Protective Antibody Titers Research Articles

Antitetanus toxoid antibodies in mothers and neonates: a single-centre study from Uganda

BackgroundNeonatal mortality due to tetanus persists in Uganda despite the mandatory vaccination of pregnant mothers. Maternal antibodies wane within a year. Uganda’s maternal vaccination guidelines do not specify the timing...

Evaluation of Antibody Titre in Dogs Vaccinated against Canine Parvovirus in Jos, Plateau State, Nigeria

Canine parvoviral enteritis is a highly contagious disease with fatal outcomes, in most cases populations with high morbidity and mortality rate. The study was conducted to determine the immune status of dogs vaccinated against Canine Parvovirus (CPV) using enzyme linked immunosorbent assay (ELISA). Sixty randomly selected dogs were used for the study, out of which four had no level of determined antibody titre (1-2 S – unit), fifty six had protective immunity (3-6 S-unit) which comprised 24 (40%) males and 36(60%) females. Among the males, 23(95.83%) were protective while 33(91.67%) among the females were protective. A total of 17 dogs were puppies and all had protective immunity (3-6 S-unit) while 43 were adults out of which 39 (90.70%) had protective immunity (3-6 S-unit). A total of 30 dogs were sampled from each local government area out of which 28(93.33%) had protective immunity (3-6 S unit) in each local government. The breeds included in the study were Caucasian, Mongrel, Rottweiler, Lhasa, Bull mastiff and German Shepard out of which all had protective immunity 56(93.33%) (3-6 S-unit) except 4(6.67%) for Caucasian that were unprotected. Based on the number of primary vaccinations, 3 dogs had single, 4 dogs had double and 52 dogs had triple primary vaccination out of which 56 dogs had protective antibody titre (3-6 S-unit). There was no significant difference (P>0.05) between sex, age, location, breeds and level of immunity while there was a significant difference (P< 0.05) between the number of primary vaccination and immune titre of the dogs sampled

Clinical assessment of a point-of-care assay to determine protective vaccinal antibody titers to canine viral diseases

Guidelines recommend that dogs are vaccinated for canine distemper virus (CDV), canine parvovirus (CPV), and canine adenovirus (CAV) every 3 years. Alternatively, their antibody titers are measured and vaccines given when titers fall below a protective threshold. In this study, a point-of-care (POC) assay was compared to hemagglutination inhibition (for CPV) and virus neutralization (for CAV and CDV) assays to predict the need for revaccination Ninety-two dogs presented for vaccination were enrolled. The POC assay indicated protective titers against CDV in 79/80, CPV in 89/90, and CAV in 91/91 dogs with reference standard antibody measurements that were over a protective threshold. The sensitivity of the POC assay for to detect protective concentrations of CDV antibodies was 99% (95% confidence interval [CI 95%], 93.3–99.9%). Ten dogs were falsely considered protected against CDV by the POC assay with a specificity of 17% (CI 95%, 3.0–44.8%). The sensitivity of the POC assay for protective concentrations of CPV titers was 99% (CI 95%, 93.9–99.9%). The sensitivity of the POC assay to detect protective concentrations of CAV antibodies was 100% (CI 95%, 95.9–100%). Only classifying high-positive CDV and CPV titers on the POC assay as protective improved assay specificity to 100%, but sensitivity decreased to 51% and 76% respectively. This POC assay had a high sensitivity for the detection of protective antibody titers; however, some dogs were falsely categorized as protected, especially for CDV.

