Acellular Pertussis Component Research Articles

Comparing the pertussis antibody levels of healthy children immunized with four doses of DTap-IPV/Hib (Pentaxim) combination vaccine and DTaP vaccine in Quzhou, China.

Despite the high coverage of pertussis vaccines in high-income countries, pertussis resurgence has been reported in recent years, and has stimulated interest in the effects of vaccines and vaccination strategies. Immunoglobulin G (IgG) antibodies against pertussis toxoid (PT), filamentous hemagglutinin (FHA), and pertactin (PRN) after immunization with four doses of co-purified or component vaccines were determined by enzyme-linked immunosorbent assay (ELISA). Serological data of PT-IgG geometric mean concentrations (GMCs) over time since vaccination were used to fit the mathematical models. A total of 953 children were included in this study; 590 participants received four doses of the component acellular vaccine and 363 participants received four doses of the co-purified acellular vaccine. The GMCs and the seropositivity rate of pertussis IgG were significantly influenced by the production methods, and the immunogenicity of the component acellular vaccine was superior to that of the co-purified acellular vaccine. The fitted mathematical models for the component acellular vaccine and the co-purified acellular vaccine were Y=91.20e-0.039x and Y=37.71x-0.493, respectively. The initial GMCs of the component acellular vaccine was higher than that of the co-purified acellular vaccine, but both were similar at 72 months after immunization. Pertussis IgG levels waned over time after four doses of acellular pertussis vaccine, regardless of whether component or co-purified vaccine was used. The development and promotion of component acellular pertussis vaccines should be accelerated in China, and booster doses of pertussis vaccine in adolescents, adults, and pregnant women should be employed.

Trka milosrđa - kada čovekoljublje pomera granice

Diphtheria is an infection of the respiratory tract or skin with systemic intoxication caused by aerobic gram-positive bacteria, Corynebacterium diphtheriae. Epidemiology of infection and clinical manifestations of the disease vary in different parts of the world. In the past, this disease was among the leading causes of child mortality and occurred in massive outbreaks. Developed at the end of the 19th century, diphtheria antitoxin (DAT) played a key role in the history of public health and vaccinology prior to the diphtheria-tetanus toxoid and combined vaccines against diphtheria, tetanus and pertussis with the acellular pertussis component (DTaP). One of the more significant events from the past that showcase the importance of DAT was the dire need for its use during the diphtheria outbreak in the town of Nome, Alaska. It was January, 1925, when Doctor Curtis Welch declared a diphtheria outbreak and sent a radio telegram to all major cities in Alaska, as well as to the US Public Health Service in Washington, D.C., begging for help. Despite the quarantine, the disease spread, and the only available serum supplies were discovered at a hospital in the small town of Anchorage, hundreds of kilometres away from Nome. The serum was delivered from Anchorage by train to the Nenana village, where the nearest railway station was located, and from there teams of sledding dogs were organised to take the serum to Nome in a relay dash. They needed to cross 1085 kilometers as fast as possible, in dire weather conditions. The teams took over from each other, pushing the limits of their endurance. The musher, the dog sled driver, had to be prepared for these conditions. All the dogs on the team had significant roles, but the lead dog was the key, and he had to be resourceful, strong and well trained. It took five and a half days (127 and a half hours), 20 people and more than 150 dogs for the so-called "Great race of mercy". A coordinated emergency delivery of this serum, thanks to the sled relay accomplished by Alaskan malamutes and Siberian huskies and their mushers in extreme weather conditions in order to save lives, left a great legacy in the history of vaccinology and public health. The most difficult parts of the relay were led by Siberian huskies, Balto and Togo and their mushers, Gunnar Kaasen and Leonhard Seppala, but it should be noted that most of the mushers were native Alaskans, Athabascans. This race, where the dogs pulled the sleds carrying the precious serum represents a dynamic illustration of the contribution of a non-human species to mass immunization in the history of vaccinology. Many dogs died during this relay, while their mushers suffered severe frostbite due to extremely low temperatures. Every single individual on our planet (both human and animal) plays a part, the significance of which should not be forgotten, in the historical chain of survival and not giving up the goal of improving the life of every living creature, while at the same time trying not to harm another living being. This unique example of cooperation between human and animal species emphasizes the importance of a human-animal relationship in the one health approach initiative.

