A randomised controlled trial with a diphtheria-tetanus-acellular pertussis (dTpa) vaccine in adults

ERRATA CORRIGE

[This corrects the article on p. E530-E541 in vol. 61, PMID: 33628957.].

Immunogenicity, safety, and reactogenicity of combined reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine administered as a booster vaccine dose in healthy Russian participants: a phase III, open-label study

As vaccine-induced immunity and protection following natural pertussis infection wane over time, adults and adolescents may develop pertussis and become transmitters to unprotected infants. In Russia, diphtheria and tetanus but not pertussis-containing vaccines are registered for older children, adolescents, or adults. The reduced-antigen-content diphtheria toxoid, tetanus toxoid, and acellular pertussis (dTpa) vaccine (Boostrix, GSK) was developed for booster vaccination of children ≥4 years of age, adolescents, and adults. A phase III, open-label, non-randomized study was performed in eight centers in Russia between January and July 2018. The objective of this study was to assess immunogenicity, reactogenicity and safety of a single dose of dTpa vaccine in healthy Russian participants ≥4 years of age (age categories 4-9 years, 10-17 years, 18-64 years, and ≥65 years). At 1 month post-booster vaccination, across all age groups, >99.0% of participants were seroprotected against diphtheria and tetanus and >96.0% of participants were seropositive for anti-pertussis antibodies. For all antibodies across all age groups, antibody GMCs increased from pre- to 1 month post-booster vaccination and booster responses to diphtheria (in 71.5% of participants), tetanus (85.3%), and pertussis antigens (≥85.6%) were observed. One serious adverse event that was not causally related to the study vaccine was reported. No fatal cases were reported throughout the study period. In conclusion, administration of the dTpa vaccine as a booster dose in healthy Russian participants induced a robust immune response to all vaccine antigens and was generally well tolerated across all age groups.

The effectiveness and safety of pertussis booster vaccination for adolescents and adults: A systematic review and meta-analysis

BACKGROUND

Due to the resurgence of pertussis, many countries have revised the pertussis immunization schedules and recommended booster doses of pertussis component vaccine for adolescents and adults. Here we aim to investigate the effectiveness and safety of pertussis component vaccines in adolescents and adults.

METHODS

Based on a prospectively registered protocol, we reviewed the literature and selected trials in adolescents and adults using pertussis component vaccine. We followed Cochrane and GRADE (Grading of Recommendations, Assessment, Development and Evaluation) guidance to assess risk of bias, quality of evidence and to perform meta-analyses.

RESULTS

A total of 17 clinical trials were included. At post-vaccination with pertussis component vaccine, the vaccine protective rate of pertussis reached 88.89%, the vaccine response rate of pertussis antibodies in most trials were above 85%, and the antibody titers at post-vaccination were higher than at pre-vaccination. Reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine was associated with significantly higher incidences of nausea [RR = 1.26, 95%CI:1.01, 1.57] and vomiting [RR = 2.08, 95%CI:1.21, 3.58] in acellular pertussis vaccines combined with tetanus and diphtheria (Tdap) group than diphtheria tetanus-toxoid vaccines (Td) group. Higher dose of diphtheria toxoid and adjuvant in dTap might cause higher incidence of fever.

CONCLUSIONS

Except for significant difference in gastrointestinal reaction (nausea, vomiting), acellular pertussis component vaccines are quite safe and has short-term effectiveness for the adolescents and adults. The adverse event of acellular pertussis component vaccine is similar to or safer than that of placebo or other vaccines without pertussis component.

Assessment of safety and efficacy against Bordetella pertussis of a new tetanus-reduced dose diphtheria-acellular pertussis vaccine in a murine model

BACKGROUND

Tetanus-reduced dose diphtheria-acellular pertussis (Tdap) vaccination during adolescence was introduced in response to the resurgence of pertussis in various countries. A new Tdap vaccine was manufactured in Korea as a countermeasure against a predicted Tdap vaccine shortage. This study was performed to evaluate the immunogenicity, safety, and protection efficacy against Bordetella pertussis of the new Tdap vaccine in a murine model.

METHODS

Four-week-old BABL/c mice were used for assessment of immunogenicity and protection efficacy. A single dose of primary diphtheria-tetanus-acellular pertussis (DTaP) vaccine was administered, followed by a single dose of Tdap booster vaccine after a 12-week interval. Anti-pertussis toxin (PT), anti-filamentous hemagglutinin (FHA), and anti-pertactin (PRN) IgG titers were measured before primary vaccination, and before and after booster vaccination. An intranasal challenge test was performed after booster vaccination to determine protection efficacy. To assess safety, mouse weight gain test and leukocytosis promotion test were performed using 4-week-old ddY female mice.

RESULTS

Anti-PT and anti-FHA IgG titers after booster vaccination were significantly higher than those before booster vaccination with either the new vaccine or a commercially available Tdap vaccine (P = 0.01 for all occasions). After booster vaccination, no significant difference was observed between the two vaccines in antibody titers against pertussis antigens (P = 0.53 for anti-PT IgG, P = 0.91 for anti-FHA IgG, P = 0.39 for anti-PRN IgG). In the intranasal challenge test, inoculated B. pertussis was eradicated 7 days after infection. On days 4 and 7 after infection, colony counts of B. pertussis were not significantly different between the new and positive control vaccine groups (P = 1.00). Mean body weight changes and leukocyte counts of the new vaccine, positive control, and negative control groups were not significantly different 7 days after vaccination (P = 0.87 and P = 0.37, respectively). All leukocyte counts in the new vaccine group were within a mean ± 3 standard deviations range.

CONCLUSIONS

A murine model involving a single dose primary DTaP vaccination followed by a single dose Tdap booster vaccination can be used for non-clinical studies of Tdap vaccines. The new Tdap vaccine manufactured in Korea exhibited comparable immunogenicity, protection efficacy, and safety with a commercially available Tdap vaccine.

