Steroid treatment suppresses the CD4+ T-cell response to the third dose of mRNA COVID-19 vaccine in systemic autoimmune rheumatic disease patients.

Prolonged steroid treatment has a suppressive effect on the immune system, however, its effect on the cellular response to mRNA vaccine is unknown. Here we assessed the impact of prolonged steroid treatment on the T-cell and humoral response to the SARS-CoV-2 spike (S) peptide following the third dose of the BNT162b2 vaccine in systemic autoimmune rheumatic disease patients. We found that CD4 T-cell response to the S peptide in patients on high-dose long-term steroid treatment showed significantly less S-peptide specific response, compare to low-dose or untreated patients. Remarkably, these results were not reflected in their humoral response, since almost all patients in the cohort had sufficient antibody levels. Moreover, S-peptide activation failed to induce significant mRNA levels of IFNγ and TNFα in patients receiving high-dose steroids. RNA-sequencing datasets analysis implies that steroid treatments' inhibitory effect of nuclear factor kappa-B signaling may interfere with the activation of S-specific CD4 T-cells. This reveals that high-dose steroid treatment inhibits T-cell response to the mRNA vaccine, despite having sufficient antibody levels. Since T-cell immunity is a crucial factor in the immune response to viruses, our findings highlight the need for enhancing the efficiency of vaccines in immune-suppressive patients, by modulation of the T-cell response.

Humoral Response to the Third Dose of Sars-Cov-2 Vaccine in Kidney Transplant Recipients.

BACKGROUND: Most solid organ transplant recipients did not develop an appreciable serologic response after 2 doses of the mRNA SARS-CoV-2 vaccine. METHODS: We analyzed the humoral response after a third dose of the BNT162b2 vaccine in 130 kidney transplant recipients, compared to 48 health care workers, and associated factors, including prevaccine cellular immune response, by evaluating intracellular cytokine production after stimulation of donor's peripheral blood mononuclear cells. RESULTS: After 2 doses, most of the controls (47 out of 48, 98%) and only 40% of kidney recipients (52 of 130) kidney recipients were seropositive (P < .001). Most seronegative recipients developed a serologic response after the booster (47 out 78, 60%), thus bringing the total number of seropositive recipients to 99 out of 130 (76%). After the third dose, there was a significant increase in antibodies titers in both groups. Decreased humoral response was significantly associated with an older age, lower lymphocyte count, and a lower level of antibodies before booster administration. CD4+TNFα+ and CD4+INFγ+ were correlated with mean increase in antibody titers. CONCLUSIONS: A third dose of the BNT162b2 mRNA vaccine in kidney recipients is safe and effectively results in increased IgG anti-S levels, including in individuals who were seronegative after 2 doses. Long-term studies of the length of the immune response and protection are required.

Immunogenicity of a Third Dose of the BNT162b2 mRNA Covid-19 Vaccine in Patients with Impaired B Cell Reconstitution After Cellular Therapy-A Single Center Prospective Cohort Study.

Patients with delayed B-cell reconstitution/B-cell aplasia after cellular therapy show decreased immunogenicity to the BNT162b2 mRNA COVID-19 vaccine. We prospectively evaluated both humoral and cellular immune response to a third vaccine dose in patients after allogeneic HCT (n = 10) or CD19-based chimeric antigen receptor T cells (CAR-T) therapy (n = 6) with low absolute B cell numbers and who failed to mount a humeral response after 2 vaccine doses. Humoral response was documented in 40% and 17% after allogeneic HCT and CAR-T therapy, respectively. None of the patients with complete B-cell aplasia developed anti-vaccine antibodies. Cellular response was documented in all patients after allogeneic HCT and in 83% of the patients after CAR-T. T-cell subclasses levels were not predictive for response, while a longer duration from infusion of cells was associated with a better cellular response. We conclude that cellular response develops with repeated vaccine doses even in patients with B-cell aplasia or delayed B-cell reconstitution, and these patients should therefore be vaccinated. These results should be considered in future studies analyzing immunogenicity in this population. Larger and longer follow-up studies are required to confirm whether cellular immunogenicity translates into vaccine efficacy.

