Adequate Titers Research Articles

Immune Response after Anti-SARS-CoV-2 mRNA Vaccination in Relation to Cellular Immunity, Vitamin D and Comorbidities in Hemodialysis Patients.

In the global threat of SARS-CoV-2, individuals undergoing maintenance dialysis represent a vulnerable population with an increased risk of severe COVID-19 outcomes. Therefore, immunization against SARS-CoV-2 is an essential component of healthcare strategy for these patients. Existing data indicate that they tend to exhibit a reduced immune response to vaccines compared to the general population. Our study aimed to assess both humoral and cellular immune responses following two doses of an anti-SARS-CoV-2 mRNA vaccine, an ability to maintain adequate antibody titers over time, and potential relations with vitamin D, comorbidities and other factors in hemodialysis patients based on a single center experience. A total of 41/45 patients (91.1%) responded to the second dose of the anti-SARS-CoV-2 mRNA vaccine. The titer of anti-SARS-CoV-2 IgG class antibodies and levels of T cells three to four weeks after vaccination were lower in dialysis patients than in healthy controls. Antibodies titer in dialysis patients had a positive correlation with B lymphocytes and was related to cardiovascular diseases. The level of CD4+ cells had a negative correlation with hemodialysis vintage, as did the vitamin D level with post-vaccination seroconversion and decline in anti-SARS-CoV-2 antibodies titer during six months after vaccination. Hemodialysis patients had decreased amounts of CD4+ and CD8+ cells and lower levels of anti-SARS-CoV-2 antibodies than healthy controls. Therefore, chronic hemodialysis could lead to diminished cellular immunity and humoral immune response to the anti-SARS-CoV-2 mRNA vaccination and reduced protection from COVID-19. Comorbidity in cardiovascular diseases was associated with a lower level of specific anti-SARS-CoV-2 antibody titer. Vitamin D may be important in maintaining stable levels of anti-SARS-CoV-2 antibodies, while the duration of dialysis treatment could be one of the factors decreasing anti-SARS-CoV-2 antibody titer and determining lower CD4+ cell counts.

Low-Dose Immune Tolerance Induction Therapy for Severe Hemophilia a Inhibitor Patients: Immunosuppressants Improve Outcomes but Are Generally Not Necessary for Inhibitor-Titer below 200 BU/Ml

