined vaccines and simultaneous administration in newborns]

Combined vaccines and simultaneous administration are widely studied due to the increasing number of antigens available for newborns immunization. By means of simultaneous administration and combination of vaccines, an effective preventive strategy can be adopted, in order to obtain parents compliance and an optimal coverage of the target population.

[Vaccination of children born from HIV-infected mothers against Haemophilus influenzae type b infection]

Course of postvaccinal period after injection of vaccine against Haemophilus influenzae type b administered simultaneously with vaccines of Russian national immunization schedule was studied in children born from HIV-infected mothers. Good tolerability of the vaccine administered concomitantly with diphtheria-tetanus-whole cell pertussis and inactivated polio vaccines (Imovax Polio), which is comparable with tolerability in healthy children, was demonstrated. Prevaccination titers of antibodies and their dynamics during immunization process were described. Increase of levels of antibodies was detected both in the group of children with perinatal contact with HIV infection and in the group of HIV-infected children.

Prevention of pertussis, tetanus, and diphtheria among pregnant and postpartum women and their infants recommendations of the Advisory Committee on Immunization Practices (ACIP)

In 2005, two tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines were licensed and recommended for use in adults and adolescents in the United States: ADACEL (sanofi pasteur, Swiftwater, Pennsylvania), which is licensed for use in persons aged 11--64 years, and BOOSTRIX (GlaxoSmithKline Biologicals, Rixensart, Belgium), which is licensed for use in persons aged 10-18 years. Both Tdap vaccines are licensed for single-dose use to add protection against pertussis and to replace the next dose of tetanus and diphtheria toxoids vaccine (Td). Available evidence does not address the safety of Tdap for pregnant women, their fetuses, or pregnancy outcomes sufficiently. Available data also do not indicate whether Tdap-induced transplacental maternal antibodies provide early protection against pertussis to infants or interfere with an infant's immune responses to routinely administered pediatric vaccines. Until additional information is available, CDC's Advisory Committee on Immunization Practices recommends that pregnant women who were not vaccinated previously with Tdap: 1) receive Tdap in the immediate postpartum period before discharge from hospital or birthing center, 2) may receive Tdap at an interval as short as 2 years since the most recent Td vaccine, 3) receive Td during pregnancy for tetanus and diphtheria protection when indicated, or 4) defer the Td vaccine indicated during pregnancy to substitute Tdap vaccine in the immediate postpartum period if the woman is likely to have sufficient protection against tetanus and diphtheria. Although pregnancy is not a contraindication for receiving Tdap vaccine, health-care providers should weigh the theoretical risks and benefits before choosing to administer Tdap vaccine to a pregnant woman. This report 1) describes the clinical features of pertussis, tetanus, and diphtheria among pregnant and postpartum women and their infants, 2) reviews available evidence of pertussis vaccination during pregnancy as a strategy to prevent infant pertussis, 3) summarizes Tdap vaccination policy in the United States, and 4) presents recommendations for use of Td and Tdap vaccines among pregnant and postpartum women.

Four is better than nine. a combined diphtheria-tetanus-pertussis-hepatitis B-Haemophilus influenzae type b vaccine for routine immunization in Malaysia

Malaysian infants would have to receive nine injections during the first few months of life in order to be protected against disease caused by hepatitis B (HBV), diphtheria, tetanus, pertussis and Haemophilus influenzae type b (Hib) if single HBV and Hib vaccines were used. We evaluated a combined DTPw-HBV/Hib vaccine administered at 1.5, 3 and 5 months after a birth dose of hepatitis B vaccine (HBV). One month after completion of the primary vaccination, 99% of subjects had seroprotective anti-HBV antibody levels, and at least 98% had seroprotective antibodies against diphtheria, tetanus, and Hib, and were seropositive for pertussis antibodies. The immune response to the combined vaccine was comparable to that induced by separate injections with DTPw, HBV and Hib vaccines. Overall, the DTPw-HBV/Hib vaccine was as well tolerated as separate administration of DTPw, HBV and Hib vaccines. The combined DTPw-HBV/Hib vaccine induces protection against five diseases as recommended in the Malaysian routine vaccination schedule. Use of the combined DTPw-HBV/Hib vaccine can reduce the required number of injections from nine to four in the first few months of life.

