Use Of Tdap Research Articles

Use of Tetanus Toxoid, Reduced Diphtheria Toxoid, and Acellular Pertussis Vaccines: Updated Recommendations of the Advisory Committee on Immunization Practices - United States, 2019.

Since 2005, a single dose of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine has been recommended by the Advisory Committee on Immunization Practices (ACIP) for adolescents and adults (1,2). After receipt of Tdap, booster doses of tetanus and diphtheria toxoids (Td) vaccine are recommended every 10 years or when indicated for wound management. During the October 2019 meeting of ACIP, the organization updated its recommendations to allow use of either Td or Tdap where previously only Td was recommended. These situations include decennial Td booster doses, tetanus prophylaxis when indicated for wound management in persons who had previously received Tdap, and for multiple doses in the catch-up immunization schedule for persons aged ≥7 years with incomplete or unknown vaccination history. Allowing either Tdap or Td to be used in situations where Td only was previously recommended increases provider point-of-care flexibility. This report updates ACIP recommendations and guidance regarding the use of Tdap vaccines (3).

Safety review of tetanus toxoid, reduced diphtheria toxoid, acellular pertussis vaccines (Tdap) in adults aged ≥65 years, Vaccine Adverse Event reporting System (VAERS), United States, September 2010–December 2018

IntroductionThe Advisory Committee on Immunization Practices (ACIP) recommends vaccination with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) in persons ≥65 years of age. To date, few studies have assessed the safety of Tdap in this population. We aimed to summarize reports submitted to the Vaccine Adverse Event Reporting System (VAERS) following receipt of Tdap in this age group. MethodsWe searched for and analyzed U.S. VAERS reports of Tdap among individuals ≥65 years of age submitted from September 1, 2010 through December 31, 2018. We classified reports according to concurrent vaccination, seriousness, and outcome (death, non-death) and determined the frequency of reported adverse events (AEs). For serious reports, we reviewed available medical records. Data mining analyses were undertaken to detect disproportionality in reporting. ResultsVAERS received a total of 1,798 reports following Tdap, of which 104 (6%) were serious. The most common AEs were injection site erythema (26%; n = 468), injection site pain (19%; n = 335), injection site swelling (18%; n = 329), and erythema (18%; n = 321). We identified seven deaths; none were attributed to Tdap. Among serious non-death reports, nervous system disorders (35.1%; n = 34) and infections and infestations (n = 18.6%; n = 18) were most commonly reported. Data mining did not identify any vaccine-AE combination reported more frequently than expected. ConclusionsWe did not identify any new safety concern over nearly a decade of recommended Tdap use among adults ≥65 years of age. Findings from this post-marketing review are consistent with prior post-marketing observations and pre-licensure studies.

Pertussis Immunisation in Pregnancy Safety (PIPS) Study: A retrospective cohort study of safety outcomes in pregnant women vaccinated with Tdap vaccine

BackgroundNew Zealand has funded the administration of tetanus, diphtheria and acellular pertussis (Tdap) vaccine during pregnancy to prevent infant pertussis since 2013. The aim of this study was to assess the safety of Tdap vaccine administered to pregnant women as part of a national maternal immunisation programme. MethodsWe conducted a national retrospective observational study using linked administrative New Zealand datasets. The study population consisted of pregnant women eligible to receive funded Tdap vaccination from 28 to 38 weeks gestation in 2013. Primary study outcomes were based on prioritised adverse events for the assessment of vaccine safety in pregnant women, as defined by WHO and Brighton Collaboration taskforces. We examined the effect of Tdap vaccination on prioritised maternal outcomes using Cox proportional hazard models. Adjusted hazard ratios controlled for key confounding variables. ResultsIn the cohort of 68,550 women eligible to receive funded antenatal Tdap vaccination during 2013, 8178 (11.9%) were vaccinated and 60,372 (88.1%) were unvaccinated. The use of Tdap in pregnancy was not associated with an increase in the rate of primary outcomes, including preterm labour; pre-eclampsia; pre-eclampsia with severe features; eclampsia; gestational hypertension; fetal growth restriction; or post-partum haemorrhage. Tdap also did not increase secondary outcomes, including gestational diabetes mellitus; antenatal bleeding; placental abruption; premature rupture of membranes; preterm delivery; fetal distress; chorioamnionitis; or, maternal fever during or after labour. Lactation disorders was the only secondary maternal outcome with a significantly increased hazard ratio. Tdap vaccine had a protective effect on pre-eclampsia with severe features, preterm labour, preterm delivery, and antenatal bleeding. ConclusionWe did not detect any biologically plausible adverse maternal outcomes following Tdap vaccination during pregnancy. This study provides further assurance that Tdap administration during pregnancy is not associated with unexpected safety risks.

