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1.
Front Immunol ; 12: 801797, 2021.
Article in English | MEDLINE | ID: covidwho-1793017

ABSTRACT

Background: Limited data are available regarding the balance of risks and benefits from human milk and/or breastfeeding during and following maternal infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Objective: To investigate whether SARS-CoV-2 can be detected in milk and on the breast after maternal coronavirus disease 2019 (COVID-19) diagnosis; and characterize concentrations of milk immunoglobulin (Ig) A specific to the SARS-CoV-2 spike glycoprotein receptor binding domain (RBD) during the 2 months after onset of symptoms or positive diagnostic test. Methods: Using a longitudinal study design, we collected milk and breast skin swabs one to seven times from 64 lactating women with COVID-19 over a 2-month period, beginning as early as the week of diagnosis. Milk and breast swabs were analyzed for SARS-CoV-2 RNA, and milk was tested for anti-RBD IgA. Results: SARS-CoV-2 was not detected in any milk sample or on 71% of breast swabs. Twenty-seven out of 29 (93%) breast swabs collected after breast washing tested negative for SARS-CoV-2. Detection of SARS-CoV-2 on the breast was associated with maternal coughing and other household COVID-19. Most (75%; 95% CI, 70-79%; n=316) milk samples contained anti-RBD IgA, and concentrations increased (P=.02) during the first two weeks following onset of COVID-19 symptoms or positive test. Milk-borne anti-RBD IgA persisted for at least two months in 77% of women. Conclusion: Milk produced by women with COVID-19 does not contain SARS-CoV-2 and is likely a lasting source of passive immunity via anti-RBD IgA. These results support recommendations encouraging lactating women to continue breastfeeding during and after COVID-19 illness.


Subject(s)
Antibodies, Viral/analysis , Immunoglobulin A/analysis , Milk, Human/immunology , SARS-CoV-2/immunology , Adult , Antibodies, Viral/immunology , Breast Feeding , COVID-19/immunology , Female , Humans , Immunization, Passive , Immunoglobulin A/immunology , Lactation , Longitudinal Studies , Milk, Human/virology , RNA, Viral/genetics
2.
Obstet Gynecol ; 139(2): 181-191, 2022 02 01.
Article in English | MEDLINE | ID: covidwho-1774425

ABSTRACT

OBJECTIVE: To evaluate immune responses to coronavirus disease 2019 (COVID-19) mRNA-based vaccines present in breast milk and transfer of the immune responses to breastfeeding infants. METHODS: We enrolled 30 lactating women who received mRNA-based COVID-19 vaccines from January through April 2021 in this cohort study. Women provided serial milk samples, including milk expressed before vaccination, across 2-3 weeks after the first dose, and across 3 weeks after the second dose. Women provided their blood, spotted on cards (dried blood spots), 19 days after the first dose and 21 days after the second dose. Stool samples from the breastfed infants were collected 21 days after mothers' second vaccination. Prepandemic samples of milk, dried blood spots, and infant stool were used as controls. Milk, dried blood spots, and infant stool were tested by enzyme-linked immunosorbent assay for receptor-binding domain (RBD)-specific immunoglobulin (Ig)A and IgG. Milk samples were tested for the presence of neutralizing antibodies against the spike and four variants of concern: D614G, Alpha (B.1.1.7), Beta (B.1.351), and Gamma (P.1). Levels of 10 cytokines were measured in milk samples. RESULTS: Milk from COVID-19-immunized women neutralized the spike and four variants of concern, primarily driven by anti-RBD IgG. The immune response in milk also included significant elevation of interferon-γ. The immune response to maternal vaccination was reflected in breastfed infants: anti-RBD IgG and anti-RBD IgA were detected in 33% and 30% of infant stool samples, respectively. Levels of anti-RBD antibodies in infant stool correlated with maternal vaccine side effects. Median antibody levels against RBD were below the positive cutoffs in prepandemic milk and infant stool samples. CONCLUSION: Humoral and cellular immune responses to mRNA-based COVID-19 vaccination are present in most women's breast milk. The milk anti-RBD antibodies can neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike and variants of concern. Anti-RBD antibodies are transferred to breastfed infants, with the potential to confer passive immunity against SARS-CoV-2.


