scholarly journals Asymptomatic or mild symptomatic SARS-CoV-2 infection elicits durable neutralizing antibody responses in children and adolescents

2021 ◽  
Author(s):  
Carolina Garrido ◽  
Jillian H Hurst ◽  
Cynthia G. Lorang ◽  
Jhoanna N. Aquino ◽  
Javier Rodriguez ◽  
...  
Keyword(s):  
Immune Responses ◽  
Children And Adolescents ◽  
Acute Infection ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Symptomatic Infection ◽  
Neutralizing Activity ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Broad Array

As SARS-CoV-2 continues to spread globally, questions have emerged regarding the strength and durability of immune responses in specific populations. In this study, we evaluated humoral immune responses in 69 children and adolescents with asymptomatic or mild symptomatic SARS-CoV-2 infection. We detected robust IgM, IgG, and IgA antibody responses to a broad array of SARS-CoV-2 antigens at the time of acute infection and 2 and 4 months after acute infection in all participants. Notably, these antibody responses were associated with virus neutralizing activity that was still detectable 4 months after acute infection in 94% of children. Moreover, antibody responses and neutralizing activity in sera from children and adolescents were comparable or superior to those observed in sera from 24 adults with mild symptomatic infection. Taken together, these findings indicate children and adolescents with mild or asymptomatic SARS-CoV-2 infection generate robust and durable humoral immune responses that are likely to protect from reinfection.

scholarly journals Viral Replicative Capacity, Antigen Availability via Hematogenous Spread, and High TFH:TFRRatios Drive Induction of Potent Neutralizing Antibody Responses

2019 ◽  
Vol 93 (6) ◽  
Author(s):  
Preethi Eldi ◽  
Geeta Chaudhri ◽  
Stephen L. Nutt ◽  
Timothy P. Newsome ◽  
Gunasegaran Karupiah
Keyword(s):  
Immune Responses ◽  
Antibody Response ◽  
Germinal Center ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Replicative Capacity ◽  
Hematogenous Spread ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Early Predictor

ABSTRACTLive viral vaccines elicit protective, long-lived humoral immunity, but the underlying mechanisms through which this occurs are not fully elucidated. Generation of affinity matured, long-lived protective antibody responses involve close interactions between T follicular helper (TFH) cells, germinal center (GC) B cells, and T follicular regulatory (TFR) cells. We postulated that escalating concentrations of antigens from replicating viruses or live vaccines, spread through the hematogenous route, are essential for the induction and maintenance of long-lived protective antibody responses. Using replicating and poorly replicating or nonreplicating orthopox and influenza A viruses, we show that the magnitude of TFH cell, GC B cell, and neutralizing antibody responses is directly related to virus replicative capacity. Further, we have identified that both lymphoid and circulating TFH:TFRcell ratios during the peak GC response can be used as an early predictor of protective, long-lived antibody response induction. Finally, administration of poorly or nonreplicating viruses to allow hematogenous spread generates significantly stronger TFH:TFRratios and robust TFH, GC B cell and neutralizing antibody responses.IMPORTANCENeutralizing antibody response is the best-known correlate of long-term protective immunity for most of the currently licensed clinically effective viral vaccines. However, the host immune and viral factors that are critical for the induction of robust and durable antiviral humoral immune responses are not well understood. Our study provides insight into the dynamics of key cellular mediators of germinal center reaction during live virus infections and the influence of viral replicative capacity on the magnitude of antiviral antibody response and effector function. The significance of our study lies in two key findings. First, the systemic spread of even poorly replicating or nonreplicating viruses to mimic the spread of antigens from replicating viruses due to escalating antigen concentration is fundamental to the induction of durable antibody responses. Second, the TFH:TFRratio may be used as an early predictor of protective antiviral humoral immune responses long before memory responses are generated.

scholarly journals Antibody responses in buffalos immunized with Clostridium perfringens beta and epsilon toxoids

2001 ◽  
Vol 46 (No. 9–10) ◽  
pp. 241-243 ◽  
Author(s):  
S. Rahman M ◽  
K. Baek B ◽  
T. Hong S ◽  
H. Lee J
Keyword(s):  
Antibody Titre ◽  
Clostridium Perfringens ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Control Group ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Antibody Titres ◽  
Group A ◽  
And Control

