Immune responses in adults to revaccination with a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine 10 years after a previous dose

Background

Although decennial adult boosters of tetanus and diphtheria toxoids are recommended in Canada and the United States, a second dose of pertussis vaccine during adulthood is not currently recommended.

Methods

This open-label, multicenter study compared the safety and immunogenicity of a first dose of an adult formulation of tetanus, diphtheria, and acelluar pertussis vaccine (Tdap) with a repeat dose of Tdap in adults who had received Tdap 10 years previously.

Results

A total of 769 participants ranging in age from 20 to 72 years took part in this study; 92.3% of naïve and 92.7% of repeat-dose participants had at least one solicited adverse event. Injection-site pain (84.4% and 87.8%), erythema (29.7% and 23.1%), and swelling (23.3% and 20.5%), and myalgia (53.5% and 60.1%), headache (37.6% and 40.6%), malaise (29.0% and 29.4%), and fever (4.9% and 4.2%) were the most common solicited adverse events reported in the naïve and repeat-dose groups, respectively. Postvaccination antibody levels ≥0.1 IU/mL were achieved by 99.7% of the naïve-group participants and all of the repeat-dose participants for tetanus and 96.1% of the naïve group and 98.5% of the repeat-dose group for diphtheria, both meeting the predefined noninferiority criteria. For pertussis antibodies, anti-PT (89.2 EU/mL vs. 116 EU/mL) was higher in the repeat-dose group, anti-FHA (249 vs. 214) and anti-PRN (216 vs. 266) were similar, and anti-FIM (1015 vs. 779) was higher in the naïve group. Noninferiority criteria were met for all antigens except for anti-FIM.

Conclusion

A repeat dose of Tdap vaccine 10 years after the first dose was well tolerated and immunogenic in adults (ClinicalTrials.gov identifier: NCT00712959).     

Persistence of antibodies 3 years after booster vaccination of adults with combined acellular pertussis, diphtheria and tetanus toxoids vaccine

The duration of protection after vaccination with reduced antigen content diphtheria, tetanus and acellular pertussis vaccines (Tdap) is not known. Long-term post-vaccination serological data will help to improve understanding of the duration of humoral immunity and guide vaccination policy for the timing of repeat dose administration. The persistence of antibodies to Tdap antigens was measured 3 years after vaccination of adults 19-64 years of age with one of 2 Tdap vaccines (Boostrix^®, GlaxoSmithKline Biologicals; Tdap-B: or Adacel^®, Sanofi Pasteur; Tdap-A). In both groups, geometric mean concentrations for antibodies to diphtheria, tetanus, and pertussis vaccine antigens were decreased at year 3 relative to levels observed 1 month and 1 year following vaccination, but remained higher than pre-vaccination levels. Seroprotection rates for diphtheria and tetanus remained high for both Tdap vaccines (for diphtheria, 96.9% and 97.8% for the Tdap-B and Tdap-A groups, respectively; for tetanus, 98.1% and 99.6%, respectively).     

Impact and cost-effectiveness of a second tetanus toxoid,reduced diphtheria toxoid,and acellular pertussis (Tdap) vaccine dose to prevent pertussis in the United States

IntroductionThe United States experienced a substantial increase in reported pertussis cases over the last decade. Since 2005, persons 11 years and older have been routinely recommended to receive a single dose of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine. The objective of this analysis was to evaluate the potential impact and cost-effectiveness of recommending a second dose of Tdap.MethodsA static cohort model was used to calculate the epidemiologic and economic impact of adding a second dose of Tdap at age 16 or 21 years. Projected costs and outcomes were examined from a societal perspective over a 20-year period. Quality-adjusted Life Years (QALY) saved were calculated.ResultsUsing baseline pertussis incidence from the National Notifiable Diseases Surveillance System, Tdap revaccination at either age 16 or 21 years would reduce outpatient visits by 433 (5%) and 285 (4%), and hospitalization cases by 7 (7%) and 5 (5%), respectively. The costs per QALY saved with a second dose of Tdap were approximately US $19.7 million (16 years) and $26.2 million (21 years). In sensitivity analyses, incidence most influenced the model; as incidence increased, the costs per QALY decreased. To a lesser degree, initial vaccine effectiveness and waning of effectiveness also affected cost outcomes. Multivariate sensitivity analyses showed that under a set of optimistic assumptions, the cost per QALY saved would be approximately $163,361 (16 years) and $204,556 (21 years).ConclusionA second dose of Tdap resulted in a slight decrease in the number of cases and other outcomes, and that trend is more apparent when revaccinating at age 16 years than at age 21 years. Both revaccination strategies had high dollar per QALY saved even under optimistic assumptions in a multivariate sensitivity analysis.     