Primary vaccination with a new heptavalent DTPw–HBV/Hib–Neisseria meningitidis serogroups A and C combined vaccine is well tolerated

OBJECTIVE

Safety and reactogenicity of a new heptavalent DTPw-HBV/Hib-MenAC (diphtheria, tetanus, whole cell pertussis-hepatitis B virus/Haemophilus influenzae type b-Neisseria meningitidis serogroups A and C) vaccine was compared with a widely used pentavalent DTPw-HBV/Hib vaccine.

METHODS

Three phase III randomized studies comparable in design and methodology, in which healthy infants received DTPw-HBV/Hib-MenAC (N=1334) or DTPw-HBV/Hib (N=446) at 2, 4, and 6 months, were pooled for analysis. Solicited symptoms were recorded for 4 days, and unsolicited adverse events for 31 days after each dose. Serious adverse events (SAEs) were recorded throughout the studies.

RESULTS

There were no significant differences between the two groups in the proportion of subjects with fever >39.5 degrees C or >40.0 degrees C (p<0.005). Compared to group DTPw-HBV/Hib, a significantly higher percentage of subjects in group DTPw-HBV/Hib-MenAC reported fever >39 degrees C (21.2% vs. 14.8%, p=0.004). Fever subsided quickly, did not lead to differences in attendance to medical services and did not increase from dose to dose. Sixty-seven SAEs were reported, 56/1334 (4.2%) in group DTPw-HBV/Hib-MenAC and 11/446 (2.5%) in the DTPw-HBV/Hib group.

CONCLUSION

Overall, the heptavalent and pentavalent vaccines had similar safety profiles. The difference observed in percentage of subjects with fever >39 degrees C did not lead to differences in medically attended visits for fever.

Pertussis seroimmunity among mother-infant pairs and infant immune response to pertussis vaccination

This study was designed to evaluate seroprevalence rates of antibodies to pertussis in mothers and their infants, and the immunogenicity of pertussis vaccine in the presence or absence of pertussis antibodies in infants. Blood samples were collected from 110 mother-infants pairs before the first dose of pertussis vaccination and from 69 infants 4-8 weeks after administration of the third dose of DTwP vaccine. Pertussis antibodies were >25 U/mL in 88(78.9%) mothers and 50(45.3%) infants with a mean titer of 67(SD 48.1) and 33.5 (34.7) U/mL, respectively. After administration of three doses of DTwP vaccine, 53(76.8%) infants were seroconverted (MCA titer 87.4 (51.3)U/mL. Immunologic response to vaccination was similar between the two groups of infants; 30/37 (81.1%) of seronegative infants and 23/32 (71.9%) of seropositive infants at pre-vaccination, showed seroconversion after the vaccination (P = 0.36). The results of this study demonstrated that most of the studied mothers were serologically immune to pertussis, and this immunity was transferred to their infants. Pre-vaccination antibody did not affect infants immune response to vaccination.

Booster vaccination and 1-year follow-up of 4-8-year-old children with a reduced-antigen-content dTpa-IPV vaccine