Pertussis: Microbiology, Disease, Treatment, and Prevention

Pertussis is a severe respiratory infection caused by Bordetella pertussis, and in 2008, pertussis was associated with an estimated 16 million cases and 195,000 deaths globally. Sizeable outbreaks of pertussis have been reported over the past 5 years, and disease reemergence has been the focus of international attention to develop a deeper understanding of pathogen virulence and genetic evolution of B. pertussis strains. During the past 20 years, the scientific community has recognized pertussis among adults as well as infants and children. Increased recognition that older children and adolescents are at risk for disease and may transmit B. pertussis to younger siblings has underscored the need to better understand the role of innate, humoral, and cell-mediated immunity, including the role of waning immunity. Although recognition of adult pertussis has increased in tandem with a better understanding of B. pertussis pathogenesis, pertussis in neonates and adults can manifest with atypical clinical presentations. Such disease patterns make pertussis recognition difficult and lead to delays in treatment. Ongoing research using newer tools for molecular analysis holds promise for improved understanding of pertussis epidemiology, bacterial pathogenesis, bioinformatics, and immunology. Together, these advances provide a foundation for the development of new-generation diagnostics, therapeutics, and vaccines.

Immunization against pertussis in adolescents and adults

Pertussis is a highly contagious infectious disease caused by Bordetella pertussis that can be extremely serious, particularly in young infants. For many years the efforts of health authorities throughout the world to prevent pertussis had the main goals of reducing the morbidity of infants and children under 5 years of age, maintaining protection for several years during the school-age period and developing a significant herd immunity to directly and indirectly reduce the risk of the spread of the disease among young infants and the risk of transmission of the infection from preschool children to infants. However, the increased risk of B. pertussis infection among adolescents and adults due to the waning immunity to this bacterium induced by vaccines and natural infection seems to be the main reason for the resurgence of pertussis. We discuss the reasons for the administration of pertussis vaccines to individuals for whom they were previously not recommended, the expected results of the administration of additional pertussis vaccine doses and the differences in the administration of pertussis vaccines in different countries. An analysis of the literature revealed several reports indicating the need for the modification of immunization schedules against pertussis, with booster doses among adolescents and the need for the vaccination of pregnant women. However, to monitor the true epidemiology of pertussis, effective programmes to collect pertussis cases, adequate reporting systems and vaccination coverage monitoring should be urgently implemented.

Safety of Tdap vaccine in pregnant women: an observational study

OBJECTIVES

Actively recruit and intensively follow pregnant women receiving a dose of acellular pertussis vaccine for 4 weeks after vaccination.

DESIGN AND SETTINGS

A prospective observational study conducted in 2 New Zealand regions.

PARTICIPANTS

Women in their 28th-38th week of pregnancy, recruited from primary care and antenatal clinics at the time of Tdap administration. Telephone interviews were conducted at 48 h and 4 weeks postvaccination.

MAIN OUTCOMES MEASURES

Outcomes were injection site reactions, systemic symptoms and serious adverse events (SAEs). Where available, data have been classified and reported according to Brighton Collaboration definitions.

RESULTS

793 women participated with 27.9% receiving trivalent inactivated influenza vaccine concomitantly. 79% of participants reported mild or moderate pain and 2.6% severe pain. Any swelling was reported by 7.6%, induration by 12.0% (collected from 1 site only, n=326), and erythema by 5.8% of participants. Fever was reported by 17 (2.1%) participants, 14 of these occurred within 24 h. Headache, dizziness, nausea, myalgia or arthralgia was reported by <4% of participants, respectively, and fatigue by 8.4%. During the study period, there were 115 adverse events in 113 participants, most of which were minor. At the end of the reporting period, 31 events were classified as serious (eg, obstetric bleeding, hypertension, infection, tachycardia, preterm labour, exacerbation of pre-existing condition and pre-eclampsia). All had variable onset time from vaccination. There were two perinatal deaths. Clinician assessment of all SAEs found none likely to be vaccine related.

CONCLUSIONS

Vaccination with Tdap in pregnant women was well tolerated with no SAE likely to be caused by the vaccine.

TRIAL REGISTRATION NUMBER

ACTRN12613001045707.

Vaccination in the elderly: what can be recommended?

The age-associated increased susceptibility to infectious disease would suggest that vaccination should be a route to promote healthy aging and keep our seniors autonomous and independent. While vaccination represents a cost-effective and efficient strategy at community level, the ability of the immune system to mount a protective immune response is still unpredictable at the level of the individual. Thus, at a similar age, some individuals, including the elderly, might still be 'good' responders while some other, even younger, would definitely fail to mount a protective response. In this review, the current burden of vaccine-preventable diseases in the aging and aged population will be detailed with the aim to identify the ideal vaccine candidates over the age of 50 years. This article will conclude with potential strategies to reduce, as best as possible, this burden and the imperative need to overcome barriers in extending current vaccine coverage towards to a lifelong vaccine schedule.

A randomised, double-blind, non-inferiority clinical trial on the safety and immunogenicity of a tetanus, diphtheria and monocomponent acellular pertussis (TdaP) vaccine in comparison to a tetanus and diphtheria (Td) vaccine when given as booster vaccinations to healthy adults

BACKGROUND

Increasing incidence of pertussis in adolescents and adults has stimulated the development of safe and immunogenic acellular pertussis vaccines for booster vaccination of adolescents and adults.

PURPOSE

To obtain clinical documentation of the safety and immunogenicity of a tetanus, diphtheria and monocomponent acellular pertussis combination vaccine (TdaP), when given as a booster vaccination to adults.

METHODS

The trial was double-blind, controlled and randomised. 802 healthy adults, aged 18-55 years who had completed childhood vaccination with diphtheria, tetanus and whole cell pertussis vaccine (DTwP), were booster vaccinated with TdaP or Td. Blood samples were taken before and one month after the vaccination for serological analysis and adverse events were recorded during the one-month-follow-up period.

RESULTS

The monocomponent acellular pertussis vaccine (aP) in the TdaP vaccine was immunogenic in adults with 92.0% of TdaP vaccinated subjects obtaining an anti-pertussis toxin (anti-PT) antibody booster response. TdaP was non-inferior to Td in eliciting seroprotective anti-tetanus and diphtheria antibody concentrations with more than 98% of subjects obtaining post-vaccination seroprotective concentrations (≥ 0.1 IU/mL). T and d booster response rates were 93.0% and 97.5%, respectively. The frequencies of solicited local adverse reactions were low and comparable between TdaP and Td vaccinees. In the TdaP group, 30.7% reported pain, 4.2% swelling and 2.0% erythema at the injection site. The most frequent solicited general symptoms were headache (20.4%), fatigue (17.0%) and myalgia (10.0%). In the Td group, 35.7% reported pain, 2.5% swelling and 3.2% erythema at the injection site, whereas headache, fatigue and myalgia were reported by 15.7%, 14.5% and 12.5%, respectively. In conclusion, TdaP Vaccine SSI was safe and immunogenic when given as a booster vaccination to adults.