Protection of Khaki Campbell Ducks against Duck Plague Using an Inactivated Duck Plague Vaccine

Duck plague (DP) or duck viral enteritis is a fatal viral disease of ducks that causes huge economic losses in the duck industry. The present study was performed to determine the immune response and protective efficacy of an inactivated DP vaccine prepared from a local virulent DP virus. A virulent DP virus was obtained from the laboratory repository of the Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh (Bangladesh). The DP virus (EID50 105.3/ml) was inactivated using 0.04% formalin. The alum (40 g/L) was added to the inactivated DP virus as an adjuvant. A total of 60 Khaki Campbell male ducks aged 17 weeks were randomly divided into three groups. Ducks of groups A (n = 20) and B (n = 20) were vaccinated intramuscularly in the breast muscle with 1 ml of inactivated DP vaccine and a live attenuated DP vaccine, respectively. Ducks of group C (n = 20) were kept as unvaccinated control. Booster vaccination was administered at 2 weeks after primary vaccination. Antibody titers of vaccinated ducks were measured at 7, 14, 21, and 28 days post-vaccination (DPV) using a passive haemagglutination (PHA) test. Ducks of both vaccinated and unvaccinated groups were challenged with 1 ml virulent DP virus (EID50 104.3/ml) at 28 DPV. Clinical signs, morbidity and mortality, and gross pathological lesions of vaccinated and control ducks were observed for 10 days post-challenge to evaluate the protective efficacy of inactivated DP vaccine. The mean PHA antibody titers of vaccinated ducks of group A at 7, 14, 21, and 28 DPV were 5 ± 0.43, 26 ± 1.71, 43 ± 3.4, and 54 ± 3.28, respectively. Ducks in group B had mean serum PHA antibody titers of 21 ± 1.71, 41 ± 3.28, 52 ± 3.41, and 84 ± 7.25 at 7, 14, 21, and 28 DPV, respectively. No mortality or gross pathological lesions were observed in vaccinated ducks after they were subjected to a challenge infection. Additionally, no significant difference was observed between groups A and B in terms of the challenge infection. The mortality rate of the control group of ducks was 70%. Hemorrhage in the trachea and intestine and necrotic foci in the liver were seen in unvaccinated control ducks (group C). Experimentally developed inactivated DP vaccine induced a protective serum antibody titer and conferred 100% protection against virulent challenge infection up to 10 days observation period.

Effect of Aging on the Immune Response to Core Vaccines in Senior and Geriatric Dogs.

Elderly dogs are steadily increasing worldwide as well as veterinarians' and owners' interest in their health and wellness. Aging is not a disease, but a combination of changes negatively affecting the organism in general and the immune system in particular, resulting in a decline in protection over time. The aim of this study was to measure the specific serum antibody titers against the main dangerous and widespread viral diseases preventable by core vaccinations in senior and geriatric dogs using the in-practice test VacciCheck. A cohort of three hundred fifty elderly dogs was analyzed for Protective Antibody Titers (PATs) against CPV-2, CDV and CAdV-1. The age ranged from 5 to 19 years, with two hundred fifty-eight seniors (73.7%) and ninety-two geriatrics (26.3%), and 97.4% of them were vaccinated at least once in their lives. More than half of the entire study population (52.9%) had PATs simultaneously for all three diseases, with 80.5% seniors and 19.5% geriatrics. Specific PATs were found in 88.6% of aging dogs for CPV-2, 82.3% for CadV-1 and 66.0% for CDV, demonstrating that unprotected aging dogs represent a minority. Unexpectedly, the larger elderly dogs resulted as more protected than smaller ones for CPV-2. Protection then decreases over time, with geriatric dogs less protected than senior ones. Veterinary practitioners should therefore always consider whether to maintain core vaccinations in aging dogs as in adults on a three-year basis or opt instead for closer boosters (every 1 or 2 years). PATs for core vaccines could then represent a good biomarker of protection and their titration could become a standard of care, especially in such a sensitive period of the dogs' life.

