Effectiveness of pericapsular nerve group block with ultrasonography in patients diagnosed with hip fracture in the emergency department.

BACKGROUND: Hip fractures (HF) are among the most common fractures present in the emergency department and are very painful. Pericapsular nerve group block (PENG) is a new regional anesthesia technique developed for analgesia in total hip arthroplas-ties. We aimed to determine the effectiveness of PENG block used to reduce pain in patients with HF in the emergency department. METHODS: This single-center, randomized, and prospective study was carried out in the emergency department. The patients in-cluded in the study were selected according to the suitability of the personnel who will perform the procedure. The sealed envelope system was used for randomization. RESULTS: Statistical analysis was performed with 39 patients (18 patients in the PENG group, 21 patients in the control group). Thir-teen (33.3%) of the patients were female and 26 (66.7%) were male. The mean age was 75.3. At rest post-procedure, the mean Numeric Rating Scale (NRS) scores of the patients at the 30th min, 2nd, 6th, and 24th h were 1.78±1.83, 0.00±0.00, 0.00±0.00, and 1.28±1.41 in the PENG group. On the other hand, it was 3.38±1.86, 0.05±0.22, 2.86±2.37, and 4.95±1.47 in the control group, respectively. The mean NRS scores of the patients at 15° elevation of the leg at the 30th min, 2nd, 6th, and 24th h were 3.06±1.80, 0.06±0.24, 0.22±0.43, and 2.44±1.50 in the PENG group and it was 5.24±1.81, 1.05±0.92, 4.29±2.35, and 7.14±1.24 in the control group, respectively. CONCLUSION: PENG block can reduce pain and the need for systemic analgesics as a practical option in patients with HF.

Symptoms Associated With Personal Protective Equipment Among Frontline Health Care Professionals During the COVID-19 Pandemic.

OBJECTIVE: Personal protective equipment (PPE) use is frequently construed as inconvenient and disturbing by health care professionals (HCPs). We hypothesized that new-onset symptoms among HCPs may be associated with extended use of PPE and aimed to investigate risk factors related with new-onset symptoms. In addition, the effects of new-onset symptoms on working performance were evaluated. METHODS: In this cross-sectional study, 315 participants filled out a questionnaire that contains 4 main parts: (1) demographics, (2) new-onset symptoms with PPE use, (3) PPE usage hours, and (4) personal opinion about the effect of sensed symptoms on working performance. RESULTS: The mean age was 31.58 ± 4.6 years, and 50.5% (n = 159) were female. New-onset symptom rate was 66% (n = 208). The most common new-onset symptom was headache (n = 115, 36.5%) followed by breathing difficulty-palpitation (n = 79, 25.1%), and dermatitis (n = 64, 20.3%). Extended use of PPE, smoking, and overweight were independently associated with developing new-onset symptoms. A clear majority of symptomatic participants pointed out the impact on working performance (193/208, 92.7%). CONCLUSION: Hospitals should take the necessary precautions (eg, shorter shifts and more frequent breaks) to prevent symptoms associated with PPE and ensure that HCPs comply with these precautions.

The effect of personal protective equipment on cardiac compression quality.

INTRODUCTION: Cardiac compression is a cumbersome procedure. The American Heart Association suggests switching of cardiopulmonary resuscitation (CPR) provider every 2 min to prevent any decrease in resuscitation quality. High quality CPR is associated with improved outcomes. Previous studies have highlighted the difficulties in providing high quality CPR particularly while wearing personal protective equipment (PPE). This study aimed to evaluate the impact of personal protective equipment (PPE) use on CPR quality in prehospital cardiac arrest situations. METHODS: In this prospective simulation study, we compared the cardiac compression qualities and fatigue rates among prehospital health care professionals (HCPs) who were or were not using PPE. RESULTS: A total of 76 prehospital HCPs comprising 38 compression teams participated in this study. The mean compression rate was 117.71 ± 8.27/min without PPE and 115.58 ± 9.02/min with PPE (p = 0.191). Overall compression score was 86.95 ± 4.39 without PPE and 61.89 ± 14.43 with PPE (p < 0.001). Post-cardiac compression fatigue score was 4.42 ± 0.5 among HCPs who used their standard uniform and 7.74 ± 0.92 among those who used PPE (p < 0.001). The overall compression score difference between the two conditions was 25.05 ± 11.74 and the fatigue score difference was 3.31 ± 0.98. DISCUSSION: PPE use is associated with decreased cardiac compression quality and significantly higher fatigue rates than those associated with the use of standard uniforms. Routine use of mechanical compression devices should be considered when PPE is required for out-of-cardiac arrests.