Immunization update 2017

Abstract Objective To provide an overview of the recent changes that affect immunization practices. Summary The 2017 immunization schedules for children and adults include a variety of changes. A new figure has been created for children and adolescents aged 18 years and younger that provides vaccine recommendations based on medical indications. Updates have been made to the vaccine recommendations for influenza, human papillomavirus, meningococcal disease, hepatitis B, and Tdap use in pregnancy. The recommendation that providers should not administer the live attenuated influenza vaccine has been extended to the 2017–18 influenza season. New vaccines that have been introduced to the market include an adjuvanted trivalent influenza vaccine and a live, attenuated, oral vaccine to prevent cholera. A 10-year booster dose of yellow fever vaccine is no longer recommended for the majority of travelers to areas in which the vaccine is warranted. Numerous vaccine administration errors have been reported for a variety of vaccines. Recognizing opportunities to prevent errors and reporting errors when they occur are both important measures to ensure the safety of patients who are receiving vaccines. Conclusion Failing to meet the goals that pertain to increasing immunization rates and reducing vaccine-preventable diseases has shown to be detrimental to the well-being of patients and health care costs. The contributions of pharmacists as immunization providers can help reduce the burden of vaccine-preventable diseases. As such, pharmacists have a responsibility to keep current with immunization practices.

Enhanced surveillance of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines in pregnancy in the Vaccine Adverse Event Reporting System (VAERS), 2011–2015

BackgroundIn October 2011, the Advisory Committee on Immunization Practices (ACIP) issued updated recommendations that all pregnant women routinely receive a dose of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine. ObjectivesWe characterized reports to the Vaccine Adverse Event Reporting System (VAERS) in pregnant women who received Tdap after this updated recommendation (2011–2015) and compared the pattern of adverse events (AEs) with the period before the updated recommendation (2005–2010). MethodsWe searched the VAERS database for reports of AEs in pregnant women who received Tdap vaccine after the routine recommendation (11/01/2011–6/30/2015) and compared it to published data before the routine Tdap recommendation (01/01/2005–06/30/2010). We conducted clinical review of reports and available medical records. The clinical pattern of reports in the post-recommendation period was compared with the pattern before the routine Tdap recommendation. ResultsWe found 392 reports of Tdap vaccination after the routine recommendation. One neonatal death but no maternal deaths were reported. No maternal or neonatal deaths were reported before the recommendation. We observed an increase in proportion of reports for stillbirths (1.5–2.8%) and injection site reactions/arm pain (4.5–11.9%) after the recommendation compared to the period before the routine recommendation for Tdap during pregnancy. We noted a decrease in reports of spontaneous abortion (16.7–1%). After the 2011 Tdap recommendation, in most reports, vaccination (79%) occurred during the third trimester compared to 4% before the 2011 Tdap recommendation. Twenty-six reports of repeat Tdap were received in VAERS; 13 did not report an AE. One medical facility accounted for 27% of all submitted reports. ConclusionsNo new or unexpected vaccine AEs were noted among pregnant women who received Tdap after routine recommendations for maternal Tdap vaccination. Changes in reporting patterns would be expected, given the broader use of Tdap in pregnant women in the third trimester.

The Centers for Disease Control and Prevention's public health response to monitoring Tdap safety in pregnant women in the United States

In 2010, in response to a widespread pertussis outbreak and neonatal deaths, California became the first state to recommend routine administration of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine during pregnancy. In 2011, the Advisory Committee on Immunization Practices (ACIP) followed with a similar recommendation for Tdap vaccination during pregnancy for previously unvaccinated women. In 2012, this recommendation was expanded to include Tdap vaccination of every pregnant woman during each pregnancy. These recommendations were based on urgent public health needs and available evidence on the safety of other inactivated vaccines during pregnancy. However, there were limited data on the safety of Tdap during pregnancy. In response to the new ACIP recommendations, the Centers for Disease Control and Prevention (CDC) implemented ongoing collaborative studies to evaluate whether vaccination with Tdap during pregnancy adversely affects the health of mothers and their offspring and provide the committee with regular updates. The current commentary describes the public health actions taken by CDC to respond to the ACIP recommendation to study and monitor the safety of Tdap vaccines in pregnant women and describes the current state of knowledge on the safety of Tdap vaccines in pregnant women. Data from the various monitoring activities support the safety of Tdap use during pregnancy.