Reduced-antigen-content pertussis vaccines designed initially for booster vaccination of adolescents and adults can also be used to vaccinate pre-school age children. Combination vaccines, which reduce the number of administered injections, combine multiple antigens including inactivated poliovirus (IPV), which is recommended in this age group in some countries. This randomised, controlled study compared a combined diphtheria-tetanus-acellular pertussis-inactivated polio-containing booster vaccine, dTpa-IPV (Boostrix Polio, n=822), to separately administered dTpa (Boostrix) and IPV (IPV Mérieux, n=136) in 4-8-year-old children who had previously received four doses of DTPa. Additional serological assessment was performed 1 year after the booster dose. One month after vaccination, seroprotection/vaccine response rates were similar for both groups. At least 99.9% of the subjects had protective antibodies against diphtheria, tetanus and polio, and at least 90.1% had a vaccine response to pertussis antigens after dTpa-IPV. Reactogenicity of dTpa-IPV was comparable to dTpa + IPV. Fever and grade 3 loss of appetite occurred more commonly after dTpa-IPV, whereas swelling and grade 3 pain occurred more frequently after separately administered dTpa + IPV (P<0.05 for all). However, 95% CIs overlapped in all cases. Large swelling reactions after dTpa-IPV occurred less commonly than have been reported after a fifth dose of DTPa. One year after the booster, 98.6% of the subjects tested continued to have protective antibodies against diphtheria, tetanus and polio, and at least 81.2% were seropositive for pertussis components. The reduced-antigen-content dTpa-IPV vaccine was immunogenic, well tolerated and safe in pre-school age children. It provides immunity against four diseases in a single injection, with the potential reactogenicity benefit of a reduced-antigen dose.

DPT vaccine-induced lipoatrophy: an observational study

INTRODUCTION

Diphtheria Pertussis Tetanus (DPT) vaccine is universally used in infants and children. It is generally safe and well tolerated. Local reactions such as erythema, induration, palpable nodules, and injection site abscess are well known. Injection site lipoatrophy has not been reported earlier.

PATIENTS AND METHODS

Retrospective review of all cases presenting with lipoatrophy developing at injection site following DPT administration between 2000-2005 in 3 hospitals in New Delhi, India was performed. In each case, the patients were extensively evaluated for other possible causes of lipoatrophy.

RESULTS

8 infants (2 boys & 6 girls), age range 4-12 months, had presented with injection site lipoatrophy following DPT vaccination. The duration between the last injection and lipoatrophy ranged from 4 to 8 weeks. All had been administered the vaccine in the buttock instead of the thigh, as generally recommended in infants. Majority (6/8) developed lipoatrophy after the second dose. No systemic causes were found.

CONCLUSION

DPT vaccine may, in rare instances, lead to injection site lipoatrophy. Inadvertent administration into the subcutaneous fat of the buttock may have been causative. Other possible mechanisms are discussed. Paramedics and general practitioners need to be educated to administer intramuscular vaccines in the thigh in infants and young children.

Routine Immunizations and Adverse Events in Infants With Single-Ventricle Physiology

BACKGROUND

Infants with single-ventricle congenital heart defects are at risk of sudden unexpected death. In an effort to decrease the risk of sudden death, some centers have advocated that routine immunizations be deferred in this population. However, it is not known if an association exists between immunizations and adverse events.

METHODS

The present study examined the relationship of routine immunizations with adverse events, which were defined as sudden death or hospital readmission. The diphtheria-tetanus-acellular pertussis (DTaP) vaccine was considered in the analysis. The patient population consisted of infants younger than 9 months old who resided locally and had not yet undergone bidirectional cavopulmonary anastomosis (BCPA). Immunization data were obtained from a mandatory statewide database.

RESULTS

During a 35-month period, 137 patients with single-ventricle physiology were discharged home after neonatal surgery or directly from the newborn nursery. Hypoplastic left heart syndrome (HLHS) was the diagnosis in 58 patients (42%) and was the most common. In the entire cohort, there were four sudden deaths (3%), and 53 patients (38%) had at least one interval hospital admission. Immunization within 48 hours was not associated with adverse events (odds ratio, 1.48; 95% confidence interval, 0.73 to 2.90; p = 0.31). No sudden death events occurred within 48 hours of immunization.

CONCLUSIONS

No association could be identified between routine immunizations and adverse events in infants with single-ventricle physiology. As such, the proposal to alter the immunization regimen in this population does not appear justified.

Vaccinations, infections and antibacterials in the first grass pollen season of life and risk of later hayfever

BACKGROUND

It has been hypothesized that early-life exposure to vaccinations, infections or antibacterials influence allergic disease development. Concurrent exposure to grass pollens may alter any effect.