Assessment of the humoral immune response in children after immunization with different types of inactivated influenza vaccines in the 2019-2020 season

Causing millions of cases worldwide every year, influenza is one of the most common respiratory infections. The effectiveness of influenza vaccination and the nature of the resulting immune response may vary depending on the vaccine composition and age group. Since children are at the highest risk of disease and act as the main carriers of influenza, the assessment of the immunological efficacy of vaccines in this group is crucial for controlling the epidemic. Therefore, this study aimed to evaluate the characteristics of the humoral immune response in children after immunization with various types of inactivated influenza vaccines. An observational study was conducted in the 2019-2020 season and involved 230 children (< 18 years old) and a comparison group of 87 adults aged 18 to 60 years. The subjects, who provided informed consent to participate, were vaccinated with one of three vaccines (Grippol Plus, Sovigripp, or Ultrix) in an open-label fashion. The humoral immune response was assessed by measuring the hemagglutination inhibition (HI) titer in the paired sera taken before and three weeks after vaccination. The immunogenicity of the vaccines in the age group under 18, met the CPMP criteria for the assessment of inactivated influenza vaccines in terms of the fold increase in antibody titers and the proportion of individuals with seroconversion to all three components (A/H1N1pdm09, A/H3N2, and B/Victoria). Although 6 to 18-year-old participants showed a more robust immune response to the B/Victoria component compared to the adult participants (aged 18 to 60), it was insufficient to ensure that 70% of the participants have a protective antibody titer. A comparative analysis of the vaccines’ immunogenicity was carried out for a subgroup of children aged 6-18 who had initially low antibody levels at the time of vaccination. The analysis showed that the split vaccine Ultrix outperformed the adjuvanted vaccine Grippol Plus in generating an antibody response to the component B/Victoria; however, the antibody responses to the A/H1N1pdm09 and A/H3N2 components did not differ between the two vaccines. The children under 6 years of age demonstrated a less pronounced humoral immune response to vaccination compared with the other age groups, which may be due to the age-related characteristics of the immune system in children of preschool age.

Prediction of effective humoral response to SARS-CoV-2 vaccines in healthy subjects by cortical thickness of post-vaccination reactive lymphadenopathy

PurposeTo study the association between ultrasound cortical thickness in reactive post-vaccination lymph nodes and the elicited humoral response and to evaluate the performance of cortical thickness as a predictor of vaccine effectiveness in patients with and without a previous history of COVID-19 infection.MethodsA total of 156 healthy volunteers were recruited and followed prospectively after receiving two COVID-19 vaccination doses using different protocols. Within a week after receiving the second dose, an axillary ultrasound of the ipsilateral vaccinated arm was performed, and serial post-vaccination serologic tests (PVST) were collected. Maximum cortical thickness was chosen as a nodal feature to analyze association with humoral immunity. Total antibodies quantified during consecutive PVST in previously-infected patients and in coronavirus-naïve volunteers were compared (Mann–Whitney U test). The association between hyperplastic-reactive lymph nodes and effective humoral response was studied (odds ratio). The performance of cortical thickness in detecting vaccination effectiveness was evaluated (area under the ROC curve).ResultsSignificantly higher values for total antibodies were observed in volunteers with a previous history of COVID-19 infection (p < 0.001). The odds ratio associating immunized coronavirus-naïve volunteers after 90 and 180 days of the second dose with a cortical thickness ≥ 3 mm was statistically significant (95% CI 1.52–6.97 and 95% CI 1.47–7.29, respectively). The best AUC result was obtained comparing antibody secretion of coronavirus-naïve volunteers at 180 days (0.738).ConclusionsUltrasound cortical thickness of reactive lymph nodes in coronavirus-naïve patients may reflect antibody production and a long-term effective humoral response elicited by vaccination.Clinical relevance statementIn coronavirus-naïve patients, ultrasound cortical thickness of post-vaccination reactive lymphadenopathy shows a positive association with protective antibody titers against SARS-CoV-2, especially in the long term, providing new insights into previous publications.Key Points• Hyperplastic lymphadenopathy was frequently observed after COVID-19 vaccination.• Ultrasound cortical thickness of reactive post-vaccine lymph nodes may reflect a long-term effective humoral response in coronavirus-naïve patients.