Tetanus,diphtheria and acellular pertussis (Tdap) vaccination among healthcare personnel—United States, 2011

Background

Health-care personnel (HCP) are at risk for exposure to and possible transmission of vaccine-preventable diseases. Receiving recommended vaccines is an essential prevention practice for HCP to protect themselves and their patients. The tetanus, diphtheria and acellular pertussis vaccine (Tdap) was recommended by the Advisory Committee on Immunization Practices (ACIP) for HCP in 2006 for protection against pertussis. We assessed the recent compliance of U.S. HCP in receiving Tdap vaccination.

Methods

To estimate Tdap vaccination coverage among HCP, we analyzed data from the 2011 National Health Interview Survey (NHIS). Multivariable logistic regression and predictive marginal models were performed to identify factors independently associated with vaccination among HCP.

Results

Overall, Tdap vaccination coverage was 26.9% among HCP aged 18–64 years (95% confidence interval (CI) = 24.3%, 29.7%), which was significantly higher compared with non-HCP among the same age group (11.1%; 10.5–11.8%). Overall, vaccination coverage was significantly higher among physicians (41.5%) compared with nurses (36.5%) and other types of HCP (range 11.7–29.9%). Vaccination coverage was significantly higher among HCP aged 18–49 years compared with those 50–64 years (30.0% vs. 19.2%, respectively). Characteristics independently associated with an increased likelihood of Tdap vaccination among HCP were: younger age, higher education, living in the western United States, being hospitalized within past year, having a place for routine health care in clinic or health center, and receipt of influenza vaccination in the previous year. Marital status of widowed, divorced, or separated was independently associated with a decreased likelihood of Tdap vaccination among HCP.

Conclusions

By 2011, Tdap vaccination coverage was only 26.9% among HCP. Vaccination coverage varied widely by types of HCP and demographic characteristics. Emphasizing the benefits of HCP vaccination for staff and patients, providing vaccinations in the workplace and other non-traditional settings, and providing Tdap at no charge may help increase Tdap vaccination among HCP in all health-care settings.     

A decennial booster dose of reduced antigen content diphtheria, tetanus, acellular pertussis vaccine (Boostrix™) is immunogenic and well tolerated in adults

Reduced-antigen-content diphtheria-tetanus-acellular-pertussis (dTpa) vaccines are predominantly recommended for once-in-a-lifetime use. A second dTpa (Boostrix™, GlaxoSmithKline Biologicals) administration in 164 adults previously vaccinated with dTpa 10 years previously was evaluated. Before the decennial booster, 89.4% and 94.8% subjects were seroprotected (antibodies ≥0.1 IU/mL) for diphtheria and tetanus, respectively. One-month post-booster, all subjects were seroprotected/seropositive against all vaccine antigens. Robust GMC increases indicated a booster response similar to the first booster. The decennial booster was well tolerated without serious adverse events, consistent with product experience. This study supports replacing traditional Td boosters with dTpa, and use of Boostrix™ as a decennial booster.This study is registered at www.clinicaltrials.comNCT00548171.     

