Vaccine Antibody Titers Research Articles

Impaired SARS-CoV-2 mRNA Vaccine Antibody Response in Chronic Medical Conditions: A Real-World Analysis

Impaired SARS-CoV-2 mRNA Vaccine Antibody Response in Chronic Medical Conditions: A Real-World Analysis

Severe aplastic anemia after COVID-19 mRNA vaccination: Causality or coincidence?

The development of various autoimmune diseases has been reported after COVID-19 infections or vaccinations. However, no method for assessing the relationships between vaccines and the development of autoimmune diseases has been established. Aplastic anemia (AA) is an immune-mediated bone marrow failure syndrome. We report a case of severe AA that arose after the administration of a COVID-19 vaccine (the Pfizer-BioNTech mRNA vaccine), which was treated with allogeneic hematopoietic stem cell transplantation (HSCT). In this patient, antibodies against the SARS-CoV-2 spike protein were detected both before and after the HSCT. After the patient's hematopoietic stem cells were replaced through HSCT, his AA improved despite the presence of anti-SARS-CoV-2 antibodies. In this case, antibodies derived from the COVID-19 vaccine may not have been directly involved in the development of AA. This case suggests that the measurement of vaccine antibody titers before and after allogeneic HSCT may provide clues to the pathogenesis of vaccine-related autoimmune diseases. Although causality was not proven in this case, further evaluations are warranted to assess the associations between vaccines and AA.

S805 SARS-CoV-2 Vaccine Antibody Response in Patients With IBD

Introduction: Patients with inflammatory bowel disease (IBD) are often on immunosuppressive therapies which may reduce the immunologic response to the SARS-CoV-2 vaccine. At this time, there is limited data on vaccine response in patients on different therapies. Furthermore, the CDC does not recommend antibody testing to confirm immunity, and revaccination is not recommended. Methods: Our study evaluated antibody response measured by a quantitative IgG antibody to the spike antigen of SARS-CoV-2 via ELISA in a group of 73 vaccinated IBD patients who have undergone or are receiving infusions of vedolizumab, infliximab, and ustekinumab, or a combination of multiple biologics. All patients have received the 2-dose vaccination and must have completed them for minimum 2 weeks or longer before testing. Statistical analysis was performed by segmenting the patient population into two subgroups of normal ( >20 U/mL) and abnormal (< 20 U/mL) titer levels. Independent T-tests were then performed on specific patient characteristics, inflammatory markers, and medications to determine statistical significance. Results: Responses greater than 20 IU/mL were considered normal responses. Patients older than age 50 were more likely to have abnormal antibody titers after vaccination. There were no differences in antibody response when comparing patients on different biologics including those that were on more frequent dosing (q4 week injections/ infusions vs q8 weeks, or between ulcerative colitis (UC) vs. Crohn’s disease (CD), or in those with biomarker evidence of active disease based on erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) (See Table 1). None of these patients, including those with abnormal titer levels developed COVID infection after vaccination. Conclusion: In our study, it was found that only age was a statistically significant predictor among our immunosuppressed IBD patients for antibody response levels. Importantly, even more aggressive combination biological therapies did not appear to affect antibody response in our patient population. Lastly, inflammatory markers and presumably disease activity, did not appear to have a statistically significant impact on antibody response. More studies will be needed to further assess if there is clinical utility in evaluating for vaccine antibody titers in our IBD patients.Table 1.: Healthcare Utilization by Employment Status and Insurance (UCSF) Colitis and Crohn’s Disease Center at University of California San Francisco (ZSFG) Zuckerberg San Francisco General Hospital and Trauma Center (ACA) Affordable Care Act

Tolerance and humoral immune response to the yellow fever vaccine in sickle cell disease children treated with hydroxyurea: a multicentre prospective study

