scholarly journals Booster and anergic effects of the Covishield vaccine among healthcare workers in South India

2021 ◽  
Author(s):  
Priya Kannian ◽  
Pasuvaraj Mahanathi ◽  
Ashwini Veeraraghavan ◽  
Nagalingeswaran Kumarasamy
Keyword(s):  
Healthcare Workers ◽  
South India ◽  
Senior Citizens ◽  
Fold Increase ◽  
Antibody Responses ◽  
Responder Rate ◽  
Limited Data ◽  
Serum Samples ◽  
Antibody Levels ◽  
Booster Effect

Covishield (same as ChAdOx1) vaccine was rolled out in January 2021 against SARS-CoV2 in India. Although studies show good efficacy after two doses, there is limited data on the fate of the elicited antibody responses over time in groups with or without prior exposure to SARS-CoV2. Therefore, in this study we proposed to test naive or previously exposed healthcare workers (HCWs) longitudinally after both doses for anti-SARS-CoV2 spike antibody (ASSA) levels. Serum samples were collected from 205 HCWs at days 14 and 28 after first dose, and at days 14, 28 and 3-months after second dose. ASSA levels were quantitated by ECLIA method. Non-responder rate was 17% (35 of 205) on day 14 and 2% (5 of 205) on day 28 after the first dose. After the second dose, the responder rate was 100%. Non-responder rate was significantly higher among males (p<0.00001) and senior citizens (p=0.008). The second dose boosted a 27-fold increase in the COVID-19 naive (CN) group, but caused a 1.5-fold decline in the previously exposed groups. By three months, the antibody levels declined 3-4-folds in all the groups. In spite of high antibody levels (GM-1007 U per ml) after the second dose, 14% developed mild breakthrough infections (BTI). The booster effect was significantly higher when given 10-14 weeks later. The responder rate for Covishield was 98% after first dose and 100% after second dose. The vaccine elicited a prime-boost effect in CN HCWs and a boost-anergy effect in the previously exposed HCWs. ASSA levels began to decline proportionately by three months.

scholarly journals Vaccination strategy and anti - SARS-CoV-2 S titers in healthcare workers of the INT – IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy)

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ernesta Cavalcanti ◽  
Maria Antonietta Isgrò ◽  
Domenica Rea ◽  
Lucia Di Capua ◽  
Giusy Trillò ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Healthcare Workers ◽  
Geometric Mean ◽  
Vaccination Strategy ◽  
Antibody Responses ◽  
Cancer Center ◽  
Serum Samples ◽  
Humoral Immune ◽  
History Of

Abstract Background Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and the resulting disease, coronavirus disease 2019 (COVID-19), have spread to millions of people globally, requiring the development of billions of different vaccine doses. The SARS-CoV-2 spike mRNA vaccine (named BNT162b2/Pfizer), authorized by the FDA, has shown high efficacy in preventing SARS-CoV-2 infection after administration of two doses in individuals 16 years of age and older. In the present study, we retrospectively evaluated the differences in the SARS-CoV-2 humoral immune response after vaccine administration in the two different cohorts of workers at the INT - IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy): previously infected to SARS-CoV-2 subjects and not infected to SARS-CoV-2 subjects. Methods We determined specific anti-RBD (receptor-binding domain) titers against trimeric spike glycoprotein (S) of SARS-CoV-2 by Roche Elecsys Anti-SARS-CoV-2 S immunoassay in serum samples of 35 healthcare workers with a previous documented history of SARS-CoV-2 infection and 158 healthcare workers without, after 1 and 2 doses of vaccine, respectively. Moreover, geometric mean titers and relative fold changes (FC) were calculated. Results Both previously infected and not infected to SARS-CoV-2 subjects developed significant immune responses to SARS-CoV-2 after the administration of 1 and 2 doses of vaccine, respectively. Anti-S antibody responses to the first dose of vaccine were significantly higher in previously SARS-CoV-2-infected subjects in comparison to titers of not infected subjects after the first as well as the second dose of vaccine. Fold changes for subjects previously infected to SARS-CoV-2 was very modest, given the high basal antibody titer, as well as the upper limit of 2500.0 BAU/mL imposed by the Roche methods. Conversely, for naïve subjects, mean fold change following the first dose was low ($$ \overline{x} $$ x ¯ =1.6), reaching 3.8 FC in 72 subjects (45.6%) following the second dose. Conclusions The results showed that, as early as the first dose, SARS-CoV-2-infected individuals developed a remarkable and statistically significant immune response in comparison to those who did not contract the virus previously, suggesting the possibility of administering only one dose in previously SARS-CoV-2-infected subjects. FC for previously infected subjects should not be taken into account for the generally high pre-vaccination values. Conversely, FC for not infected subjects, after the second dose, were = 3.8 in > 45.0% of vaccinees, and ≤ 3.1 in 19.0%, the latter showing a potential susceptibility to further SARS-CoV-2 infection.