The antibody responses to toxoids were measured to investigate whether Clostridium perfringens beta and epsilon toxoids induced protective humoral immune responses in buffalos. Total of 24 buffalos were divided into 4 groups (n = 6), beta toxoid, epsilon toxoid, combination and control groups. These buffalo groups were administered each of the designated toxoids. Immunizations in the beta and epsilon toxoid groups induced strong antibody responses. The neutralizing antibody titres from the beta and epsilon toxoid groups were equally log101.2 on day 21 after inoculation whereas there was no antibody titre detected from the control group. A statistically significant (P < 0.01) increase in antibody titre was observed from day 0 to day 14 and 21 after inoculation. The antibody production did not vary significantly due to day of inoculation and toxoid interactions.

scholarly journals mRNA vaccination in people over 80 years of age induces strong humoral immune responses against SARS-CoV-2 with cross neutralization of P.1 Brazilian variant

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Helen Parry ◽  
Gokhan Tut ◽  
Rachel Bruton ◽  
Sian Faustini ◽  
Christine Stephens ◽  
...  
Keyword(s):  
Immune Responses ◽  
Cellular Response ◽  
Humoral Response ◽  
Antibody Responses ◽  
Vaccine Platform ◽  
Humoral Immune ◽  
Vaccine Responses ◽  
Cellular Immune Responses ◽  
Humoral Immune Responses ◽  
Cellular Immune

Age is the major risk factor for mortality after SARS-CoV-2 infection and older people have received priority consideration for COVID-19 vaccination. However, vaccine responses are often suboptimal in this age group and few people over the age of 80 years were included in vaccine registration trials. We determined the serological and cellular response to spike protein in 100 people aged 80–96 years at 2 weeks after the second vaccination with the Pfizer BNT162b2 mRNA vaccine. Antibody responses were seen in every donor with high titers in 98%. Spike-specific cellular immune responses were detectable in only 63% and correlated with humoral response. Previous SARS-CoV-2 infection substantially increased antibody responses after one vaccine and antibody and cellular responses remained 28-fold and 3-fold higher, respectively, after dual vaccination. Post-vaccine sera mediated strong neutralization of live Victoria infection and although neutralization titers were reduced 14-fold against the P.1 variant first discovered in Brazil they remained largely effective. These data demonstrate that the mRNA vaccine platform delivers strong humoral immunity in people up to 96 years of age and retains broad efficacy against the P.1 variant of concern.

scholarly journals The vaccinia-based Sementis Copenhagen Vector COVID-19 vaccine induces broad and durable cellular and humoral immune responses

2021 ◽  
Author(s):  
Preethi Eldi ◽  
Tamara H Cooper ◽  
Natalie A Prow ◽  
Liang Liu ◽  
Gary K Heinemann ◽  
...  
Keyword(s):  
Immune Responses ◽  
Neutralizing Antibodies ◽  
First Generation ◽  
Neutralizing Antibody ◽  
Immune Memory ◽  
Antibody Activity ◽  
Post Vaccination ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Heterologous Boost

The ongoing COVID-19 pandemic perpetuated by SARS-CoV-2 variants, has highlighted the continued need for broadly protective vaccines that elicit robust and durable protection. Here, the vaccinia virus-based, replication-defective Sementis Copenhagen Vector (SCV) was used to develop a first-generation COVID-19 vaccine encoding the spike glycoprotein (SCV-S). Vaccination of mice rapidly induced polyfunctional CD8 T cells with cytotoxic activity and robust Th1-biased, spike-specific neutralizing antibodies, which are significantly increased following a second vaccination, and contained neutralizing activity against the alpha and beta variants of concern. Longitudinal studies indicated neutralizing antibody activity was maintained up to 9 months post-vaccination in both young and aging mice, with durable immune memory evident even in the presence of pre-existing vector immunity. This immunogenicity profile suggests a potential to expand protection generated by current vaccines in a heterologous boost format, and presents a solid basis for second-generation SCV-based COVID-19 vaccine candidates incorporating additional SARS-CoV-2 immunogens.

scholarly journals Limited Local and Systemic Antibody Responses toNeisseria gonorrhoeae during Uncomplicated Genital Infections

1999 ◽  
Vol 67 (8) ◽  
pp. 3937-3946 ◽  
Author(s):  
Spencer R. Hedges ◽  
Matthew S. Mayo ◽  
Jiri Mestecky ◽  
Edward W. Hook ◽  
Michael W. Russell
Keyword(s):  
Immune Responses ◽  
Transmitted Disease ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Genital Infections ◽  
Sexually Transmitted ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Repeated Infections ◽  
Antibody Levels