Establishment of the national reference standard of acellular pertussis vaccine

Currently, Viet Nam is in need of a national acellular pertussis reference standard to use in the quality control of vaccines that contain acellular pertussis component. In 2017, National Institute for Control of Vaccine and Biologicals conducted a research with two aims: develop the specifications for the national reference standard of acellular pertussis vaccine suitable for the condition of Vietnam, and establish a lot of that reference standard. The research has given specifications for the national reference standard of acellular pertussis vaccine, produced a candidate lot of the reference. Upon manufacture, the candidate was evaluated for quality, calibrated against the international standard. The results: The candidate meets the requirements with potency of 72 (30,67- 113,97) IU/ampoule, was recognized as a national reference standard, lot as MCQG.aP.01.

Investigation of a pertussis outbreak and comparison of two acellular booster pertussis vaccines in a junior school in South East England, 2019.

In March 2019, a pertussis outbreak occurred in children in a junior school (7–11 years) in England who had been offered pertussis-containing booster vaccine at 40 months of age. In a case–control investigation, we assessed the extent of transmission and any difference in protection afforded to those who had previously received a booster 3- or 5-component acellular pertussis vaccine (aP). We took oral fluid specimens from the students to determine IgG antibodies against pertussis toxin (anti-PT). Parents of students attending the school were sent a questionnaire on pertussis symptoms and vaccination status was retrieved from general practitioner records for all students. Of 381 students, 134 (35.2%) were classified as pertussis cases, 133 by demonstration of significant anti-PT IgG titres and one clinically. There was no significant difference in the risk of pertussis between students receiving 3-component (33.7%) or 5-component (32.3%) aP boosters. However, pertussis infection differed significantly in school year 4, with 22.9%, 50.0%, 23.7% and 38.1% pertussis cases in years 3, 4, 5 and 6, respectively. The proportion of students with incomplete vaccinations recorded was higher than the proportion of those not covered according to the national reported coverage, possibly contributing to sustained transmission within the school.

Safety of pertussis vaccines for adolescents

Aim: to investigate the safety of acellular pertussis vaccines for adolescents.Materials and methods. The clinical tolerability of revaccination against pertussis (cell-free component), diphtheria and tetanus was analyzed in 107 children aged 13,5–14 years. Group 1 consisted of children revaccinated with DTacP-IPV combined vaccine (Tetraxim), group 2 – vaccinated with Td and group 3 – children who received Tdap vaccine (Adacel).Results. Statistically significant differences in the frequency of local reactions between the group that received Tdap and the other two (DTacP-IPV and Td) were detected (p = 0.001and p = 0.04, respectively). Analysis of the structure of local reactions revealed a difference only in the occurrence of the hyperemia at the site of injection, with the most frequent registration in the groups of children vaccinated with DTacPIPV (29,4%) and Td (14,7%), whereas in patients vaccinated with Tdap – only in 5,9% (χ2 = 6,8 p = 0,03). Systemic reactions occurred with the same frequency in all studied groups and did not require medical correction, as well as local reactions. Thus, revaccination against pertussis, diphtheria and tetanus of adolescents using Tdap, containing the acellular pertussis component, does not exceed the frequency of systemic reactions and the number of local reactions is significantly lower in comparison with the vaccine with a reduced content of diphtheria and tetanus toxoids (Td) that is used in practice for a long time.

Valuing the cost of improving Chilean primary vaccination: a cost minimization analysis of a hexavalent vaccine

BackgroundThe phased withdrawal of oral polio vaccine (OPV) and the introduction of inactivated poliovirus vaccine (IPV) is central to the polio ‘end-game’ strategy.MethodsWe analyzed the cost implications in Chile of a switch from the vaccination scheme consisting of a pentavalent vaccine with whole-cell pertussis component (wP) plus IPV/OPV vaccines to a scheme with a hexavalent vaccine with acellular pertussis component (aP) and IPV (Hexaxim®) from a societal perspective. Cost data were collected from a variety of sources including national estimates and previous vaccine studies. All costs were expressed in 2017 prices (US$ 1.00 = $Ch 666.26).ResultsThe overall costs associated with the vaccination scheme (4 doses of pentavalent vaccine plus 1 dose IPV and 3 doses OPV) from a societal perspective was estimated to be US$ 12.70 million, of which US$ 8.84 million were associated with the management of adverse events related to wP. In comparison, the cost associated with the 4-dose scheme with a hexavalent vaccine (based upon the PAHO reference price) was US$ 19.76 million. The cost of switching to the hexavalent vaccine would be an additional US$ 6.45 million. Overall, depending on the scenario, the costs of switching to the hexavalent scheme would range from an additional US$ 2.62 million to US$ 6.45 million compared with the current vaccination scheme.ConclusionsThe switch to the hexavalent vaccine schedule in Chile would lead to additional acquisition costs, which would be partially offset by improved logistics, and a reduction in adverse events associated with the current vaccines.