Sickle Cell Disease (SCD) children are frequent travellers to countries where Yellow Fever (YF) is endemic, but there are no data regarding the safety and immunogenicity of the vaccine in such children treated with hydroxyurea (HU). The main objective of this study was to compare the tolerance and immune response to YF vaccination in SCD children treated or not with HU. SCD Children < 18years attending the international travel clinics of three large paediatric centres and requiring a first YF vaccination were included in a prospective study. Adverse events were collected 2weeks after vaccination. YF vaccine antibody titres were measured approximately 6months after vaccination. Among the 52 SCD children vaccinated against YF, 17 (33%) were treated with HU. Only mild adverse events, mainly fever and local reaction, were observed in the HU group with a similar frequency in the non-HU group (57% and 35%, respectively, p = 0.30). YF antibody titres were measured in 15/17 patients in the HU group and 23/35 patients in the non-HU group after a median of 6.0months (3.5-8.5) following vaccination. The geometric mean of YF antibody titre was similar in both groups. A protective antibody level was observed in 85% of the children in the HU group versus 100% in the non-HU group (p = 0.14), suggesting a lower effectiveness of the vaccine in patients on HU similarly to what has been described in patients on immune suppressive therapy for other vaccines. YF vaccination seems to be safe and efficient in SCD children treated with HU. Considering the potential risk of severe complications in cases of YF while travelling in Africa for those patients, the benefit-to-risk ratio argues for YF vaccination in all SCD children. Control of a protective antibody titre may also be useful to ascertain an adequate response in those treated with HU.

Effectiveness of the Quadrivalent HPV Vaccine in Preventing Anal ≥ HSILs in a Spanish Population of HIV+ MSM Aged > 26 Years.

Anal squamous cell carcinoma is the most frequent virus-related non-AIDS-defining neoplasia among HIV-infected individuals, especially MSM. The objectives of this study were to analyze the effectiveness of the quadrivalent HPV (qHPV) vaccine to prevent anal ≥ high-grade squamous intraepithelial lesions (≥HSILs), external ano-genital lesions (EAGLs), and infection by qHPV vaccine genotypes in HIV+ MSM, and to study the immunogenicity of the vaccine and risk factors for ≥ HSILs. This study is nested within a randomized, double-blind, placebo-controlled trial of the qHPV vaccine, which enrolled participants between May 2012 and May 2014, with a 48-month follow-up. A vaccine or placebo was administered at 0, 2, and 6 months, and vaccine antibody titers were evaluated at 7, 12, 24, 36, and 48 months. Data were gathered at 12, 24, 36, and 48 months on sexual habits, CD4/CD8 cell/counts, HIV viral load, and the results of cytology (Thin Prep® Pap Test), HPV PCR genotyping (Linear Array HPV Genotyping Test), and high-resolution anoscopy (Zeiss 150 fc© colposcope). The study included 129 patients (mean age of 38.8 years, 40 [31%] with a history of AIDS, 119 [92.2%] receiving ART, and 4 [3.3%] with virological failure), 66 (51.2%) in vaccine arm and 63 (48.4%) in placebo arm. The vaccine and placebo groups did not differ in ≥ HSILs (14.1 vs. 13.1%, respectively, p = 0.98) or EAGL (11.1 vs. 6.8%, p = 0.4) rates during follow-up; however, a protective effect against HPV 6 was observed during the first year of follow-up in the vaccine versus placebo group (7.5% vs. 23.4%; p = 0.047). A between-arm difference (p = 0.0001) in antibodies against qHPV vaccine genotypes was observed at 7 months (76.9% in vaccine arm vs. 30.2% in placebo arm), 12 months (68.1% vs. 26.5%), 24 months (75% vs. 32.5%), 36 months (90% vs. 24.4%), and 48 months (87.2% vs. 30%). Finally, the factor associated with the risk of anal ≥ HSIL onset during the four-year follow-up was the receipt of the last dose of the vaccine less than 6 months earlier in comparison to those vaccinated for a longer period (82.4% vs. 17.6% (OR 0.869 [95% CI, 0.825–0.917]). Vaccine and placebo arms did not significantly differ in ≥ HSIL or EAGL rates or in protection against infection by HPV genotype vaccine except for HPV6 at 12 months after the first dose. A long-lasting immune response was observed in almost all the vaccinated men. The main protective factor against ≥ HSIL was to have completed the vaccination regimen more than 6 months earlier.