Pertussis vaccination in adult trauma patients: Are we missing an opportunity?

Trauma centers commonly administer tetanus prophylaxis to patients sustaining open wounds. In the United States, there are different vaccinations available for adult administration: tetanus/diphtheria toxoid (Td) or tetanus/reduced diphtheria and acellular pertussis (Tdap). The importance of the Tdap preparation lies in its vaccination against pertussis while providing tetanus immunity. Vaccination against pertussis is paramount for disease prevention. In recent decades, there has been a steady rise in pertussis cases. This epidemic increase caused the Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) to recommend the routine use of Tdap when tetanus prophylaxis is indicated. The aim of this study was to gather data on which formulation of tetanus vaccination is currently being given to adult trauma patients. We hoped to increase awareness of the expanded recommendations for vaccination against pertussis when tetanus prophylaxis is indicated, thus providing patients with protection against pertussis. An institutional review board exempt, web-based, nationwide survey was sent to adult trauma center coordinators that could be located via an Internet search. Questions included trauma center level designation, number of trauma evaluations per year, zip code, hospital description (university, university affiliated, or community), and which vaccination is given for adults <65years and those ≥65. At the conclusion of the survey, hyperlinks to the CDC ACIP recommendations were provided as an educational tool. A total of 718 emails were successfully sent and 439 (61%) completed surveys were returned. Level 4/5 centers had the highest compliance rates for those patients between ages 18 and 64 (93%), followed by level 2/3 (87%), and then level 1 centers (57%). Among all centers, the use of Tdap was lower in the ≥65year group. Level 2 trauma centers were the most compliant with this age group (61%) followed by level 4/5 (57%) and level 1 (43%) centers. With the increase in pertussis cases, vaccination remains crucial to prevention. The CDC recommendations for Tdap have existed for adults <65years since 2005 and those ≥65years since 2012. However, many adult trauma centers do not adhere to the current CDC ACIP guidelines for tetanus/pertussis vaccination. In particular, level 1 trauma centers and those classified as university hospitals have the lowest rate of compliance with these recommendations. Through this survey, trauma centers were educated on current recommendations. Increased vaccination of trauma patients with Tdap should improve protection against this virulent pathogen.

Impact of tetanus, diphtheria, and acellular pertussis (Tdap) vaccine use in wound management on health care costs and pertussis cases.

The Advisory Committee on Immunization Practices (ACIP) recommends the use of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine for routine wound management in adolescents and adults who require a tetanus toxoid-containing vaccine who were vaccinated ≥ 5 years earlier with tetanus toxoid, reduced diphtheria toxoid (Td) vaccine, and who have not previously received Tdap. To estimate the overall budget and health impact of vaccinating individuals presenting for wound management with Tdap instead of Td vaccine, the current standard of care in practices that do not use Tdap for purposes of wound management. A decision-analytic economic model was developed to estimate the expected increase in direct medical costs and the expected number of cases of pertussis avoided associated with the use of Tdap instead of Td vaccine in the wound management setting. Patients eligible for Tdap were aged 10+ years and required a tetanus-containing vaccine. Age-specific wound incidence data and Td and Tdap vaccination rates were taken from the National Health Interview Survey and the National Immunization Survey for the most recent available year. Age-specific pertussis incidence used in this analysis (151 per 100,000 for adolescents, 366 per 100,000 for those aged 20-64 years, and 176 per 100,000 for those aged 65+ years) used reported incidence rates adjusted by a factor of 10 for adolescents and by a factor of 100 for adults, based on assumptions previously made by ACIP to account for underreporting. Vaccine wholesale acquisition costs without federal excise tax were assumed in the base case. Efficacy of vaccination with Tdap in preventing pertussis was based on clinical trial data. Possible herd immunity effects of vaccination were not included in the model. Costs associated with vaccination and treatment of pertussis cases were reported as total annual costs and per-member-per-month (PMPM) costs for hypothetical health plans and for the U.S. population. Aggregate and incremental costs and pertussis cases avoided were presented undiscounted (as recommended for budget-impact analyses) annually and cumulatively over a 3-year time horizon in 2012 U.S. dollars. Scenario analyses were conducted on key parameters, including wound incidence, pertussis incidence, vaccine efficacy and waning protection against pertussis, uptake rates for Tdap, and vaccine prices using alternative data sources or alternative clinically relevant assumptions. For a health plan with 1 million covered lives aged < 65 years, vaccination with Tdap instead of Td was estimated to cost an additional $132,364 ($0.01 PMPM) in the first year and an additional $368,640 ($0.01 PMPM) cumulatively over 3 years. For a health plan with 1 million covered lives aged 65+ years, vaccination with Tdap instead of Td was estimated to cost an additional $201,165 ($0.02 PMPM) in the first year and an additional $549,568 ($0.02 PMPM) cumulatively over 3 years. For the U.S. population aged 10+ years, vaccination with Tdap instead of Td was estimated to result in protection against pertussis for an additional 2.7 million patients with wounds annually and was estimated to cost an additional $121,101,671 to avoid 42,104 cases of pertussis over the 3-year time horizon. Results were sensitive to input parameter values, particularly parameters associated with the number of patients with wounds vaccinated with Tdap (range 2.7 to 5.1 million patients). However, for all of the alternative scenarios tested, the expected increase in PMPM costs ranged from < $0.01 to $0.03. Vaccination of adolescents and adults with Tdap for wound management may result in an increase in PMPM costs for health plans of < $0.01 to $0.03. Given the potential reduction in pertussis cases at the population level, vaccination with Tdap for routine wound management could be considered as another strategy to help address the pertussis public health concern in the United States.