DTaP5-HBV-IPV-Hib pediatric hexavalent combination vaccine for use in children from 6 weeks through to 4 years of age

ABSTRACTIntroduction: Combination vaccines reduce the number of injections received by children, hence improving timeliness and coverage, and general acceptability among caregivers and health-care providers. The most recent hexavalent vaccine, DTaP5-HBV-IPV-Hib, has been also approved by the FDA.Areas covered: DTaP5-HBV-IPV-Hib has demonstrated good immunogenic and safety profiles, not inferior to other hexavalent vaccines already in use in the European market. Either (2p+1/3p+1) immunization schedules can be used with no significant differences. A low incidence of severe adverse events has been shown, similar to other combination vaccines. No issues have arisen when concomitantly administered with other vaccines.Expert opinion: The inclusion of two additional acellular pertussis components (FIM2 and FIM3) might yield better protection against the disease, but this remains to be clinically proven. The new vaccine uses Hib with unique protein carrier (PRP-OMPC) which elicits higher earlier immune response without compromising safety. Compliance with the immunization schedules is expected to increase by decreasing the number of injections needed in combined vaccines for a single visit. In addition, the improvements on the ease-of-use by its liquid-formulation, makes the vaccine preparation more acceptable for use in clinics and may reduce the odds of administration errors.

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.

Needle size for vaccination procedures in children and adolescents.

Needle size for vaccination procedures in children and adolescents.

Humoral immunity 10 years after booster immunization with an adolescent and adult formulation combined tetanus, diphtheria, and 5-component acellular pertussis vaccine in the USA

BackgroundIn a prospective, randomized pivotal phase III clinical trial, the immunogenicity and reactogenicity of a tetanus-diphtheria-acellular pertussis vaccine (Tdap) and a tetanus-diphtheria vaccine (Td) vaccine were studied in participants aged 11–64 years. Here we report antibody persistence through 10 years after vaccination. MethodsParticipants who received Tdap or Td in the original phase III trial and provided pre- and post-vaccination serum samples were recruited to donate sera at 1, 3, 5 and 10 years post-vaccination. Antibody concentrations were measured using standard assay techniques. ResultsInitially, 1457 Tdap and 1152 Td recipients were included; of these, 175 persons from Tdap group were available at the final study bleed point. Nearly all adolescents in both groups had diphtheria antibody levels ≥0.1 IU/mL 1 month after vaccination, which were maintained in ≥95% of vaccinees at 5 and 10 years. Among adults, ≥94% had diphtheria antibody levels ≥0.1 IU/mL 1 month after vaccination, which were maintained in ≥80% at 5 and 10 years. Nearly all participants had tetanus antibodies ≥0.1 IU/mL throughout the study. PT antibodies declined to pre-vaccination levels approximately 5 years post-vaccination; FHA, PRN and FIM antibodies waned at 5 and 10 years but remained several-fold higher than pre-vaccination levels. ConclusionsTdap and Td provide long-lasting protective immune responses against diphtheria and tetanus. Pertussis antibodies following Tdap generally exceeded pre-vaccination levels throughout the study, but showed substantial waning. These data may inform discussion of the need for repeat Tdap booster vaccinations among adults. Trial registrationThe original phase III clinical trial, as well as the 1-, 3-, and 5-year serology follow-up studies were conducted prior to mandatory registration. The 10-year serology follow-up data collection was performed as part of a repeat Tdap administration clinical trial that was registered under clinicaltrials.gov number NCT01439165.