OBJECTIVE

To test the hypothesis that exposure to antibacterials, vaccinations (DTP or MMR) or specific infections during the first grass pollen seasons of life influences the risk of hayfever more than at any other time of the year.

METHODS

Nested case-control studies were based on birth cohorts within two large databases of computerized patient records from UK general practices: the General Practice Research Database (GPRD) and Doctors' Independent Network (DIN). Seven thousand ninety-eight hayfever cases, diagnosed after age 2, were matched to controls for practice, age, sex and follow-up of control to case ascertainment date. Conditional logistic regression was used to compare exposure by age 1 (age 2 for MMR) inside vs. outside the grass pollen season (May, June, July). Odds ratios (ORs) were pooled across databases.

RESULTS

There were no associations in either database between MMR during vs. outside the grass pollen season and later hayfever. Of 23 infections studied, none were statistically significant; although analyses for the less common conditions were limited by low statistical power. The pooled OR for hayfever comparing exposure to antibacterials only in the grass pollen season with only outside it was 1.20 (95% CI 0.98-1.47) and for DTP was 0.84 (95% CI 0.72-0.98).

CONCLUSION

Although an interaction between early exposure to microbial agents and concurrent grass pollen exposure on hayfever risk seemed plausible, there was little evidence to support it across a range of analyses. However, the effect of DTP though weak deserves further study.

Safety monitoring of a new pentavalent vaccine in the expanded programme on immunisation in Ghana

BACKGROUND AND OBJECTIVE

Safety monitoring of vaccines used in expanded programmes on immunisation is important in all countries, including those with limited resources. As the rates of target diseases decrease, parents become less accepting of even minor common adverse events. Identification, detection, prevention and appropriate communication of adverse events following immunisation (AEFI) are therefore essential to preserve the integrity of immunisation programmes and protect public health. The objective of this study was to document the occurrence of common minor AEFI associated with a newly introduced pentavalent vaccine for routine immunisation in Ghana's expanded programme on immunisation.

METHODS

A prospective descriptive study on AEFI associated with the administration of a pentavalent diphtheria, tetanus, pertussis, hepatitis B and Haemophilus influenzae type B (DTP-hepatitis B vaccine/Hib vaccine) vaccine that is part of the Expanded Programme on Immunisation was carried out in four locations in Accra, Ghana. These locations were the nation's premier teaching hospital (the Korle-Bu Teaching Hospital) two urban polyclinics (the Mamprobi and Ussher Town polyclinics) and a community immunisation centre (the Zongo Junction Immunisation Centre).A total of 406 infants were recruited for the study. Upon receipt of signed informed consent from the parents/guardians of the infants, the parents/guardians were supplied with a pink card that functioned as a pseudo-diary for recording AEFI that occurred at home and for measuring and noting the sizes of any injection-site swellings that might occur. It also enabled each participant to obtain free medical care at the Department of Child Health, Korle-Bu Teaching Hospital for the duration of the study (from September 2003 to December 2004) and until the child was 12 months old. Information about the occurrence of AEFI was actively solicited during each visit for immunisation and also at a visit 4 weeks after administration of the last dose of pentavalent vaccine, when participants were asked to report to the respective immunisation centres for the specific purpose of reporting any AEFI which might have occurred in the intervening period. These AEFI were analysed separately from those reported to the dedicated hospital unit at the Department of Child Health, Korle-Bu Teaching Hospital, since the AEFI reported to that unit were all verified and recorded by trained physicians.

RESULTS

Of the 406 infants, 368 completed the study, whereas 38 defaulted or were lost to follow-up. There were 104 attendances to report cases of suspected AEFI requiring physician attention at the Department of Child Health, Korle-Bu Teaching Hospital. These attendances were made by 74 patients who reported 190 events; notable among these were cough (26.3% of all AEFI reported to the hospital), fever (17.4%), common cold (12.1%), vomiting (7.4%) and diarrhoea (6.8%). Three of these visits involved AEFI that were classified as 'serious', since they required hospitalisation, but all three were considered to be unlikely to be related to vaccine administration. In addition, actively solicited information on AEFI following immunisation from 921 individual interviews with the parents/guardians of immunised infants during the follow-up visits resulted in reports of 259 events being reported, the most common, according to crude incidence rates, being fever (14.7%), common cold (3.8%), crying (3%) and cough (2.8%).