Subject(s)
Antibodies, Neutralizing/analysis , Breast Feeding , COVID-19 Vaccines/immunology , Cytokines/analysis , Milk, Human/chemistry , SARS-CoV-2/immunology , Adult , Antibodies, Viral/analysis , Cohort Studies , Female , Humans , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Infant , Infant, Newborn , Middle Aged , Vaccination
3.
Front Immunol ; 13: 751705, 2022.
Article in English | MEDLINE | ID: covidwho-1686480

ABSTRACT

COVID-19 affects children to a lesser extent than adults but they can still get infected and transmit SARS-CoV-2 to their contacts. Field deployable non-invasive sensitive diagnostic techniques are needed to evaluate the infectivity dynamics of SARS-CoV-2 in pediatric populations and guide public health interventions, particularly if this population is not fully vaccinated. We evaluated the utility of high-throughput Luminex assays to quantify saliva IgM, IgA and IgG antibodies against five SARS-CoV-2 spike (S) and nucleocapsid (N) antigens in a contacts and infectivity longitudinal study in 122 individuals (52 children and 70 adults). We compared saliva versus serum/plasma samples in infected children and adults diagnosed by weekly RT-PCR over 35 days (n=62), and those who consistently tested negative over the same follow up period (n=60), in the Summer of 2020 in Barcelona, Spain. Saliva antibody levels in SARS-CoV-2 RT-PCR positive individuals were significantly higher than in negative individuals and correlated with those measured in sera/plasmas. Asymptomatic infected individuals had higher levels of anti-S IgG than symptomatic individuals, suggesting a protective anti-disease role for antibodies. Higher anti-S IgG and IgM levels in serum/plasma and saliva, respectively, in infected children compared to infected adults could also be related to stronger clinical immunity in them. Among infected children, males had higher levels of saliva IgG to N and RBD than females. Despite overall correlation, individual clustering analysis suggested that responses that may not be detected in blood could be patent in saliva, and vice versa. In conclusion, measurement of SARS-CoV-2-specific saliva antibodies should be considered as a complementary non-invasive assay to serum/plasma to determine COVID-19 prevalence and transmission in pediatric populations before and after vaccination campaigns.


Subject(s)
Antibodies, Viral/analysis , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Immunoassay/methods , Saliva , Adult , Child , Female , Humans , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Male , SARS-CoV-2 , Spain
4.
PLoS One ; 17(2): e0263419, 2022.
Article in English | MEDLINE | ID: covidwho-1674014

ABSTRACT

Mucosal immunity plays a crucial role in controlling upper respiratory infections, including influenza. We established a quantitative ELISA to measure the amount of influenza virus-specific salivery IgA (sIgA) and salivary IgG (sIgG) antibodies using a standard antibody broadly reactive to the influenza A virus. We then analyzed saliva and serum samples from seven individuals infected with the A(H1N1)pdm09 influenza virus during the 2019-2020 flu seasons. We detected an early (6-10 days post-infection) increase of sIgA in five of the seven samples and a later (3-5 weeks) increase of sIgG in six of the seven saliva samples. Although the conventional parenteral influenza vaccine did not induce IgA production in saliva, vaccinated individuals with a history of influenza infection had higher basal levels of sIgA than those without a history. Interestingly, we observed sIgA and sIgG in an asymptomatic individual who had close contact with two influenza cases. Both early mucosal sIgA secretion and late systemically induced sIgG in the mucosal surface may protect against virus infection. Despite the small sample size, our results indicate that the saliva test system can be useful for analyzing upper mucosal immunity in influenza.