Characterizing the Plasma IgG Antibody Repertoire of Malaria-Naïve United Kingdom Adults Vaccinated with Novel Blood Stage Vaccine RH5.1/AS01 B

Abstract Plasmodium falciparum, the most lethal species of human malaria, is susceptible to vaccine-induced antibodies, yet current efforts are challenged by limited efficacy, lack of durability, and parasite evasion. A promising blood-stage vaccine antigen, Reticulocyte Binding Protein Homologue 5 (RH5), has low polymorphism frequencies and uses a non-redundant red blood cell (RBC) invasion pathway. The Draper Lab (Oxford University) clinically tested RH5.1, an engineered variant of RH5, in AS01 Badjuvant (GSK) designed to boost long-lasting, protective antibody titers. RH5-specific B cell receptors (BCRs) from United Kingdom malaria–naïve adult volunteers vaccinated with RH5.1/AS01 Bwere sequenced. Monoclonal antibodies (mAbs) were found to inhibit in vitrogrowth of RBC-invading parasite merozoites. Notably, the polyclonal plasma IgG of the volunteers exhibited high neutralizing potency, exceeding that of individual mAbs from the same donors, which raises the question: what is the disconnect between the BCR and circulating IgG repertoires? To examine this further, our lab completed BCR sequencing coupled with plasma IgG proteomics to characterize the plasma antibody repertoires of volunteers. Plasma mAbs were identified that bind to known growth inhibitory epitopes, including those that block binding between RH5 and its RBC coreceptor, CD147, alongside a population of non-neutralizing, synergizing mAbs. Additionally, non-neutralizing mAbs targeting cryptic epitopes on the N- and C-terminus were found at consistently high levels. This dynamic between neutralizing and non-neutralizing plasma mAbs suggests a role for non-neutralizing mAbs, which should be further explored in future RH5 vaccine engineering. Supported by grants from U.S. Agency for International Development (USAID) contract no. 7200AA20C00017 and the National Science Foundation Graduate Research Fellowship Program (NSF GRFP).

Lupus nephritis with clinical and laboratory features of humoral immune deficiency in a 29-year-old female with a novel NCF1 variant consistent with autosomal recessive chronic granulomatous disease

Chronic Granulomatous Disease (CGD) is a rare, inherited disorder of the innate immune system characterized by defects in the phagocyte NADPH oxidase complex. This results in poor phagocyte function causing frequent infections (bacterial and fungal) and chronic inflammation. Here we discuss a rare presentation of lupus nephritis and antibody deficiency in an adult female patient with a novel homozygous nonsense mutation in the NCF-1 gene causing autosomal recessive CGD.Our patient is a 29-year-old female with history of ITP, biopsy-confirmed lupus nephritis, systemic lupus erythematosus (SLE), idiopathic avascular necrosis of the hip, and previous diagnosis of common variable immune deficiency (CVID) treated with Immunoglobulin replacement therapy (IVIG). She presented to our clinic to establish care in the setting of persistent skin abscesses/cellulitis, poor wound healing, necrotic lymphadenitis, and recurrent urinary tract infections and pneumonia despite years of IVIG therapy. She had near-normal total IgG, absent IgA and IgE, and protective vaccine antibody titers (pneumococcus, diphtheria, and tetanus) prior to the start of IVIG. Immunophenotyping demonstrated quantitatively normal number of total B cells, absent CD27+ memory B cells, and normal T cell subsets. She had reassuring lymphocyte proliferation with mitogen stimulation and normal TLR function. Dihydrorhodamine (DHR) flow cytometric assay demonstrated abnormally low neutrophil oxidative burst activity. Gene sequencing revealed homozygous nonsense mutation in the NCF-1 gene (c.75-76del; pY26Hfs*26) and a pathogenic heterozygous variant in FANCM (c.3732-3735dup; p. Leu1246Asnfs*8). She was started on daily prophylactic trimethoprim-sulfamethoxazole and itraconazole. She has marked decrease in infections/hospitalizations and her lupus nephritis is well controlled with hydroxy-chloroquine. She is being referred to the NIH for HSCT evaluation. The majority of CGD cases in the United States are due to X-linked CGD (70%) and AR variants in NCF1 (20%). While rare, discoid lupus erythematosus and SLE have been documented with X-linked forms of CGD. Similarly, there are few case reports of antibody deficiency in patients with CGD. This is the first documented case of AR CGD with SLE/lupus nephritis and humoral immune defects. Additionally, we report a disease-causing, novel variant in the NCF1 gene. This case report adds to the existing literature on CGD and associated diseases.