Reactogenicity and immunogenicity of tetanus toxoid,reduced diphtheria toxoid,and acellular pertussis vaccine (Tdap) in pregnant and nonpregnant women

ObjectiveTetanus toxoid, reduced diphtheria toxoid, and acellular pertusiss (Tdap) vaccine is recommended during each pregnancy, regardless of prior receipt. Data on reactogenicity and immunogenicity, particularly after repeated Tdap, are limited. We compared local injection-site and systemic reactions and serologic response following Tdap in (1) pregnant and nonpregnant women and (2) pregnant women by self-reported prior Tdap receipt.Study designPregnant women (gestational age 20–34 weeks) and nonpregnant women receiving Tdap were enrolled in this observational study. Injection-site and systemic reactions were assessed for one week post-vaccination. Pertussis toxin, filamentous hemagglutinin, pertactin, fimbriae, tetanus and diphtheria specific IgG antibody titers were determined by standardized enzyme-linked immunosorbent assay at baseline and 28 days post-vaccination. Reactogenicity and serologic responses were compared by pregnancy status, and within pregnant women by self-reported prior Tdap receipt.Results374 pregnant and 225 nonpregnant women were vaccinated. Severe local or systemic reactions or “any” fever were uncommon (≤3% for both groups). Moderate/severe injection-site pain was significantly higher in pregnant (17.9%) versus nonpregnant (11.1%) women, but did not prompt a healthcare visit. Proportions of other moderate/severe or any severe reactions were not significantly higher in pregnant compared to nonpregnant women. Moderate/severe (including pain) and severe reactions were not significantly higher in pregnant women receiving repeat versus first-time Tdap. Antibody titers increased from baseline to post-vaccination for all vaccine antigens in pregnant and nonpregnant women; post-vaccination titers against pertussis toxin and filamentous hemagglutinin were significantly higher in nonpregnant versus pregnant women (p < 0.01).ConclusionTdap was well-tolerated in pregnant and nonpregnant women. Pregnant women were more likely to report moderate/severe pain at the Tdap injection-site compared with nonpregnant women, but did not necessitate medical visits. Prior Tdap receipt did not increase occurrence of moderate/severe local or systemic reactions in pregnant women. Serologic responses to all vaccine antigens were robust.Clinical Trial Registration@ClinicalTrials.gov. NCT02209623.https://clinicaltrials.gov/ct2/show/NCT02209623.     

Booster vaccination of adults with reduced-antigen-content diphtheria,Tetanus and pertussis vaccine: Immunogenicity 5 years post-vaccination

At 60 months post-vaccination, adults (mean age 45.6 years) randomised to receive combined reduced-antigen-content diphtheria–tetanus and acellular pertussis vaccine (dTpa) versus tetanus–diphtheria (Td) + monovalent acellular pertussis (pa) were seroprotected against diphtheria (≥0.016 IU/mL Vero cell assay) and tetanus (≥0.1 IU/mL ELISA assay) in 94.4% and 96.2%, respectively (dTpa), compared with 93.7% and 90.6% (Td + pa). Anti-FHA, anti-PT and anti-PRN antibodies (≥5 EL.U/mL) were maintained in 100%, 89.5% and 95.0% of dTpa versus 100%, 85.5% and 90.6% of pa vaccine recipients. At 5 years post boosting, antibody levels to diphtheria and tetanus are similar amongst adults receiving a dTpa or dT, and pertussis antibodies remain above pre-booster levels in at least 85%.     

Economic impact of implementing decennial tetanus toxoid,reduced diphtheria toxoid and acellular pertussis (Tdap) vaccination in adults in the United States