CONCLUSION

The results of this study show agreement with safety studies on vaccines containing identical or similar antigens performed elsewhere and indicate the safety and tolerability of the pentavalent DTP-hepatitis B vaccine/Hib vaccine in Ghanaian children.

Concomitant administration of a virosome-adjuvanted hepatitis a vaccine with routine childhood vaccines at age twelve to fifteen months: a randomized controlled trial

BACKGROUND

The objectives of this trial were to test for noninferiority of a virosomal hepatitis A virus (HAV) vaccine (Epaxal) coadministered with routine childhood vaccines compared with Epaxal given alone and to an alum-adjuvanted HAV vaccine (Havrix Junior) coadministered with routine childhood vaccines.

METHODS

Healthy children 12- to 15-month-old were randomized to receive either a pediatric dose (0.25 mL) of Epaxal coadministered with DTPaHibIPV, oral polio vaccine, and measles-mumps-rubella vaccine (n = 109; group A), or Epaxal given alone (n = 105; group B), or Havrix Junior coadministered with DTPaHibIPV, oral polio vaccine, and measles-mumps-rubella vaccine (n = 108; group C). A booster dose was given 6 months later. Anti-HAV antibodies were tested before and 1 month after each vaccination. Safety was assessed for 1 month after each vaccination. Solicited adverse events were assessed for 4 days after each vaccination.

RESULTS

: HAV seroprotection rates (> or =20 mIU/mL) at 1 and 6 months after first dose were: A: 94.2% and 87.5%, B: 92.6% and 80.0%, C: 78.2% and 71.3%, respectively (A versus C: P < 0.001 and P = 0.017 at month 1 and 6, respectively). The respective geometric mean concentrations were: A: 51 and 64 mIU/mL, B: 49 and 59 mIU/mL, C: 33 and 37 mIU/mL (A versus C: P < 0.001 at both time points). All groups achieved 100% seroprotection after the booster dose. The geometric mean concentrations after the booster dose were 1758, 1662, and 1414, for groups A, B and C, respectively (A versus C: P = 0.15). No clinically significant reduction in immune response to all concomitant vaccine antigens was seen. All vaccines were well tolerated.

CONCLUSIONS

: Coadministration of pediatric Epaxal with routine childhood vaccines showed immunogenicity and safety equal to Epaxal alone as well as to Havrix Junior. After first dose, Epaxal was significantly more immunogenic than Havrix Junior.

Clinical outcome of pertussis in Sweden: association with pulsed-field gel electrophoresis profiles and serotype

In Sweden, acellular pertussis vaccines were introduced at 3, 5 and 12 months of age in 1996, after a 17-year hiatus without pertussis vaccination. An intensified surveillance of pertussis was initiated in October 1997, including collection of clinical data as well as Bordetella pertussis isolates in culture or PCR-confirmed cases of pertussis among children born from January 1996 to September 2004. We analysed the association of pulsed-field gel electrophoresis (PFGE) profile and serotype with severity of disease for all children followed during the first 7 years of the project. There were in all 927 children for whom both clinical information and strain characterisation data were available. 260 of these children were hospitalised during the pertussis episode. When duration of hospital stay was compared between children with different groups of strains, characterised by PFGE profile or serotype, there was a significantly higher proportion of children with long duration of hospital stay in the most frequent PFGE profile group (BpSR11) compared to the PFGE group of all other profiles (p=0.041). There was no statistically significant association between serotype and hospitalisation rate or duration of hospital stay, neither was there any statistically significant association between serotype or PFGE profile and duration of spasmodic cough or presence of complications.