Surveillance of adverse events following immunization in Oman, 2006-2015

In 1996, Oman launched its surveillance programme for adverse events following immunization (AEFI) to address vaccine safety concerns. In 2010, an analysis of surveillance activities for AEFI was done for 10 years (1996-2005). The main objective of the study was to describe the trend of AEFI over the 10-year period, 2006-2015, and compare the findings with a previous report in Oman and reports from other countries. A descriptive record-based review of AEFI was carried out using the national AEFI surveillance database for the study period, 2006-2015. A total of 890 adverse event reports were received, giving an annual rate during the review period of 21.4 per 100 000 population or 8.3 per 100 000 doses administered. The most frequently reported AEFI were BCG adenitis and local reactions - 31.1 and 4.1 per 100 000 doses respectively. There were no reported deaths. Pentavalent vaccine was responsible for the greatest proportion of adverse events (30%). Local reaction was the most common adverse event among all vaccines administered. The Hexa vaccine caused fewer adverse events compared with the pentavalent vaccine, probably due to the acellular pertussis component - 0.8 versus 1.5 per 100 000 doses administered respectively. The overall rate of AEFI (8.3 per 100 000 doses administered) is comparable to the rate (10.8/100 000 doses) in the previous decade (1996-2005) in Oman. The reported rates for individual vaccines are similar to or below international rates.

Pertussis vaccination in pregnancy: Security and effectiveness in the protection of the infant

Whooping cough is an immune preventable disease that can be life threatening. Despite infant immunization starting at 2 month of age, there are many cases and outbreaks in our country and also around the world, with a high risk of mortality specially in infants under 6 month of age. It has been proposed that antenatal vaccination with acellular pertussis component (Tdap) would be useful, safe and effective since it transfers a high antibody rate to the child, reducing the incidence of pertussis in this group by 85%. No higher incidence of adverse effects has been found in pregnant women with this vaccine. This strategy has been implemented in several developed and Latin American countries. The purpose of this manuscript is to review and discuss the benefits of antenatal vaccination with Tdap. It was concluded that maternal immunization with Tdap vaccine should be promoted to prevent infection and associated mortality in the less than 6 months of age by Bordetella pertussis.

Maternal Pertussis Vaccination with a Mono-component Pertussis Toxoid Vaccine is Sufficient to Protect Newborns

Abstract Bordetella pertussis is a highly infectious human pathogen causing serious illness in infants, children and adults. The first pertussis vaccination is administered at two months of age, therefore, infants under two months of age are most vulnerable to infection. Rising incidence of pertussis resulted in the 2012 recommendation by the Advisory Committee on Immunization Practices (ACIP) to immunize all pregnant women to protect infants from birth until their first vaccination. Using a baboon model, we demonstrated that maternal vaccination with the three or four component acellular pertussis vaccines protected newborn baboons from the disease but not from the colonization. We hypothesized this protection was due to the transfer of maternal anti-PT antibodies to the infant. Therefore we evaluated the protection conferred by maternal vaccination with a pertussis toxoid (PTx) only vaccine. Infant baboons born to mothers vaccinated with the PTx-only vaccine were free from disease and had low WBC counts following exposure to B. pertussis at five weeks of age. In contrast, infants born to unvaccinated mothers experienced severe disease with high WBC counts. Our results demonstrate that vaccination of baboons during pregnancy with a PTx-only vaccine is sufficient to protect newborn baboons from disease following exposure to pertussis. Because pertussis toxin is a secreted protein that can be purified from bacterial supernatants, a single-component vaccine comprised of pertussis toxoid is very likely the most cost-effective acellular pertussis vaccine possible. The development and use of mono-component PTx vaccines may enable the extension of maternal vaccine programs to low and middle income countries.