Protected or not? Hepatitis B vaccination status among healthcare workers and the level of protection post-vaccination

BackgroundHepatitis B virus infection is one of the major concerns in global health care. With a far-reaching health, social, economic impact, preventive strategies form the cornerstone of its management. Knowledge about vaccination status and protection rendered thereof would aid in more wholesome management among highrisk population groups like healthcare workers. The aim of this study was to evaluate the Hepatitis B vaccination status among Healthcare workers (HCW) and the level of protection post-vaccination. MethodsDuring the study period a total of 420 HCWs were included in the study. The details of vaccination status was ascertained by an online questionnaire. Serum samples were evaluated for HBsAg status and Anti HBs titres to assess the level of protection against HBV infection. Those who were HBsAg negative, anti-HBc total was assessed. ResultsOur study revealed a high vaccination status among HCWs, n-384 (93.2%). However, the percentage of HCWs who were completely vaccinated was low (56.3%). Most of the study population, n-395 (95.6%) had protective titres of anti-HBs which showed a declining trend with increasing duration since the last dose of the vaccine. ConclusionHepatitis B infection continues to be an important health hazard with significant morbidity and mortality. Healthcare workers are at higher risk of contracting the infection. Merely considering the vaccination status without knowing the protective anti-HBs titres is to be discouraged as it has been observed that the protective antibody titres show a declining trend with time as even completely vaccinated individuals had non-protective levels of antibody titres.

Post-hospitalization rehabilitation alleviates long-term immune repertoire alteration in COVID-19 convalescent patients.

The global pandemic of Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an once-in-a-lifetime public health crisis. Among hundreds of millions of people who have contracted with or are being infected with COVID-19, the question of whether COVID-19 infection may cause long-term health concern, even being completely recovered from the disease clinically, especially immune system damage, needs to be addressed. Here, we performed seven-chain adaptome immune repertoire analyses on convalescent COVID-19 patients who have been discharged from hospitals for at least 6 months. Surprisingly, we discovered lymphopenia, reduced number of unique CDR3s, and reduced diversity of the TCR/BCR immune repertoire in convalescent COVID-19 patients. In addition, the BCR repertoire appears to be activated, which is consistent with the protective antibody titres, but serological experiments reveal significantly lower IL-4 and IL-7 levels in convalescent patients compared to those in healthy controls. Finally, in comparison with convalescent patients who did not receive post-hospitalization rehabilitation, the convalescent patients who received post-hospitalization rehabilitation had attenuated immune repertoire abnormality, almost back to the level of healthy control, despite no detectable clinic demographic difference. Overall, we report the potential long-term immunological impairment for COVID-19 infection, and correction of this impairment via post-hospitalization rehabilitation may offer a new prospect for COVID-19 recovery strategy.

POSTVACCINAL VIRAL DISEASE PRESENTATION IN TWO LITTERS OF CHEETAHS (ACINONYX JUBATUS).