Boostrix: a reduced-dose acellular pertussis vaccine for use in adolescents and adults

Pertussis remains a serious problem in many countries. Even in countries with high vaccine coverage and a long vaccination history, pertussis outbreaks occur periodically. Rather than being a disease of young children, pertussis has shifted to affect adolescents and adults. Increased pertussis burden in adolescents and adults is the major source of severe infection for young infants. An effective vaccine is needed to control the spread of pertussis beyond preschool children. Boostrix is a reduced-dose acellular pertussis vaccine with diphtheria and tetanus toxoids, and is designed for use in adolescents and adults. Current evidence suggests that Boostrix is immunogenic and well tolerated. The pertussis component of Boostrix has been shown to be efficacious in a large-scale Phase III trial. More than 50 countries have given permit to the use of Boostrix, and many of them formally recommend the use of Boostrix in adolescents and adults. Designed as a vaccine for adolescence and adults, Boostrix has a long way to go to achieve large-scale use in those target groups. Nevertheless, we expect that the advent of Boostrix will lead to a much better control of pertussis in the general population.

Adverse events after administration of tetanus-diphtheria-acellular pertussis vaccine to healthcare workers

Healthcare workers who received the tetanus-diphtheria-acellular pertussis (Tdap) vaccine were surveyed about adverse events. Local adverse events were more common among women and among those who received the Tdap vaccine less than 5 years after they had received the tetanus-diphtheria vaccine. Systemic adverse events were more common among healthcare workers aged less than 30 years. These findings provide guidance for counseling of healthcare workers who receive Tdap vaccine.

Pretravel consultation: rapid dipstick test as a decision guidance for the application of tetanus booster vaccinations

BACKGROUND

When deciding whether to administer a tetanus vaccination--for international travel or injury--a subject's vaccination certificate should be investigated. As many people lack valid vaccination cards and are unable to recall their vaccination history, the Tetanos Quick Stick (TQS) test rapidly detects protective tetanus immunoglobulin IgG antibodies in whole blood, serum, or plasma. This immunochromatographic dipstick test yields a positive or negative result.

METHODS

Our study evaluates the effectiveness of the TQS test by comparing the binary TQS test results of 100 sera with the tetanus antibody levels as measured by the standardized enzyme-linked immunosorbent assay (ELISA) method. We used the TQS test to determine whether a person needed a tetanus booster vaccination. If the test showed a clearly visible line that was similar to the control line, the result was determined to be positive.

RESULTS

All positive TQS test results had a concentration of IgG antibodies above 0.5 IU/mL as measured by ELISA, indicating that no booster vaccination was required. Similarly, in all cases with an antibody level below 0.1 IU/mL, where a vaccination would have been recommended based on the ELISA test result, the TQS test yielded a negative result. The positive predictive value and the specificity for the dipstick test were therefore 100%.

CONCLUSIONS

The TQS test is a reliable, fast, and cost-effective means of identifying subjects with a preexisiting level of tetanus IgG antibodies above approximately 0.5 IU/mL. This can help to avoid unnecessary tetanus vaccinations in travel clinics, emergency departments, and practices of family doctors.

Administration of tetanus, diphtheria, and acellular pertussis vaccine to parents of high-risk infants in the neonatal intensive care unit

OBJECTIVE

Tetanus, diphtheria, and acellular pertussis vaccination is recommended for adults who are in contact with infants who are younger than 12 months and in the NICU. The objective of this study was to determine the feasibility of tetanus, diphtheria, and acellular pertussis vaccine administration to parents in a tertiary care, level III NICU and to measure its effect on vaccination rates among parents of this high-risk population.

METHODS

For a 4-month period from July to October 2007, all parents of admitted patients were informed of the risks and benefits of tetanus, diphtheria, and acellular pertussis vaccine by placing an information letter at their infant's bedside. All staff were educated about the dangers of pertussis infection and instructed to reinforce the need to obtain vaccination. Immunization was available for 20 hours per day at no cost. Student's t tests were used for data analysis.

RESULTS

During the study period, 352 children (598 eligible parents) were admitted to the NICU at gestational ages ranging from 23 to 42 weeks, and 495 (82.8%) parents were offered the vaccine. Overall vaccination rate was 86.9% (430 parents) of the screened population. Fifty-five (11.1%) parents in the screened cohort refused vaccination, predominately citing pertussis as an insignificant health threat or disbelief in vaccination. There were no differences in vaccination rate on the basis of parental age. No allergic reactions to vaccination were observed. The 54 infants whose parents were not offered vaccine had a significantly shorter length of stay, higher birth weight, and higher gestational age than parents who were offered vaccine.

CONCLUSIONS

Administration of tetanus, diphtheria, and acellular pertussis vaccine in the NICU is an effective means of increasing vaccination rates of parents of this population. Logistic barriers persist when implementing this program for infants with a short (<3-day) length of stay.

Tetanus-diphtheria-acellular pertussis vaccination of adults in the USA

Pertussis is an important cause of morbidity and mortality, and its incidence has been increasing in adolescents and adults over the past two decades. Waning immunity in adolescents and adults may be partially responsible. Adults can suffer significant illness from pertussis and its complications, such as pneumonia, rib fractures and syncope. Moreover, adults serve as a source of disease for infants, who are more vulnerable to severe complications and even death. The economic burden of pertussis is substantial, in terms of both medical and nonmedical costs. Fortunately, the burden of pertussis disease can now be safely and effectively reduced by vaccinating adults with tetanus-diphtheria-acellular pertussis (Tdap) vaccine. Further research is needed to elucidate the role of vaccination in pregnant women and those over 65 years of age, and also to determine whether further booster doses of Tdap are needed.

Pertussis vaccination for health care workers

Pertussis, an acute respiratory infection caused by Bordetella pertussis, classically manifests as a protracted cough illness. The incidence of pertussis in the United States has been increasing in recent years. Immunity wanes after childhood vaccination, leaving adolescents and adults susceptible to infection. The transmission of pertussis in health care settings has important medical and economic consequences. Acellular pertussis booster vaccines are now available for use and have been recommended for all adolescents and adults. These vaccines are safe, immunogenic, and effective. Health care workers are a priority group for vaccination because of their increased risk of acquiring infection and the potential to transmit pertussis to high-risk patients. Health care worker vaccination programs are likely to be cost-effective, but further research is needed to determine the acceptability of pertussis vaccines among health care workers, the duration of immunity after booster doses, and the impact of vaccination on the management of pertussis exposures in health care settings.