The effect of a third-dose BNT162b2 vaccine on anti-SARS-CoV-2 antibody levels in immunosuppressed patients.

OBJECTIVES: The recent surge in coronavirus disease 2019 cases led to the consideration of a booster vaccine in previously vaccinated immunosuppressed individuals. However, the immunogenic effect of a third-dose severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in immunosuppressed patients is still unknown. METHODS: This was an observational cohort study of 279 previously vaccinated immunosuppressed patients followed at a single tertiary hospital in Israel. Patients were administered a third dose of the Pfizer-BioNTech mRNA vaccine (BNT162b2) between July 14 and July 21, 2021. Levels of IgG antibodies against the spike receptor-binding domain of SARS-CoV-2 were measured 3 to 4 weeks after vaccination. RESULTS: Of the cohort of 279 patients, 124 (44.4%) had haematologic malignancies, 57 (20.4%) had rheumatologic diseases, and 98 (35.1%) were solid organ-transplant recipients. Anti-SARS-CoV-2 antibody levels increased in 74.9% of cases. Across the entire cohort, the median absolute antibody levels (expressed in AU/mL) increased from 7 (interquartile range (IQR), 0.1-69) to 243 (IQR, 2-4749) after the booster dose. The response significantly varied across subgroups: The transplant cohort showed the greatest increase in absolute antibody levels (from 52 (IQR, 7.25-184.5) to 1824 (IQR, 161-9686)), followed by the rheumatology (from 22 (IQR, 1-106) to 1291 (IQR, 6-6231)) and haemato-oncology (from 1 (IQR, 0.1-7) to 7.5 (IQR, 0.1-407.5)) cohorts. The χ2 test was 8.30 for difference in fold change (p = 0.016). Of the 193 patients who were seronegative at baseline, 76 became seropositive after vaccination, corresponding to a 39.4% (95% CI, 32.8%-46.4%) seroconversion rate. Transplant patients had the highest seroconversion rate (58.3% (95% CI, 44.3%-71.2%)), followed by rheumatology (44.1% (95% CI, 28.9%-60.5%)) and haemato-oncology (29.7% (95% CI, 22%-38.8%); χ2 = 11.87; p = 0.003) patients. DISCUSSION: A third dose of BNT162b2 is immunogenic in most immunosuppressed individuals, although antibody response may differ based on the type of disease and immunosuppression. The antibody level that correlates with protection is still unknown; thus, future studies are needed to evaluate clinical outcomes.

BNT162b2 mRNA COVID-19 vaccine booster induces seroconversion in patients with B-cell non-Hodgkin lymphoma who failed to respond to two prior vaccine doses.

This prospective study evaluated seroconversion rates in response to BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine booster in 44 B-cell non-Hodgkin lymphoma (B-NHL) patients who failed to respond to two prior doses [42 previously exposed to anti-CD20 monoclonal antibodies (moAbs) including 13 under maintenance treatment]. Seroconversion was obtained in 29.5% of the patients. Longer time from last anti-CD20 moAb (>6 months) and diagnosis of aggressive lymphoma compared to other, incurable B-NHLs were associated with increased seroconversion rates (47.8% vs.10.5%, p = 0.019 and 50% vs. 17.9%, p = 0.025 respectively). Thus, seronegative patients with B-NHL that completed anti-CD20 therapy more than 6 months prior to the booster have greater chances to achieve seroconversion.

The association of maternal SARS-CoV-2 vaccination-to-delivery interval and the levels of maternal and cord blood antibodies.