Primary immunization of premature infants with gestational age <35 weeks: cardiorespiratory complications and C-reactive protein responses associated with administration of single and multiple separate vaccines simultaneously

OBJECTIVE

To determine the incidence of cardiorespiratory events and abnormal C-reactive protein (CRP) level associated with administration of a single vaccine or multiple separate vaccines simultaneously.

STUDY DESIGN

Prospective observational study on 239 preterm infants at > or =2 months of age in the neonatal intensive care unit (NICU). Each infant received either a single vaccine or multiple vaccines on one day. CRP levels and cardiorespiratory manifestations were monitored for 3 days following immunization.

RESULTS

Abnormal elevation of CRP level occurred in 85% of infants administered multiple vaccines and up to 70% of those given a single vaccine. Overall, 16% of infants had vaccine-associated cardiorespiratory events within 48 hours postimmunization. In logistic regression analysis, abnormal CRP values were associated with multiple vaccines (OR, 15.77; 95% CI 5.10-48.77) and severe intraventricular hemorrhage (IVH) (OR, 2.28; 95% CI 1.02-5.13). Cardiorespiratory events were associated marginally with receipt of multiple injections (OR, 3.62; 95% CI 0.99-13.25) and significantly with gastroesophageal reflux (GER) (OR, 4.76; 95% CI 1.22-18.52).

CONCLUSION

CRP level is expected to be elevated in the 48 hours following immunization. In a minority of infants immunized, cardiorespiratory events were associated with presumed need for intervention. Underlying medical conditions and possibly multiple injections are associated with cardiorespiratory events. Precautionary monitoring following immunizations is warranted.

Design and Simulation Study of the Immunization Data Quality Audit (DQA)

The goal of the Data Quality Audit (DQA) is to assess whether the Global Alliance for Vaccines and Immunization-funded countries are adequately reporting the number of diphtheria-tetanus-pertussis immunizations given, on which the "shares" are awarded. Given that this sampling design is a modified two-stage cluster sample (modified because a stratified, rather than a simple, random sample of health facilities is obtained from the selected clusters); the formula for the calculation of the standard error for the estimate is unknown. An approximated standard error has been proposed, and the first goal of this simulation is to assess the accuracy of the standard error. Results from the simulations based on hypothetical populations were found not to be representative of the actual DQAs that were conducted. Additional simulations were then conducted on the actual DQA data to better access the precision of the DQ with both the original and the increased sample sizes.

Prevalence of high antibody titers of pertussis in Turkey: reflection of circulating microorganism and a threat to infants

Acute pertussis infection among adults can cause its transmission to the larger population, especially to infants and young children, who can develop severe disease. In order to determine an age-dependent pertussis immune response, anti-pertussis toxin (PT) antibody was detected by the indirect enzyme-linked immunosorbent assay (ELISA) method in serum samples from 2,085 healthy subjects ranging in age from 6 months to > or = 60 years. Also included in the evaluation were responses to a questionnaire including sociodemographic characteristics, vaccination, and infection history. Titers of 50-99 ELISA units (EU)/mL and of > or = 100 EU/mL were accepted as indicative for recent exposure or infection. In addition, 30 EU/mL was estimated to be a sufficient titer in women of childbearing age to protect their newborns until administration of their first dose of pertussis vaccine. After the age of 4-5 years, presence of high-titered antibodies that increase with age might be a reflection of circulating infection and indicate the magnitude of the threat to infants. According to the questionnaires, in the groups younger than 15 years old, three to four doses of diphtheria toxoid-whole cell pertussis-tetanus toxoid (DwPT) were administered in 47.2 to 77.4%, 91.2 to 100.0%, and 83.5 to 100.0% of participants in Diyarbakir, Samsun, and Antalya, respectively. In addition, up to half of the expectant mothers we studied lacked a sufficient level of estimated antibody titers. To protect infants from life-threatening pertussis infection, improving vaccination coverage to ensure herd immunity and uniformly establishing coverage throughout the country are essential. Furthermore, revaccination with acellular vaccine for schoolchildren as well as for the households of pregnant women is recommended.