Background We previously showed that low-dose immune tolerance induction (ITI) incorporating immunosuppressants (IS) for severe hemophilia A patients with inhibitor titer ≥40 Bethesda Units (BU)/mL (LD-ITI-IS 40 regimen) had relatively high success rate with lower cost compared to those on high-dose ITI. Recent evidence suggested that patients with inhibitor titer <200 BU/mL do not need high-dose ITI raising the question that IS may also not be necessary. Objectives To compare the efficacy of LD-ITI incorporating IS only for inhibitor titer ≥200 BU/mL (LD-ITI-IS 200 regimen) with that of LD-ITI-IS 40 regimen. Methods A prospective, single-arm, single-center cohort study on patients receiving LD-ITI-IS 200 beginning 2021, compared to those receiving LD-ITI-IS 40 before 2021. The inclusion criteria were: (i) patients with an established diagnosis of SHA [FVIII clotting activity (FVIII: C) <1% before inhibitor development]; (ii) patients ≤14 years age at the ITI-start; (iii) patients with high-titer inhibitors (≥5BU/mL). All study patients received a LD-ITI with pd-FVIII/VWF (at 50 FVIII IU/kg) every-other-day. IS (rituximab + prednisone) were added for peak inhibitor-tier ≥40 BU/mL in LD-ITI-IS 40 regimen and ≥200 BU/mL in LD-ITI-IS 200 regimen. IS used for each regimen included rituximab 375 mg/m 2/week (maximum 600 mg) for 4 weeks, together with prednisone 2 mg/kg/day (maximum 60 mg) for one month, then tapered over 3 months. For patients receiving rituximab, intravenous immunoglobulin (200 mg/kg/month for 6 months) was administered for infection prophylaxis. Success is defined as negative inhibitor plus FVIII recovery ≥66% of the expected. Partial success is defined as achieving inhibitor elimination but with persistently abnormal FVIII recovery. Results We enrolled 30 patients on LD-ITI-IS 200 and 64 patients on LD-ITI-IS 40, with similar baseline clinical characteristics (Table 1). Given that IS was initiated at a higher peak inhibitor-titer in the LD-ITI-IS 200 regimen, IS in the LD-ITI-IS 200 group was introduced at a significantly lower rate than that in the LD-ITI-IS 40 regimen group (30% vs. 62.5%, p = 0.003). The 2 regimens (LD-ITI-IS 200 vs.LD-ITI-IS 40) had similar success rate (66.7% vs. 79.7%), median time to success (7.4 vs. 10.6 months) (Figure 1), and ABR during ITI (3.7 vs. 2.8). The per kg treatment cost from ITI-start to ITI success in the LD-ITI-IS 200 (US$2167) was significantly lower than that in the LD-ITI-IS 40 (US$3349). Among patients taking IS in the two regimens rituximab infusion-related side effects were similar, being 22.2% (2/9) for the LD-ITI-IS 200 patients and 22.5% (9/40) for the LD-ITI-IS 40 patients. All these side effects could be resolved and subsequently prevented by antihistamine drugs. No severe adverse events occurred. Among patients with peak inhibitor-titer 40-199 BU/mL, 10 non-IS-using (on LD-ITI-IS 200 regimen) and 28 IS-using (on LD-ITI-IS 40 regimen) had similar success rate (60% vs. 78.6%) and time to success (9.0 vs. 8.8 months). The per kg treatment cost from ITI-start to ITI partial success in the LD-ITI-IS 200 (US$891) was significantly lower than that in the LD-ITI-IS 40 (US$2819). Between the two protocols, there were 12 patients with peak inhibitor-titer ≥200BU/mL (all using IS, 7 in LD-ITI-IS 200, 5 in LD-ITI-IS 40). Among them, 8 patients (66.7%, 4 on each regimen) achieved success over a median 10.1 months, and none relapsed at median 13.5 months follow-up since achieving success. Between the 2 protocols, there were 44 patients (13 in LD-ITI-IS 200, 31 in LD-ITI-IS 40) with peak inhibitor-titer 5-39 BU/mL. Their overall success rate was 79.5%. Nine of the 44 patients (2 in LD-ITI-IS 200, 7 in the LD-ITI-IS 40) received IS because they failed to have adequate inhibitor titer decline in the first 3 months of ITI. All 9 achieved success at median 11.3 months from ITI-start with no relapsed after a median 22.6 months follow-up since success. Conclusions We have optimized the use of IS in our low-dose ITI protocol for SHA patients with high-titer inhibitors. We showed that more restrictive use of IS only for patients with peak inhibitor-titer ≥200 BU (instead of at a lower titer of ≥40 BU) maintained the same efficacy while decreasing the cost. Decreasing use of IS would decrease its potential side effects including infection risks.

Failure of Rabies Post-exposure Prophylaxis Despite Achieving Adequate Antibody Titers in a Goat at Veterinary Hospital Rehan, District Kangra, Himachal Pradesh, India

Failure of Rabies Post-exposure Prophylaxis Despite Achieving Adequate Antibody Titers in a Goat at Veterinary Hospital Rehan, District Kangra, Himachal Pradesh, India

Impaired immunogenicity after vaccination for SARS-CoV-2 in patients with gastrointestinal cancer: does tumor entity matter?

SARS-CoV-2 immunogenicity in patients with gastrointestinal cancer (GI cancer) following second and third vaccination was analyzed. A total of 125 patients under active anticancer therapy or in follow-up care were included in this prospective study. Seroprevalence of SARS-CoV-2 anti-spike and surrogate neutralization antibodies (NABs) was measured. Four weeks after second vaccination, adequate titers of SARS-CoV-2 anti-spike immunoglobulin G (IgG) [≥282.0 binding antibody units (BAU)/mL] were found in 62.2% of patients under treatment versus 96.3% of patients in follow-up care (P<0.01). Sufficient titers of SARS-CoV-2 surrogate NAB (≥85.0%) were found in 32.7% of patients under treatment versus 70.6% in follow-up care (P<0.01). Titers of SARS-CoV-2 anti-spike IgG were especially low in patients with colorectal cancer (CRC). For SARS-CoV-2 surrogate NAB, patients with hepatocellular carcinoma (HCC) and with pancreaticobiliary cancer showed the lowest titers (P<0.01). SARS-CoV-2 anti-spike IgG and SARS-CoV-2 surrogate NAB were associated with a correlation coefficient of 0.93. Reaching a titer of SARS-CoV-2 anti-spike IgG ≥482.0 BAU/mL, protective levels of SARS-CoV-2 surrogate NAB (≥85.0%) could be assumed. Following booster vaccination, all patients reached effective antibody titers. Patients with active GI cancer showed impaired immunogenicity after second SARS-CoV-2 vaccination which was overcome by booster vaccination. Our findings were tumor-related and pronounced in patients with CRC and HCC. Waning immunity over time and antibody escape phenomena by variant of concern Omicron must be considered in these especially vulnerable patients.