OBJECTIVE: To evaluate the correlation of maternal and cord blood levels of SARS-CoV-2 antibodies in pregnant women immunized against COVID-19. METHODS: A prospective cohort study was performed of pregnant women who delivered at a single university affiliated tertiary medical center. Women who received the COVID-19 vaccine (BNT162b2 Pfizer©) were approached. The correlation between levels of maternal sera and umbilical cord SARS-CoV-2 specific IgG was assessed. RESULTS: Overall, 58 women were included; of them, 19 had received a single dose and 39 received two doses of the COVID-19 vaccine. Positive levels of umbilical cord IgG were found in 13/19 (68.4%) and 38/39 (97.4%) women after the administration of a single dose and two doses of the vaccine, respectively. The levels of SARS-CoV-2 IgG antibodies in the maternal sera of vaccinated women were positively correlated to their respective concentrations in cord blood sera (ρ = 0.857; R2 linear = 0.719; P < 0.001). Thirteen days after vaccination, the ratio of maternal-to-umbilical cord anti Spike IgG antibodies was approximately 1, indicating relatively similar levels in maternal and cord sera. CONCLUSION: After the SARS-CoV-2 vaccine, levels of maternal and cord blood antibodies were positively correlated, especially when tested after 13 days following administration of the first dose of the vaccine.

Immunogenicity and Safety of the BNT162b2 mRNA COVID-19 Vaccine Among Actively Treated Cancer Patients.

BACKGROUND: Activity and safety of the SARS-CoV-2 BNT162b2 vaccine in actively treated patients with solid tumors is currently unknown. METHODS: We conducted a retrospective study of 326 patients with solid tumors treated with anticancer medications to determine the proportion of cancer patients with immunogenicity against SARS-CoV-2 following 2 doses of the BNT162b2 vaccine. The control group comprised 164 vaccinated healthy adults. Anti-SARS-CoV-2 S immunoglobulin G antibodies were measured using a level greater than 50 AU/mL as a cutoff for seropositivity. Information on adverse effects was collected using a questionnaire. All statistical tests were 2-sided. RESULTS: Most patients (205, 62.9%) were treated with chemotherapy either alone or with additional therapy; 55 (16.9%) were treated with immune checkpoint inhibitors and 38 (11.7%) with targeted therapy alone; 28 (8.6%) received other combinations. The vaccine was well tolerated, and no severe side effects were reported. Among patients with cancer, 39 (11.9%) were seronegative compared with 5 (3.0%) of the control group (P = .001). Median immunoglobulin G titers were statistically significantly lower among patients with cancer compared with control (931 AU/mL vs 2817 AU/mL, P = .003). Seronegativity proportions were higher in the chemotherapy-treated group (n = 19; 18.8%) compared with the immune checkpoint inhibitor-treated patients (n = 5; 9.1%) and with those treated with targeted therapy (n = 1; 2.6%) (P = .02). Titers were also statistically significantly different among treatment types (P = .002). CONCLUSIONS: The BNT162b2 vaccine is safe and effective in actively treated patients with cancer. The relatively lower antibody titers and lower proportion of seropositive patients, especially among chemotherapy-treated patients, call for continuing the use of personal protective measures in these patients, even following vaccination.

Seroprevalence of SARS-CoV-2 antibodies in patients with autoimmune inflammatory rheumatic diseases.

OBJECTIVES: To assess the prevalence of anti-SARS-CoV-2 antibodies in autoimmune inflammatory rheumatic disease (AIIRD) patients, and to define clinical factors associated with seropositivity. METHODS: A cross sectional study was conducted at a tertiary rheumatology department in Israel. Consecutive patients completed a questionnaire and were tested for SARS-CoV-2 anti-nucleoprotein IgG (N-IgG). If this was positive, an anti-S1/S2 spike IgG (S-IgG) test was done. If both were positive, the patient was considered seropositive. Seropositive patients were retested after 3 months. RESULTS: The study included 572 AIIRD patients. Thirty patients were found seropositive, for a seroprevalence of 5.24%. The seropositive rate was significantly lower for patients treated with immunosuppressive medications (3.55%, p≤0.01), and specifically for patients treated with biologic disease-modifying anti-rheumatic drugs (bDMARDs) (2.7%, p≤0.05). These associations remained significant in the multivariate regressions adjusting for age, sex and exposure to a known COVID-19 patient. A second serology test 3 months later was collected in 21 of the 30 seropositive patients. In a mean±standard deviation (SD) of 166.63±40.76 days between PCR and second serology, 85% were still positive for N-IgG, and 100% were still positive for S-IgG, with a higher mean±SD titre compared to the first S-IgG (166.77±108.77 vs. 132.44±91.18, respectively, p≤0.05). CONCLUSIONS: Humoral response to SARS-CoV-2 in AIIRD patients may be affected be immunosuppressive treatment, especially bDMARDs. In patients with AIIRD, titres of SARS-CoV-2 IgG antibodies, especially N-IgG antibodies, fade with time, while S-IgG antibodies persist.