Pertussis vaccines: Position paper of Indian Academy of Pediatrics (IAP)

Pertussis continues to be a major public health problem in both developing and developed countries. Data on exact burden and incidence of pertussis in the developing countries including India is sparse. However, the disease is widespread, even if not adequately measurable. Pertussis incidence has been increasing steadily in the last decade especially in industrialized countries. Outbreaks are reported from many developed countries in recent years despite widespread use of acellular pertussis vaccines with high coverage. The current status of coverage with pertussis vaccines is still sub-optimal in many states of the country. There is scarcity of data on vaccine efficacies of both whole-cell and acellular pertussis vaccines from India and other developing countries. Most of the recommendations on pertussis vaccination are based on the experience gained from the use of them in industrialized countries. Taking in to the consideration the recent evidence of faster waning of acellular pertussis vaccines in comparison to whole-cell vaccines and superior priming with whole-cell than acellular pertussis vaccines, Indian Academy of Pediatrics has now revised its recommendations pertaining to pertussis immunization in office practice. The Academy has now proposed whole-cell pertussis vaccines for the primary series of infant vaccination. Guidelines are also now issued on the preference of a particular acellular product. The Academy has also recommended use of Tdap during each pregnancy to provide protection to the very young infants. It urges the Government of India to initiate studies on the quality of available pertussis vaccines in India and to set indigenous national guidelines for the manufacturers to produce and market different pertussis vaccines in the country.

Assessment of Tdap Administration Rates from 2009 to 2012 at a Large Urban Nonteaching Hospital

Due to the significant rise in pertussis cases reported in 2012, these authors investigated the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine administration at our institution from 2009 to 2012 to determine if changes in prescribing practices reflected published updates from the Advisory Committee on Immunization Practices (ACIP). A single large, urban, private, non-teaching hospital. Documented Tdap vaccines administered from January 2009 through December 2012 were retrieved using an electronic data pull. The incidence of Tdap vaccine administration was reported as number of events per 1,000 patient visits. This data pull served to provide the longitudinal context to prescribing pattern changes at our facility, which were then compared to ACIP vaccination recommendation changes. Tdap administrations increased from 1,365 vaccinations in 2009 to 3,048 vaccinations in 2012. Tdap vaccine administration increased significantly each successive year from 2009 to 2012 from 23.96±1.25 to 47.15±1.63 vaccines per 1,000 patient visits to the facility. Confidence intervals did not overlap for consecutive years representing statistically significant differences between vaccination rates from year to year. Review of Tdap administrations demonstrates a clear and significant increase over consecutive years from 2009 to 2012. Over this time period there were no institutional initiatives aimed at increasing appropriate Tdap use at our institution. This study suggests a correlation between ACIP vaccination recommendations and provider prescribing of Tdap, although no definitive association can be made.