scholarly journals Longitudinal Analysis of Cryptosporidium Species-Specific Immunoglobulin G Antibody Responses in Peruvian Children

2006 ◽  
Vol 13 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Jeffrey W. Priest ◽  
Caryn Bern ◽  
Lihua Xiao ◽  
Jacquelin M. Roberts ◽  
James P. Kwon ◽  
...  
Keyword(s):  
Immunoglobulin G ◽  
Antibody Responses ◽  
Health Interventions ◽  
Older Children ◽  
Serum Samples ◽  
Igg Antibody ◽  
Specific Immunoglobulin ◽  
Antibody Assays ◽  
Species Specific ◽  
Antibody Levels

ABSTRACT Cryptosporidium species are ubiquitous in the environment and are frequently detected in the stools of children who live where sanitation conditions are poor. To better characterize the immune response to these parasites, we monitored immunoglobulin G (IgG) antibody levels in a cohort of children from Lima, Peru. Two new enzyme-linked immunosorbent assays based on the C. parvum (bovine, subtype IIa) Iowa strain 17-kDa and 27-kDa antigens were used to measure IgG antibody levels in longitudinal serum samples. Antibody responses were detected during infections with C. parvum, C. felis, and C. meleagridis and with four different subtypes of C. hominis. We also noted that the magnitude of the antibody response was related to the number of previous infections and that older children generally had higher levels of antibodies to the two C. parvum antigens. Antibody responses were not associated with infections with either Cyclospora sp. or Giardia sp. We believe the antibody assays will be important tools for monitoring the success of future public health interventions.

scholarly journals Can individuals with low antibody responses to vaccines against other viruses acquire adequate SARS-CoV-2 antibody after vaccination with the BNT162b2 mRNA vaccine?

2021 ◽  
Author(s):  
Wataru Ogura ◽  
Kouki Ohtsuka ◽  
Sachiko Matsuura ◽  
Takahiro Okuyama ◽  
Satsuki Matsushima ◽  
...  
Keyword(s):  
Cohort Study ◽  
Neutralizing Antibodies ◽  
Healthcare Workers ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Antibody Activity ◽  
Low Responders ◽  
Before And After ◽  
Positive Threshold ◽  
Antibody Levels

Objective In Japan, healthcare workers (HCWs) are vaccinated against coronavirus disease (COVID-19) and other contagious viruses (measles, rubella, chickenpox, mumps, and hepatitis B) to prevent nosocomial infection. However, some do not produce sufficient antibodies after vaccination (low responders). This study investigated changes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody levels among HCWs after SARS-CoV-2 vaccination and assessed whether low responders produced adequate SARS-CoV-2 anti-spike and neutralizing antibodies. Methods We conducted a prospective cohort study of HCWs before and after vaccination with the BNT162b2 mRNA vaccine in a hospital in Tokyo, Japan. The HCWs received two doses of BNT162b2 vaccine, 3 weeks apart. Those whose antibody levels against previous antiviral vaccines did not reach protective antibody levels after receiving two doses were defined as low responders, whereas those who produced adequate antibodies were defined as normal responders. SARS-CoV-2 anti-spike antibodies were measured 11 times from before the first BNT162b2 vaccination to 5 months after the second vaccination. SARS-CoV-2 neutralizing antibody activity was measured twice in low responders, 1 week to 1 month and 5 months after the second vaccination. Results Fifty HCWs were included in the analytic cohort. After vaccination, SARS-CoV-2 anti-spike antibody was detectable in the samples from both responders at each timepoint, but the level was lower at 5 months than at 1 week after the second vaccination. Low responders had SARS-CoV-2 neutralizing antibody activity 1 week to 1 month after the second vaccination, which exceeded the positive threshold after 5 months. Conclusion After BNT162b2 vaccination, low responders acquired adequate SARS-CoV-2 anti-spike and SARS-CoV-2 neutralizing antibodies to prevent SARS-CoV-2. However, SARS-CoV-2 anti-spike antibody levels were lower at 5 months than at 1 week after the second dose of BNT162b2 vaccine in low and normal responders. Therefore, low responders should also receive a third dose of BNT162b2 vaccine.