Hepatitis B virus prevalence and vaccine antibody titers in children HIV exposed but uninfected in Botswana.

Botswana introduced the HBV vaccine at birth for all newborns in 2000. To the best of our knowledge, since the introduction of HBV vaccination, there have been limited data for vaccine response to HBV and its impact on early childhood HBV infections among children HIV exposed but uninfected in Botswana. To determine the prevalence of hepatitis B surface antigen (HBsAg) and HBV vaccine response in 18 months old children HIV exposed but uninfected in Botswana. Stored plasma samples from 304 children at 18 months of age and 287 mothers from delivery were tested for HBsAg. Mothers with positive HBsAg had HBV DNA level tested, and their HBV genotypes were determined by amplifying a 415-base pair (bp) region of the surface gene. Plasma samples from children exposed to HIV were tested for hepatitis B surface antibody (anti-HBs) titers. No children (0 of 304) were positive for HBsAg at 18 months while 5 (1.74%) of 287 HIV-positive mothers were HBsAg positive. Four of the HBsAg positive mothers were infected with genotype A1, while 1 was infected with genotype E. The median anti-HBs titer in children was 174 mIU/mL [QR: 70, 457]. Three (1.1%) of 269 children had an inadequate vaccine response (<10 mIU/mL), while 266 (98.9%) of 269 had protective immunity. However, when using the ≥100mIU/mL threshold, only 170 (63.2%) of 269 children had complete protection. No HBsAg positivity was identified in a cohort of children HIV exposed but uninfected. The absence of HBsAg positives was associated with good HBV vaccine responses and low maternal HBsAg prevalence in Botswana.

Rabies in Eswatini: What are the Issues and Challenges?

National efforts to control canine rabies have encountered some challenges, hence the disease is becoming endemic in Eswatini. The purpose of this study was to establish the extent to which resources and other relevant constraints may have an impact on implementing the national rabies programms in the country. In this study retrospective data going as far back as 1999 to 2018 was used to highlight the rabies situation in the country. The available insight into the existing and previous control measures may become useful guidelines for designing and implementing future control strategies.&#x0D; The major challenges identified were issues of vaccine and vaccination, government fiscal challenges, High birth rate of stray dogs were responsible for the rabies virus circulation in the domestic environment, provision of diagnostic facilities for testing of vaccine efficacy, vaccine quality, healthy dog carriers, check for vaccination antibody titres.&#x0D; Observations from this study were that the continuing efforts of the competent authority to spearhead the rabies control programms were acceptable and commendable considering the challenges encountered. A few recommendations are outlined for possible consideration as a contribution towards the rabies disease elimination.

EPR20-073: The Effects of Chemotherapy on the Efficacy of Pneumococcal Vaccination Using Pneumococcal Vaccine Antibody Titers as Correlate

EPR20-073: The Effects of Chemotherapy on the Efficacy of Pneumococcal Vaccination Using Pneumococcal Vaccine Antibody Titers as Correlate

Will We Have a Cohort of Healthcare Workers Full Vaccinated against Measles, Mumps, and Rubella?

Healthcare workers are a population exposed to several infectious diseases, and an immunization programme is essential for the maintenance of good vaccination coverage to protect workers and patients. A population of 10,653 students attending degree courses at Padua Medical School (medicine and surgery, dentistry and health professions) was screened for vaccination coverage and antibody titres against rubella, mumps, and measles. The students were subdivided into five age classes according to their date of birth: those born before 1980, between 1980 and 1985, between 1986 and 1990, between 1991 and 1995, and after 1995. Vaccination coverage was very low in students born before 1980, but the rate of positive antibody titre was high due to infection in infancy. Increasing date of birth showed increased vaccination coverage. In contrast, immune coverage was high for rubella (more than 90%) but not for mumps and measles (approximately 80%). An “anomaly” was observed for mumps and measles in the cohort born between 1991 and 1995, probably due to the trivalent vaccine formulation. Students born after 1990 showed vaccination coverage that exceeded 90%. It is therefore very likely that we will have a future generation of healthcare workers with optimal vaccination coverage.