BackgroundIn the United States, persons ≥11 years are recommended to receive one dose of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine, followed by decennial tetanus- and diphtheria-toxoid (Td) boosters. Many providers use Tdap instead of Td. We evaluated epidemiologic and economic impacts of replacing Td boosters with Tdap.MethodsWe used a static cohort model to examine replacing Td with Tdap over the lifetime of 4,386,854 adults ≥21 years. Because pertussis is underdiagnosed and true incidence is unknown, we varied incidence from 2.5 cases/100,000 person-years to 500 cases/100,000 person-years. We calculated vaccine and medical costs from claims data. We estimated cost per case prevented and per quality-adjusted life year (QALY) saved; sensitivity analyses were conducted on vaccine effectiveness (VE), protection duration, vaccine cost, disease duration, hospitalization rates, productivity loss and missed work. We did not include programmatic advantages resulting from use of a single tetanus-toxoid containing vaccine.ResultsAt lowest incidence estimates, administering Tdap resulted in high costs per averted case ($111,540) and QALY saved ($8,972,848). As incidence increased, cases averted increased and cost per QALY saved decreased rapidly. With incidence estimates of 250 cases/100,000 person-years, cost per averted case and QALY saved were $984 and $81,678 respectively; at 500 cases/100,000 person-years, these values were $427 and $35,474. In multivariate sensitivity analyses, assuming 250 cases/100,000 person-years, estimated cost per QALY saved ranged from $971 (most favorable) to $217,370 (least favorable).ConclusionsOur findings suggest that replacing Td with Tdap for the decennial booster would result in high cost per QALY saved based on reported cases. However, programmatic considerations were not accounted for, and if pertussis incidence, which is incompletely measured, is assumed to be higher than reported through national surveillance, substituting Tdap for Td may lead to moderate decreases in pertussis cases and cost per QALY.     

Safety of tetanus,diphtheria, acellular pertussis (Tdap) vaccination during pregnancy

The objective of this study was to evaluate the safety of prenatal tetanus, diphtheria, acellular pertussis (Tdap) vaccination. This cohort study was conducted among pregnant members at Kaiser Permanente Southern California (KPSC). The exposed cohort consisted of women who received Tdap vaccine on or after the 27th week of pregnancy between January 2018 and January 2019. The unexposed cohort consisted of matched women who were pregnant between January 2012 and December 2014 and were not vaccinated with any Tdap vaccine throughout their pregnancy. Maternal and infant characteristics and pre-specified endpoints were collected through automated data and review of the electronic health records. Unadjusted and adjusted relative risks (aRRs) with confidence intervals (CIs) were estimated by Poisson regression. Non-inferiority testing (i.e., to rule out a two-fold increase) was conducted for primary endpoints with adjustment for multiplicity. Superiority testing was conducted without multiplicity adjustment for secondary endpoints. The analysis consisted of 16,606 pairs of Tdap recipients and unexposed pregnant women. For the primary endpoints, the aRR for preeclampsia/eclampsia was 1.38 (98.75% CI:1.21–1.58) and the aRR for intrauterine infection was 1.28 (98.75% CI:1.12–1.47). These increases were consistent with the background increasing trend of these diagnoses among all pregnant women at KPSC since 2011, and the upper limit of the 98.75% CI of both aRRs did not exceed the pre-specified threshold of 2. No increased risks of small for gestational age (aRR = 1.04, 98.75% CI:0.94–1.16) or preterm delivery (aRR = 0.71, 98.75% CI:0.64–0.78) were observed. No evidence of increased risks for secondary endpoints, including poor fetal growth, preterm pre-labor rupture of membranes, stillbirth/fetal death, placental abruption, transfusion during delivery hospitalization, and neonatal death, was observed. Prenatal Tdap vaccination after the 27th week of pregnancy was not associated with increased risks of pre-specified maternal and infant outcomes, supporting the safety of Tdap vaccination during pregnancy.     

Universal tetanus,diphtheria, acellular pertussis (Tdap) vaccination of adults: What the Canadian public knows and wants to know

Tetanus, diphtheria, and acellular pertussis vaccine (Tdap) is recommended for all adults in Canada but uptake is low. This study measured the knowledge, attitudes, beliefs, and behaviors of Canadian adults to identify potential barriers and facilitators to Tdap uptake. A survey was undertaken on a geographically representative sample of Canadian adults (n = 4023) and 8 focus groups (62 participants) were conducted nationwide. The survey revealed that knowledge about pertussis and Tdap was low (38.3% correct answers). Only 36.0% of respondents reported being aware that all adults were recommended to receive Tdap and only 10.7% reported being immunized; 36.7% did not know whether they had received Tdap. Respondents who were aware of the immunization recommendations were twice as likely to be immunized (16.6% vs. 8.3%; p < 0.001). Only 9.3% believed that their health care provider thought that Tdap was important for adults. The focus group data supported the survey results. Participants wanted information about pertussis and Tdap communicated through multiple modalities, but a recommendation by their family physician was most important to their decision to be immunized or not. This study demonstrates that current recommendations for universal adult vaccination with Tdap are not reaching the general public in Canada and an alternative strategy will be required to improve Tdap vaccine uptake.     