Primary vaccination of adults with reduced antigen-content diphtheria-tetanus-acellular pertussis or dTpa-inactivated poliovirus vaccines compared to diphtheria-tetanus-toxoid vaccines

OBJECTIVE

To evaluate immunogenicity and reactogenicity of primary vaccination with reduced-antigen-content diphtheria-tetanus-acellular pertussis (dTpa) or dTpa-inactivated poliovirus (dTpa-IPV) vaccine compared to diphtheria-tetanus-toxoid vaccines (Td) in adults > or = 40 years of age without diphtheria or tetanus vaccination for 20 years or with an unknown vaccination history.

RESEARCH DESIGN AND METHODS

Double-blind, randomized, controlled clinical trial. Primary vaccination with either three doses of dTpa, one dose of dTpa-IPV followed by two doses of Td, or three doses of Td vaccine (control) administered in a 0-1-6-month schedule.

MAIN OUTCOME MEASURES

Blood samples were collected before commencement and 1 month after each dose. Local and general symptoms were solicited for 15 days after each dose.

RESULTS

A total of 460 adults were enrolled, of whom over 48% did not have protective antibody concentrations against diphtheria and tetanus. One month after dose 3 > 99% had seroprotective anti-diphtheria and tetanus antibodies. Three doses were required to maximize anti-diphtheria seroprotection rates. A vaccine response to pertussis antigens was observed in > 92% of dTpa and dTpa-IPV recipients after dose 1. One month after dTpa-IPV, > 98.4% had seroprotective anti-polio titres. No statistically significant differences in local or general symptoms between groups were observed.

CONCLUSIONS

dTpa and dTpa-IPV can provide primary vaccination of adults. Combinations of dTpa or dTpa-IPV can be used to replace Td and provide booster vaccination against pertussis and polio simultaneously with diphtheria and tetanus, even in situations where the primary vaccination history is unknown.

Pertussis booster vaccination in HIV-infected children receiving highly active antiretroviral therapy

OBJECTIVE

Our goal was to evaluate the immunogenicity and safety of pertussis booster vaccination in children infected with HIV on highly active antiretroviral therapy (HAART).

PATIENTS AND METHODS

HIV-infected children on stable HAART for > or = 3 months with plasma HIV-RNA concentrations of < 30,000 to 60,000 copies per mL who previously received > or = 4 doses of diphtheria-tetanus-pertussis (DTP)-containing vaccine were eligible. Diphtheria-tetanus-acellular pertussis (DTaP) vaccine was administered to subjects 2 to < 7 years old who had 4 previous DTP-containing vaccines, subjects 2 to < 7 years old who had > or = 5 previous DTP-containing vaccines and negative tetanus antibody, and subjects > or = 7 to < or = 13 years old who had negative tetanus antibody. Pertussis toxin and filamentous hemagglutinin antibodies were measured before and 8, 24, and 72 weeks after DTaP vaccine.

RESULTS

Ninety-two subjects received DTaP vaccine and met criteria for analysis. Antibody concentrations were low at entry: pertussis toxin geometric mean concentration at 4.8 enzyme-linked immunosorbent assay units (EU) per mL and filamentous hemagglutinin geometric mean concentration at 4.1 EU/mL. Pertussis toxin and filamentous hemagglutinin geometric mean concentrations rose to 22.3 and 77.0 EU/mL, respectively, 8 weeks after the study DTaP vaccine. Antibody concentrations fell by 24 weeks after vaccination but remained higher than before vaccination. Predictors of response 8 weeks after DTaP vaccine included the concentration of homologous antibody, lower HIV-RNA level, and higher CD4 percentage at entry. One vaccinated subject experienced erythema and induration of > or = 25 mm.

CONCLUSIONS

A DTaP vaccine booster was well tolerated by children on HAART and induced increases in antibodies. Antibody concentrations after vaccination were lower than those reported in populations uninfected by HIV. Although comparison among studies must be made with caution, these data suggest that children infected with HIV may be deficient in immunologic memory from previous DTP-containing vaccination and/or that immune reconstitution with HAART may be incomplete for pertussis antigens.

Cost effectiveness of pertussis vaccination in adults

BACKGROUND

Prior economic analyses have reached disparate conclusions about whether vaccinating adults against pertussis would be cost effective. Newly available data on pertussis incidence were used to evaluate the cost effectiveness of one-time adult vaccination and adult vaccination with decennial boosters.

METHODS

A Markov model was used to calculate the health benefits, risks, costs, and cost effectiveness of the following strategies: (1) no adult pertussis vaccination, (2) one-time adult vaccination at 20-64 years, and (3) adult vaccination with decennial boosters. The impact of the severity of pertussis illness, vaccine adverse events, and herd immunity on model outcomes were also examined.

RESULTS

At a disease incidence of 360 per 100,000, the one-time adult vaccination strategy would prevent 2.8 million cases, and the decennial vaccination strategy would prevent 8.3 million cases. As disease incidence varied from 10 to 500 per 100,000, the one-time adult vaccination strategy was projected to prevent 79,000 to 3.8 million adult pertussis cases, while the decennial vaccination program would prevent 239,000 to 11.4 million cases. A one-time adult vaccination strategy would result in 106 million people vaccinated, or approximately 64% of the adult cohort, for a total program cost of $2.1 billion, while a decennial vaccination strategy would cost $6.7 billion. The one-time and decennial booster vaccination strategies result in cost-effectiveness ratios of <$50,000 per quality-adjusted life year saved if disease incidence in adults were greater than 120 cases per 100,000 population.

CONCLUSIONS

Routine vaccination of adults aged 20 to 64 years with combined tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis is cost effective if pertussis incidence in this age group is greater than 120 per 100,000 population.