Cardiopulmonary Bypass and Infant Vaccination Titers.

Infants with congenital heart disease remain vulnerable to potentially preventable pathogens. Although immunization can significantly reduce this risk, it is unknown how immunization status can be affected by cardiac surgery with cardiopulmonary bypass (CPB). The objective was to evaluate the effect of CPB on infant vaccination status after cardiac surgery. We conducted a prospective observational study of patients between 2 and 14 months of age who had received at least their first round of infant vaccinations and who required cardiac surgery with CPB. Antibody titers were measured before CPB and again the following morning. Demographic and surgical variables were assessed via regression methods for their effects on the change in titers. Among the 98 patients followed, there was no demonstrated difference between the pre- and postoperative values in regard to diphtheria, tetanus, polio 1, polio 3, or Haemophilus influenzae titers. Bordetella (1.03 vs 0.84, P < .001), and hepatitis B (log 2.10 vs 1.89, P = .001) titers did reduce after CPB but did not fall below the immunized threshold. Changes in antibody titers were not associated with time between immunization and surgery, age or weight at surgery, blood products administered, number of previous doses, time on CPB, or heterotaxy diagnosis for most of the vaccines. Infant vaccine antibody titers were minimally affected by CPB and not associated with any easily modifiable surgical variables. Although antibody titers are only 1 marker of immunity, deviation from the recommended vaccination schedule may be unnecessary for children requiring congenital heart surgery.

Multi-Level Model to Predict Antibody Response to Influenza Vaccine Using Gene Expression Interaction Network Feature Selection.

Vaccination is an effective prevention of influenza infection. However, certain individuals develop a lower antibody response after vaccination, which may lead to susceptibility to subsequent infection. An important challenge in human health is to find baseline gene signatures to help identify individuals who are at higher risk for infection despite influenza vaccination. We developed a multi-level machine learning strategy to build a predictive model of vaccine response using pre−vaccination antibody titers and network interactions between pre−vaccination gene expression levels. The first-level baseline−antibody model explains a significant amount of variation in post-vaccination response, especially for subjects with large pre−existing antibody titers. In the second level, we clustered individuals based on pre−vaccination antibody titers to focus gene−based modeling on individuals with lower baseline HAI where additional response variation may be predicted by baseline gene expression levels. In the third level, we used a gene−association interaction network (GAIN) feature selection algorithm to find the best pairs of genes that interact to influence antibody response within each baseline titer cluster. We used ratios of the top interacting genes as predictors to stabilize machine learning model generalizability. We trained and tested the multi-level approach on data with young and older individuals immunized against influenza vaccine in multiple cohorts. Our results indicate that the GAIN feature selection approach improves model generalizability and identifies genes enriched for immunologically relevant pathways, including B Cell Receptor signaling and antigen processing. Using a multi-level approach, starting with a baseline HAI model and stratifying on baseline HAI, allows for more targeted gene−based modeling. We provide an interactive tool that may be extended to other vaccine studies.