Antibody status following booster vaccination against SARS-CoV-2 virus in patients with haematologic malignancies.

Antibody titres in 462 patients with haematological malignancies after the second (D2) and third (D3) SARS-CoV-2 vaccine were compared with those of healthy controls (HCs). Significant decay of antibody titre was observed pre D3, but titre surged post D3. The number of seronegative patients decreased from 79 (17.1%) to 44 (9.5%) from post D2 to post D3, and patients with adequate antibody titre increased from 204 (44.2%) to 358 (77.5%). Of the patients who received B-cell-targeted therapy, 80% were seronegative and 71% remained seronegative after D3. CD19+, CD4+, CD8+ cell counts, and immunoglobulin G (IgG) levels were identified as independent predictors for adequate serologic response.

Association between NOD2 and autoinflammation presenting as Yellow Nail Syndrome

Background: Yellow Nail Syndrome is defined as a triad of lymphedema, respiratory symptoms, and nail discolouration. The precise etiology remains unknown, however it has been reported alongside a broad spectrum of conditions including malignancies, autoinflammatory diseases, and immunodeficiencies. Aim: To highlight the association between defects in the intracellular bacterial sensor gene NOD2 and Yellow Nail Syndrome. Methods: A retrospective review of the patient’s chart was performed, including family history, characteristics, immune laboratory evaluation, and genetics. Results: A 65-year-old female was referred to our centre for lymphedema and bronchiectasis. She had recurrent episodes of pneumonia, cellulitis, and oral ulcers. Bilateral lymphedema on her lower limbs up to the hip and discoloured yellow nails were reported. Given her clinical picture, she was diagnosed with Yellow Nail Syndrome. The immunological evaluation was unremarkable overall, with normal T cell subsets and function and adequate antibody titers. Genetic testing identified a heterozygous mutation in the NOD2 gene, c.2107C&gt;T (p.Arg703Cys), considered a variant of uncertain significance. Conclusion: Heterozygous variants in NOD2 can result in a spectrum of autoimmune and autoinflammatory disorders, including Yellow Nail Syndrome. Statement of novelty: We describe a patient with Yellow Nail Syndrome, presenting with the classic triad of clinical features. Genetic evaluation identified a heterozygous variant in NOD2, which has been extensively associated with several autoinflammatory diseases, but not Yellow Nail Syndrome.

Efficacy of convalescent plasma therapy in the patient with COVID-19: a randomised control trial (COPLA-II trial)

ImportanceNo proven treatment is available for severely ill COVID-19. Therapeutic use of COVID-19 convalescent plasma (COPLA) is under investigation.ObjectiveTo compare the efficacy of COPLA with standard medical therapy (SMT) alone...

Coronavirus disease 2019 and the liver.

The objective of this review is to examine the epidemiology and pathogenesis of liver injury in coronavirus disease 2019 (COVID-19) and the impact of COVID-19 on patients with chronic liver disease (CLD) and liver transplant recipients. Abnormal liver chemistries occur in up to 60% of COVID-19 patients and are typically mild. COVID-19- associated liver injury may be because of direct viral cytopathic effect, immune-mediated damage, hypoxia, drug-induced liver injury (DILI), or exacerbation of CLD. COVID-19 patients with CLD and who are liver transplant recipients are at risk for severe disease and mortality. COVID-19 precipitated hepatic decompensation in 20-46% of cirrhotic patients. Alcohol consumption and cases of acute alcohol- associated hepatitis increased during the COVID-19 pandemic. Corticosteroids and calcineurin inhibitors are well tolerated to use during COVID-19 but immunomodulators have been associated with mortality. Less than 50% of transplant recipients produce adequate antibody titers after COVID-19 vaccination. COVID-19 patients with CLD should be monitored for liver injury and hepatic decompensation. Patients with CLD and liver transplant recipients should be considered for targeted COVID-19 pharmacotherapeutics and advised vaccination against COVID-19, including a third booster dose. CLD treatments and immunosuppression in liver transplant recipients could generally continue without interruption during COVID-19 infection, with the possible exception of immunomodulators.