Kidney transplant recipients vaccinated before transplantation maintain superior humoral response to SARS-CoV-2 vaccine.

Majority of transplant recipients did not develop an appreciable humoral response following SARS-CoV-2 vaccine, in contrast to dialysis patients and healthy individuals. We analyzed the serologic response to BNT162b2 (Pfizer-BioNTech) vaccine in a cohort of 19 kidney transplant recipients, vaccinated prior to transplantation, compare to 109 recipients vaccinated after transplantation, and to 39 healthcare workers, by determining the level of anti-spike antibodies after transplantation. All controls and 17 of 19 (90%) of recipients vaccinated before transplant were seropositive, while only 49 of 109 (45%) recipients vaccinated post-transplant had positive serology (P < .001). Median anti-spike IgG in the group of kidney transplant recipients vaccinated after transplantation (10.7 AU/ml, [IQR 0-62.5]) was lower than the patients vaccinated before transplantation (66.2 AU/ml [21.6-138]), which was significantly lower than in the controls (156 AU/ml [99.7-215.5]). Negative humoral response was associated with vaccination post transplantation (odds ratio 22.4), older age (OR = 1.04), and longer time on dialysis (OR = 1.02), while higher lymphocyte count at time of vaccination was protective (OR = .52). Our findings of sustained superior humoral response to SARS-CoV-2 vaccine in kidney transplant recipients vaccinated prior to transplantation strongly support the recommendations of SARS-CoV-2 vaccination of transplant candidates, especially those younger than 60 years.

Immunogenicity of Pfizer-BioNTech COVID-19 vaccine in patients with inborn errors of immunity.

BACKGROUND: In mid-December 2020, Israel started a nationwide mass vaccination campaign against coronavirus disease 2019 (COVID-19). In the first few weeks, medical personnel, elderly citizens, and patients with chronic diseases were prioritized. As such, patients with primary and secondary immunodeficiencies were encouraged to receive the vaccine. Although the efficacy of RNA-based COVID-19 vaccines has been demonstrated in the general population, little is known about their efficacy and safety in patients with inborn errors of immunity (IEI). OBJECTIVE: Our aim was to evaluate the humoral and cellular immune response to COVID-19 vaccine in a cohort of patients with IEI. METHODS: A total of 26 adult patients were enrolled, and plasma and peripheral blood mononuclear cells were collected from them 2 weeks following the second dose of Pfizer-BioNTech COVID-19 vaccine. Humoral response was evaluated by testing anti-SARS-CoV-2 spike (S) receptor-binding domain and antinucleocapsid antibody titers and evaluating neutralizing ability by inhibition of receptor-binding domain-angiotensin-converting enzyme 2 binding. Cellular immune response was evaluated by using ELISpot, estimating IL-2 and IFN-γ secretion in response to pooled SARS-CoV-2 S- or M-peptides. RESULTS: Our cohort included 18 patients with a predominantly antibody deficiency, 2 with combined immunodeficiency, 3 with immune dysregulation, and 3 with other genetically defined diagnoses. Twenty-two of them were receiving immunoglobulin replacement therapy. Of the 26 patients, 18 developed specific antibody response, and 19 showed S-peptide-specific T-cell response. None of the patients reported significant adverse events. CONCLUSION: Vaccinating patients with IEI is safe, and most patients were able to develop vaccine-specific antibody response, S-protein-specific cellular response, or both.