Subject(s)
Immunity, Mucosal/physiology , Influenza, Human/immunology , Saliva/immunology , Adult , Aged , Antibodies, Viral/analysis , Antibodies, Viral/metabolism , Antibody Formation , Cohort Studies , Female , History, 21st Century , Humans , Immunoglobulin A/analysis , Immunoglobulin A/metabolism , Immunoglobulin A, Secretory/analysis , Immunoglobulin A, Secretory/metabolism , Immunoglobulin G/analysis , Immunoglobulin G/metabolism , Influenza A Virus, H1N1 Subtype/immunology , Influenza Vaccines/therapeutic use , Influenza, Human/diagnosis , Influenza, Human/prevention & control , Japan , Longitudinal Studies , Male , Predictive Value of Tests , Prognosis , Saliva/chemistry , Saliva/metabolism , Young Adult
5.
Pediatrics ; 149(2)2022 02 01.
Article in English | MEDLINE | ID: covidwho-1607590

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibodies have been detected in human milk up to 6 weeks post-coronavirus disease 2019 (COVID-19) vaccination. We evaluated SARS-CoV-2-specific antibodies, neutralization activity, effect of pasteurization, and persistence through 6 months after vaccination. METHODS: This prospective longitudinal study enrolled 30 pregnant or lactating women. SARS-CoV-2 antibodies and neutralization capacity were analyzed using an enzyme-linked immunosorbent assay compared at prevaccination and 1, 3, and 6 months postvaccination, and through Holder pasteurization. RESULTS: Human milk SARS-CoV-2-specific IgG levels peaked at 1 month postvaccination and persisted above prevaccination levels for at least 6 months (P = .005). SARS-CoV-2-specific IgA was detected at 1 and 3 months (both P < .001) but waned by 6 months compared with baseline (P = .07). Milk SARS-CoV-2-specific IgG and IgA correlated with serum IgG at the same time point (R2 = 0.37, P < .001 and R2 = 0.19, P < .001). Neutralization activity was seen in 83.3%, 70.4%, and 25.0% of milk samples at 1, 3, and 6 months postvaccination. Neutralization most strongly correlated with SARS-CoV-2-specific IgG (R2 = 0.57, P < .001). Pre- and postpasteurization samples showed similar IgG (0.84 vs 1.07, P = .36) and neutralizing activity (57.7% vs 58.7% inhibition, P = .27), but lower IgM and IgA levels postpasteurization (0.09 vs 0.06, P = .004 and 0.21 vs 0.18, P = .043). CONCLUSIONS: The data suggest that human milk SARS-CoV-2-specific antibodies may be available to milk-fed infants for up to 6 months. In addition, donor milk from vaccinated mothers retain IgG and neutralizing activity.


Subject(s)
Antibodies, Viral/analysis , COVID-19 Vaccines , Milk, Human/chemistry , SARS-CoV-2/immunology , Adult , Breast Feeding , Female , Humans , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Infant , Infant, Newborn , Lactation , Longitudinal Studies , Pasteurization , Prospective Studies
7.
Front Immunol ; 12: 744887, 2021.
Article in English | MEDLINE | ID: covidwho-1497079