Clinical outcomes of syphilis in HIV-negative and HIV-positive MSM: occurrence of repeat syphilis episodes and non-treponemal serology responses

ObjectivesHIV-positive men who have sex with men (MSM) may be at a higher risk of repeat syphilis, have different clinical manifestations and have a different serological response to treatment compared...

Cytomegalovirus DNA detection in pregnant women with a high IgG avidity index: a valuable tool for diagnosing non-primary infections?

Background/Aim Congenital human cytomegalovirus infection (cCMV) is the commonest congenital infection, and it can result in hearing loss and neurodevelopmental delay. Even if primary infections are more frequent and cause more severe congenital cCMV manifestations compared to NPIs, and despite partial protection from maternal immunity, the highest birth prevalence of cCMV is observed in seropositive women with non-primary CMV infection (NPI). Given that NPI contribute significantly to the overall burden of cCMV, their accurate diagnosis of NPI remains clinically important. Considering that the serological testing for CMV infection is not always reliable, we sought to determine whether detection of CMV DNA in pregnant women with a high IgG avidity index (AI) can help diagnose NPI. Materials and methods Human CMV serology screening (IgG, IgM, and IgG AI) was performed for confirmation of CMV infection in serum samples from mainly pregnant women with indications of CMV infection due to IgG+ and IgM+-positive samples in other laboratories. Pregnant women (or those with termination of pregnancy during the last period) with adequate IgG levels to perform IgG AI were included. Demographic data and mean gestation week at the time of screening were recorded. Serological testing was performed using CE-IVD commercial kits. CMV DNAemia detection by real time PCR (RT-PCR) was applied to confirm suspected CMV infection. Results Nine-hundred and thirty-four pregnant women CMV IgG positive with adequate IgG titers for AI testing were included in the study. The percentage of women with a high AI was 71.8% (671/934); among them, nearly 2.4% (16/671) had presence of CMV DNA. Also, 12.4% of women (116/934) had intermediate IgG AI and 15.7% of women (147/934) had low IgG AI. The presence of CMV DNA was observed in 13.8% (16/116) and 39.5% (58/147) of the groups with intermediate and low IgG AI, respectively. A high CMV IgG AI was associated with a negative CMV PCR status (p-value <.00001). Conclusions CMV DNA was present in 2.4% of seropositive women with high IgG AI, indicating active NPI and thus, harboring the risk of cCMV sequelae to the fetus. Moreover, the incidence of NPI may have been underestimated due to single timepoint testing. In order to detect CMV NPI in a seropositive woman, regular and frequent serology testing as well as detection of CMV DNAemia are required which render the whole diagnostic process impractical and not cost-effective.

POS-923 RESPONSE TO AND OUTCOMES OF THE Pfizer BNT162B2 VACCINE IN HEMODIALYSIS PATIENTS- A PROSPECTIVE OBSERVATIONAL STUDY

COVID-19 infection is associated with high mortality among hemodialysis patients. Standard vaccine response is generally lower among these patients. The adequate antibody titer response and the outcome of COVID-19 vaccine responders versus non-responders is unknown.

Response to and outcomes of the Pfizer BNT162B2 vaccine in hemodialysis patients-A prospective observational study.