Reduced humoral response to mRNA SARS-CoV-2 BNT162b2 vaccine in kidney transplant recipients without prior exposure to the virus.

COVID-19 is associated with increased morbidity and mortality in transplant recipients. There are no efficacy data available regarding these patients with any of the available SARS-CoV-2 vaccines. We analyzed the humoral response following full vaccination with the BNT162b2 (Pfizer-BioNTech) in 136 kidney transplant recipients, and compared it to 25 controls. In order to exclude prior exposure to the virus, only participants with negative serology to SARS-CoV-2 nucleocapsid protein were included. All controls developed a positive response to spike protein, while only 51 of 136 transplant recipients (37.5%) had positive serology (p < .001). Mean IgG anti-spike level was higher in the controls (31.05 [41.8] vs. 200.5 [65.1] AU/mL, study vs. control, respectively, p < .001). Variables associated with null humoral response were older age (odds ratio 1.66 [95% confidence interval 1.17-2.69]), high-dose corticosteroids in the last 12 months (1.3 [1.09-1.86]), maintenance with triple immunosuppression (1.43 [1.06-2.15]), and regimen that includes mycophenolate (1.47 [1.26-2.27]). There was a similar rate of side effects between controls and recipients, and no correlation was found between the presence of symptoms and seroconversion. Our findings suggest that most kidney transplant recipients remain at high risk for COVID-19 despite vaccination. Further studies regarding possible measures to increase recipient's response to vaccination are required.

Low immunogenicity to SARS-CoV-2 vaccination among liver transplant recipients.

BACKGROUND & AIMS: Two SARS-CoV-2 mRNA vaccines were approved to prevent COVID-19 infection, with reported vaccine efficacy of 95%. Liver transplant (LT) recipients are at risk of lower vaccine immunogenicity and were not included in the registration trials. We assessed vaccine immunogenicity and safety in this special population. METHODS: LT recipients followed at the Tel-Aviv Sourasky Medical Center and healthy volunteers were tested for SARS-CoV-2 IgG antibodies directed against the Spike-protein (S) and Nucleocapsid-protein (N) 10-20 days after receiving the second Pfizer-BioNTech BNT162b2 SARS-CoV-2 vaccine dose. Information regarding vaccine side effects and clinical data was collected from patients and medical records. RESULTS: Eighty LT recipients were enrolled. Mean age was 60 years and 30% were female. Twenty-five healthy volunteer controls were younger (mean age 52.7 years, p = 0.013) and mostly female (68%, p = 0.002). All participants were negative for IgG N-protein serology, indicating immunity did not result from prior COVID-19 infection. All controls were positive for IgG S-protein serology. Immunogenicity among LT recipients was significantly lower with positive serology in only 47.5% (p <0.001). Antibody titer was also significantly lower in this group (mean 95.41 AU/ml vs. 200.5 AU/ml in controls, p <0.001). Predictors for negative response among LT recipients were older age, lower estimated glomerular filtration rate, and treatment with high dose steroids and mycophenolate mofetil. No serious adverse events were reported in either group. CONCLUSION: LT recipients developed substantially lower immunological response to the Pfizer-BioNTech SARS-CoV-2 mRNA-based vaccine. Factors influencing serological antibody responses include age, renal function and immunosuppressive medications. The findings require re-evaluation of vaccine regimens in this population. LAY SUMMARY: The Pfizer-BioNTech BNT162b2 SARS-CoV-2 vaccine elicited substantially inferior immunity in liver transplant recipients. Less than half of the patients developed sufficient levels of antibodies against the virus, and in those who were positive, average antibody levels were 2x less compared to healthy controls. Factors predicting non-response were older age, renal function and immunosuppressive medications.