ABSTRACT

Background: Although the serological antibody responses induced by SARS-CoV-2 vaccines are well characterized, little is known about their ability to elicit mucosal immunity. Objectives: This study aims to examine and compare the mucosal and systemic responses of recipients of two different vaccination platforms: mRNA (Comirnaty) and inactivated virus (CoronaVac). Methods: Serial blood and nasal epithelial lining fluid (NELF) samples were collected from the recipients of either Comirnaty or CoronaVac. The plasma and NELF immunoglobulins A and G (IgA and IgG) specific to SARS-CoV-2 S1 protein (S1) and their neutralization effects were quantified. Results: Comirnaty induced nasal S1-specific immunoglobulin responses, which were evident as early as 14 ± 2 days after the first dose. In 64% of the subjects, the neutralizing effects of NELF persisted for at least 50 days. Moreover, 85% of Comirnaty recipients exhibited S1-specific IgA and IgG responses in plasma by 14 ± 2 days after the first dose. By 7 ± 2 days after the booster, all plasma samples possessed S1-specific IgA and IgG responses and were neutralizing. The induction of S1-specific plasma antibodies by CoronaVac was IgG dominant, and 83% of the subjects possessed S1-specific IgG by 7 ± 2 days after the booster, with neutralizing effects. Conclusion: Comirnaty induces S1-specific IgA and IgG responses with neutralizing activity in the nasal mucosa; a similar response is not seen with CoronaVac. Clinical Implication: The presence of a nasal response with mRNA vaccine may provide additional protection compared with inactivated virus vaccine. However, whether such widespread immunological response may produce inadvertent adverse effects in other tissues warrants further investigation.


Subject(s)
COVID-19 Vaccines/immunology , Immunity, Mucosal , SARS-CoV-2/immunology , Adult , Age Factors , Aged , Antibodies, Neutralizing/analysis , Antibodies, Viral/analysis , COVID-19/immunology , COVID-19/prevention & control , Female , Humans , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Male , Middle Aged , Nasal Mucosa/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination , Vaccines, Inactivated/immunology , Vaccines, Synthetic/immunology , Young Adult
8.
J Infect Dis ; 225(4): 578-586, 2022 02 15.
Article in English | MEDLINE | ID: covidwho-1462363

ABSTRACT

BACKGROUND: Immunoglobulin A (IgA) is an important component of the early immune response to SARS-CoV-2. Prior serosurveys in high-risk groups employing IgG testing alone have provided discordant estimates. The potential added benefit of IgA in serosurveys has not been established. METHODS: Longitudinal serosurvey of first responders (police, emergency medical service providers, fire fighters, and other staff) employing 3 serologic tests (anti-spike IgA, anti-spike IgG, and anti-nucleocapsid IgG) correlated with surveys assessing occupational and nonoccupational risk, exposure to COVID-19, and illnesses consistent with COVID-19. RESULTS: Twelve percent of first responders in Colorado at baseline and 22% at follow-up were assessed as having SARS-CoV-2 infection. Five percent at baseline and 6% at follow-up were seropositive only for IgA. Among those IgA positive only at baseline, the majority (69%) had a positive antibody at follow-up; 45% of those infected at baseline and 33% at follow-up were asymptomatic. At all time points, the estimated cumulative incidence in our study was higher than that in the general population. CONCLUSIONS: First responders are at high risk of infection with SARS-CoV-2. IgA testing identified a significant portion of cases missed by IgG testing and its use as part of serologic surveys may improve retrospective identification of asymptomatic infection.


Subject(s)
Antibodies, Viral/analysis , Asymptomatic Infections , COVID-19 , Emergency Responders , Immunoglobulin A/analysis , COVID-19/diagnosis , COVID-19/immunology , Humans , Immunoglobulin G/analysis , Retrospective Studies
9.
Pediatrics ; 148(5)2021 11.
Article in English | MEDLINE | ID: covidwho-1365458