A Retrospective Analysis of the Impact of the Coronavirus Disease 2019 Pandemic on Health Care Workers in a Tertiary Hospital in Turkey.

INTRODUCTION: Several vaccines have been developed and approved for use against severe acute respiratory syndrome coronavirus-2; however, the use of personal protective equipment remains important owing to the lack of effective specific treatment and whole community immunity. Hydroxychloroquine sulfate was a treatment option in the early days of the pandemic; however, it was subsequently removed owing to a lack of evidence as an effective treatment. We aimed to evaluate the testing and infection characteristics of coronavirus disease 2019 among health care personnel and determine the effectiveness of prophylactic hydroxychloroquine sulfate use to prevent transmission. METHODS: This retrospective observational study was conducted between May 1 and September 30, 2020. The health care personnel included in the study were physicians, nurses, and paraprofessional support personnel. The health records of health care personnel who had been tested for severe acute respiratory syndrome coronavirus-2 using polymerase chain reaction were retrospectively analyzed. RESULTS: In total, 508 health care personnel were included in the study. A total of 152 (29.9%) health care personnel were diagnosed with coronavirus disease 2019. The positive polymerase chain reaction rate was 80.3% (n = 122). A comparison of infected and uninfected health care personnel showed a difference in age and occupation and no difference in sex, working area, and prophylactic hydroxychloroquine sulfate use. DISCUSSION: Protective measures in low-risk areas of our hospital require improvements. All health care personnel should be trained on personal protective equipment use. There was no evidence to support the effectiveness of prophylactic hydroxychloroquine sulfate against severe acute respiratory syndrome coronavirus-2 transmission.

Dexketoprofen vs. Tamsulosin vs. Silodosin vs. Tadalafil as Medical Expulsive Therapy for Distal Ureteral Stones in Men.

OBJECTIVE: To assess the effectiveness of the use of dexketoprofen, tamsulosin, silodosin, and tadalafil in medical expulsive therapy for distal ureteral stones in male patients. STUDY DESIGN: Cohort study. PLACE AND DURATION OF STUDY: Department of Urology, Gazi Hospital, Samsun, Turkey, from March 2020 to March 2021. METHODOLOGY: Adult males satisfying the inclusion criteria were randomly assigned into dexketoprofen (Group 1), tamsulosin (Group 2), silodosin (Group 3), or tadalafil (Group 4) treatment arms. The primary endpoint consisted of the stone expulsion rate at the end of four weeks, while the secondary endpoints were the expulsion rate after two weeks and the occurrence of adverse events. Clinical findings were then compared among the study groups. RESULTS: Altogether 193 patients, 50 (25.9%) in group 1, 48 (24.9%) in group 2, 49 (25.4%) in group 3, and 46 (23.8%) in group 4, were enrolled in the study. No significant difference was determined in terms of age, body mass index, stone characteristics, expulsion time, pain episodes, or total analgesic consumption among the four groups. Expulsion rates in the fourth week were 48%, 79.2%, 81.6%, and 78.3% in groups 1, 2, 3, and 4, respectively. Stone expulsion rates were significantly greater in groups 2, 3, and 4 compared to group 1 (p <0.001), but no significant differences were determined between groups 2, 3, and 4. No severe adverse effects occurred throughout the study period. CONCLUSION:   Tamsulosin, silodosin and tadalafil exhibited higher expulsion rates for distal ureteral stones in male patients, although none was significantly superior to the others. All three are safe, efficacious, and well-tolerated, with only very minor side-effects. Key Words: Dexketoprofen, Distal ureteral stones, Medical expulsive therapy, Silodosin, Tadalafil, Tamsulosin.