scholarly journals Quantitative SARS-CoV-2 Antibody Screening of Healthcare Workers in the Southern Part of Kyoto City During the COVID-19 Pre-pandemic Period

2020 ◽  
Vol 8 ◽  
Author(s):  
Kohei Fujita ◽  
Shinpei Kada ◽  
Osamu Kanai ◽  
Hiroaki Hata ◽  
Takao Odagaki ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Early Stage ◽  
Case Fatality ◽  
Serum Samples ◽  
Igg Antibody ◽  
Kyoto City ◽  
History Of ◽  
Heavy Burden ◽  
Antibody Levels ◽  
Mental And Physical Health

Background: The coronavirus disease-2019 (COVID-19) pandemic is associated with a heavy burden on the mental and physical health of patients, regional healthcare resources, and global economic activity. While understanding of the incidence and case-fatality rates has increased, there are limited data concerning seroprevalence of antibodies against the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) in healthcare workers during the pre-pandemic period. This study aimed to quantitatively evaluate seroprevalence of SARS-CoV-2 antibodies in healthcare workers in the southern part of Kyoto city, Japan.Methods: We prospectively recruited healthcare workers from a single hospital between April 10 and April 20, 2020. We collected serum samples from these participants and quantitatively evaluated SARS-CoV-2 IgG antibody levels using enzyme-linked immunosorbent assays.Results: Five (5.4%), 15 (16.3%), and 72 (78.3%) participants showed positive, borderline, and negative serum SARS-CoV-2 IgG antibody status, respectively. We found the mean titer associated with each antibody status (overall, positive, borderline, and negative) was clearly differentiated. Participants working at the otolaryngology department and/or with a history of seasonal common cold symptoms had a significantly higher SARS-CoV-2 IgG antibody titer (p = 0.046, p = 0.046, respectively).Conclusions: Five (5.4%) and 15 (16.3%) participants tested positive and borderline, respectively, for SARS-CoV-2 IgG antibody during the COVID-19 pre-pandemic period. These rates were higher than expected, based on government situation reports. These findings suggest that COVID-19 had already spread within the southern part of Kyoto city at the early stage of the pandemic.

scholarly journals The duration, dynamics and determinants of SARS-CoV-2 antibody responses in individual healthcare workers

2021 ◽  
Author(s):  
Sheila F Lumley ◽  
Jia Wei ◽  
Denise O’Donnell ◽  
Nicole E Stoesser ◽  
Philippa C Matthews ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Linear Models ◽  
Antibody Responses ◽  
Credibility Interval ◽  
Mixed Linear Models ◽  
Igg Antibody ◽  
Asian Ethnicity ◽  
Interval Censored ◽  
Antibody Levels

Abstract Background SARS-CoV-2 IgG antibody measurements can be used to estimate the proportion of a population exposed or infected and may be informative about the risk of future infection. Previous estimates of the duration of antibody responses vary. Methods We present 6 months of data from a longitudinal seroprevalence study of 3276 UK healthcare workers (HCWs). Serial measurements of SARS-CoV-2 anti-nucleocapsid and anti-spike IgG were obtained. Interval censored survival analysis was used to investigate the duration of detectable responses. Additionally, Bayesian mixed linear models were used to investigate anti-nucleocapsid waning. Results Anti-spike IgG levels remained stably detected after a positive result, e.g., in 94% (95% credibility interval, CrI, 91-96%) of HCWs at 180 days. Anti-nucleocapsid IgG levels rose to a peak at 24 (95% credibility interval, CrI 19-31) days post first PCR-positive test, before beginning to fall. Considering 452 anti-nucleocapsid seropositive HCWs over a median of 121 days from their maximum positive IgG titre, the mean estimated antibody half-life was 85 (95%CrI, 81-90) days. Higher maximum observed anti-nucleocapsid titres were associated with longer estimated antibody half-lives. Increasing age, Asian ethnicity and prior self-reported symptoms were independently associated with higher maximum anti-nucleocapsid levels and increasing age and a positive PCR test undertaken for symptoms with longer anti-nucleocapsid half-lives. Conclusion SARS-CoV-2 anti-nucleocapsid antibodies wane within months, and faster in younger adults and those without symptoms. However, anti-spike IgG remains stably detected. Ongoing longitudinal studies are required to track the long-term duration of antibody levels and their association with immunity to SARS-CoV-2 reinfection.