PROFILES OF CYTOKINES IN MICE DURING IMMUNIZATION WITH ADTP-VACCINE WITH ACELLULAR PERTUSSIS COMPONENT

Study cytokine status in mice immunized with vaccines containing acellular pertussis component. Vaccines developed in Mechnikov RIVS - acellular pertussis vaccine (aPV) and adsorbed pertussis-diphtheria-tetanus vaccine (aDTaP), containing a complex of protective antigens of pertussis microbe - were used in the study. F₁ (CBAxC₅₇B1₆) line mice weighing 12 - 14 g were immunized intraperitoneally 3 times at an interval of 7 days with aPV and aDTaP at human immunization dose (0.5 ml), containing 25 μg of pertussis component. Intact mice were used as a control group. Levels of IFN-,γ, IL-2, IL-4, IL-5, IL-12 cytokines were de- termined after each immunization in enzyme immunoassay using commercial test-systems from Cusabio (China). An increase of levels of IFN-γ, IL-2, IL-5, IL-12 and lack of stimulation of production of IL-4 was established in dynamics of immune response after administration of aPV and aDTaP vaccines. The data obtained indicate that immunization of mice with aPV and aDTaP vaccines resulted in activation of production of cytokines characteristic for im- mune response during pertussis infection and immunization with whole-cellular aDTP-vaccines.

Post-licensure safety surveillance study of routine use of tetanus toxoid, reduced diphtheria toxoid and 5-component acellular pertussis vaccine

ABSTRACTAn observational post-licensure (Phase IV) retrospective large-database safety study was conducted at Kaiser Permanente, a US integrated medical care organization, to assess the safety of Tetanus Toxoid, Reduced Diphtheria Toxoid and 5-Component Acellular Pertussis Vaccine (Tdap5) administered as part of routine healthcare among adolescents and adults. We evaluated incidence rates of various clinical events resulting in outpatient clinic, emergency department (ED), and hospital visits during various time intervals (windows) following Tdap5 vaccination using 2 pharmacoepidemiological methods (risk interval and historic cohort) and several screening thresholds. Plausible outcomes of interest with elevated incidence rate ratios (IRRs) were further evaluated by reviewing individual patient records to confirm the diagnosis, timing (temporal relationship), alternative etiology, and other health record details to discern possible relatedness of the health events to vaccination. Overall, 124,139 people received Tdap5 vaccine from September 2005 through mid-October 2006, and 203,154 in the comparison cohort received a tetanus and diphtheria toxoid adsorbed vaccine (and no live virus vaccine) during the year prior to initiation of this study. In the outpatient, ED and hospital databases, respectively, we identified 11/26, 179/700 and 187/700 unique health outcomes with IRRs significantly >1.0. Among the same unique health outcomes in the outpatient, ED, and hospital databases, 9, 146, and 385, respectively, had IRRs significantly <1.0. Further scrutiny of the outcomes with elevated IRRs did not reveal unexpected signals of adverse outcomes related to vaccination. In conclusion, Tdap5 vaccine was found to be safe among this large population of adolescents and adults.

TOLERANCE OF CHILDREN OLDER THAN 4 YEARS TO ACELLULAR DPT-VACCINES: RESULTS OF A RETROSPECTIVE STUDY

Background. Pertussis is a highly contagious bacterial infection of airborne transmission type that still remains a serious problem in Russia and around the world. The only reliable means of specific prophylaxis of pertussis is vaccination. In Russia, only one revaccination from pertussis is provided at the age of one and a half years, which is done with whole-cell DTP vaccine, which is not used with children older than 4 years due to high reactogenicity. Imported acellular DTP vaccines are an alternative to whole-cell vaccines licensed for use with older children. Objective: Our aim was to study children’s tolerability of the vaccine containing acellular pertussis component. Methods . The safety of acellular DTP vaccines (DTaP, DTaP/IPV/Hib) has been analyzed in a retrospective study with children older than 4 years at the department of vaccinal prevention of Scientific Center of Children’s Health (Moscow) in the period from December 2014 to December 2015. Results. The results of 123 vaccinated children aged 4 to 9 have been studies. Among them, healthy children — 62, those having allergic disease — 30, those with other chronic diseases — 31. In the post-vaccination period (3–7 days), local reactions (weak and/or strong) were recorded with 19 (31%) healthy children, 11 (37%) with children having allergic diseases, 9 (29%) with children having other chronic diseases. General reactions to vaccination (weak and/or strong) occurred with 11 (18%), 6 (20%), and 8 (26%) children respectively. Conclusion. The compared groups did not differ in frequency of post-vaccination reactions and their intensity, with the exception of strong local reactions that occurred more frequently with children having allergic diseases.