Committee Opinion No. 566

In the face of dramatic and persistent increases in pertussis disease in the United States, the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices has updated its guidelines for the use of the tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine (Tdap) for pregnant women. The new guidance was issued based on an imperative to minimize the significant burden of pertussis disease in vulnerable newborns, the reassuring safety data on the use of Tdap in adults, and the evolving immunogenicity data that demonstrate considerable waning of immunity after immunization. The revised Advisory Committee on Immunization Practices guidelines recommend that health care personnel administer a dose of Tdap during each pregnancy, irrespective of the patient's prior history of receiving Tdap. To maximize the maternal antibody response and passive antibody transfer and levels in the newborn, optimal timing for Tdap administration is between 27 weeks and 36 weeks of gestation, although Tdap may be given at any time during pregnancy. However, there may be compelling reasons to vaccinate earlier in pregnancy. There is no evidence of adverse fetal effects from vaccinating pregnant women with an inactivated virus or bacterial vaccines or toxoids, and a growing body of robust data demonstrates safety of such use. For women who previously have not received Tdap, if Tdap was not administered during pregnancy it should be administered immediately postpartum to the mother in order to reduce the risk of transmission to the newborn. Additionally, other family members and planned direct caregivers also should receive Tdap as previously recommended (sustained efforts at cocooning). Given the rapid evolution of data surrounding this topic, immunization guidelines are likely to change over time and the American College of Obstetricians and Gynecologists will continue to issue updates accordingly.

Tdap Vaccine Safety Comparable to That of Td for Seniors

The tetanus-diphtheria-acellular pertussis vaccine was as safe in seniors as the tetanus-diphtheria vaccine, a finding that supports a federal recommendation to reduce pertussis risk among the elderly via Tdap vaccination. The findings offer “empirical safety data to suggest that the … recommendation for immunizing adults 65 years and older with Tdap to reduce the risk of pertussis in the elderly and their contacts should not have untoward safety consequences,” noted Hung Fu Tseng, PhD, of Kaiser Permanente Southern California and his associates (Clin. Infect. Dis. 2013;56[3]:315–21). In 2010, the Advisory Committee on Immunization Practices' recommended Tdap for seniors instead of Td. But with limited safety data on Tdap's use among adults 65 years and older, “evaluation of the safety of the vaccine in this population becomes essential,” the study authors noted. Dr. Tseng's study used data from seven HMOs participating in the Vaccine Safety Datalink Project. A total of 119,573 adults 65 years and older received the Tdap vaccine between Jan. 1, 2006, and Dec. 31, 2010. All participants had been continuously enrolled in their HMO for a year before vaccination and until at least 84 days afterward. The adverse events in the Tdap group were compared with those among 119,573 seniors in the same HMOs who received the Td vaccine during the same period. Patients were matched based on sex, site, season (April-October, November-March), and age group (65–69 years, 70–74 years, 75 years and older). The researchers examined seven categories of adverse events: Guillain-Barré syndrome; brachial neuritis; paralytic syndromes; medically attended inflammatory or allergic events; cranial nerve disorders (including Bell's palsy); “anaphylaxis and generalized reaction”; and meningitis, encephalitis, and encephalopathy. The incidence of these adverse events was comparable between the Tdap and Td cohorts, after medical records reviews confirmed diagnoses. The researchers also assessed safety with a self-controlled case series. Time periods in which adverse events occurred in Tdap-vaccinated patients were compared with subsequent periods of the same length, starting the day after each adverse event's risk window ended. All adverse events except “medically attended inflammatory or allergic events” were similar in the compared time periods. During the risk window, 612 patients experienced an inflammatory or allergic event, compared with 385 in the comparison time frame, for an incidence risk ratio of 1.59 (95% confidence interval, 1.40–1.81). This elevated risk matches past clinical trials data and Vaccine Adverse Event Reporting System reports and is comparable to the risk profile of inflammatory or allergic events following Td vaccination. Overall, “the risk of the prespecified events following Tdap is comparable to that following Td vaccination in the elderly population,” the authors noted. Limitations of this study include the exclusion of non-prespecified adverse events and the potential for misclassification of exposure or event status (such as false negatives) in the electronic medical records used. The study was funded through the Centers for Disease Control and Prevention and America's Health Insurance Plans. Dr. Tseng reported receiving support from Novartis Vaccine, and several of the study's other authors reported receiving research support from pharmaceutical companies.