Risk Factors for Systemic Inflammatory Response Syndrome in Patients with Negative Preoperative Urine Culture after Percutaneous Nephrolithotomy.

OBJECTIVE: To explore the risk factors for systemic inflammatory response syndrome (SIRS) after percutaneous nephrolithotomy (PCNL) in patients with preoperative negative urine culture (UC). STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: Department of Urology, Gazi Hospital, Samsun, Turkey, from January 2015 to January 2020. METHODOLOGY: Two hundred and twenty-eight patients, who underwent conventional PCNL for renal stones, were evaluated. The patients were divided into non-SIRS (Group 1) and SIRS (Group 2) groups, and the effects of the variables were investigated to predict the development of SIRS. RESULTS: Despite preoperative sterile UC, SIRS developed postoperatively in 29 (12.7%) patients. The univariate analysis revealed a statistically significant difference between groups in preoperative serum C-reactive protein (CRP) (p <0.001), platelet-to-lymphocyte ratio (PLR) (p <0.001), neutrophil-to-lymphocyte ratio (p = 0.001), urine white blood cell (p = 0.034), stone size (p = 0.023), operative time (p = 0.041), hemoglobin drop (p <0.001), blood transfusion (p = 0.002), hospital stay (p = 0.006), and complication rate (p = 0.001). Receiver operating characteristic analysis indicated that PLR >117.36 (p <0.001), CRP >3.16 mg/L (p <0.001), stone burden >471 mm2 (p = 0.023) and hemoglobin drop >2.3 g/L (p <0.001) are independent risk factors for post-operative SIRS after PCNL. CONCLUSION: PLR, CRP, stone size, and hemoglobin drop can predict SIRS after PCNL. This finding may help classify risk in patients before PCNL, especially in those with a sterile urine culture. Key Words: C-reactive protein, Percutaneous nephrolithotomy, Platelet/lymphocyte ratio, Systemic inflammatory response syndrome.

Elevated Immune Response Among Children 4 Years of Age With Pronounced Local Adverse Events After the Fifth Diphtheria, Tetanus, Acellular Pertussis Vaccination.

BACKGROUND: In the Netherlands, acellular pertussis vaccines replaced the more reactogenic whole-cell pertussis vaccines. This replacement in the primary immunization schedule of infants coincided with a significant increase in pronounced local adverse events (AEs) in 4 years old children shortly after the administration of a fifth diphtheria, tetanus, acellular pertussis and inactivated polio (DTaP-IPV) vaccine. The objective of this study was to investigate possible differences in vaccine antigen-specific immune responses between children with and without a pronounced local AE after the fifth DTaP-IPV vaccination. METHODS: Blood was sampled in 2 groups of 4-year-olds: a case group reporting pronounced local swelling and/or erythema up to extensive limb swelling at the injection site (n = 30) and a control group (n = 30). Peripheral blood mononuclear cells were stimulated with individual vaccine antigens. Plasma antigen-specific IgG, IgG subclass and total IgE concentrations and T-cell cytokine [interferon-gamma, interleukin (IL)-13, IL-17 and IL-10] production by stimulated peripheral blood mononuclear cells were determined by multiplex bead-based fluorescent multiplex immunoassays. RESULTS: In children with AEs, significantly higher total IgE and vaccine antigen-specific IgG and IgG4 responses as well as levels of the T-helper 2 (Th2) cytokine IL-13 were found after pertussis, tetanus and diphtheria stimulation compared with controls. CONCLUSIONS: Children with pronounced local reactions show higher humoral and cellular immune responses. Acellular vaccines are known to skew toward more Th2 responses. The pronounced local AEs may be associated with more Th2 skewing after the fifth DTaP-IPV vaccination, but other biologic factors may also impact the occurrence of these pronounced local reactions.