Immunogenicity of a low-dose diphtheria, tetanus and acellular pertussis combination vaccine with either inactivated or oral polio vaccine compared to standard-dose diphtheria, tetanus, acellular pertussis when used as a pre-school booster in UK children: A 5-year follow-up of a randomised controlled study

This serological follow up study assessed the kinetics of antibody response in children who previously participated in a single centre, open-label, randomised controlled trial of low-dose compared to standard-dose diphtheria booster preschool vaccinations in the United Kingdom (UK). Children had previously been randomised to receive one of three combination vaccines: either a combined adsorbed tetanus, low-dose diphtheria, 5-component acellular pertussis and inactivated polio vaccine (IPV) (Tdap–IPV, Repevax®; Sanofi Pasteur MSD); a combined adsorbed tetanus, low-dose diphtheria and 5-component acellular pertussis vaccine (Tdap, Covaxis®; Sanofi Pasteur MSD) given concomitantly with oral polio vaccine (OPV); or a combined adsorbed standard-dose diphtheria, tetanus, 2-component acellular pertussis and IPV (DTap–IPV, Tetravac®; Sanofi Pasteur MSD). Blood samples for the follow-up study were taken at 1, 3 and 5 years after participation in the original trial (median, 5.07 years of age at year 1), and antibody persistence to each vaccine antigen measured against defined serological thresholds of protection.All participants had evidence of immunity to diphtheria with antitoxin concentrations greater than 0.01IU/mL five years after booster vaccination and 75%, 67% and 79% of children who received Tdap–IPV, Tdap+OPV and DTap–IPV, respectively, had protective antitoxin levels greater than 0.1IU/mL. Long lasting protective immune responses to tetanus and polio antigens were also observed in all groups, though polio responses were lower in the sera of those who received OPV.Low-dose diphtheria vaccines provided comparable protection to the standard-dose vaccine and are suitable for use for pre-school booster vaccination.

Needle size for vaccination procedures in children and adolescents.

Needle size for vaccination procedures in children and adolescents.

Implementation of pertussis immunization in health-care personnel

Background and aimInfection with Bordetella pertussis is most severe in young infants who frequently acquire it from adults. Pertussis immunization in adults 25–29 years of age and all adults in close contact with infants <6 months was introduced in Switzerland in 2012. We immediately implemented this new recommendation in our hospital with a vaccination campaign. MethodsBetween April 2012 and March 2013 we provided information about the campaign to our staff through several channels and offered appointments for counseling and immunization. After checking indications and contraindications of responding health-care personnel (HCP), informed consent for tetanus–diphtheria–acellular pertussis component (Tdap) immunization was obtained. Specific adverse events (AE) were self-assessed by standardized diaries for 7 days. Statistical analyses were performed using a t-test and Mann–Whitney U-tests SPSS (V21). ResultsOf 852 HCP eligible for pertussis immunization, 427 (51%) responded. Of these, 72 (17%) had already received Tdap <10 years ago, 304 (71%) received Tdap now, 38 (9%) were scheduled for vaccination and 12 (3%) declined. Diaries were returned by 272 (89%) of 304 vaccinees; 56 HCP reported ≥1 local AE, most frequently local swelling (8%), redness (2%), redness and swelling (7%), and fever (5=2%); no serious AE occurred. ConclusionsComprehensive efforts were needed to achieve pertussis immunization coverage of ≥49% among all HCP in our institution. Good tolerability of the vaccine and continuous and individual information to HCP about the rationale and benefits of pertussis immunization contributed to this partial success, but increased efforts are needed to mobilize non-responding HCP.

Pertactin deficient Bordetella pertussis present a better fitness in mice immunized with an acellular pertussis vaccine

Bordetella pertussis is the etiologic agent of whooping cough and has been the target of vaccination for over fifty years. The latest strategies include the use of acellular pertussis vaccines that induce specific immunity against few virulence factors amongst which pertactin is included in three and five component acellular pertussis vaccines. Recently, it has been reported that B. pertussis clinical isolates loose the production of this adhesin in regions reaching high vaccine coverage with vaccines targeting this virulence factor. We here demonstrate that isolates not producing pertactin are capable of sustaining longer infection as compared to pertactin producing isolates in an in vivo model of acellular pertussis immunization. Loosing pertactin production might thus provide a selective advantage to these isolates in this background, which could account for the upraise in prevalence of these pertactin deficient isolates in the population.