Different Regimes for Challenge Instigation against Newcastle Disease Virus in Layer Birds

Newcastle disease is a highly contagious disease of poultry and causes huge economic loss in Bangladesh. In the study, the efficacy of different vaccination programs against Newcastle disease virus was performed to examine duration and level of antibody in two layer farms with different diluents. The experiment was carried out in Dinajpur district and serological test was performed in the Department of Microbiology, Hajee Mohammad Danesh Science and Technology University, Dinajpur during the period of July, 2017 to December, 2017. A total of 200 blood samples were randomly collected from different age groups of layer birds which were vaccinated with commercially available two live and one killed vaccine namely Avi ND LaSota, CEVAC NEW L and ITA-New (ND). Pre-vaccination serum antibody titers (Mean ± SD) of group A birds were 5.97±0.75. Firstly, birds were vaccinated with Avi ND LASOTA® vaccine, and CEVAC® NEW L vaccine. MASTERBLUE powder and ADVANCE NON-FAT were used as diluents in vaccination. After 40 days of post-vaccination, sera samples were procured and showed serum antibody titer (Mean ± SD) 7.0 ± 0.93. In case of farm-B, before vaccination antibody titers levels against NDV were Mean ± SD 5.85±0.75. Birds of farm-B were vaccinated with Avi ND LaSota® vaccine. After 40 days of post-vaccination, titer was Mean ± SD 6.7 ± 0.93. Then birds were vaccinated with ITA-New (ND) ® which were killed vaccine. After 40 days of post-vaccination, the titer was Mean ± SD 8.15± 0.93. MASTERBLUE powder and ADVANCE NON-FAT are suitable diluents to be used in vaccination against Newcastle disease because tap water may inactivate the vaccine due to its impurity in addition to containing higher level of chlorine and even the type of pipes or vessels used to distribute the drinking water. The results showed that the level of protection of vaccinated birds was satisfactory.

In Search of Factors Negatively Affecting Vaccine Immunity to Pertussis in Preschool Children Before the Administration of the First Booster.

Introduction: The top priority for active immunoprophylaxis of pertussis is the immunisation of infants as they can sometimes develop severe multiple-organ complications. Objectives: The aim of the work is the identification of factors negatively affecting vaccine immunity to pertussis in preschool children prior to the administration of the first booster. Patients and Methods: The research was conducted on 352 children from 4.5 to 5.9 years of age who were hospitalised in the University Children’s Hospital in Lublin (Poland) from 1 January 2012 to 31 December 2015. The children taking part in the study had been administered all the mandatory vaccines from their birth to the age of 2 or 2.5 years old according to the Polish Immunisation Program 2008–2009. The immunoenzymatic method ELISA (enzyme-linked immunosorbent assay) was applied to assess vaccine immunity to tetanus, diphtheria, pertussis, Haemophilus influenzae type b (Hib), poliomyelitis (IPV), mumps, rubella and measles. The level of vaccine antibodies to hepatitis type B was determined chemilumiscently. Results: The protective antibody titre was not found in 41 (11.65%) children before the administration of the booster. To verify the collective impact of parameters analysed on antibody titre to pertussis, the Generalized Linear Model (GLZ) was used. Gender, type of vaccine, asthma, Hib and mumps antibody titres have been shown to be predictors of vaccine immunity to pertussis. Conclusions: Immunomodulation considered on the example of titre of IgG antibody to pertussis can serve as a useful model of the assessment of development of acquired immunity after mandatory vaccinations.

Influence of delayed sample processing on blood immune cell phenotypes, immune cell responses and serum anti-influenza vaccine antibody titres

Provision of blood from distant research partners to a central laboratory can result in delayed blood processing prior to assessment of immune parameters. It is important to evaluate the effect of such delays on immune parameters. This study investigated the effect of storage of blood at room temperature for up to 72 h prior to processing and analysis on a range of immune parameters. Blood was collected from 10 healthy participants and analysed immediately (day 0) or after storage at room temperature for 24, 48 or 72 h (days 1, 2 and 3). A full blood count, immune cell phenotypes (flow cytometry), plasma cytokines, chemokines and soluble receptors (multiplex immunoassay), neutrophil and monocyte phagocytosis (flow cytometry), whole blood cytokine responses to stimulation and antibody titres to the seasonal influenza vaccine were assessed. The full blood count, most immune cell phenotypes, monocyte phagocytosis and anti-influenza vaccine antibody titres were little affected by blood storage of ≤72 h prior to processing. Plasma cytokine concentrations increased with blood storage time while whole blood responses to stimulation with lipopolysaccharide or phytohaemagglutinin decreased with blood storage time. In conclusion, while fresh blood is optimal for analysing human immune parameters, it is possible to store blood for up to 72 h at room temperature and obtain reliable measures of several immune markers. However, plasma cytokines and related mediators as well as whole blood cultures should be analysed using freshly isolated blood. Storage of blood for longer than one day may result in the unreliable assessment of these outcomes.