scholarly journals Quantitative SARS-CoV-2 antibody screening of healthcare workers in the southern part of Kyoto city during the COVID-19 peri-pandemic period

2020 ◽  
Author(s):  
Kohei Fujita ◽  
Shinpei Kada ◽  
Osamu Kanai ◽  
Hiroaki Hata ◽  
Takao Odagaki ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Early Stage ◽  
Case Fatality ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Igg Antibody ◽  
Kyoto City ◽  
History Of ◽  
Heavy Burden ◽  
Antibody Levels

Background: The coronavirus disease-2019 (COVID-19) pandemic is associated with a heavy burden on the mental and physical health of patients, regional healthcare resources, and global economic activity. While our understanding of the incidence and case-fatality rates increases, data on seroprevalence of antibodies against the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) in healthcare workers during the peri-pandemic period is insufficient. This study quantitatively evaluated seroprevalence of SARS-CoV-2 antibody in healthcare workers in the southern part of Kyoto city, Japan. Methods: We prospectively recruited healthcare workers from a single hospital between April 10 and April 20, 2020. We collected serum samples from these participants and quantitatively evaluated SARS-CoV-2 IgG antibody levels by enzyme-linked immunosorbent assay. Results: Five (5.4%), 15 (16.3%), and 72 (78.3%) participants showed positive, borderline, and negative serum SARS-CoV-2 IgG antibody status, respectively. We found the mean titer associated with each antibody status (overall, positive, borderline, and negative) was clearly differentiated. Participants working at the otolaryngology department and/or having a history of seasonal common cold symptoms had a significantly higher titer of SARS-CoV-2 IgG antibody (p=0.046, p=0.046, respectively). Conclusions: Five (5.4%) and 15 (16.3%) participants tested positive and borderline, respectively, for SARS-CoV-2 IgG antibody during the COVID-19 peri-pandemic period. These rates were higher than expected based on government situation reports. The present findings suggest that COVID-19 was already spread in the southern part of Kyoto city at the early stage of pandemic.

scholarly journals Vaccination strategy and anti - SARS-CoV-2 S titers in healthcare workers of the INT – IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy)

2021 ◽  
Author(s):  
Ernesta Cavalcanti ◽  
Maria Antonietta Isgrò ◽  
Domenica Rea ◽  
Lucia Di Capua ◽  
Giusy Trillò ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Healthcare Workers ◽  
Geometric Mean ◽  
Vaccination Strategy ◽  
Antibody Responses ◽  
Cancer Center ◽  
Serum Samples ◽  
Humoral Immune ◽  
History Of

Abstract Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and the resulting disease, coronavirus disease 2019 (COVID-19), have spread to millions of people globally, requiring the development of billions of different vaccine doses. The SARS-CoV-2 spike mRNA vaccine (named BNT162b2/Pfizer), authorized by the FDA, has shown high efficacy in preventing SARS-CoV-2 infection after administration of two doses in individuals 16 years of age and older. In the present study, we retrospectively evaluated the differences in the SARS-CoV-2 humoral immune response after vaccine administration in the two different cohorts of workers at the INT - IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy): previously exposed to SARS-CoV-2 subjects and not exposed to SARS-CoV-2 subjects.Methods: We determined specific anti-RBD (receptor-binding domain) titers against trimeric spike glycoprotein (S) of SARS-CoV-2 by Roche Elecsys Anti-SARS-CoV-2 S immunoassay in serum samples of 35 healthcare workers with a previous documented history of SARS-CoV-2 infection and 158 healthcare workers without, after 1 and 2 doses of vaccine, respectively. Moreover, geometric mean titers and relative fold changes (FC) were calculated.Results: Both previously exposed and not exposed to SARS-CoV-2 subjects developed significant immune responses to SARS-CoV-2 after the administration of 1 and 2 doses of vaccine, respectively. Anti-S antibody responses to the first dose of vaccine were significantly higher in previously SARS-CoV-2-exposed subjects in comparison to titers of not exposed subjects after the first as well as the second dose of vaccine. Fold changes for subjects previously exposed to SARS-CoV-2 was very modest, given the high basal antibody titer, as well as the upper limit of 2500.0 BAU/mL imposed by the Roche methods. Conversely, for naïve subjects, mean fold change following the first dose was low ( =1.6), reaching 3.8 FC in 72 subjects (45.6%) following the second dose.Conclusions: The results showed that, as early as the first dose, SARS-CoV-2-exposed individuals developed a remarkable and statistically significant immune response in comparison to those who did not contract the virus previously, suggesting the possibility of administering only one dose in previously SARS-CoV-2-exposed subjects. FC for previously exposed subjects should not be taken into account for the generally high pre-vaccination values. Conversely, FC for not exposed subjects, after the second dose, were = 3.8 in >45.0% of vaccinees, and ≤3.1 in 19.0%, the latter showing a potential susceptibility to further SARS-CoV-2 infection.