ABSTRACT

BACKGROUND AND OBJECTIVES: Passive and active immunity transfer through human milk (HM) constitutes a key element in the infant's developing immunity. Certain infectious diseases and vaccines have been described to induce changes in the immune components of HM. METHODS: We conducted a prospective cohort single-institution study from February 2 to April 4, 2021. Women who reported to be breastfeeding at the time of their coronavirus disease 2019 (COVID-19) vaccination were invited to participate. Blood and milk samples were collected on day 14 after their second dose of the vaccine. Immunoglobulin G (IgG) antibodies against nucleocapsid protein as well as IgG, immunoglobulin M and immunoglobulin A (IgA) antibodies against the spike 1 protein receptor-binding domain against severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2 RBD-S1) were analyzed in both serum and HM samples. RESULTS: Most of the participants (ie, 94%) received the BNT162b2 messenger RNA COVID-19 vaccine. The mean serum concentration of anti-SARS-CoV-2 RBD-S-IgG antibodies in vaccinated individuals was 3379.6 ± 1639.5 binding antibody units per mL. All vaccinated study participants had anti-SARS-CoV-2 RBD-S1-IgG, and 89% of them had anti-SARS-CoV-2 RBD-S-IgA in their milk. The antibody concentrations in the milk of mothers who were breastfeeding 24 months were significantly higher than in mothers with breastfeeding periods <24 months (P < .001). CONCLUSIONS: We found a clear association between COVID-19 vaccination and specific immunoglobulin concentrations in HM. This effect was more pronounced when lactation periods exceeded 23 months. The influence of the lactation period on immunoglobulins was specific and independent of other variables.


Subject(s)
Antibodies, Viral/analysis , COVID-19 Vaccines , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Milk, Human/chemistry , Milk, Human/immunology , SARS-CoV-2/immunology , Adult , Female , Humans , Infant , Infant, Newborn , Male , Prospective Studies , Vaccination
10.
Ann Lab Med ; 41(6): 577-587, 2021 Nov 01.
Article in English | MEDLINE | ID: covidwho-1264321

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody assays have high clinical utility in managing the pandemic. We compared antibody responses and seroconversion of coronavirus disease 2019 (COVID-19) patients using different immunoassays. METHODS: We evaluated 12 commercial immunoassays, including three automated chemiluminescent immunoassays (Abbott, Roche, and Siemens), three enzyme immunoassays (Bio-Rad, Euroimmun, and Vircell), five lateral flow immunoassays (Boditech Med, SD biosensor, PCL, Sugentech, and Rapigen), and one surrogate neutralizing antibody assay (GenScript) in sequential samples from 49 COVID-19 patients and 10 seroconversion panels. RESULTS: The positive percent agreement (PPA) of assays for a COVID-19 diagnosis ranged from 84.0% to 98.5% for all samples (>14 days after symptom onset), with IgM or IgA assays showing higher PPAs. Seroconversion responses varied across the assay type and disease severity. Assays targeting the spike or receptor-binding domain protein showed a tendency for early seroconversion detection and higher index values in patients with severe disease. Index values from SARS-CoV-2 binding antibody assays (three automated assays, one LFIA, and three EIAs) showed moderate to strong correlations with the neutralizing antibody percentage (r=0.517-0.874), and stronger correlations in patients with severe disease and in assays targeting spike protein. Agreement among the 12 assays was good (74.3%-96.4%) for detecting IgG or total antibodies. CONCLUSIONS: Positivity rates and seroconversion of SARS-CoV-2 antibodies vary depending on the assay kits, disease severity, and antigen target. This study contributes to a better understanding of antibody response in symptomatic COVID-19 patients using currently available assays.


Subject(s)
Antibodies, Viral/analysis , COVID-19 Testing/methods , COVID-19/diagnosis , SARS-CoV-2/immunology , COVID-19/pathology , COVID-19/virology , Humans , Immunoassay , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Reagent Kits, Diagnostic , SARS-CoV-2/isolation & purification , Sensitivity and Specificity , Severity of Illness Index
12.
Transfusion ; 61(6): 1740-1748, 2021 06.
Article in English | MEDLINE | ID: covidwho-1243668