Identification of pertussis-specific effector memory T cells in preschool children.

Whooping cough remains a problem despite vaccination, and worldwide resurgence of pertussis is evident. Since cellular immunity plays a role in long-term protection against pertussis, we studied pertussis-specific T-cell responses. Around the time of the preschool acellular pertussis (aP) booster dose at 4 years of age, T-cell memory responses were compared in children who were primed during infancy with either a whole-cell pertussis (wP) or an aP vaccine. Peripheral blood mononuclear cells (PBMCs) were isolated and stimulated with pertussis vaccine antigens for 5 days. T cells were characterized by flow-based analysis of carboxyfluorescein succinimidyl ester (CFSE) dilution and CD4, CD3, CD45RA, CCR7, gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α) expression. Before the aP preschool booster vaccination, both the proliferated pertussis toxin (PT)-specific CD4(+) and CD8(+) T-cell fractions (CFSE(dim)) were higher in aP- than in wP-primed children. Post-booster vaccination, more pertussis-specific CD4(+) effector memory cells (CD45RA(-) CCR7(-)) were induced in aP-primed children than in those primed with wP. The booster vaccination did not appear to significantly affect the T-cell memory subsets and functionality in aP-primed or wP-primed children. Although the percentages of Th1 cytokine-producing cells were alike in aP- and wP-primed children pre-booster vaccination, aP-primed children produced more Th1 cytokines due to higher numbers of proliferated pertussis-specific effector memory cells. At present, infant vaccinations with four aP vaccines in the first year of life result in pertussis-specific CD4(+) and CD8(+) effector memory T-cell responses that persist in children until 4 years of age and are higher than those in wP-primed children. The booster at 4 years of age is therefore questionable; this may be postponed to 6 years of age.

Differential T- and B-cell responses to pertussis in acellular vaccine-primed versus whole-cell vaccine-primed children 2 years after preschool acellular booster vaccination.

This study investigated long-term cellular and humoral immunity against pertussis after booster vaccination of 4-year-old children who had been vaccinated at 2, 3, 4, and 11 months of age with either whole-cell pertussis (wP) or acellular pertussis (aP) vaccine. Immune responses were evaluated until 2 years after the preschool booster aP vaccination. In a cross-sectional study (registered trial no. ISRCTN65428640), blood samples were taken from wP- and aP-primed children prebooster and 1 month and 2 years postbooster. Pertussis vaccine antigen-specific IgG levels, antibody avidities, and IgG subclasses, as well as T-cell cytokine levels, were measured by fluorescent bead-based multiplex immunoassays. The numbers of pertussis-specific memory B cells and gamma interferon (IFN-γ)-producing T cells were quantified by enzyme-linked immunosorbent spot assays. Even 2 years after booster vaccination, memory B cells were still present and higher levels of pertussis-specific antibodies than prebooster were found in aP-primed children and, to a lesser degree, also in wP-primed children. The antibodies consisted mainly of the IgG1 subclass but also showed an increased IgG4 portion, primarily in the aP-primed children. The antibody avidity indices for pertussis toxin and pertactin in aP-primed children were already high prebooster and remained stable at 2 years, whereas those in wP-primed children increased. All measured prebooster T-cell responses in aP-primed children were already high and remained at similar levels or even decreased during the 2 years after booster vaccination, whereas those in wP-primed children increased. Since the Dutch wP vaccine has been replaced by aP vaccines, the induction of B-cell and T-cell memory immune responses has been enhanced, but antibody levels still wane after five aP vaccinations. Based on these long-term immune responses, the Dutch pertussis vaccination schedule can be optimized, and we discuss here several options.

T-cell responses before and after the fifth consecutive acellular pertussis vaccination in 4-year-old Dutch children.