scholarly journals Correlation of SARS-CoV-2 Serology and Clinical Phenotype Amongst Hospitalised Children in a Tertiary Children’s Hospital in India

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Aishwarya Venkataraman ◽  
S Balasubramanian ◽  
Sulochana Putilibai ◽  
S Lakshan Raj ◽  
Sumanth Amperayani ◽  
...  
Keyword(s):  
Antibody Titre ◽  
South India ◽  
Clinical Phenotype ◽  
Antibody Responses ◽  
Antibody Testing ◽  
Middle Income ◽  
Children's Hospital ◽  
Children’S Hospital ◽  
Disease Stratification ◽  
Antibody Levels

Abstract Introduction Children usually present with minimal or no symptoms of COVID-19 infection. Antibody responses to SARS-CoV-2 in children from low- and middle-income countries (LMIC) have not been well described. We describe the prevalence of anti-SARS-CoV-2 antibodies and clinical phenotype of seropositive children admitted to a tertiary children’s hospital in South India. Methods To determine the seropositivity and describe the clinical characteristics of COVID-19 infection amongst hospitalised children, we performed a prospective clinical data collection and blood sampling of children admitted to Kanchi Kamakoti CHILDS Trust Hospital, Chennai, India over 4 months of the COVID-19 pandemic. In seropositive children, we compared antibody titres between children with and without PIMS-TS. Results Of 463 children, 91 (19.6%) were seropositive. The median (range) age of seropositive children was 5 years (1 month–17 years). Clinical presentation was consistent with Paediatric inflammatory multisystem syndrome associated or related with SARS-CoV-2 infection (PIMS-TS) in 48% (44/91) of seropositive children. The median (range) antibody titre was 54.8 (11.1–170.9) AU/ml among all seropositive children. The median antibody titre among the children with PIMS-TS (60.3 AU/mL) was significantly (p = 0.01) higher when compared to the children without PIMS-TS (54.8 AU/mL). Conclusion We describe the antibody responses to SARS-CoV-2 amongst hospitalised children in a LMIC tertiary children’s hospital. Almost half of the seropositive children had PIMS-TS. Antibody levels may be helpful in the diagnosis and disease stratification of PIMS-TS. LAY SUMMARY Children usually present with minimal or no symptoms of COVID-19 infection. However, Multisystem Inflammatory Syndrome in Children (MIS-C) or Paediatric inflammatory multisystem syndrome associated or related with SARS-CoV-2 infection (PIMS-TS) has emerged as a distinctive paediatric illness related to SARS-CoV-2. Recently, antibody testing for SARS-CoV-2 is being used increasingly as a diagnostic test for PIMS-TS. However, data on the antibody responses to SARS-CoV-2 in children are sparse. We, therefore, attempted to identify the seropositivity and describe the clinical spectrum of COVID-19 infection amongst infants and children getting hospitalised in a children’s hospital in south India. Nearly one-fifth of the hospitalised children tested serology positive over 4 months. Antibody levels in children with PIMS-TS were significantly higher in comparison to the other two groups (acute COVID-19 infection and children without PIMS-TS). Results from our study suggest that all children are at risk of COVID-19 infection though they may present with mild illness or no symptoms. We also observed that antibody testing may have a possible role in diagnosis of PIMS-TS.

scholarly journals Correlation of SARS-CoV-2 serology and clinical phenotype amongst hospitalised children in a tertiary children’s hospital in India

2021 ◽  
Author(s):  
Aishwarya Venkataraman ◽  
S Balasubramanian ◽  
Sulochana Putilibai ◽  
S Lakshan Raj ◽  
Sumanth Amperayani ◽  
...  
Keyword(s):  
Antibody Titre ◽  
South India ◽  
Clinical Phenotype ◽  
Antibody Responses ◽  
Antibody Testing ◽  
Middle Income ◽  
Children's Hospital ◽  
Children’S Hospital ◽  
Disease Stratification ◽  
Antibody Levels