Protective antibody titers against core vaccines have not been standardized for cheetahs (Acinonyx jubatus) under human care. Vaccine-induced disease has been suspected after administration of modified live virus vaccine (MLVV), but it has not been confirmed as the causative agent. MLVV and killed virus vaccines (KVV) elicit humoral response in cheetahs; however, the use of both vaccines for initial immunization in cheetah cubs <6 months old within the same population has not been reported. The current case series describes viral disease presentation in two cheetah litters after using both vaccines and presents results for serum neutralization titers against feline calicivirus (FCV) and feline herpesvirus-1 (FHV-1) and hemagglutination inhibition titers against feline panleukopenia virus (FPV). For Litter 1, MLVV was administered at 6 and 9 wk old. On week 11, one male developed ocular, oral, and dermal lesions. Viral isolation recovered FCV. Because of suspected vaccine-induced FCV, KVV was administered on weeks 13 and 16. Litter 2 was vaccinated with KVV via the same vaccination schedule. Fifty-three days after the last booster, two cubs presented with ocular, respiratory, and oral clinical signs; both were PCR positive for FHV-1. Serology reported a better anamnestic response and protective titers against FCV and FPV with the protocol used with Litter 1. In Litter 2, FCV and FHV-1 titer measurement failed in three of four cubs, limiting comparison of titers between litters. In spite of limited measurements, absence of a statistical evaluation, and presence of infection, serology showed a better humoral response when MLVV was used.

Antibody response to the COVID-19 ChAdOx1nCov-19 and BNT162b vaccines after temporary suspension of DMARD therapy in immune-mediated inflammatory disease: an extension study (RESCUE 2)

The persistence of immunogenicity in patients with immune-mediated inflammatory diseases (IMID) on disease-modifying antirheumatic therapy (DMARD) has been less well studied. This extension study evaluates the SARS-CoV2 antibody decay kinetics...

Prevalence of Serum Antibody Titers against Core Vaccine Antigens in Italian Dogs.

Canine vaccination is the main tool for preventing dangerous and widespread diseases. The strongly recommended (core) dog vaccines are against Canine Parvovirus type 2 (CPV-2), Canine Distemper Virus (CDV), and Canine Adenovirus (CAdV-1), but vaccination protocols should be tailored to dog lifestyles. Vaccination guidelines suggest vaccinating adult dogs no more frequently than every 3 years using modified live (attenuated) vaccines (MLV), thus obtaining a long-lasting (sometimes throughout life) specific protection in many but not all animals. The aim of this study was to determine the actual levels of seroprotection against CPV-2, CDV and CAdV-1 in a cohort of Italian dogs by using the in-practice test VacciCheck. A total of 1,027 dogs (951 vaccinated and 76 unvaccinated) were analyzed for Protective Antibody Titers (PATs) against CPV-2, CDV, and CAdV-1. Differences related to sex, age, breed size, health status, and time elapsed since last vaccination were evaluated. Half of the entire canine cohort (50.6%) had PATs for all three viruses (68.5% considering only vaccinated dogs). In particular, 90.8% of dogs were protected against CPV-2, 68.6% against CDV, and 79.8% against CAdV-1. Most dogs remained protected for 3 years after vaccination or longer. Revaccination on a 3-year basis can then be recommended for core MLV vaccines without altering individual's seroprotection or even herd immunity.

Development of cell culture based peste des petits ruminants (PPR) virus vaccine candidate from Bangladeshi isolates

This study was conducted to develop a cell culture based PPR virus vaccine candidate using recent Bangladeshi strain of peste des petits ruminant’s (PPR) virus. PPR virus was isolated from field outbreaks, confirmed by RT-PCR and used as viral inoculum for serial passaging in Vero cells for adaptation and attenuation. 60th serial passage had completed and RT-PCR and real time RT-PCR were done in every 5 passages for confirmation of PPR virus in tissue culture fluid (TCF). To assess the adaptation and attenuation cytopathology, virus titration, sequencing of both F and N genes and live animal experimentation were done. Different cellular alterations produced by PPR virus in infected Vero cells including syncytia formation, development of both intranuclear and intra cytoplasmic inclusion bodies and finally cell degradation are the indications of adaptation. The virus titre was found 2.5, 3.31, 3.55, 4.44, 4.71 and 6.5 Log10 TCID50/ml at 10th, 20th, 30th, 40th, 50th and 60th passages level respectively. In F gene sequence analysis it has been observed that few nucleotide (nt) and mino acid (aa) has been substituted as the effects of serial passaging of PPR virus in Vero cells. TCF at 60th passage level was found effective to produced protective antibody (Ab) titre in live animal experimentation. It is concluded that serially passaged and Vero cells adapted PPR virus TCF could be used as a vaccine candidate for further use to develop a potent & effective vaccine against PPR diseases.