IntroductionCOVID‐19 infection is associated with high mortality among hemodialysis patients. Standard vaccine response is generally lower among these patients. The adequate antibody titer response and the outcome of COVID‐19 vaccine responders versus non‐responders are unknown.MethodsHemodialysis patients on maintenance hemodialysis who have received two doses of Pfizer BNT162B2 vaccine were studied. Antibody response was tested after 14 days of the second dose. LIAISON SARS‐CoV2 S1/S2 IgG test by DiaSorin (Italy) was used to assess antibody response. Patients were followed between 3 and 7 months after vaccination for COVID‐19 infection, hospitalization and death related to COVID‐19.FindingsA total of 138 patients received two doses of Pfizer BNT162B2 vaccine. One hundred and twenty‐seven patients had adequate response to the vaccine with IgG level ≥ 15 AU/ml versus 11 patients had poor response with IgG level ≤ 15 AU/ml. The response was 92% (127/138). Patient with history of prior COVID‐19 infection had higher antibody titer mean of 339 ± 113 versus 157 ± 140 for patient with no prior history of COVID‐19.Seven patients in both groups had COVID‐19 infection post vaccine. Among the responders, five patients had COIVD‐19 infection and two were hospitalized. These two patients had lower antibody titer of 23.9 and 75.2 AU/ml. In comparison, three patients who were not hospitalized had higher antibody titer 96.3, 118, and 319 AU/ml, respectively. In the non‐responders one patient was hospitalized and one death occurred with rate of infection of 18%.DiscussionSeropositive patients with low antibody titer might be associated with worse outcome among responders. The ideal antibody titer level among dialysis patient is not known. Also, prior COVID‐19 infection is associated with higher response to vaccine with higher antibody titer. All non‐responders did not have prior COVID‐19 infection. More research is required to further evaluated protective antibody titer.

Led astray by serology

A 27-year-old man of South Asian ethnicity presented with abdominal pain, nausea and constipation. Eight months earlier he had undergone myeloablative, haplo-identical, allogeneic stem cell transplantation (SCT) for acute lymphoblastic leukaemia. Immunosuppression had been stopped 4 months before presentation; he had continued prophylactic aciclovir, co-trimoxazole and phenoxymethylpenicillin. He was febrile and abdominal imaging revealed oedematous pancreatitis and non-obstructive cholecystitis. Despite fluids and antibiotics (co-amoxiclav, gentamicin), he deteriorated and two days later, a painless, non-pruritic rash emerged, spreading from the face to trunk and limbs. He also developed profuse diarrhoea, melaena and anaemia. His abdomen was soft with generalised tenderness and active bowel sounds. A diffuse rash affected face, trunk and limbs, sparing palms and soles. Lesions were dark, 1–4 mm haemorrhagic vesicles over an erythematous base. Pigmented, ulcerating lesions were noted over the hard palate. An endoscopy showed multiple gastric ulcers. Methylprednisolone was commenced for possible acute Graft-versus-Host Disease, and disseminated infection was treated empirically with piperacillin-tazobactam, ivermectin and aciclovir. Disseminated varicella zoster virus (VZV) infection was confirmed by identifying VZV viraemia and positive VZV PCR from lesion swabs. Pre- and post-SCT VZV IgG titres were > 150mIU/ml. There was CD4 + lymphopenia (56 x106/L). As no additional cause was identified, the pancreatitis and small bowel inflammation was felt most likely to be due to visceral reactivation of VZV. Take-home messages: 1. VZV reactivation may still occur despite aciclovir prophylaxis. 2. Immune reconstitution post-SCT is highly variable. 3. Seemingly adequate VZV IgG titres do not necessarily prevent infection if there is immunosuppression. Abstract without diagnosis A 27-year-old man of South Asian ethnicity presented with abdominal pain, nausea and constipation. Eight months earlier he had undergone myeloablative, haplo-identical, allogeneic stem cell transplantation (SCT) for acute lymphoblastic leukaemia. Immunosuppression had been stopped 4 months before presentation; he had continued prophylactic aciclovir, co-trimoxazole and phenoxymethylpenicillin.

Hepatitis B Vaccination in Advanced Chronic Kidney Disease: A Quality Improvement Project at a Veteran Affairs Chronic Kidney Disease Clinic.

Hepatitis B vaccination is recommended in all patients with end-stage kidney disease (ESKD). However, only 50–60% of these patients achieve protective antibody levels if immunized after starting dialysis. Strategies to overcome this low seroconversion rate include a 6-month vaccination schedule starting earlier [chronic kidney disease (CKD) stage 4 and 5] to ensure immunity when patients progress to ESKD. We conducted a quality improvement program to immunize pre-dialysis patients. Patients who were found to have a negative baseline serology with a negative hepatitis B surface antibody level (HBsAb) were offered vaccination on a 6-month schedule (0, 1 and 6 months) with one of two available vaccines within the VA system (Recombivax™ or Engerix™). HBsAb titers were checked 3–4 months later, and titers ≥ 12 mIU/mL were indicative of immunity at VA. Patients who did not seroconvert were offered a repeat schedule of three more doses. We screened 198 patients (187 males and 11 females) with CKD 4 and 5 [glomerular filtration rate (GFR) < 29 mL/min/1.73 m2]. The median age of this cohort was 72 years (range 38–92 years). During the study period of 5 years (2015–2020), 10 patients were excluded since their GFR had improved to more than 30 mL/min/1.73 m2, 24 others had baseline immunity and 2 refused vaccination. The hepatitis B vaccination series was not started on 106 patients. Of the remaining 56, 12 patients progressed to ESKD and started dialysis before completion of the vaccination schedule, 6 expired and 1 did not come to clinic in 2020 due to the pandemic. Of the 37 patients who completed the vaccination schedule, 16 achieved seroconversion with adequate HBsAb titers, 10 did not develop immunity despite a second hepatitis B vaccination series, while 11 did not get a second series. Given the low seroconversion rate, albeit in a small cohort, vaccination should be considered in patients with earlier stages of CKD. Other options include studies on FDA approved vaccines of shorter duration. We plan to increase awareness among nephrologists, patients and nursing staff about the importance of achieving immunity against hepatitis B.