Comparison of the safety and immunogenicity of concomitant and sequential administration of an adult formulation tetanus and diphtheria toxoids adsorbed combined with acellular pertussis (Tdap) vaccine and trivalent inactivated influenza vaccine in adults

The annual contact for influenza vaccination provides an opportunity to ensure that adults have received other recommended vaccines such as Tdap. Healthy 19-64 year-olds were randomized to receive concomitant administration of Tdap and influenza vaccines or influenza vaccine followed (in 4-6 weeks by) Tdap. 720 participants were enrolled. No clinically relevant between-group differences were observed in the rates or severities of erythema, swelling, or pain at the Tdap injection site. Injection-site pain was the most commonly reported adverse event (66.6% concomitant administration group versus 60.8% sequential administration group); most pain was graded as mild and resolved by day 3. Seroprotection and seroresponse rates for all influenza strains were comparable between the two groups. For diphtheria and tetanus, seroprotection rates and post-vaccination GMTs were non-inferior in the concomitant administration group compared to the sequential administration group. A trend for lower antibody responses to pertussis antigens PT, FHA, and FIM was observed after concomitant administration and, for PRN, this difference failed the non-inferiority criteria. While there is a small diminution in antibody response to tetanus and pertussis antigens, concomitant administration of Tdap and influenza vaccine was well tolerated and immunogenic and may offer practical advantages including convenience, compliance, and cost-savings.

Update on adolescent immunization: review of pertussis and the efficacy, safety, and clinical use of vaccines that contain tetanus-diphtheria-acellular pertussis

Adolescents, who comprise 14% of the US population, are historically resistant to receiving health care. As a result, adolescents have low immunization rates and are becoming more susceptible to diseases that are preventable by vaccine, such as pertussis. The incidence of pertussis has increased during the past 25 years, with a notable shift in incidence from young children to adolescents and young adults. New vaccines that provide protection against pertussis for use in adolescents have been proven to be safe, effective, and cost-beneficial. Regional epidemics among infants and other vulnerable populations can be reduced or eliminated with improved immunity in adolescents.

Combined diphtheria???tetanus???pertussis vaccine for tetanus-prone wound management in adults

INTRODUCTION

Booster vaccination against tetanus, diphtheria and pertussis is recommended throughout life. Adults are difficult to reach and vaccination coverage in this group is often inadequate. The use of a reduced-antigen content combined diphtheria-tetanus-acellular pertussis ('adult' dTpa) vaccine for tetanus prophylaxis in emergency room wound management provides an opportunity to boost immunity against three infections simultaneously, thereby optimizing the efficiency of medical interventions with adults assessed.

METHODS

A single-blind, randomized, controlled study of 320 healthy adults, the anti-tetanus antibody response within 10 days following vaccination with Boostrix (reduced-antigen diphtheria-tetanus-acellular pertussis).

RESULTS

The anti-tetanus antibody response to the reduced-antigen diptheria-tetanus-acellular pertussis vaccine was equivalent to Tetavax, a licensed monovalent tetanus-toxoid vaccine.

CONCLUSION

The use of diphtheria-tetanus-acellular pertussis is a safe and effective way to provide vaccination to adults against three diseases during emergency room visits for wound management.

Immunogenicity of a single dose of reduced-antigen acellular pertussis vaccine in a non-vaccinated adolescent population

German adolescents (n=123) without previous pertussis vaccination, no history of pertussis and low IgG-anti-pertussis-toxin (PT) levels received one dose of the Tdap vaccine Boostrix. Blood samples were taken before, and 5-12 days and 29-49 days after vaccination. IgG- and IgA-anti-PT, IgG- and IgA-anti filamentous hemagglutinin, IgG-anti-pertactin, IgG-anti-tetanus-toxin, and IgG-anti-diphtheria-toxin were measured by ELISA. 88.6% of subjects had an immune response to PT, and all vaccinees had an immune response to at least one pertussis antigen 29-49 days after vaccination. IgA-anti-PT and IgA-anti-FHA responses were found in 43 and 81% of subjects, respectively. This study shows that in unvaccinated German adolescents pertussis immunity can be achieved by a single dose of Tdap.

Immunogenicity and reactogenicity of a reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine in healthy Taiwanese children and adolescents

PURPOSE

Disease caused by Bordetella pertussis is increasingly being identified among older children and adults in immunized populations, indicating a waning of the vaccine-induced immunity. These findings suggest the need for booster immunization of older children and adults. Modern acellular reduced-antigen-content vaccines have been developed, which can be given as a booster in individuals more than 4 years of age. This study was to assess the immunogenicity and reactogenicity of Boostrix, GlaxoSmithKline Biologicals' reduced-antigen-content diphtheria-tetanus acellular pertussis (dTpa) vaccine, when administered as a booster in healthy subjects previously primed with DTP vaccine.

METHODS

Healthy Taiwanese children and adolescents aged 6-8 years and 15-20 years, previously primed with DTP vaccine, were enrolled. All received one dose of Boostrix. Two blood samples were taken from each of them, one before vaccination and one at 1 month after vaccination. Serum antibodies to diphtheria and tetanus toxoids and immunoglobulin G (IgG) antibodies against the pertussis components PT, FHA and PRN were measured by enzyme-linked immunosorbent assay (ELISA) technique. Adverse reactions following vaccination were recorded.

RESULTS

A total of 180 subjects were recruited. The vaccine response rates to the pertussis antigens ranged between 89.0-100%. There were no serious adverse events reported during the study period.

CONCLUSIONS

The results of this study suggest that Boostrix may be safely and effectively administered as a booster dose to children previously primed with DTP vaccine.

Efficacy of an acellular pertussis vaccine among adolescents and adults

BACKGROUND

Pertussis immunization of adults may be necessary to improve the control of a rising burden of disease and infection. This trial of an acellular pertussis vaccine among adolescents and adults evaluated the incidence of pertussis, vaccine safety, immunogenicity, and protective efficacy.

METHODS

Bordetella pertussis infections and illnesses were prospectively assessed in 2781 healthy subjects between the ages of 15 and 65 years who were enrolled in a national multicenter, randomized, double-blind trial of an acellular pertussis vaccine. Subjects received either a dose of a tricomponent acellular pertussis vaccine or a hepatitis A vaccine (control) and were monitored for 2.5 years for illnesses with cough that lasted for more than 5 days. Each illness was evaluated with use of a nasopharyngeal aspirate for culture and polymerase-chain-reaction assay, and serum samples from patients in both acute and convalescent stages of illness were analyzed for changes in antibodies to nine B. pertussis antigens.

RESULTS

Of the 2781 subjects, 1391 received the acellular pertussis vaccine and 1390 received the control vaccine. The groups had similar ages and demographic characteristics, and the median duration of follow-up was 22 months. The acellular pertussis vaccine was safe and immunogenic. There were 2672 prolonged illnesses with cough, but the incidence of this nonspecific outcome did not vary between the groups, even when stratified according to age, season, and duration of cough. On the basis of the primary pertussis case definition, vaccine protection was 92 percent (95 percent confidence interval, 32 to 99 percent). Among unimmunized controls with illness, 0.7 percent to 5.7 percent had B. pertussis infection, and the percentage increased with the duration of cough. On the basis of other case definitions, the incidence of pertussis in the controls ranged from 370 to 450 cases per 100,000 person-years.