ABSTRACT

BACKGROUND: While convalescent plasma (CP) may benefit patients with COVID-19, fundamental questions remain regarding its efficacy, including the components of CP that may contribute to its therapeutic effect. Most current serological evaluation of CP relies on examination of total immunoglobulin or IgG-specific anti-SARS-CoV-2 antibody levels. However, IgA antibodies, which also circulate and are secreted along the respiratory mucosa, represent a relatively uncharacterized component of CP. STUDY DESIGN AND METHODS: Residual samples from patients and CP donors were assessed for IgM, IgG, and IgA anti-SARS-CoV-2 antibody titers against the receptor-binding domain responsible for viral entry. Symptom onset was obtained by chart review. RESULTS: Increased IgA anti-SARS-CoV-2 antibody levels correlated with clinical improvement and viral clearance in an infant with COVID-19, prompting a broader examination of IgA levels among CP donors and hospitalized patients. Significant heterogeneity in IgA levels was observed among CP donors, which correlated weakly with IgG levels or the results of a commonly employed serological test. Unlike IgG and IgM, IgA levels were also more likely to be variable in hospitalized patients and this variability persisted in some patients >14 days following symptom onset. IgA levels were also less likely to be sustained than IgG levels following subsequent CP donation. CONCLUSIONS: IgA levels can be very heterogenous among CP donors and hospitalized patients and do not necessarily correlate with commonly employed testing platforms. Examining isotype levels in CP and COVID-19 patients may allow for a tailored approach when seeking to fill specific gaps in humoral immunity.


Subject(s)
COVID-19/immunology , COVID-19/therapy , Convalescence , Immunoglobulin A/blood , SARS-CoV-2/immunology , Antibodies, Viral/blood , Blood Donors , Down Syndrome/complications , Down Syndrome/immunology , Down Syndrome/therapy , Female , Heart Septal Defects/complications , Heart Septal Defects/immunology , Heart Septal Defects/therapy , Humans , Immunity, Humoral/immunology , Immunization, Passive/methods , Immunoglobulin A/analysis , Immunoglobulin G/blood , Immunoglobulin M/blood , Infant , Retrospective Studies , Serologic Tests , United States
13.
Am J Clin Pathol ; 155(6): 773-775, 2021 05 18.
Article in English | MEDLINE | ID: covidwho-1202372

ABSTRACT

OBJECTIVES: Serologic assay performance studies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-​2) in pediatric populations are lacking, and few seroprevalence studies have routinely incorporated orthogonal testing to improve accuracy. METHODS: Remnant serum samples for routine bloodwork from 2,338 pediatric patients at UPMC Children's Hospital of Pittsburgh were assessed using the EUROIMMUN Anti-SARS-CoV-2 ELISA IgG (EuroIGG) assay. Reactive cases with sufficient volume were also tested using 3 additional commercial assays. RESULTS: Eighty-five specimens were reactive according to the EuroIGG, yielding 3.64% (95% confidence interval [CI], 2.91%-4.48%) seropositivity, of which 73 specimens had sufficient remaining volume for confirmation by orthogonal testing. Overall, 19.18% (95% CI, 10.18%-28.18%) of samples were positive on a second and/or third orthogonal assay. This 80.82% false positivity rate is disproportionate to the expected false positivity rate of 50% given our pediatric population prevalence and assay performance. CONCLUSIONS: In pediatric populations, false-positive SARS-CoV-2 serology may be more common than assay and prevalence parameters would predict, and further studies are needed to establish the performance of SARS-CoV-2 serology in children.


Subject(s)
COVID-19 Testing , COVID-19/diagnosis , SARS-CoV-2/pathogenicity , Sensitivity and Specificity , Seroepidemiologic Studies , Antibodies, Viral/blood , COVID-19 Testing/methods , Child , Enzyme-Linked Immunosorbent Assay/methods , Humans , Immunoglobulin A/analysis , Male
15.
Cell ; 184(2): 476-488.e11, 2021 01 21.
Article in English | MEDLINE | ID: covidwho-1012326