Functional heterogeneity in the memory B-cell response.

Most vaccines induce robust antibody and memory B-cell (MBC) responses that are capable of mediating protective immunity. However, antibody titers wane following vaccination necessitating the administration of booster vaccines to maintain a protective antibody titer. MBCs are stably maintained following vaccination and can rapidly give rise to antibody-secreting cells or undergo further affinity maturation upon antigen re-encounter. Repeated antigen encounter results in the development of MBCs that encode antibodies capable of mediating broadly protective immunity against viruses such as SARS-CoV-2 and influenza. Here, we summarize emerging evidence that MBCs are a heterogeneous population composed of transcriptionally and phenotypically distinct subsets that have discrete roles in mediating protective immunity upon antigen re-encounter and examine the implications of these findings for the development of vaccines capable of eliciting broadly protective immunity.

COVID-19 coronavirus infection in children: Clinical presentation, diagnosis, vaccination, and treatment

In late 2019, a new subtype of coronavirus named Severe Acute Respiratory Syndrome Coronavirus 2 (COVID-19 SARS-CoV-2) rapidly spread around the world, causing a global pandemic. Initially, the proportion of confirmed cases among children was relatively small, and it was believed that children were rarely infected. Subsequent observations have shown that in children and adolescents, the infection is either asymptomatic or paucisymptomatic, and therefore the true incidence is underestimated due to the lack of testing. The article systematizes the results of studies on the prevalence, diagnosis, clinical features, vaccination, and treatment of children with a new coronavirus infection COVID-19 SARS-CoV-2. The SARS-CoV-2 positivity rate throughout the peak of the pandemic in children was low compared to adults. Children are not only less likely to become infected with the virus, but they also endure the infection more easily than adults. The mortality rate in children with COVID-19 was &lt;0.5%. In most children, infection is either asymptomatic or paucisymptomatic. Vaccination of children and adolescents is recommended mainly to achieve herd immunity in all age groups. However, there are no convincing data on the duration of the immune response, the level of the required protective antibody titer, as well as on the long-term side effects of vaccination due to the insufficient follow-up period and the uncertainty of the immune response criteria. As information is accumulated on the viral load of children and adolescents, their role in the transmission of the virus, diagnostic approaches in this age group are optimized. The effectiveness of the treatment was tested on patients admitted to the hospital, and recommendations for treatment were developed. Currently, global research efforts are focused on the protection of particularly vulnerable children, the prospects for total childhood vaccination, its effectiveness and safety.

Dynamics of the content of immunoglobulin G to severe acute respiratory syndrome-2 in convalescents who have had a new coronavirus infection

The study investigated the dynamics of class G immunoglobulins to severe acute respiratory syndrome-2 coronavirus in the blood serum of convalescents who had a new coronavirus infection for 6 months after the polymerase chain reaction conversion. Among the most common symptoms, 30 (73.8%) convalescents had an increase in body temperature to 38C, 32 (83.3%) had asthenia, 21 (59.5%) had cough, 29 (73.8%) had perversion or loss of sense of smell, pain, and throat discomfort. The duration of symptoms varied from 34 days to 34 weeks. Within a month after the end of the acute disease period, 8 (20%) patients had a decrease in working capacity, 13 (33%) had difficulty breathing, 9 (22%) had a cough, and 4 (10%) had pain and sore throat. During severe acute respiratory syndrome 2 infection, the virus activates the innate and adaptive immunity, resulting in the formation of specific class G immunoglobulins to the pathogens. After leveling the clinical manifestations, class G immunoglobulins were detected in the majority of convalescents (79%90%) during the first 6 months, starting from day 14 from disease onset with a predominantly high ( 10 conl. units) positivity coefficient. Moreover, this pattern occurred in both men and women; however, in some studies, the levels of the positivity coefficient of class G immunoglobulins began to decrease by the fifth month of follow-up and sometimes at an earlier time (2 months). Perhaps, this is due to the different functional activities of the immune system of each convalescent, infecting dose of the pathogen, and peculiarities of its interaction with the macroorganism and its immune system. Nevertheless, the class G immunoglobulins identified in the study do not yet indicate the probability of reinfection of convalescents with the same pathogen. The protective titer of antibodies has yet to be investigated further.