Anti-HBs levels in children under the age of two years born to HBV carrier mothers after immunoprophylaxis: a multicenter cross-sectional study

BackgroundSerological testing for the presence of Hepatitis B Virus (HBV) markers and anti-HBs titers in infants born to HBsAg positive women is critically important for estimation in immunisation programme.MethodsThis was a multi-center and cross-sectional study conducted in Zhejiang province, China. Children aged 7 to 24 months born to HBsAg positive women during December 2018 to February 2019, completed additional HBV serological markers screening. We indicated distribution of HBV serological markers and anti-HBs titers in children. Multiple logistic regression model with adjusted odds ratio and 95% confidence interval (ORadj and 95% CI) was used to explore the factors associated with inadequate immune response (anti-HBs titers< 100 mIU/ml) among children.ResultsA total of 1849 children were included. Overall 25 children tested HBsAg positive, giving HBsAg positive rate of 1.35%(95%CI: 0.83-1.88%). 92.00% (23/25) HBsAg positive children were delivered by HBeAg positive mothers. The proportion of protective seroconversion (anti-HBs titers≥10mIU/ml) was 99.29% in all children, and 86.48% children were reported with adequate anti-HBs titers (≥100mIU/ml).We found a significant higher proportions of early antenatal health care (< 13 gestational weeks), and term birth in children with adequate response compared with inadequate response (all P < 0.05). Logistic regression showed preterm birth was a negative factor for inadequate anti-HBs titers (ORadj = 1.868,95%CI 1.132-3.085,P = 0.015).ConclusionsChildren delivered by HBeAg positive mothers had higher risk of vertical transmission of HBV, despite completion of 3 doses of hepatitis B vaccine and HBIG injection. Inadequate anti-HBs level was significantly associated with preterm birth in HBsAg positive women.

Evaluating Disease Threats to Sustainable Poultry Production in Africa: Newcastle Disease, Infectious Bursal Disease, and Avian Infectious Bronchitis in Commercial Poultry Flocks in Kano and Oyo States, Nigeria.

The growth of the poultry industry in Nigeria is constrained by major poultry diseases, despite the implementation of vaccination programs. This study aimed to assess the level of protection against Newcastle disease (ND), infectious bursal disease (IBD), and avian infectious bronchitis (IB) afforded by current vaccination schedules and characterize the circulating virus strains in commercial poultry flocks in Nigeria. A cross-sectional study was conducted on 44 commercial poultry farms in Oyo and Kano states of Nigeria. Serum and tissue samples and data on flock, clinical and vaccination records were collected on each farm. Farms were classified as being protected or not protected against ND, IBD and IB based on a defined criterion. Real-time reverse transcription polymerase chain reaction (rRT-PCR) testing was performed for each target virus on tissue samples and positive samples were sequenced. A total of 15/44 (34.1%), 35/44 (79.5%), and 1/44 (2.3%) farms were considered to be protected against ND, IBD, and IB, respectively, at the time of sampling. NDV RNA was detected on 7/44 (15.9%) farms and sequences obtained from 3/7 farms were characterized as the lentogenic strain. Infectious bursal disease virus (IBDV) RNA was detected on 16/44 (36.4%) farms tested; very virulent (vv) IBDV and non-virulent (nv) IBDV strains were both detected in 3/16 (18.8%) positive samples. Sequences of IBDV isolates were either clustered with a group of genotype 3 virulent IBDV strains or were related to vaccine strains MB and D78 strains. IBV RNA was detected on 36/44 (81.8%) farms, with variant02, Massachusetts, 4/91, and Q1 variants detected. Sequences of IBV isolates were either clustered with the vaccines strains Massachusetts M41 and H120 or were most closely related to the D274-like strains or a clade of sequences reported in Nigeria and Niger in 2006 and 2007. This study revealed that most study farms in Oyo and Kano states did not have adequate protective antibody titers against IBV and NDV and were therefore at risk of field challenge. Infectious bursal disease virus and IBV RNA were detected on farms with a history of vaccination suggesting potential vaccination failure, or that the vaccine strains used mismatch with the circulating strains and are therefore not protective.