ABSTRACT

Coronavirus disease 2019 (COVID-19) exhibits variable symptom severity ranging from asymptomatic to life-threatening, yet the relationship between severity and the humoral immune response is poorly understood. We examined antibody responses in 113 COVID-19 patients and found that severe cases resulting in intubation or death exhibited increased inflammatory markers, lymphopenia, pro-inflammatory cytokines, and high anti-receptor binding domain (RBD) antibody levels. Although anti-RBD immunoglobulin G (IgG) levels generally correlated with neutralization titer, quantitation of neutralization potency revealed that high potency was a predictor of survival. In addition to neutralization of wild-type SARS-CoV-2, patient sera were also able to neutralize the recently emerged SARS-CoV-2 mutant D614G, suggesting cross-protection from reinfection by either strain. However, SARS-CoV-2 sera generally lacked cross-neutralization to a highly homologous pre-emergent bat coronavirus, WIV1-CoV, which has not yet crossed the species barrier. These results highlight the importance of neutralizing humoral immunity on disease progression and the need to develop broadly protective interventions to prevent future coronavirus pandemics.


Subject(s)
Antibodies, Neutralizing/immunology , Biomarkers/analysis , COVID-19/immunology , COVID-19/physiopathology , Adult , Antibodies, Neutralizing/analysis , Antibodies, Viral/analysis , Antibodies, Viral/blood , Biomarkers/blood , COVID-19/blood , COVID-19/epidemiology , Comorbidity , Coronavirus/classification , Coronavirus/physiology , Cross Reactions , Cytokines/blood , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin A/analysis , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , Massachusetts/epidemiology , Middle Aged , Protein Domains , SARS-CoV-2/chemistry , SARS-CoV-2/physiology , Severity of Illness Index , Spike Glycoprotein, Coronavirus/chemistry , Survival Analysis , Treatment Outcome
17.
Sci Rep ; 10(1): 20818, 2020 11 30.
Article in English | MEDLINE | ID: covidwho-951690

ABSTRACT

To facilitate containment of the COVID-19 pandemic currently active in the United States and across the world, options for easy, non-invasive antibody testing are required. Here we have adapted a commercially available, serum-based enzyme-linked immunosorbent assay (ELISA) for use with saliva samples, achieving 84.2% sensitivity and 100% specificity in a set of 149 clinical samples. This strategy will enable widespread, affordable testing for patients who experienced this disease, whilst minimizing exposure risk for healthcare workers.


Subject(s)
Antibodies, Viral/analysis , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Saliva/immunology , Carrier State/diagnosis , Clinical Laboratory Techniques , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Immunoglobulin M/analysis , SARS-CoV-2/immunology , Sensitivity and Specificity
18.
J Med Virol ; 92(11): 2863-2865, 2020 11.
Article in English | MEDLINE | ID: covidwho-935139

ABSTRACT

The diagnosis of coronavirus disease 2019 (COVID-19) is mainly based on a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) result. PCR samples are obtained from upper or lower respiratory tract specimens. However, the sensitivity of PCR is known to have some limitations. We report on a patient who was admitted to our hospital with dyspnea, fever, cough, and history of contact with a SARS-CoV-2 infected relative. The initial chest computed tomography (CT) showed only minimal changes and SARS-CoV-2 PCR from a nasopharyngeal swab sample was negative. PCR results obtained from further nasopharyngeal swabs, qualified sputum samples, and from a lower respiratory tract specimen also remained negative. At day 13 after admission, a second chest CT showed radiological findings suspicious for viral pneumonia. Finally, serologic results showed high levels of immunoglobulin G and immunoglobulin A antibodies against the S1 domain of the SARS-CoV-2 spike protein, and the patient was diagnosed with COVID-19 pneumonia.


Subject(s)
Antibodies, Viral/blood , COVID-19 Nucleic Acid Testing , COVID-19 Serological Testing , COVID-19/diagnosis , Tomography, X-Ray Computed , Aged , Humans , Immunoglobulin A/analysis , Immunoglobulin G/blood , Male , RNA, Viral/genetics , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/immunology
19.
Emerg Microbes Infect ; 9(1): 2547-2549, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-933806