The immunological response of Thai infants to haemophilus influenzae type B polysaccharide-tetanus conjugate vaccine co-administered in the same syringe with locally produced diphtheria-tetanus-pertussis vaccine

OBJECTIVE

Comparing the immunogenicity and reactogenicity of three vaccine combinations. These were GlaxoSmithKline Biologicals' (GSK) Haemophilus influenzae type b vaccine (Hib-TT, Hiberix) administered with the local Government Pharmaceutical Organization's (GPO) diphtheria-tetanus-pertussis whole cell (DTPw) vaccine, Hib-TT mixed with GPO's DTPw vaccine, or Hib-IT mixed with GSKs' DTPw vaccine (Tritanrix).

MATERIAL AND METHOD

An open, randomized, controlled, single center study of three hundred and sixty infants. They were randomized into three groups to receive either Hib-TT Hiberix mix with GPOs' DTPw vaccine (group 1), Hib-TT mixed with GPO's DTPw vaccine (group 2), or Hib-TT mixed with GSKs' DTPw vaccine (Tritanrix; group 3) at two, four and six months of age.

RESULT

One month after the third dose, all subjects had antibodies level against Hib polyribosylribitol phosphate (PRP) > or = 0.15 microg/ml. All 11 subjects except two (in group 2) had anti-PRP levels > or = 1.0 microg/ml. The geometric mean concentrations were similar in all three groups. Over 96% of the subjects in all three groups demonstrated an immunological response to diphtheria, tetanus, and pertussis antigens. There was no diference among the three groups in terms of severe local reaction and fever.

CONCLUSION

The present study showed that the combined vaccines produced an effective antibody response with no increase in reactogenicity compared to separately administrated vaccines.

Effectiveness of Haemophilus influenzae type B conjugate vaccine on prevention of pneumonia and meningitis in Bangladeshi children: a case-control study

BACKGROUND

Few Asian countries have introduced Haemophilus influenzae type b (Hib) conjugate vaccine because of its cost and uncertainty regarding disease burden.

METHODS

To estimate the effectiveness of Hib conjugate vaccine in preventing pneumonia and meningitis in children age <2 years, an incident case-control study was conducted in a birth cohort of about 68,000 infants in Dhaka city, Bangladesh. DPT vaccine was systematically replaced by a combined Hib-DPT vaccine in selected immunization centers of the study area. Four matched community- and 2 hospital-controls were randomly selected for each confirmed case of pneumonia and meningitis from the study area.

RESULTS

About 35% of the infants received each of the 3 doses of Hib-DPT vaccine. There were 2679 children who had a chest roentgenogram. For 475 children, a radiologist and a pediatrician independently identified substantial alveolar consolidation. Following at least 2 doses of Hib vaccine, the preventable fractions [95% confidence intervals (CI)] using community and hospital controls were 17% (-10% to 38%) and 35% (13% to 52%) respectively. Of these 475 cases, 2 radiologists with the World Health Organization concurred with the findings for 343 patients, yielding preventable fractions of 34% (6% to 53%) and 44% (20% to 61%). Fifteen confirmed Hib meningitis cases were identified; the preventable fractions (95% CI) using community and hospital controls, respectively, were 89% (28% to 100%) and 93% (53% to 100%).

CONCLUSIONS

The study documented that significant fractions of pneumonia and meningitis in Bangladeshi children age <2 years can be prevented by the Hib conjugate vaccine.

[The humoral immunity against diphtheria]

Results of the conducted study showed that naturally acquired antibacterial and postvaccinal antitoxic antibodies against diphtheria were found in human blood sera. Challenge of ADT-M toxoid to adults resulted in production of antitoxic as well as antibacterial antibodies in high concentrations. In response to challenge of ADT-M toxoid simultaneously with bacterial vaccine against diphtheria Codivac both antibacterial and antitoxic antibodies were synthesized in blood on optimal physiologic levels. This study revealed dynamics of some specific characteristics of humoral immune response after challenge of two different vaccines against diphtheria--ADT-M toxoid and Codivac vaccine.