Seroprotection rate in adults after 1-dose, 2-dose,and 3-dose series of a reduced-diphtheria-tetanus toxoid vaccine (Td) during a diphtheria outbreak in Thailand

To evaluate seroprotection of different dosing strategies of reduced-diphtheria-tetanus-toxoid vaccine (Td) for adults during a diphtheria outbreak in Thailand, we enrolled 160 healthcare workers and 161 adults aged 20–60 years old and measured diphtheria antitoxin (DAT) level before administration of a Td vaccine. We scheduled a second Td at 4–8 weeks and a third Td at 6–12 months interval. DAT was measured 4 weeks after each dose. DAT levels of ≥0.1 and ≥1 IU/mL were considered as seroprotective and long-term seroprotective. Persons achieving long-term seroprotection were not given a further dose.The baseline seroprotection rate was 32.6%, which increased to 87.1% (95% confidence interval, 83.4–90.8%) after one dose. The seroprotection rate increased slightly with additional doses. The immune response was lowest among persons 30–49 years of age. We suggest 1-dose Td for adults during a diphtheria outbreak, and a 2-dose series being considered for those born before 1980.     

Differences of IgG antibody avidity after an acellular pertussis (aP) booster in adolescents after a whole cell (wcP) or aP primary vaccination

Compared to whole cell pertussis (wcP) vaccines, acellular pertussis vaccines (aP) have a better safety profile with lower reactogenicity, although their short and long-term efficacy was found to be slightly lower. Up to now, no established serological parameter to predict long-term protection exists. IgG-anti-pertussis avidity possibly determines the effect of different pertussis vaccines and boosting intervals on long-term immunity. Thus, the avidity of a tetanus-diphtheria-aP booster at 10–14 years was tested in three groups of adolescents who had been previously immunized with either five doses of aP (5aP) at 2, 4, 6, 15–18 months and 5–6 years of age, four doses of aP (4aP) or four doses of wcP (4wcP) at 2, 4, 6 and 15–18 months of age.     

Barriers to early uptake of tetanus, diphtheria and acellular pertussis vaccine (Tdap) among adults-United States, 2005-2007

Background

The tetanus, diphtheria and acellular pertussis vaccine (Tdap) was recommended by the Advisory Committee on Immunization Practices (ACIP) for U.S. adults in 2005. Our objective was to identify barriers to early uptake of Tdap among adult populations.

Methods

The 2007 National Immunization Survey (NIS)-Adult was a telephone survey sponsored by the Centers for Disease Control and Prevention (CDC). Immunization information was collected for persons aged ≥18 years on all ACIP-recommended vaccines. A weighted analysis accounted for the complex survey design and non-response.

Results

Overall, 3.6% of adults aged 18-64 years reported receipt of a Tdap vaccination. Of unvaccinated respondents, 18.8% had heard of Tdap, of which 9.4% reported that a healthcare provider had recommended it. A low perceived risk of contracting pertussis was the single most common reason for either not vaccinating with Tdap or being unwilling to do so (44.7%). Most unvaccinated respondents (81.8%) indicated a willingness to receive Tdap if it was recommended by a provider.

Conclusions

During the first two years of availability, Tdap uptake was likely inhibited by a low collective awareness of Tdap and a low perceived risk of contracting pertussis among U.S. adults, as well as a paucity of provider-to-patient vaccination recommendations. Significant potential exists for improved coverage, as many adults were receptive to vaccination.     