ABSTRACT

The objective of this study was to evaluate the validity and reliability of NG-Test® when used as a finger-prick test on healthcare workers and to compare it to the ELISA Wantai Immunoassay. Fifty-one healthcare workers who were RT-PCR SARS-CoV-2 positive and 59 who were RT-PCR SARS-CoV-2 negative accepted to participate in this study. They were subjected to an NG-Test® finger-prick test and collection of a blood sample on the same day. A second NG-Test® on another finger was performed for the first 30 cases and controls and read blinded to the first. Sera obtained from blood samples were used to perform the Wantai SARS-CoV-2 ELISA. The interobserver agreement for the NG-Test® test was perfect (kappa coefficient = 100% [98%-100%]). The sensitivity of NG-Test® was estimated to be 85% [71.9%-92.3%] and the specificity 98.3% [95.0%-100.0%]) for both IgG and IgM. The percentage of agreement between the Wantai immunoassay and NG-Test® was 92.73% for IgG (Kappa = 0.85 [0.75-0.95]) and 65.45% (Kappa = 0.42 [0.26-0.58]) for IgM. Our study highlights the need to validate rapid immunoassay tests under real-life conditions. If NG-Test® is used in seroprevalence surveys, we recommend that its diagnostic performance be taken into consideration to obtain a reliable estimation.


Subject(s)
Antibodies, Viral/analysis , COVID-19/diagnosis , Health Personnel/statistics & numerical data , Immunoassay/standards , Reagent Kits, Diagnostic/standards , Serologic Tests/standards , Adult , Female , Humans , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Male , Middle Aged , Reproducibility of Results , SARS-CoV-2/isolation & purification , Sensitivity and Specificity , Seroepidemiologic Studies , Time Factors
20.
PLoS One ; 15(4): e0231723, 2020.
Article in English | MEDLINE | ID: covidwho-827309

ABSTRACT

Understanding the immune responses against Porcine epidemic diarrhea virus (PEDV) is important to prevent infection and to design control strategies. We evaluated both systemic and mucosal immune responses to PEDV in pigs and assessed if prior exposure to virus protects against re-infection. Three-week-old pigs were infected with PEDV and immune response in blood, intestine, and mesenteric lymph node (MLN) was evaluated. At 30 dpi, virus exposed pigs were challenged with a field isolate of PEDV and immune response at 5 d post challenge was evaluated. We found that PEDV RNA persists in the intestine even after fecal shedding of the virus was stopped at 28 dpi and pigs previously exposed to PEDV are protected from virus shedding after re-infection. PEDV infection induced both humoral and cell mediated immune response with an increase in PEDV specific IgA and IgG antibodies in intestine and serum. Flow cytometry analysis showed a significantly higher frequency of B cells and lower frequency of T cells at 4 dpi. The frequency of CD4/CD8 double positive (DP) memory T cells was significantly increased in the MLN of challenged animals. These studies may provide further insights into understanding the mucosal immune response to PEDV and its role in protection against disease.


Subject(s)
Antibodies, Viral/analysis , Coronavirus Infections/immunology , Diarrhea/immunology , Porcine epidemic diarrhea virus/immunology , Animals , Antibodies, Viral/immunology , Antibodies, Viral/metabolism , B-Lymphocytes/immunology , Coronavirus Infections/blood , Coronavirus Infections/veterinary , Coronavirus Infections/virology , Diarrhea/blood , Diarrhea/veterinary , Diarrhea/virology , Disease Resistance/immunology , Feces/microbiology , Immunity, Cellular , Immunity, Humoral , Immunity, Mucosal , Immunoglobulin A/analysis , Immunoglobulin A/immunology , Immunoglobulin A/metabolism , Immunoglobulin G/analysis , Immunoglobulin G/immunology , Immunoglobulin G/metabolism , Intestinal Mucosa/immunology , Intestinal Mucosa/metabolism , Porcine epidemic diarrhea virus/genetics , Porcine epidemic diarrhea virus/isolation & purification , RNA, Viral/isolation & purification , Swine , T-Lymphocytes/immunology , Virus Shedding
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