U.S. Postlicensure safety surveillance for adolescent and adult tetanus, diphtheria and acellular pertussis vaccines: 2005–2007

BackgroundPre-licensure clinical trials for two U.S. licensed tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccines did not reveal any major safety concerns. However, routine use in large adolescent and adult populations could reveal rare and potentially serious adverse events (AEs). MethodsTo characterize reported AEs following Tdap vaccination and identify potential safety concerns warranting further evaluation, we analyzed data from the Vaccine Adverse Event Reporting System (VAERS) and assessed the frequency and proportions of AEs and reporting rates (reports per 100,000 vaccine doses distributed). ResultsA total of 2090 reports (7% were serious; 55% listed Tdap alone) involving Tdap vaccines were submitted to VAERS May 2005–June 2007. The crude reporting rate was 10.2 per 100,000 vaccine doses distributed. The median age of vaccinees was 22 years, and the female to male ratio was about 2 to 1. The majority of reports described common local and systemic signs and symptoms, such as injection site reactions, fever, and headache. Rarely reported AEs included myopericarditis, demyelinating diseases of the central nervous system, Guillain–Barré Syndrome, syncope, encephalopathy/encephalitis, seizure, Bell's palsy, anaphylaxis, and thrombocytopenia. ConclusionsBecause adolescents and adults were not routinely vaccinated against pertussis in the past, this surveillance summary provides important – and reassuring – information about the use of Tdap in these age groups. Although subject to the limitations of passive surveillance, the findings of this VAERS review support the pre-licensure clinical trial data with regard to the safety of the U.S. licensed Tdap vaccines. Continued monitoring of clinically significant AEs that are temporally associated with Tdap vaccination and further assessment of such events using controlled observational studies may provide additional information about the safety of these vaccines.

Editorial Commentary: Accounting for Pertussis

The resurgence of measles and pertussis in the United States [1, 2] is a reminder of the importance of maximum immunization coverage, even in a developed country with relatively high rates of childhood immunization. The exact parameters of herd immunity may not be established for some vaccine-preventable diseases, but maximal effective use of available vaccines providespopulation-level immunity toprevent or reduce transmission. Evidencebased strategies published by the Advisory Committee on Immunization Practices (ACIP) for improved control of pertussis promote effective use [3, 4]. Observation of vaccine effectiveness in routine clinical use provides insight that may not be available from clinical efficacy trials and may be used to inform recommendations. The article by Witt et al [5] in this issue of Clinical Infectious Diseases presents a retrospective study of acellular pertussis vaccine effectiveness made possible by the unique circumstances of a community-wide outbreak of Bordetella pertussis infection affecting a large population under the care of an integrated healthcare system.This allowedestimation of vaccine effectiveness by age group. The relative duration of protection achieved with diphtheria toxoid–tetanus toxoid–acellular pertussis (DTaP) vaccines (introduced in theUnited States in the 1990s) remains a question [6], one made more relevant by the possibilities arising from the availability of pertussis antigen containing vaccines (tetanus toxoid– reduced diphtheria toxoid–acellular pertussis vaccine for adolescents and adults [Tdap]) that allow for booster dosing of individuals >7 years of age. The authors were able to demonstrate less than expected effectiveness of DTaP in 8to 12year-olds, while also demonstrating substantial overall effectiveness of pertussis vaccines. On the basis of their observations, they suggest evaluation of earlier and more frequent doses of pertussis containing vaccine (Tdap) in outbreak settings, and even on a routine basis. More studies of strategic use of Tdap as a booster dose vaccine would be worthwhile, especially after the broad experience with the vaccine and its safety profile. The ACIP already recommends Tdap use in undervaccinated children as young as 7 years of age [3]. A question might be raised as to the use of polymerase chain reaction (PCR) as the exclusive diagnostic test for pertussis in the Witt et al study, especially as the minimal cough duration in the practice guidance was only 1 week. PCR is a widely used, sensitive test that is faster and easier to perform than culture and can identify evidence of B. pertussis infection in situations where culture results are negative. However, high sensitivity and low specificity, with pseudo-outbreaks described due to false positives and environmental contamination with B. pertussis genome [7, 8], suggest that PCR only be used with care and for patients with cough duration of≥2 weeks and a clinical picture consistent with pertussis. However, the observations by Witt et al [5] occurred in the presence of a widespread, welldocumented stateand community-wide outbreak of pertussis (high prevalence of diseaseimprovingpositivepredictivevalue), and testing was done in a central laboratory, using a closed system test platform, and simultaneous testing for Bordetella parapertussis. Furthermore, rates of testing were high across the spectrum of ages, but rates of positive PCR results are very different by age, so false-positive test results do not seem to be a factor contributing to the results unless there was a systematic bias in selection for testing by age. Pertussis remains a threat to infants, in whom protection awaits the initial doses of the DTaP vaccine series. Public health recommendations for the use of Tdap vaccines have been a work in progress since licensure in the United States, and approaches have been designed to protect older children, adolescents, and adults, in large part to protect infants they may expose to pertussis (as symptomatic and asymptomatic cases to the extent that overall reduction in incidence may reduce asymptomatic carriage). Initially, Tdap Received 27 February 2011; accepted 1 March 2012; electronically published 15 March 2012. Correspondence: Altred De Maria Jr, Bureau of Infectious Disease, Massachusetts Department of Public Health, William A. Hinton State Laboratory Institute, 305 South St, Jamaica Plain, MA 02130 (Alfred.DeMaria@state.ma.us). Clinical Infectious Diseases 2012;54(12):1736–8 © The Author 2012. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@ oup.com. DOI: 10.1093/cid/cis313