CONCLUSIONS

The acellular pertussis vaccine was protective among adolescents and adults, and its routine use might reduce the overall disease burden and transmission to children.

Pertussis in adolescents: increasing incidence brings attention to the need for booster immunization of adolescents

As a result of waning immunity and improved awareness, the reported incidence of pertussis is increasing among adolescents in the United States. Symptoms of pertussis are often mild and difficult to diagnose in adolescents, but these individuals can transmit the infection to schoolmates and family members, including high risk infants. Improvements in diagnosis and prevention of pertussis in adolescents are needed.

High levels of antibody in adults three years after vaccination with a reduced antigen content diphtheria-tetanus-acellular pertussis vaccine

There is increasing interest in prevention of pertussis in adults by vaccination, but little is known about the duration of the antibody response to pertussis, diphtheria or tetanus in reduced antigen content vaccines formulated for adult use. Follow-up of a clinical trial including 550 adults comparing responses to reduced antigen content diphtheria-tetanus-acellular pertussis (dTpa) vaccine, or a licensed Td vaccine, provided the opportunity to evaluate this. Blood samples were collected at 0, 1, 12, 24 and 36 months following vaccination; of the original cohort of 550, 387 subjects (dTpa group N=310, Td+pa group N=77) were tested at month 36. Following a decrease in antibody levels against all vaccine antigens between one and 24 months following vaccination, levels stabilized during the third year, remaining higher at 36 months than pre-vaccination for all vaccine antigens. In particular, more than 90% of subjects remained seropositive for pertussis toxin and pertactin antibodies at 36 months after vaccination, suggesting ongoing protection against pertussis. Adult-formulated dTpa vaccines could replace Td for routine booster vaccination of older individuals.

Acellular pertussis vaccines for adolescents

BACKGROUND

The epidemiology of pertussis is changing, with a clear increase in the number of cases diagnosed in adolescents and adults. This development has spurred studies and anticipated licensure of safer diphtheria, tetanus, acellular pertussis combined (Tdap) vaccines for this older population.

METHODS

Literature review.

RESULTS

Tdap vaccines are safe and immunogenic when administered to adolescents and adults. Correlates of immunity to pertussis after Tdap vaccination have not been established, but various combinations of antibody to pertussis antigens (pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae) provide protection. The importance of the number of antigens in Tdap vaccines for protection against mild pertussis disease is unclear. Pertussis vaccination establishes herd immunity after sufficient uptake within communities and countries. As experience with TdaP vaccines has accumulated, a 1-2% occurrence of large, local injection-site reactions with all TdaP vaccine products have been observed for booster doses in children 4-6 years of age. The frequency of large local reactions appears lower in adolescents and adults. The pathophysiologic mechanisms for the local reactions are not established, but a majority appears to be immunoglobulin E-mediated-reactive edema, and a minority appears to be immunoglobulin G-mediated Arthus-type reactions.

CONCLUSIONS

Tdap vaccines appear safe and immunogenic. The economic impact of pertussis provides a cost-benefit justification for widespread use of Tdap vaccine boosting in adolescents.

Economic considerations for pertussis booster vaccination in adolescents

BACKGROUND

Despite good acellular pertussis vaccine safety and protective efficacy, as well as high vaccination rates among young children, the incidence of pertussis in the United States has steadily increased since the 1980s. This is especially true for adolescents and adults who are susceptible because of waning immunity, which is not long lived. Other populations are at increased risk for morbidity of infection, although infants younger than 6 months of age who have not completed the primary immunization series have the greatest morbidity and mortality. Other groups who might benefit from booster immunizations include hospital workers, family contacts, and individuals with compromised health. Although older individuals generally have milder illnesses, they are often the source of infection for younger children. An adolescent/adult formulation of acellular pertussis vaccine requires a lower dose of pertussis antigens and can be combined with currently recommended diphtheria and tetanus toxoids (Tdap). These new vaccines for adolescents and adults are safe, immunogenic, and protective.

METHODS

Through an extensive review of the literature, the direct and indirect costs associated with pertussis and its complications are examined, cost-benefit analyses of pertussis booster vaccination are evaluated for different groups, and the economic considerations involved in implementing a pertussis booster vaccination program in adolescents are discussed.

RESULTS

Pertussis infections cause outbreaks in schools, families, and workplaces, resulting in prolonged morbidity and significant costs for medical care, lost time, and wages. Physician visits, chest radiographs, and antibiotics comprise the majority of direct costs, and costs associated with work loss often comprise the majority of indirect costs related to pertussis illness. Adolescents and adults also transmit their infections to nonimmune children. A cost-benefit analysis evaluated the health and economic benefits of seven strategies for administering a pertussis booster. The most economical strategy is to immunize all adolescents 10-19 years of age, which may prevent 0.4-1.8 million cases of pertussis and save US 0.3-1.6 billion dollars in a decade. A tetanus and diphtheria booster (Td) is currently recommended for children 11-12 years of age. The Tdap vaccine offers an enhancement for the Td booster by providing protection against pertussis, and it will not require an additional injection or office visit.

CONCLUSIONS

Immunizing adolescents with a pertussis booster in the form of Tdap is the most economical and easiest-to-implement strategy and should provide significant health and economic benefits.

Pertussis in adolescents and adults: should we vaccinate?

BACKGROUND

The incidence of reported pertussis among adolescents, adults, and young infants has increased sharply over the past decade. Combined acellular pertussis vaccines for adolescents and adults are available in Canada, Australia, and Germany and may soon be considered for use in the United States.

OBJECTIVE

To evaluate the potential health benefits, risks, and costs of a national pertussis vaccination program for adolescents and/or adults.

DESIGN, SETTING, AND POPULATION

The projected health states and immunity levels associated with pertussis disease and vaccination were simulated with a Markov model. The following strategies were examined from the health care payer and societal perspectives: (1) no vaccination; (2) 1-time adolescent vaccination; (3) 1-time adult vaccination; (4) adult vaccination with boosters; (5) adolescent and adult vaccination with boosters; and (6) postpartum vaccination. Data on disease incidence, costs, outcomes, vaccine efficacy, and adverse events were based on published studies, recent unpublished clinical trials, and expert panel input.