Post-licensure comparison of the safety profile of diphtheria/tetanus/whole cell pertussis/haemophilus influenza type b vaccine and a 5-in-1 diphtheria/tetanus/acellular pertussis/haemophilus influenza type b/polio vaccine in the United Kingdom

General practitioner consultation data were used to compare the reactogenicity in infants of a 5-in-1 acellular pertussis vaccine (DTaP₅/Hib/IPV) introduced in the United Kingdom in 2004 to the 4-in-1 whole cell-pertussis vaccine (DTwP/Hib) that it replaced. For each vaccine the incidence in the week following vaccination was compared to other periods to obtain a relative incidence. A lower relative incidence of crying, fever and local reactions was seen with DTaP₅/Hib/IPV than DTwP/Hib. Although there were no other significant differences between vaccines the relative incidence was significantly above one on the day of vaccination for convulsions following DTwP/Hib and for apnoea/collapse following DTaP₅/Hib/IPV.     

Vaccine effectiveness of tetanus toxoid,reduced diphtheria toxoid,and acellular pertussis vaccine during a pertussis outbreak in Maine

BackgroundMultiple school-associated pertussis outbreaks were reported in Maine from 2010 to 2011. These outbreaks were associated with an overall increase in pertussis cases statewide. Waning of protection in students recently vaccinated with tetanus, diphtheria, and acellular pertussis (Tdap) has been implicated in the increase in reported rates of pertussis nationally.MethodsWe conducted a retrospective cohort study to evaluate Tdap vaccine effectiveness (VE) among students aged 11–19 years in two schools reporting outbreaks in 2011. All pertussis cases reported from August through November, 2011 at the two schools were included. Vaccination history was verified using provider information, state vaccine registry data, and parental verification. Attack rates (AR) were calculated. VE and duration of protection was calculated as VE = 1 − (AR_vaccinated/AR_unvaccinated) × 100% using a log binomial regression model.ResultsOf 416 students enrolled, 314 were included in the analyses. Twenty-nine cases collectively in Schools A and B. Tdap coverage was 65% at School A and 42% at School B before the start of the outbreak. Among students enrolled in the study, attack rates were 11.9% and 7.7% at Schools A and B, respectively. Overall VE was 68.5% (95% confidence interval (CI) 37.7–86.2). VE was 70.4% (95% CI 17.5–89.4) for School A and 65.2% (95% CI −19.2 to 89.9) for School B. VE <2 years versus ≥2 years from outbreak onset was not significantly different.ConclusionsTdap was moderately effective in preventing disease among vaccinated students. Vaccine coverage of 65% or less was suboptimal and might contribute to outbreaks. Waning VE was not demonstrated. Increased vaccination coverage rates as well as further evaluation of the role of acellular vaccine on VE is needed.     

2015 - 2017年无锡市含无细胞百白破成分疫苗预防接种安全性评价

目的 评价无锡市无细胞百白破疫苗（DTaP）和无细胞百白破-灭活脊髓灰质炎- b型流感嗜血杆菌联合疫苗（DTaP - IPV - Hib）的预防接种安全性。方法 分别通过中国AEFI监测信息管理系统和无锡市免疫规划信息管理系统收集AEFI监测数据和疫苗接种数据,采用描述性流行病学方法对2015 - 2017年无锡市的DTaP和DTaP - IPV - Hib接种后的不良反应进行分析。结果 2015 - 2017年无锡市接种DTaP 、DTaP - IPV - Hib一般反应报告发生率分别为327.67/10万、268.23/10万,异常反应报告发生率分别为19.79/10万、15.58/10万。DTaP和DTaP - IPV - Hib 的一般反应和异常反应均以加强免疫为主,集中在接种后0～1 d。一般反应均主要表现为红肿（80.73%,65.31%）、硬结（45.14%,33.33%）和发热（22.69%,44.22%）,异常反应主要表现均以过敏性皮疹为主（58.11%,50%）。结论 DTaP和DTaP - IPV - Hib的不良反应报告发生率无差别,均主要发生在加强免疫期间,具有良好的预防接种安全性。     

Updated recommendations for use of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine in adults aged 65 years and older - Advisory Committee on Immunization Practices (ACIP), 2012