Committee Opinion No. 521

In light of the recent increased incidence of pertussis in the United States, in 2011, the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices approved recommendations for the use of the tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine (Tdap) for pregnant women. Furthermore, the committee updated Tdap recommendations for special situations during pregnancy and for persons in contact with infants. The revised guidelines, which are based on a review of data on Tdap safety, immunogenicity, and barriers to receipt of Tdap, are designed to facilitate the use of Tdap to reduce the burden of disease and risk of transmission to infants. There is no evidence of adverse fetal effects from the vaccination of pregnant women with an inactivated virus, bacterial vaccine, or toxoid, and these should be administered if indicated. The American College of Obstetricians and Gynecologists' Committee on Obstetric Practice supports the revised recommendations on the administration of Tdap during pregnancy.

Early Impact of the US Tdap Vaccination Program on Pertussis Trends

To evaluate the impact of the adolescent Tdap (tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine) vaccination program on pertussis trends in the United States. Retrospective analysis of nationally reported pertussis cases, January 1, 1990, through December 31, 2009. United States. Confirmed and probable pertussis cases. Intervention The US Tdap vaccination program. Rate ratios of reported pertussis incidence (defined as incidence among 11- to 18-year-olds divided by the combined incidence in all other age groups) modeled through segmented regression analysis and age-specific trends in reported pertussis incidence over time. A total of 200 401 pertussis cases were reported in the United States from 1990 to 2009. Overall incidence ranged from 1.0 to 8.8 per 100,000 persons (1991 and 2004, respectively). Slope coefficients (estimated annual rate of change in rate ratios) from segmented regression showed a steady increase in pertussis incidence among adolescents 11 to 18 years old compared with all other age groups before Tdap introduction (slope = 0.22; P < .001), and a steep decreasing trend post introduction (slope = -0.48; P < .001), suggesting a direct impact of vaccination among adolescents. Indirect effects of adolescent vaccination were not observed among infants younger than 1 year. Changes in pertussis incidence in the United States from 2005 to 2009 revealed a divergence between 11- to 18-year-olds and other age groups, suggesting that targeted use of Tdap among adolescents reduced disease preferentially in this age group. Increased Tdap coverage in adolescents and adults is needed to realize the full direct and indirect benefits of vaccination.

Additional Recommendations for Use of Tetanus Toxoid, Reduced-Content Diphtheria Toxoid, and Acellular Pertussis Vaccine (Tdap)

The American Academy of Pediatrics and the Centers for Disease Control and Prevention are amending previous recommendations and making additional recommendations for the use of tetanus toxoid, reduced-content diphtheria toxoid, and acellular pertussis vaccine (Tdap). Review of the results from clinical trials and other studies has revealed no excess reactogenicity when Tdap is given within a short interval after other tetanus- or diphtheria-containing toxoid products, and accrual of postmarketing adverse-events reports reveals an excellent safety record for Tdap. Thus, the recommendation for caution regarding Tdap use within any interval after a tetanus- or diphtheria-containing toxoid product is removed. Tdap should be given when it is indicated and when no contraindication exists. In further efforts to protect people who are susceptible to pertussis, the American Academy of Pediatrics and Centers for Disease Control and Prevention recommend a single dose of Tdap for children 7 through 10 years of age who were underimmunized with diphtheria-tetanus-acellular pertussis (DTaP). Also, the age for recommendation for Tdap is extended to those aged 65 years and older who have or are likely to have contact with an infant younger than 12 months (eg, health care personnel, grandparents, and other caregivers).

Immunization 2011: Expanding Coverage, Enhancing Protection

Annually, the ACIP of the Centers for Disease Control and Prevention issues a revised Adult Immunization Schedule that is approved by the major specialty societies representing physicians who care ...

Pertussis Response to Tdap (8 mcg/dose of the Pertussis Toxoid (PT) In Recipients of Allogeneic Hematopoietic Stem Cell Transplants (Allo HSCT).