MAIN OUTCOME MEASURES

Cases prevented, adverse events, costs (in 2004 US dollars), cost per case prevented, and cost per quality-adjusted life-year (QALY) saved.

RESULTS

One-time adolescent vaccination would prevent 30800 cases of pertussis (36% of projected cases) and would result in 91000 vaccine adverse events (67% local reactions). If pertussis vaccination cost $15 and vaccine coverage was 76%, then 1-time adolescent vaccination would cost $1100 per case prevented (or $1200 per case prevented) or $20000 per QALY (or $23000 per QALY) saved, from the societal (or health care payer) perspective. With a threshold of $50000 per QALY saved, the adolescent and adult vaccination with boosters strategy became potentially cost-effective from the societal perspective only if 2 conditions were met simultaneously, ie, (1) the disease incidence for adolescents and adults was > or =6 times higher than base-case assumptions and (2) the cost of vaccination was less than $10. Adult vaccination strategies were more costly and less effective than adolescent vaccination strategies. The results were sensitive to assumptions about disease incidence, vaccine efficacy, frequency of vaccine adverse events, and vaccine costs.

CONCLUSIONS

Routine pertussis vaccination of adolescents results in net health benefits and may be relatively cost-effective.

Immunogenicity and reactogenicity of combined acellular pertussis/tetanus/low dose diphtheria vaccines given as a booster to UK teenagers

Sustained high incidence of pertussis, particularly amongst unvaccinated infants, is of concern. Inclusion of pertussis vaccination with tetanus and low dose diphtheria (Td) teenage boosters may protect individuals through reproductive years, and prevent transmission to offspring. UK teenagers who had previously received only a three-dose primary course of whole cell pertussis vaccination in infancy and who were due to receive a Td booster (n=323) were randomised to four groups: Td, TdaP, TdaP-inactivated polio vaccine (IPV) (Aventis Pasteur), TdaP (GlaxoSmithKline). There were significant pre- to post-vaccination GMC and GMFR increase for vaccine-contained pertussis antigens (p<0.001) in recipients of aP-containing vaccine. All groups demonstrated significant increases pre- to 4 weeks post-vaccination in diphtheria (D)/tetanus (T) geometric mean concentrations (GMCs) and fold rises (GMFRs) (p<0.001). Groups all achieved similar D and T post-vaccination GMCs. Local reactogenicity was generally similar between groups and was not associated with pre-booster diphtheria/tetanus antibody levels. A minority of vaccinees reported systemic symptoms with similar proportions between groups for each symptom assessed. This study demonstrated that addition of aP and/or IPV to Td vaccine did not materially alter reactogenicity or immunogenicity of Td components, and induced immune responses to pertussis antigens in teenagers who had received no pertussis vaccine since infancy.

Pertussis immunization of adolescents in the United States: an economic evaluation

The incidence of reported pertussis has increased during the past decade and poses a growing health and economic burden in developed countries, despite high rates of primary vaccination. Administration of a booster dose of acellular pertussis vaccine to adolescents may help reduce this burden, not only by reducing infections in vaccinated individuals but also by reducing transmission of Bordetella pertussis to other individuals, particularly infants. An epidemiologic model was created to assess the health and economic impact of implementing a program of routine acellular pertussis immunization in adolescents 11-18 years of age in the United States, considering both the reduction in cases in those vaccinated and among the unvaccinated population (due to herd immunity). Inputs for the base case were defined according to information derived from published literature and were supplemented by estimates provided by members of the Global Pertussis Initiative. Both direct and indirect costs were included (in 2002 US dollars) using U.S. data. Outcomes were evaluated over the lifetime of a cohort of potential adolescent vaccine candidates. Because of uncertainty in many of the inputs, extensive sensitivity analyses were conducted. With 80% vaccination coverage of adolescents and a 20% reduction of other cases because of herd immunity, >68,000 cases and 41 pertussis-related deaths would be avoided in the subsequent 10 years by routine administration of acellular pertussis boosters to a single cohort of adolescents in the United States. This strategy would be cost-effective, incurring from 6000 US dollars to 22,000 US dollars per life-year gained. The level of herd immunity attained and the true incidence of pertussis are critical determinants of cost effectiveness, as is the duration of immunity resulting from immunization. The cost of immunization and the discount rate also play a role. Although there is considerable uncertainty surrounding key inputs, the results indicate that the conditions required for adolescent immunization to be economically warranted are realistic.

Effects of lowering the aluminium content of a dTpa vaccine on its immunogenicity and reactogenicity when given as a booster to adolescents

As aluminium in vaccines has been associated with the incidence of local side effects occurring after vaccination, this observer-blind randomised clinical trial was designed to evaluate the effect of lowering the aluminium content of a combined reduced-antigen-content dTpa vaccine on immunogenicity and safety when administered to healthy adolescents aged 10-18 years. A total of 647 subjects were enrolled, 224 (35%) received a dTpa formulation with 0.5 mg aluminium, 209 (32%) a formulation with 0.3 mg aluminium and 214 (33%) a formulation with 0.133 mg aluminium. One month after boostering, all subjects were seroprotected against diphtheria and tetanus toxoids. All subjects were seropositive for anti-FHA and anti-PRN but 4% of the initially seronegatives in both reduced aluminium groups did not seroconvert for anti-PT. Booster responses did not differ significantly between groups for any antibody, but post booster vaccination anti-PT GMC's differed significantly between groups and decreased when vaccine aluminium content decreased. No clear difference between study groups in local or general side effects was demonstrated. The most frequently reported symptoms after vaccination were injection site pain (89.5-90.7%), fatigue (42.1-47.4%) and headache (41.1-45.1%). This study showed that the aluminium content has a specific influence on the immunogenicity of this dTpa vaccine.