25-hydroxyvitamin D, influenza vaccine response and healthcare encounters among a young adult population.

BackgroundInfluenza causes significant morbidity and mortality; the pandemic in 2009–2010 was a reminder of the potential for novel strains and antigenic changes. Studies have shown that vitamin D deficiency may be associated with poor vaccine immunogenicity, therefore we sought to determine if there was a correlation between 25-hydroxyvitamin D [25(OH)D] and influenza vaccine response.MethodsA retrospective observational study was conducted among young, healthy military members to evaluate the association between total 25(OH)D levels with post influenza vaccination antibody titers and healthcare encounters during the 2009–10 influenza season. Univariate analyses were performed to evaluate whether 25(OH)D levels are associated with baseline characteristics and post-vaccination antibody responses. Multivariable logistic regression models were utilized to determine the associations between antibody responses and 25(OH)D levels adjusting for possible confounders.ResultsA total of 437 subjects were studied. Most participants were young adults (91% were 18–39 years of age), 50% were male, and 56% resided in the southern U.S. Overall, 152 (34.8%) were vitamin D deficient, 167 (38.2%) insufficient, and 118 (27.0%) with normal 25(OH)D levels. There were no demographic differences by 25(OH)D category. Only 224 (51.3%) demonstrated a seroprotective anti-influenza post-vaccination titer, which did not vary by categorical 25(OH)D levels [vitamin D deficient vs. normal: OR 1.10 (0.68–1.78) and insufficient vs. normal: OR 1.25 (0.78–2.01)] or continuous vitamin D levels [OR 0.98 (0.84–1.15)]. There were also no associations with increased influenza like illnesses, respiratory diagnoses and healthcare encounters between the vitamin D groups.ConclusionVitamin D insufficiency and deficiency were highly prevalent despite evaluating a young, healthy adult population. There were no significant associations between 25(OH)D levels and post-vaccination antibody titers to influenza vaccine. Further studies are required to discover strategies to improve vaccine efficacy as well as to determine the role of 25(OH)D in vaccine immunity.

Vaccination Status and Antibody Titers against Rubella and Measles among Japanese Female College Students Majoring in Childcare between 2015 and 2018

In 2014, for the protection of medical workers against measles and rubella infection, the Japanese Society for Infection Prevention and Control (JSIPC) recommended either maintaining antibody titers of seroprotective range or two-dose vaccination. JSIPC defined antibody titers into 3 ranges: seroprotective as expected prevention of infection, seronegative as under detection levels, and seropositive as antibody titers ranged between seronegative and seroprotective. This study aimed to explore the association between the number of vaccine doses received and the antibody titers against measles and rubella among Japanese college students majoring in childcare. A total of 841 female students with no history of measles or rubella were serologically screened at the time of college admission between 2015 and 2018. All 841 students had been vaccinated against measles; 738 (87.8%) received two doses of the measles vaccine and 103 (12.2%) received one dose. Likewise, 839 students, except for two, had been vaccinated against rubella; 719 (85.7%) received two doses of the rubella vaccine and 120 (14.3%) received one dose. We thus found that 107 students (12.7%) were seropositive for measles-specific IgG and 731 (86.9%) attained seroprotective titers. By contrast, in case of rubella-specific IgG, only 462 students (55.1%) attained seroprotective titers, and 371 students (44.1%) were seropositive. The two students without receiving rubella vaccination were classified as seronegative. In conclusion, despite that > 85% of students surveyed had received two doses of measles and rubella vaccines, a substantial number of students remain susceptible to measles and especially rubella at the time of college admission.