Epidemiology and Transmitted HIV-1 Drug Resistance among Treatment-Naïve Individuals in Israel, 2010-2018.

Despite the low prevalence of HIV-1 in Israel, continuous waves of immigration may have impacted the local epidemic. We characterized all people diagnosed with HIV-1 in Israel in 2010-2018. The demographics and clinical data of all individuals (n = 3639) newly diagnosed with HIV-1 were retrieved. Subtypes, transmitted drug-resistance mutations (TDRM), and phylogenetic relations, were determined in >50% of them. In 39.1%, HIV-1 transmission was through heterosexual contact; 34.3% were men who have sex with men (MSM); and 10.4% were people who inject drugs. Many (>65%) were immigrants. Israeli-born individuals were mostly (78.3%) MSM, whereas only 9% of those born in Sub-Saharan Africa (SSA), Eastern Europe and Central Asia (EEU/CA), were MSM. The proportion of individuals from SSA decreased through the years 2010-2018 (21.1% in 2010-2012; 16.8% in 2016-2018) whereas those from EEU/CA increased significantly (21% in 2010-2012; 27.8% in 2016-2018, p < 0.001). TDRM were identified in 12.1%; 3.7, 3.3 and 6.6% had protease inhibitors (PI), nucleotide reverse transcriptase inhibitors (NRTI), and non-nucleoside reverse transcriptase inhibitors (NNRTI) TDRM, respectively, with the overall proportion remaining stable in the studied years. None had integrase TDRM. Subtype B was present in 43.9%, subtype A in 25.2% (A6 in 22.8 and A1 in 2.4%) and subtype C in 17.1% of individuals. Most MSM had subtype B. Subtype C carriers formed small clusters (with one unexpected MSM cluster), A1 formed a cluster mainly of locally-born patients with NNRTI mutations, and A6 formed a looser cluster of individuals mainly from EEU. Israelis, <50 years old, carrying A1, had the highest risk for having TDRM. In conclusion, an increase in immigrants from EEU/CA and a decrease in those from SSA characterized the HIV-1 epidemic in 2010-2018. Baseline resistance testing should still be recommended to identify TDRM, and improve surveillance and care.

The spectrum of bacteria and mechanisms of resistance identified from the casualties treated in the Israeli field hospital after the earthquake in Nepal, 2015: A retrospective analysis.

BACKGROUND: On the April 25, 2015, a 7.8 magnitude earthquake struck Nepal. Soon-after, the Israel Defense Force (IDF) dispatched a tertiary field-hospital to Kathmandu. The field-hospital was equipped with a clinical laboratory with microbiology capabilities. Limited data exists regarding the spectrum of bacteria isolated from earthquake casualties. We aimed to identify the spectrum of bacteria and their mechanisms of resistance in-order to allow preparedness of antibiotic treatment protocols for future disaster scenarios. METHODS: - The field-laboratory phenotypically processed cultures from sterile and non-sterile sites as needed clinically. Later-on, the isolates were brought to Israel for quality control, definite identification and molecular characterization including mechanisms of resistance. RESULTS: A total of 82 clinical pathogens were isolated from 56 patients; 68% of them were Gram negative bacilli. The most common isolates were Enterobacteriaceae (55%) -36% carried bla-NDM and 33% produced Extended-spectrum beta-lactamase (ESBL), mostly blaCTX-M-15. Enterococcus spp were the main Gram positive bacteria isolated (22 isolates), yet, none were vancomycin resistant. The overall level of resistance was 27% MDR and 23% extensively drug resistant (XDR) bacteria. CONCLUSIONS: - Gram negative bacteria were the predominant organism cultured from the casualties, of them 77% were MDR or XDR. NDM was the most common resistance mechanism. The Antibiotic inventory of a field-hospital should be set to cover a wide and unexpected spectrum of bacteria, including resistant organisms. This report adds important information to the scarce reports of bacterial resistance in Nepal.

Neglect of skin wounds and the risk of becoming a Staphylococcus aureus nasal carrier: a cohort study.