Acellular Pertussis Vaccine Safety and Efficacy in Children, Adolescents and Adults

This review offers a perspective on the acellular pertussis vaccine efficiency trials concluded in the 1990s and presents the main conclusions of a meta-analysis of 52 studies that assessed the safety and efficacy of the diphtheria-tetanus (DT)-whole cell pertussis (DTwP) and DT-acellular pertussis (DTaP) vaccines administered to children. A clear serological correlate of immunity to pertussis following DTaP vaccination was not identified despite an intensive analysis. It can be speculated that this may be because various combinations of antibody to agglutinogens (pertussis toxin, filamentous haemagglutinin, pertactin and fimbriae) provide protection, or because serum antibody levels and responses do not uniformly reflect mucosal IgA antibody levels.Long-term efficacy following DTaP vaccination is becoming characterised and cell-mediated immunity (T-cell memory) may have importance. DTaP vaccination appears to establish herd immunity after sufficient uptake within communities and countries. As experience with DTaP vaccine safety has accumulated, a 1-2% occurrence of large, local injection reactions with all products has been defined for booster doses. The pathophysiological mechanisms for the reactions are not established but a majority appear likely to be IgE-mediated reactive oedema and a minority to be IgG-mediated reactive Arthus-type reactions. DTwP and DTaP combinations with other vaccines have been studied and licensed; the most controversial combination products are the DTaP/Haemophilus influenzae type B polysaccharide conjugate vaccines. Pertussis epidemiology is changing with a clear increase in occurrence in adolescents and adults. This development has spurred studies and licensure of safer DTaP vaccines for this older population. The economic impact of pertussis and transmission from adults to vulnerable infants provides a cost-benefit justification for widespread use of DTaP vaccines in all age groups with routine boosting every 10 years.

Anti-diphtheria antibody seroprotection rates are similar 10 years after vaccination with dTpa or DTPa using a mathematical model

The reduced antigen content diphtheria, tetanus and pertussis (dTpa) vaccine (Boostrixtrade mark) has been shown to induce a strong booster response to all the vaccine components in 4-6 year olds. However, anti-diphtheria antibody levels were observed to be lower when compared to the "full strength" paediatric DTPa vaccine. To assess the impact of this difference on long-term protection, a mathematical model was developed to predict diphtheria antibody decay over time. The model was based on a linear decrease in log-transformed antibody concentrations after the first year post-vaccination. When applied to data collected 3.5 years after vaccination of 4-6 year olds with either DTPa or dTpa, the model predicted that 10 years post-vaccination, 98.6% of subjects vaccinated with dTpa were likely to remain seroprotected against diphtheria, compared to 99.6% vaccinated with DTPa. Therefore, the difference observed in diphtheria antibody geometric mean concentrations 1 month after booster vaccination at 4-6 years with dTpa or DTPa is unlikely to be of clinical relevance 10 years later at the time of the adolescent booster.

Serologic response and antibody-titer decay in adults with pertussis

Pertussis is a frequent and significant illness in adults. Because acellular pertussis vaccines for use in adolescents and adults have now been developed, it is important to compare serologic responses in adults after infection with serologic responses in adults after vaccination. We measured IgG and IgA antibodies to 4 Bordetella pertussis antigens at approximately 6-month intervals for 28 months in 11 adults with pertussis. After reaching peak levels, titers of antibody to pertussis toxin decreased more than did titers of antibodies to filamentous hemagglutinin, pertactin, and fimbriae type 1 and type 2. Although studies of adults who have been vaccinated with acellular pertussis vaccines have had shorter follow-up periods than studies of adults with pertussis infection, the antibody decay patterns are similar in both groups.

Predictors of death in infants hospitalized with pertussis: a case-control study of 16 pertussis deaths in Canada

OBJECTIVES

To describe the clinical course of fatal cases of pertussis and identify predictors of death at the time of presentation for medical care.

METHODS

Case-control study of 16 deaths from pertussis identified by the Immunization Monitoring Program, Active (IMPACT) surveillance network (January 1991-December 2001) matched with 32 nonfatal cases by age, date, and geography. Differences were compared by Fisher exact test and logistic regression. A multivariate model was developed using stepwise logistic regression.

RESULTS

All 16 fatal cases were < or =6 months old; 13 were <2 months old. Fatal cases were less likely to have had cough complications during pregnancy (48% vs 14%; P=.046) and more likely to have pneumonia (63% vs 16%; P=.0024) before hospital admission and more likely to have seizures, pneumonia, leukocytosis, and hypoxemia after admission (P<.001 for all comparisons). White blood cell count and pneumonia were independent predictors of fatal outcome in the multivariate model.

CONCLUSIONS

Infants too young to have begun their immunizations are at highest risk of fatal pertussis infection. Leukocytosis and pneumonia are predictors of a poor outcome; however, rapid progression of the disease may make interventions difficult.

Reduced-antigen combined diphtheria-tetanus-acellular pertussis vaccine (Boostrix)

The reduced-antigen combined diphtheria-tetanus-acellular pertussis vaccine (dTpa) is intended for use as a booster dose in individuals aged > or =4 years. A single dose of dTpa elicited generally similar levels of antibodies against pertussis antigens (pertussis toxoid [PT], filamentous haemagglutinin [FHA] and pertactin [PRN]) as a similar monovalent pertussis booster vaccine (ap) in adolescents or adults, irrespective of their prevaccination serological status or vaccination history. Levels of antibodies directed against diphtheria toxoid were similar in recipients of dTpa or a licensed reduced-antigen combined diphtheria-tetanus booster vaccine (Td). However, levels of antitetanus antibodies were significantly higher in recipients of Td vaccines compared with those receiving dTpa. Similar serological response rates were observed for anti-PT, -FHA and -PRN between those receiving dTpa or ap and a similar high percentage of recipients of dTpa and the Td vaccines had seroprotective levels of antibodies against diphtheria and tetanus toxoid. The most frequently reported local adverse reactions following immunisation with dTpa included pain, redness and swelling; general symptoms included fatigue, headache and fever.

Pertussis of adults and infants

Bordetella pertussis continues to circulate even in populations where a high vaccine coverage of infants and children is achieved. Cases in adolescents and adults are reported with increasing frequency in many countries. Adults are a reservoir for infections in very young infants, in whom pertussis may be severe and life-threatening. The salient clinical feature of pertussis in adolescents and adults is prolonged coughing, and recognising that pertussis does occur in these age groups is the most important step in its diagnosis. A laboratory diagnosis can be made by bordetella-PCR from nasopharyngeal swabs or secretions and by detection of antibodies, mainly to pertussis toxin; laboratory diagnosis is, however, not well standardised. Vaccination of adolescents and adults is now possible with acellular pertussis vaccines, which are well tolerated, immunogenic, and effective. Adolescent boosters and the vaccination of health-care workers are already included in vaccination calendars in some countries. Vaccine-recommending bodies and national health-care organisations must have locally relevant information on the transmission of pertussis from adults to infants to be able to make decisions on the advisability, feasibility, and priority for booster immunisation against pertussis.