Safety and immunogenicity of the quadrivalent human papillomavirus (qHPV) vaccine in HIV-positive Spanish men who have sex with men (MSM)

BackgroundSafety and immunogenicity of the quadrivalent human papillomavirus (qHPV) vaccine were evaluated in HIV-positive Spanish MSM. The prevalence of High Squamous Intraepithelial Lesions (HSIL) and genotypes of high-risk human papillomavirus (HR-HPV) were also determined, as well as risk factors associated with the presence of HR-HPV in anal mucosa.MethodsThis is a randomised, double blind, placebo-controlled trial of the quadrivalent HPV (qHPV) vaccine. The study enrolled from May 2012 to May 2014. Vaccine and placebo were administered at 0, 2 and 6 months (V1, V2, V3 clinical visits). Vaccine antibody titres were evaluated at 7 months. Cytology (Thin Prep® Pap Test), HPV PCR genotyping (Linear Array HPV Genotyping Test), and high-resolution anoscopy (Zeiss 150 fc© colposcope) were performed at V1.ResultsPatients (n = 162; mean age 37.9 years) were screened for inclusion; 14.2% had HSIL, 73.1% HR-HPV and 4.5% simultaneous infection with HPV16 and 18. Study participants (n = 129) were randomized to qHPV vaccine or placebo. The most common adverse event was injection-site pain predominating in the placebo group [the first dose (83.6% vs. 56.1%; p = 0.0001]; the second dose (87.8% vs. 98.4%; p = 0.0001); the third dose (67.7% vs. 91.9%; p = 0.0001). The vaccine did not influence either the viral load of HIV or the levels of CD4. Of those vaccinated, 76% had antibodies to HPV vs. 30.2% of those receiving placebo (p = 0.0001). In the multivariate analysis, Older age was associated with lower HR-HPV infection (RR 0.97; 95% CI 0.96–0.99), and risk factor were viral load of HIV >200 copies/µL (RR 1.42 95% CI 1.17–1.73) and early commencement of sexual activity (RR 1.35; 95% CI 1.001–1.811).ConclusionsThis trial showed significantly higher anti-HR-HPV antibody titres in vaccinated individuals than in unvaccinated controls. There were no serious adverse events attributable to the vaccine. In our cohort, 1 of every 7 patients had HSIL and the prevalence of combined infection by genotypes 16 and 18 was low. This suggests that patients could benefit from receiving qHPV vaccine. Older age was the main protective factor against HR-HPV infection, and non-suppressed HIV viremia was a risk factor.Clinical trial registration: ISRCTN14732216 (http://www.isrctn.com/ISRCTN14732216).

Are Higher Vitamin D Levels Associated with Improved Influenza Vaccine Immunogenicity and Fewer Healthcare Encounters for Respiratory Infections among Young Adults?

BackgroundInfluenza continues to cause significant morbidity and mortality each year. Vaccination is the primary prevention; however, its effectiveness may be limited even among young, healthy adults. Vitamin D deficiency is highly prevalent and may be associated with poor vaccine immunogenicity and an increased risk for respiratory infections.MethodsWe conducted a retrospective cross-sectional study among young, healthy military personnel to evaluate the associations between 25(OH)D levels with post-influenza vaccination antibody titers (seroprotection defined as a titer of ≥1:40 post-vaccination) and healthcare encounters for respiratory infections during the 2009–2010 influenza season. 25(OH)D levels were analyzed as continuous and categorical [normal (>30 ng/mL), insufficient (20–30 ng/mL), and deficient (<20 ng/mL)] variables. Separate univariate and multivariable logistic regression models were utilized to determine the associations between 25(OH)D levels with antibody responses and respiratory conditions adjusting for possible confounders.ResultsA total of 437 subjects were evaluated. Most participants were young adults (91% were 18–39 years of age), 50% were male, and 56% resided in the southern U.S. Overall, 152 (35%) were vitamin D deficient, 167 (38%) insufficient, and 118 (27%) had normal 25(OH)D levels. There were no demographic differences by 25(OH)3 category. Only 224 (51%) demonstrated a seroprotective anti-influenza post-vaccination titer, which did not vary by categorical 25(OH)D levels [vitamin D deficient vs. normal: OR 1.10 (0.68–1.78) and insufficient vs. normal: OR 1.25 (0.78–2.01)] or continuous vitamin D levels [OR 0.98 (0.84–1.15)]. There were no associations with respiratory diagnoses between the vitamin D groups.ConclusionVitamin D insufficiency and deficiency were highly prevalent despite evaluating a young, healthy adult population. There were no significant associations between 25(OH)D levels and post-vaccination antibody titers or respiratory infections. Strategies for improving influenza vaccine responses are needed since only one-half of vaccinees demonstrated seroprotective anti-influenza titers.Disclosures All authors: No reported disclosures.