Protective Antibody Titer against Hepatitis B in Healthcare Workers: A Cross-sectional Study from Tertiary Care Hospital of Kashmir

Introduction: Hepatitis B is not only the most transmissible blood borne viral infection, but also the only one that is preventable by vaccination. In developing countries, Hepatitis B vaccination coverage among Healthcare Workers (HCWs) is very low for various reasons. Aim: To evaluate Hepatitis B Virus (HBV) immunisation status and Hepatitis B surface antibody (anti-HBs) titer among HCWs in a tertiary care hospital in Kashmir. Materials and Methods: This cross-sectional study was conducted in the Department of Microbiology, Government Medical College, Srinagar, India from April 2019 to June 2019. Serum samples were collected from 196 HCWs and their vaccination history was collected. Those who had taken all three doses of hepatitis B were considered to be fully vaccinated those that had taken two doses as partially vaccinated. Triple serology was done for all which included testing for HBV, Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV) infection, one HCW turned out to be Hepatitis B Surface Antigen (HBsAg) positive and was dropped out of study. Those negative (195/196) were further tested for anti-HBs titer by enzyme immunoassay method. Parametric data are expressed as mean±Standard Deviation (SD) and categorical values as percentages. Results: Out of 195 HCWs selected for the study, 112 (57.4%) were males and 84 (43%) were females with mean age 38.4±6.9 years. Among them fully vaccinated were 46 (23.5%), partially vaccinated were 84 (43.07%) and not vaccinated were 65 (33.33%). Anti-HBs titers were protective in 54 (27.7%) which belonged 81.5% (44/54) to vaccinated category and 18.5% (10/54) to partially vaccinated category. Conclusion: Fully vaccinated HCWs (95.6%) had a protective antibody titer but unfortunately there are low vaccination rates among HCWs. There is a need for well-planned and clear policies for HBV screening and vaccination in HCWs, especially those who are at a greater risk of exposure to blood or other potentially infectious material.

Soroprevalência de anticorpos contra o vírus da cinomose canina, parvovírus e adenovírus em cães de um abrigo de animais brasileiro

ABSTRACT This study aimed to identify and compare the seroprevalence for canine distemper virus (CDV), canine parvovirus (CPV), and canine adenovirus (CAV) between newly admitted and already sheltered dogs. 122 dogs over six months of age and unvaccinated upon admission were sampled and divided into two groups: (A) newly admitted dogs and (B) dogs sheltered for at least two months. Sera were collected to determine IgG antibody titers against CDV, CPV, and CAV. We conducted a descriptive analysis of the samples and a chi-square test to investigate the relationship between potential elements associated with protective antibody titers. The results were: 56.5% of the dogs had protective levels of antibodies to all three pathogens. Dogs in group A had lower titers compared to those in group B for all three pathogens, with significant differences for CDV and CAV. We found no significant difference between the proportion of seropositive dogs and their age or reproductive status. The study suggests that the examined pathogens can circulate in the animal shelter and that dogs can be more exposed to these pathogens in the shelter than in the urban environment. Therefore, an effective immunization program should be carried out on all animals upon admission to shelters.