AbstractIntroductionChildren usually present with minimal or no symptoms of SARS-CoV-2 infection. Antibody responses to SARS-CoV-2 in children from low- and middle-income countries (LMIC) have not been well described. We describe the prevalence of anti-SARS-CoV-2 antibodies and clinical phenotype of seropositive children admitted to a tertiary children’s hospital in South India.MethodsTo determine the seropositivity and describe the clinical characteristics of SARS-CoV-2 infection amongst hospitalised children, we performed a prospective clinical data collection and blood sampling of children admitted to Kanchi Kamakoti CHILDS Trust Hospital, Chennai, India over 4 months of the COVID-19 pandemic. In seropositive children, we compared antibody titres between children with and without PIMS-TS.ResultsOf 463 children, 91 (19.6%) were seropositive. The median (range) age of seropositive children was 5 years (1 month - 17 years). Clinical presentation was consistent with Paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 infection (PIMS-TS) in 48% (44/91) of seropositive children. The median (range) antibody titre was 54.8 (11.1–170.9) AU/ml among all seropositive children. The median antibody titre among the children with PIMS-TS (60.3 AU/mL) was significantly (p=0.01) higher when compared to the children without PIM-TS (54.8 AU/mL).ConclusionWe describe the antibody responses to SARS-CoV-2 amongst hospitalised children in a LMIC tertiary children’s hospital. Almost half of the seropositive children had PIMS-TS. Antibody levels may be helpful in the diagnosis and disease stratification of PIMS-TS.Lay summaryChildren usually present with minimal or no symptoms of SARS-CoV-2 infection. However, Paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 infection (PIMS-TS) has emerged as a distinctive paediatric illness related to SARS-CoV-2. Recently, antibody testing for SARS-CoV-2 is being used increasingly as a diagnostic test for PIMS-TS. However, data on the antibody responses to SARS-CoV-2 in children is sparse. We therefore, attempted to identify the seropositivity and describe the clinical spectrum of SARS-CoV-2 infection amongst infants and children getting hospitalised in a children’s hospital in south India. Nearly one-fifth of the hospitalised children tested serology positive over 4 months. Antibody levels in children with PIMS-TS were significantly higher in comparison to the other two groups (acute SARS-CoV-2 infection and children without PIMS-TS). Results from our study suggest that all children are at risk of SARS-CoV-2 infection though they may present with mild illness or no symptoms. We also observed that antibody testing may have a possible role in diagnosis of PIMS-TS.

scholarly journals Antibody Responses in Patients with Staphylococcal Septicemia against Two Staphylococcus aureus Fibrinogen Binding Proteins: Clumping Factor and an Extracellular Fibrinogen Binding Protein

2000 ◽  
Vol 7 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Patricia Colque-Navarro ◽  
Marco Palma ◽  
Bo Söderquist ◽  
Jan-Ingmar Flock ◽  
Roland Möllby
Keyword(s):  
Staphylococcus Aureus ◽  
Antibody Response ◽  
Binding Proteins ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Healthy Individuals ◽  
Serum Samples ◽  
Positive Serology ◽  
Fibrinogen Binding ◽  
Antibody Levels

ABSTRACT We analyzed the serum antibody responses against twoStaphylococcus aureus fibrinogen binding proteins, the cell-bound clumping factor (Clf) and an extracellular fibrinogen binding protein (Efb). The material consisted of 105 consecutive serum samples from 41 patients suffering from S. aureussepticemia and 72 serum samples from healthy individuals. An enzyme-linked immunosorbent assay (ELISA) was developed. Healthy individuals showed variable levels of antibodies against the studied antigens, and cutoff levels (upper 95th percentile) against these antigens were determined. No correlation was seen between serum antibody levels against Clf and Efb. In acute-phase samples 27% of patients showed positive antibody levels against Clf and 10% showed positive levels against Efb, while in convalescent-phase samples 63% (26 of 41) showed a positive serology against Clf and 49% (20 of 41) showed a positive serology against Efb. Antibody levels against Efb were significantly lower in the acute-phase sera than in sera from healthy individuals (P = 0.002). An antibody response against Clf was most frequent in patients suffering from osteitis plus septic arthritis and from endocarditis (80% positive). The antibody response against Efb appeared to develop later in the course of disease. A possible biological effect of measured antibodies was demonstrated with the help of an inhibition ELISA, in which both high-titer and low-titer sera inhibited the binding of bacteria to fibrinogen. In conclusion, we have demonstrated in vivo production ofS. aureus fibrinogen binding proteins during deep S. aureus infections and a possible diagnostic and prophylactic role of the corresponding serum antibodies in such infections.

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