Since 2005, the Advisory Committee on Immunization Practices (ACIP) has recommended a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine booster dose for all adolescents aged 11 through 18 years (preferred at 11 through 12 years) and for those adults aged 19 through 64 years who have not yet received a dose. In October 2010, despite the lack of an approved Tdap vaccine for adults aged 65 years and older, ACIP recommended that unvaccinated adults aged 65 years and older be vaccinated with Tdap if in close contact with an infant, and that other adults aged 65 years and older may receive Tdap. In July 2011, the Food and Drug Administration (FDA) approved expanding the age indication for Boostrix (GlaxoSmithKline Biologicals, Rixensart, Belgium) to aged 65 years and older. In February 2012, ACIP recommended Tdap for all adults aged 65 years and older. This recommendation supersedes previous Tdap recommendations regarding adults aged 65 years and older.     

Low tetanus,diphtheria and acellular pertussis (Tdap) vaccination coverage among HIV infected individuals in Austria

Current management guidelines of HIV infected adults include recommendation to immunization against common vaccine preventable diseases. This effort is hindered by the scarce knowledge regarding the immunization status of this especially vulnerable patient group. This study analyzed the serostatus for pertussis, diphtheria and tetanus of more than 700 HIV infected individuals residing in Austria. These individuals were representative for the Austrian HIV cohort regarding sex, age, transmission risk and HIV progression markers. Overall, 73.6% were on suppressive HAART, mean CD4 cell count was 603 c/μl. Seropositivity was 84% for diphtheria, 51% for tetanus and 1% for pertussis. Migrants had a lower chance of tetanus seropositivity (OR 0.30 (CI 0.21 to 0.43)). Increase in CDC classification were associated with increased diphtheria seropositivity (OR 1.42 (CI 1.02 to 1.98)) and a CD4 nadir < 200 c/μl was associated with increased pertussis seropositivity (OR 12.2, 95% CI 1.2 to 121). Importantly due to the well preserved immune status of nearly all participants vaccination would be feasible in the majority of the seronegative patients. In patients with a CD4 count > 200 c/μl, 95% lacked seroprotection to at least one of the antigens included in the triple vaccine Tdap and could be vaccinated. Thus, a proactive approach would largely reduce the number of patients at risk for these vaccine-preventable diseases.     

Updated recommendations for use of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine from the Advisory Committee on Immunization Practices, 2010

Despite sustained high coverage for childhood pertussis vaccination, pertussis remains poorly controlled in the United States. A total of 16,858 pertussis cases and 12 infant deaths were reported in 2009. Although 2005 recommendations by the Advisory Committee on Immunization Practices (ACIP) called for vaccination with tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) for adolescents and adults to improve immunity against pertussis, Tdap coverage is 56% among adolescents and <6% among adults. In October 2010, ACIP recommended expanded use of Tdap. This report provides the updated recommendations, summarizes the safety and effectiveness data considered by ACIP, and provides guidance for implementing the recommendations.     

Immunogenicity and safety of a single intramuscular dose of a diphtheria-tetanus toxoid (Td) vaccine (GC1107) in Korean adults

The current study aimed to evaluate immunogenicity and safety of a newly developed diphtheria-tetanus toxoid (Td) vaccine, GC1107 (Green Cross Corporation, Yongin, Korea), in comparison with placebo and active comparator (licensed Td vaccine) in healthy Korean adults. A randomized, double-blind, placebo and active comparator-controlled study was conducted. Forty subjects were randomly administered a single intramuscular dose of GC1107, active comparator or placebo in a ratio of 2:1:1. At 2 and 4 weeks after vaccination, anti-diphtheria antibody levels in the GC1107 group increased 9.2 and 9.3 times, respectively, compared to predose titers. The corresponding values were 9.3 and 8.3 times for the active comparator group. Anti-tetanus antibody levels increased 39.0 and 37.9 fold at 2 and 4 weeks, respectively, after GC1107 administration, and 12.2 and 14.7 fold after active comparator administration. No increases in tetanus or diphtheria antibody were observed for the placebo group. Adverse events in the GC1107 and active comparator groups were more frequent than for the placebo group, but there were no significant differences between the two active treatments. In conclusion, GC1107 was well tolerated and provided significant boosts of anti-tetanus and anti-diphtheria antibodies.