Rubella immunity rates in women of childbearing age in an urban teaching hospital

Rubella is a highly contagious viral infection that can cause devastating effects on a growing fetus. Although rubella can be prevented with the measles, mumps and rubella (MMR) vaccine, some individuals have a weak immune response and do not sustain an adequate antibody titer to protect against the disease. MMR antibody titers are not routinely assessed in the general population, although healthcare professionals, military workers and pregnant women are commonly screened. This study aimed to investigate rubella immunity rates in primiparous women. The authors believed that the nonimmunity rate would be substantial enough to justify potential rubella immunity screening in all women of childbearing age at annual gynecologic exams prior to pregnancy. Findings recommend obtaining a rubella titer, as well as a measles titer, when women present for their first gynecological visit.

Maintenance of an Immunogenic Response to Pneumococcal Vaccination in Children With Sickle Cell Disease.

Patients with sickle cell disease (SCD) are at increased risk for invasive pneumococcal disease because of splenic dysfunction. To mitigate this risk, patients are protected with prophylactic penicillin until completion of pneumococcal vaccination series. The objective of this study was to assess the maintenance of a protective immune response to pneumococcal vaccination in children with SCD. A retrospective review was conducted between June 2019 and June 2020 of all patients with SCD patients for whom it had been 5±1 year since completion of PPSV23 vaccination series. A total of 41 patients were analyzed. The majority of children (68%) were able to maintain an adequate immune response. There was no identifiable disease characteristic associated with maintenance of an appropriate immunogenic response. This study finds that patients with SCD are able to maintain an adequate immune response at the 5±1 year time point from completion of PPSV23 vaccination series. Similarly, patients were not found to have an increased rate of invasive pneumococcal disease even if not meeting criteria for adequate pneumococcal serum titer levels. Maintenance of pneumococcal titers suggests that there may not be a need for revaccination at the 5-year time point in this patient population.

Negligible risk of rabies importation in dogs thirty days after demonstration of adequate serum antibody titer

Negligible risk of rabies importation in dogs thirty days after demonstration of adequate serum antibody titer

Post vaccination antibody titres of hepatitis B surface antigen (anti-HBs) in a mixed cohort of health care workers

BackgroundHepatitis B (HepB) is an important vaccine preventable infection among healthcare workers (HCWs). Vaccination against Hep B virus, remains the foremost preventive approach. This study aims to measure the antibody titres to Hep B surface antigen (anti-HBs) in a mixed cohort of HCWs. It also aims to study the association between time since vaccination and the anti-HBs titres thus evaluating the duration of seroprotection MethodsA total of 200 HCWs, including nursing students (n = 112), nursing staff (n = 49), laboratory technicians (n = 30) and doctors (n = 9) who had received all three doses of the Hep B vaccine and met the inclusion criteria of having taken all three doses of vaccine were included in this study. Anti-HBs titres were estimated by bioMérieux mini VIDAS® automated immunoassay based on the principle of enzyme-linked fluorescence assay. ResultsTwo hundred subjects aged 19 to 52 years were included in the study; mean age was 27.29 ± 0.568 years. Duration since vaccination in the study cohort was ≤ 5 years in 149 (74.5.0%), 6–10 years in 20 (10.0%) and >10 years in 31 (15.5%) subjects. Postvaccination antibody titres were > 100 mIU/ml in 85.0%, 10-100 mIU/ml in 11.0% and ≤ 10 mIU/ml in 3.5%. There was a decline noted in antibody titres as duration after vaccination increased. Increasing age was associated with falling protective titres. ConclusionThe study revealed that majority of the HCWs had adequate anti-HBs titres and were protected after vaccination.