Immunization with acellular pertussis vaccine (aP) induces higher specific antibody levels and fewer adverse reactions than does immunization with the whole-cell vaccine (wP). However, antibody levels in infants induced by both types of pertussis vaccines wane already after 1 year. Therefore, long-term T-cell responses upon vaccination might play a role in protection against pertussis. In a cross-sectional study (ISRCTN65428640), we investigated T-helper (Th) cell immune responses in wP- or aP-vaccinated children before and after an aP low-dose or high-dose preschool booster at 4 years of age in The Netherlands. T cells were stimulated with pertussis vaccine antigens. The numbers of gamma interferon-producing cells and Th1, Th2, Th17, and interleukin-10 (IL-10) cytokine concentrations were determined. In addition, pertussis-specific IgE levels were measured in plasma. Children being vaccinated with aP vaccinations at 2, 3, 4, and 11 months of age still showed higher pertussis-specific T-cell responses at 4 years of age than did wP-vaccinated children. These T-cell responses failed to show a typical increase in cytokine production after a fifth aP vaccination but remained high after a low-dose booster and seemed to decline even after a high-dose booster. Importantly, elevated IgE levels were induced after this booster vaccination. In contrast, wP-vaccinated children had only low prebooster T-cell responses, and these children showed a clear postbooster T-cell memory response even after a low-dose booster vaccine. Four high-dose aP vaccinations in infancy induce high T-cell responses still present even 3 years after vaccination and enhanced IgE responses after preschool booster vaccination. Therefore, studies of changes in vaccine dosage, timing of pertussis (booster) vaccinations, and the possible association with local side effects are necessary.

Pertussis circulation has increased T-cell immunity during childhood more than a second acellular booster vaccination in Dutch children 9 years of age.

UNLABELLED: Here we report the first evaluation of T-cell responses upon a second acellular pertussis booster vaccination in Dutch children at 9 years of age, 5 years after a preschool booster vaccination. Blood samples of children 9 years of age were studied longitudinally until 1 year after the second aP booster and compared with those after the first aP booster in children 4 and 6 years of age from a cross-sectional study. After stimulation with pertussis-vaccine antigens, Th1, Th2 and Th17 cytokine responses were measured and effector memory cells (CCR7-CD45RA-) were characterized by 8-colour FACS analysis. The second aP booster vaccination at pre-adolescent age in wP primed individuals did increase pertussis-specific Th1 and Th2 cytokine responses. Noticeably, almost all T-cell responses had increased with age and were already high before the booster vaccination at 9 years of age. The enhancement of T-cell immunity during the 5 year following the booster at 4 years of age is probably caused by natural boosting due to the a high circulation of pertussis. However, the incidence of pertussis is high in adolescents and adults who have only received the Dutch wP vaccine during infancy and no booster at 4 years of age. Therefore, an aP booster vaccination at adolescence or later in these populations might improve long-term immunity against pertussis and reduce the transmission to the vulnerable newborns. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN64117538.

Enhanced memory B-cell immune responses after a second acellular pertussis booster vaccination in children 9 years of age.

Whooping cough has made its comeback and the incidence of pertussis in countries with widespread pertussis vaccination is most prominent in individuals above 9 years of age. To control the burden of infection, several countries already introduced acellular pertussis (aP) booster vaccination in adolescents and/or adults. However, antibody levels wane rapidly after vaccination even at older age. In this longitudinal study we investigated the effect of a second aP booster on the pertussis-specific memory B-cell immunity in children 9 years of age that have previously been vaccinated according to the national immunization program. Longitudinal blood samples were taken before, one month and one year after the booster. Purified B-cells were polyclonally stimulated and frequencies of memory B-cells were identified by ELISPOT-assays specific for various pertussis antigens. In addition, IgG levels and avidity indices were measured with fluorescent bead-based multiplex immunoassays. Starting with low pertussis-specific antibody and memory B-cell levels, a typical booster response was measured at one month after vaccination with increased antibody and memory B-cell responses. Although these responses declined slightly after one year, they substantially exceeded pre-booster levels and the avidity indices of the anti-pertussis antibodies remained high. Furthermore, high numbers of pertussis-specific memory B-cells at one-month post-booster correlate quite reliably with the corresponding high antibody response at one-year follow-up. In conclusion, booster vaccination in children 9 years of age induced an enhanced pertussis-specific memory immune response that sustained at least for one year. Therefore, this study supports the introduction of booster vaccination in older age groups.