BACKGROUND: Nasal carriers of Staphylococcus aureus have an increased risk of acquiring skin and soft tissue infections, which could manifest as outbreaks, especially in crowded settings. Current prevention programs are ineffective, antibiotic resistance is rising and risk factors for becoming a carrier are incompletely understood. We aimed to examine whether a behavior, the neglect of skin wounds, is a risk factor for becoming a Staphylococcus aureus carrier during training. METHODS: We conducted a field-based cohort study among male infantry trainees in three seasons in Israel during 2011-12. Participants underwent anterior nares cultures and answered structured questionnaires on potential risk factors on two occasions: before and 3 weeks after start of training (N = 542). Attitudes and practices toward neglect of skin wounds were defined as perseverance in training at all costs, despite having a wound. Samples were processed within 18 hours for identification of Staphylococcus aureus. Univariable and multivariable logistic regression analyses were performed to assess risk factors for becoming a carrier. RESULTS: Carriage prevalence increased by 43.3% during training, from 33.2% to 47.6% (p < 0.01). One-fourth (25.4%) of those with a negative culture before training became carriers. None of the socio-demographic characteristics was a risk factor for becoming a carrier while the risk was lower in the winter (Odds ratio [OR] = 0.42; 95% confidence interval [CI]: 0.23-0.78, p < 0.01) and spring (OR = 0.46; 0.26-0.81, p < 0.01) seasons compared to the summer season. Neglect of skin wounds in practice and attitude was a risk factor for becoming a carrier (OR = 2.40; 1.13-5.12, p = 0.02), as well as neglect in practice or attitude (OR = 1.86; 1.04-3.34, p = 0.04) compared to no neglect when controlled for season. The preventable fraction in the population attributed to neglect of skin wounds was 33%. CONCLUSIONS: Neglect of skin wounds is an independent, common and strong risk factor for becoming a Staphylococcus aureus carrier during training. This preventable behavior should not be ignored and should be addressed in public health programs during training and in other settings. Further research on behavioral determinants of Staphylococcus aureus carriage and infection is warranted.

Seroprevalence of anti-HBs antibodies at young adulthood, before and after a booster vaccine dose, among medical personnel vaccinated in infancy.

BACKGROUND: Questions remain regarding the long-term protection provided by childhood HBV vaccination. The goals of this study were to assess HBV seroprevalence among medical personnel purportedly vaccinated in infancy; to investigate the immune response after a booster dose given in young adulthood; and to identify predictors of non-responders. METHODS: Between 2011 and 2013 we studied Israeli male military recruits purportedly vaccinated in infancy. All subjects were born after January 1st 1992 and were undergoing medic training. We collected personal data and blood samples at baseline, and administered a dose of HBV vaccine. Subjects were retested one month later and received a second dose. A third blood draw was conducted one month after the second dose. Data collected at baseline were used as predictor variables of seropositivity (anti-HBs≥10mIU/ml). RESULTS: 617 subjects were available for baseline analysis and 539 for paired observations at one month. Baseline seropositivity was 33.7%. Subjects who received post-infancy vaccine doses had a seropositivity rate double that of those denying additional doses (RR 2.22, 95% CI 1.55-3.18). One month after the first booster dose, the overall cumulative population seropositivity reached 87.7%. One month after the second vaccine dose, population seropositivity was 97.9%. Heavy smokers were 5 times less likely to demonstrate detectable antibodies after a single booster dose (OR 0.196, 95% CI 0.060-0.641, P=0.007). CONCLUSIONS: This population-based study is important for informing public health vaccination policy. Our results strongly indicate that among cohorts vaccinated in infancy, two doses in adulthood will provide maximal protective antibody levels, while one dose will provide sufficient population protection.

Association study of CAG repeats in the KCNN3 gene in Israeli patients with major psychosis.