Decreased vaccine antibody titers following exposure to multiple metals and metalloids in e-waste-exposed preschool children

We explored acquired immunity resulting from vaccination in 3 to 7-year-old children, chronically exposed to multiple heavy metals and metalloids, in an e-waste recycling area (Guiyu, China). Child blood levels of ten heavy metals and metalloids, including lead (Pb), arsenic (As), mercury (Hg), chromium (Cr), cadmium (Cd), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn) and selenium (Se), and seven vaccine antibodies (diphtheria, pertussis, tetanus, hepatitis B, Japanese encephalitis, polio, measles) were measured. The exposed group had higher levels of blood Pb, Mn, Cu, Zn and Cr compared to the reference group (P < 0.05). Levels of all vaccine antibodies in the exposed group were significantly lower than in the reference group (P < 0.01). All vaccine antibodies negatively correlated with blood concentrations of Cu, Zn and Pb, based on spearman rank correlation analysis. Multiple logistic regression and univariate analyses identified the location of residence (Guiyu), high blood Pb (>10 μg/dL) and high blood Cu and Zn (upper median value of each group) to be inversely associated with seven antibody titers. Antibody titers increased with age, BMI, high blood Mn (>15 μg/L), and high blood Cd and Ni (upper median value of each group). Results suggest multiple heavy metal and metalloid exposure, especially to Pb, Zn and Cu, may be a risk factor inhibiting the development of child immunity, resulting in decreased child antibody levels against vaccines.

Investigating the potential role of vitamin E in modulating the immunosuppressive effects of tylvalosin and florfenicol in broiler chickens

Tylvalosin (TVS) is a third-generation macrolide drug used for prophylaxis and treatment of mycoplasma, however; it is supposed to possess an immunosuppressive effect. In the current study, the immunosuppressive effect of TVS and florfenicol (FFC) and the potential immunomodulatory role of Vit E were investigated. The experiment included one day old chick groups treated with either TVS, FFC, Vit E, TVS/Vit E, FFC/Vit E and control non-treated group. Chicks were vaccinated with inactivated H9N2 avian influenza (AI) vaccine and humoral antibody titers to viral antigen as well as innate immunity (serum lysozyme activity and nitric oxide levels) were evaluated. Total and differential leucocytic counts, serum liver enzymes level, blood leucocytic DNA damage and cellular area percentages within the lymphoid organs were also screened. Treatment with TVS and FFC significantly decreased immune response of chickens while treatment with Vit E improved the humoral immune response at 4 and 5weeks post-vaccination. Vit E also significantly increased the cellular immune response. The combination of Vit E with either TVS or FFC modulated their immunosuppressive effect and resulted in mild immunostimulatory effects. TVS alone induced a genotoxic effect on chickens' blood leucocytes and the genotoxicity was inhibited by combination of TVS with Vit E. Histopathology revealed that chickens treated with either TVS or FFC exhibited toxic effect on the lymphatic tissues.