Serum IgA responses against pertussis proteins in infected and Dutch wP or aP vaccinated children: an additional role in pertussis diagnostics.

BACKGROUND: Whooping cough is a respiratory disease caused by Bordetella pertussis, which induces mucosal IgA antibodies that appear to be relevant in protection. Serum IgA responses are measured after pertussis infection and might provide an additional role in pertussis diagnostics. However, the possible interfering role for pertussis vaccinations in the induction of serum IgA antibodies is largely unknown. METHODS/PRINCIPAL FINDINGS: We compared serum IgA responses in healthy vaccinated children between 1 and 10 years of age with those in children who despite vaccinations recently were infected with Bordetella pertussis. All children have been vaccinated at 2, 3, 4 and 11 months of age with either the Dutch whole-cell pertussis (wP) vaccine or an acellular pertussis (aP) vaccine and additionally received an aP booster vaccination at 4 years of age. Serum IgA responses to pertussis toxin (PT), filamentous heamagglutinin (FHA) and pertactin (Prn) were measured with a fluorescent multiplex bead-based immuno-assay. An ELISPOT-assay was used for the detection of IgA-memory B-cells specific to these antigens. Serum IgA levels to all pertussis vaccine antigens were significantly higher in infected children compared with healthy children. High correlations between anti-PT, anti-FHA or anti-Prn IgA and IgG levels were found in infected children and to some degree in wP primed children, but not at all in aP primed children. Highest numbers of IgA-pertussis-specific memory B-cells were observed after infection and generally comparable numbers were found after wP and aP vaccination. CONCLUSIONS: This study provides new insight in the diagnostic role for serum IgA responses against PT in vaccinated children. Since aP vaccines induce high serum IgG levels that interfere with pertussis diagnostics, serum IgA-PT levels will provide an additional diagnostic role. High levels of serum IgA for PT proved specific for recent pertussis infection with reasonable sensitivity, whereas the role for IgA levels against FHA and Prn in diagnosing pertussis remains controversial.

Different IgG-subclass distributions after whole-cell and acellular pertussis infant primary vaccinations in healthy and pertussis infected children.

The distribution of IgG-subclasses provides insight in the immunological mechanisms of protection against whooping cough. We investigated the effect of Dutch whole-cell pertussis and acellular pertussis vaccines administered in infancy on the IgG-subclass distributions in healthy children aged 12 months, 4 years and 9 years as well as in children who have been infected with Bordetella pertussis. A fluorescent bead-based multiplex immunoassay was used for the measurement of IgG1, IgG2, IgG3 and IgG4 responses against pertussis toxin, filamentous heamagglutinin and pertactin. Although IgG1 was the predominant subclass for all pertussis antigens in both healthy and infected children, elevated IgG4 levels were only present in children who had received repeated number of acellular pertussis vaccinations. IgG2 and IgG3 antibodies did not contribute to the IgG response. No differences in IgG-subclasses between healthy vaccinated or infected children were found. The pertussis vaccine used for priming seems to determine the IgG-subclass composition elicited after a secondary antibody response either induced by pertussis vaccination or infection. The pronounced anti-pertussis IgG4 response might reflect the Th2-skewing of the immune response after aP vaccination.

Impact of infant and preschool pertussis vaccinations on memory B-cell responses in children at 4 years of age.