OBJECTIVES: Several studies reported contradictory findings regarding the association of major psychosis with CAG repeats in the KCNN3 gene. We investigated the contribution of the CAG repeat at the KCNN3 gene, localized to chromosome 1q21.3, to the genetic susceptibility for schizophrenia, schizoaffective and bipolar disorders. METHODS: Analysis of the number of CAG repeats and the differences in allele length were performed for Israeli Ashkenazi Jews, non-Ashkenazi Jews, and Arabs diagnosed with major psychosis (n=181) versus matched ethnic controls (n=207). RESULTS: We found no significant difference in the number of CAG repeats between the entire sample of patients and controls. However, an analysis of the differences of allele length revealed a significantly greater number of patients with identical allele length (43.1%) when compared with normal controls (30.4%). Furthermore, an earlier age of non-paranoid schizophrenia onset was found associated with differences in allele sizes. There were no significant differences in the number of CAG repeats and the differences in allele length when subjects were grouped according to gender, ethnic origins of their parents, family history, and diagnostic groups. CONCLUSIONS: Our results support the hypothesis that a contribution of the KCNN3 gene to genetic susceptibility to major psychosis and their phenotypic polymorphism may be related to the difference of allele length rather than to the number of CAG repeats.

An association of CAG repeats at the KCNN3 locus with symptom dimensions of schizophrenia.

BACKGROUND: In 1999 Cardno et al reported that long CAG repeats in the calcium-activated potassium channel gene hSKCa3/KCNN3 are associated with higher negative symptom dimension scores in schizophrenia patients. There has been no attempt to replicate the results. In this study, we investigated whether a symptom polymorphism of schizophrenia is associated with both the CAG repeat numbers and the difference in allele sizes. METHODS: We tested the association of CAG repeats with symptom models of schizophrenia in 117 unrelated Jewish patients. A multivariate analysis (MANOVA) of two models of schizophrenia with the repeat distribution and the difference in allele sizes was performed. RESULTS: We found a significant positive association of the number of CAG repeats with negative syndrome, anergia, activation, and paranoid symptoms. In addition, nonparanoid schizophrenia patients who had differences in allele sizes were characterized by earlier onset of illness. CONCLUSIONS: The study supports the hypothesis that the combined effect of long CAG repeats and the differences in allele sizes contribute to symptom expression of schizophrenia, particularly on the anergia-activation-paranoid axis.

Characterization of Chloroplast Clp proteins in Arabidopsis: Localization, tissue specificity and stress responses.

The ATP-dependent Clp protease is one of the newly identified proteolytic systems in plant organelles that incorporate the activity of molecular chaperones to target specific polypeptide substrates and avoid inadvertent degradation of others. We describe new nuclear-encoded ClpC (ClpC1) and ClpP (ClpP3-5) isomers in Arabidopsis thaliana that raise the total number of identified Clp proteins to 19. The extra Clp proteins are localized within the stroma of chloroplasts along with the ClpD, -P1 and -P6 proteins. Potential differential regulation among these Clp proteins was analysed at both the mRNA and protein level. A comparison between different tissues showed increasing amounts of all plastid Clp proteins from roots to stems to leaves suggested the greatest abundance of proteins was in chloroplasts. The increases in protein were mirrored at the mRNA level for most ClpP isomers (ClpP1, -3, -4 and -6) but not for the three Hsp100 proteins (ClpC1, -C2 and -D) and ClpP5, which exhibited little change in transcript levels, suggesting post-transcriptional/translational regulation. Potential stress induction was also tested for all chloroplast Clp proteins by a series of brief and prolonged stress conditions. Short-term moderate and severe stresses (desiccation, high salt, cold, heat, oxidation, wounding and high light) all failed to elicit significant or rapid increases in any chloroplast Clp protein. However, increases in mRNA and protein content for ClpD and several ClpP isomers did occur during long-term high light and cold acclimation of Arabidopsis plants. These results reveal the great complexity of Clp proteins within the stroma of plant chloroplasts, and that these proteins, rather than being rapidly induced stress proteins, are primarily constitutive proteins that may also be involved in plant acclimation to different physiological conditions.