AbstractAbstract 1282In 2005, in an effort to reduce the increasing incidence of pertussis in adolescents and adults, two vaccines containing tetanus, reduced diphtheria and acellular pertussis toxoids (Tdap) were approved for this population. Although both vaccines contain similar amounts of tetanus and diphtheria toxoid, they vary in their pertussis toxoid(PT) content (2.5 vs 8 mcg/dose). In 2006, the Advisory Committee on Immunization Practices recommended that all adolescents and adults receive a single dose of Tdap. In 2008, we reported at this meeting an evaluation of the Tdap containing 2.5 mcg/dose approved for individuals 11–64 years of age. Although response to tetanus was 71% when this vaccine was given as a booster, only 7 of 41 patients responded to PT, 6 of whom were children. This poor response was likely due in part to the low dose of PT and the limited numbers of pertussis specific memory T and B cells potentially transferred from the stem cell donor. At the end of 2008, the upper age limit for Tdap containing 8 mcg PT/dose was extended from 18 years of age to 64 years. We now report response to this vaccine in 64 alloHSCT recipients (20 children, 44 adults). Patients were transplanted for the treatment of acute (n=31) or chronic (n=6) leukemia, lymphoma (n=16), MDS (n=5), multiple myeloma (n=3), or other (n=3). Forty-four pts were > 18 yrs of age at time of transplant and 20 were < 18 yrs of age. Stem cell donors were an HLA matched sibling (n=31), HLA mismatched related (n=4), or unrelated adult (n=18) or unrelated cord blood (n=11) donor. Forty-four percent of patients received a T-cell-depleted allograft. Patients were a median age of 34 years at transplant and 36 years at vaccination. Over 90% of patients had pre vaccine PT of less than 2 IU/ml. Patients received one (n=47), two (n=15),or three (n=2) immunizations. Of pts receiving more than one vaccine, the median time to a second Tdap was 153 days (range 28–390). There were no severe local or systemic reactions in any recipient of Tdap including those who received > 1 vaccine. Response was defined as seroconversion > 5 IU/mL or >2 fold rise in PT titer for seropositive patients. Of the 63 patients evaluable after a single Tdap, 9 of 20 children and 9 of 43 adults responded (p=0.04) Response was associated with younger age, receipt of an unmodified transplant, and non-myeloablative or reduced intensity conditioning. None of the 11 UCBT recipients responded to a single Tdap. Currently, 9 of 12 patients evaluable for response following a second or third Tdap responded, including 2 of 3 UCBT recipients. In the last decade, pertussis in adolescents and adults has steadily increased with an estimated incidence of 800,000 to 3.3 million cases/year. Our studies suggest that use of Tdap containing 8 mcg/dose is preferable in alloHCT recipients and that administration of >1 Tdap is safe and often necessary to elicit pertussis immunity in this vulnerable patient population. Disclosures:No relevant conflicts of interest to declare.

Pertussis and Patient Safety: Implementing Tdap Vaccine Recommendations in Hospitals

Despite the availability of pediatric vaccines against pertussis ("whooping cough"), the disease is poorly controlled. Adolescents and adults with waning immunity, especially immediate family members, are responsible for 76%-83% of pertussis transmission to infants. Adolescent/adult tetanus, diphtheria, and acellular pertussis (Tdap) booster vaccines were licensed in the United States in 2005, but their use has been low and hospitals' implementation of immunization recommendations suboptimal. Efforts were implemented at two hospitals in Chicago to increase postpartum use of Tdap vaccine and to replace the tetanus and diphtheria toxoids (Td) booster with Tdap vaccine in emergency department (ED) settings. Postpartum Pertussis Vaccination Program at Prentice Women's Hospital: In the program's first 18 months (June 2008-November 2009) 9,540 doses of Tdap vaccine were administered to 78.87% of the postpartum patients. Children's Memorial Hospital: Tdap Use in Emergency Settings: In 2007, uptake of Tdap was slow. During 2008, of 43 ED patients receiving a tetanus toxoid-containing vaccine as part of wound management, 10 were given Tdap (20 had previously received a dose of Tdap vaccine). Hospital-based Tdap initiatives in postpartum and ED settings can be successfully implemented, provided that support is obtained not only from key decision makers at the hospital but also the health care providers who will be directly involved in implementing those initiatives. It is imperative that hospitals implement programs that increase the use of Tdap vaccine among postpartum women, in emergency settings, and among health care personnel.