Whooping cough, caused by Bordetella pertussis, is reemerging in the vaccinated population. Antibody levels to pertussis antigens wane rapidly after both whole-cell (wP) and acellular pertussis (aP) vaccination and protection may largely depend on long-term B- and T-cell immunity. We studied the effect of wP and aP infant priming at 2, 3, 4 and 11 months according to the Dutch immunization program on pertussis-specific memory B-cell responses before and after a booster vaccination with either a high- or low-pertussis dose vaccine at 4 years of age. Purified B-cells were characterized by FACS-analysis and after polyclonal stimulation, memory B-cells were detected by ELISPOT-assays specific for pertussis toxin, filamentous haemagglutinin and pertactin. Before and after the booster, higher memory B-cell responses were measured in aP primed children compared with wP primed children. In contrast with antibody levels, no dose-effect was observed on the numbers of memory B-cell responses. In aP primed children a fifth high-dose aP vaccination tended to induce even lower memory B-cell responses than a low-dose aP booster. In both wP and aP primed children, the number of memory B-cells increased after the booster and correlated with the pertussis-specific antibody concentrations and observed affinity maturation. This study indicates that aP vaccinations in the first year of life induce higher pertussis-specific memory B-cell responses in children 4 years of age compared with Dutch wP primary vaccinations. Since infant aP vaccinations have improved protection against whooping cough in children despite waning antibody levels, this suggests that an enhanced memory B-cell pool induction may have an important role in protection. However, the pertussis-dose of the preschool booster needs to be considered depending on the vaccine used for priming to optimize long-term protection against whooping cough.

Identifying long-term memory B-cells in vaccinated children despite waning antibody levels specific for Bordetella pertussis proteins.

Whooping cough is a respiratory disease caused by Bordetella pertussis. Since the 1950s in developed countries pertussis vaccinations are included in the national immunization program. However, antibody levels rapidly wane after both whole cell and acellular pertussis vaccination. Therefore protection against pertussis may depend largely on long-term B- and T-cell immunities. We investigated long-term pertussis-specific memory B-cell responses in children who were primed at infant age with the Dutch wP-vaccine (ISRCTN65428640). Purified B-cells were characterized by FACS-analysis and after polyclonal stimulation memory B-cells were detected by ELISPOT-assays specific for pertussis toxin, filamentous haemagglutinin, pertactin and tetanus. In addition, plasma IgG levels directed to the same antigens were measured by a fluorescent bead-based multiplex immunoassay. Two and 3 years after wP priming as well as 2 and 5 years after the aP booster at the age of 4, low plasma IgG levels to the pertussis proteins were found. At the same time, however pertussis protein-specific memory B-cells could be detected and their number increased with age. The number of tetanus-specific memory B-cells was similar in all age groups, whereas IgG-tetanus levels were high 2 years after tetanus booster compared to pre- and 5 years post-booster levels. This study shows the presence of long-term pertussis protein-specific memory B-cells in children despite waning antibody levels after vaccination, which suggests that memory B-cells in addition to antibodies may contribute to protection against pertussis.

Host transcription profiles upon primary respiratory syncytial virus infection.

Respiratory syncytial virus (RSV) is a common cause of severe lower respiratory tract infection in children. Severe RSV disease is related to an inappropriate immune response to RSV resulting in enhanced lung pathology which is influenced by host genetic factors. To gain insight into the early pathways of the pathogenesis of and immune response to RSV infection, we determined the transcription profiles of lungs and lymph nodes on days 1 and 3 after infection of mice. Primary RSV infection resulted in a rapid but transient innate, proinflammatory response, as exemplified by the induction of a large number of type I interferon-regulated genes and chemokine genes, genes involved in inflammation, and genes involved in antigen processing. Interestingly, this response is much stronger on day 1 than on day 3 after infection, indicating that the strong transcriptional response in the lung precedes the peak of viral replication. Surprisingly, the set of down-regulated genes was small and none of these genes displayed strong down-regulation. Responses in the lung-draining lymph nodes were much less prominent than lung responses and are suggestive of NK cell activation. Our data indicate that at time points prior to the peak of viral replication and influx of inflammatory cells, the local lung response, measured at the transcriptional level, has already dampened down. The processes and pathways induced shortly after RSV infection can now be used for the selection of candidate genes for human genetic studies of children with severe RSV infection.