ABSTRACT Repeated infections with Neisseria gonorrhoeae are common among patients attending sexually transmitted disease clinics. We examined whether previous infections or site of infection altered the local and systemic antigonococcal antibody levels in males and females. Antibodies against N. gonorrhoeae MS11 and the patients’ homologous infecting isolates were measured by enzyme-linked immunosorbent assay. In general, the local and systemic immune responses to gonococci were extremely modest. There was a slight increase in serum immunoglobulin G (IgG) against the MS11 strain and the homologous isolates in infected males. Levels of serum IgA1 antibodies against MS11 were slightly higher in infected than in uninfected females. A history of previous infections with N. gonorrhoeae did not alter the antibody levels in patients with a current infection, suggesting that immunological memory is not induced by uncomplicated gonococcal infections. Antibody responses to infected subjects’ homologous isolates were observed in cervical mucus; IgA1 levels increased while IgG levels decreased. The decline in mucosal IgG against the homologous isolates was less common in subjects having both rectal and cervical infections; otherwise, no effect of rectal involvement was observed. The absence of substantially higher antibody levels to gonococci where there is infection at a site known to contain organized lymphoid tissue suggests that the low levels of responses to uncomplicated infections may not be due simply to an absence of inductive sites in the genital tract. We propose that in addition to its potential ability to avoid the effects of an immune response,N. gonorrhoeae does not elicit strong humoral immune responses during uncomplicated genital infections.

Regulation of humoral immunity in rats by pituitary hormones

1981 ◽  
Vol 98 (4) ◽  
pp. 506-513 ◽  
Author(s):  
Istvan Berczi ◽  
Eva Nagy ◽  
Kalman Kovacs ◽  
Eva Horvath
Keyword(s):  
Immune Responses ◽  
Antibody Formation ◽  
Pituitary Hormones ◽  
Antibody Responses ◽  
Igg Antibodies ◽  
E Coli ◽  
Humoral Immune ◽  
Fischer 344 ◽  
Humoral Immune Responses ◽  
Hypophysectomized Rats

Abstract. Hypophysectomized female Fischer 344 and Wistar-Furth rats had severely impaired primary and secondary antibody responses to sheep red blood cells (SRBC). Mercaptoethanol-sensitive (IgM) and mercaptoethanol-resistant (IgG) antibodies were similarly affected. Titers to E. Coli 055:B5 lipopolysaccharide were also significantly decreased in such animals. The antibody response of hypophysectomized rats could be restored by syngeneic pituitary grafts when placed under the kidney capsule or by prolactin treatment. Growth hormone was less effective in this respect than prolactin. Treatment of normal rats with ACTH suppressed their antibody formation to SRBC. These results indicate that the pituitary gland has the potential to regulate humoral immune responses.

scholarly journals Limited ability of humoral immune responses in control of viremia during infection with SIVsmmD215 strain

Blood ◽  
2009 ◽  
Vol 113 (18) ◽  
pp. 4250-4261 ◽  
Author(s):  
Thaidra Gaufin ◽  
Rajeev Gautam ◽  
Melissa Kasheta ◽  
Ruy Ribeiro ◽  
Erin Ribka ◽  
...  
Keyword(s):  
Immune Responses ◽  
Antibody Production ◽  
Neutralizing Antibody ◽  
Viral Loads ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Significant Difference ◽  
Anti Cd20 ◽  
And Control ◽  
The Impact

AbstractWe investigated the impact of rhesus macaque (RM) B-cell depletion before inoculation with the isolate SIVsmmD215. Seven RMs were treated every 3 weeks with 50 mg/kg of an anti-CD20 antibody (rituximab) starting 7 days before inoculation for 2 (n = 4) and 5 (n = 3) months. Four control animals received no antibody. Three animals were completely depleted of CD20+ B cells, but 4 were only partially depleted of CD20 cells in the LNs and intestine. The decrease in antibody production was consistent with the efficacy of tissue CD20 depletion. Seroconversion and neutralizing antibody production was significantly delayed in animals showing complete tissue CD20 depletion and remained at low titers in all CD20-depleted RMs. Surprisingly, there was no significant difference in acute or chronic viral loads between CD20-depleted and control animal groups. There was a tendency for lower viral set points in CD20-depleted animals. At 6 weeks after inoculation, cellular immune responses were significantly stronger in CD20-depleted animals than in controls. There was no significant difference in survival between CD20-depleted and control animals. Our data suggest that a deficiency of Ab responses did not markedly affect viral replication or disease progression and that they may be compensated by more robust cellular responses.

scholarly journals Cellular and Humoral Immune Responses toBorrelia burgdorferi Antigens in Patients with Culture-Positive Early Lyme Disease

2001 ◽  
Vol 69 (12) ◽  
pp. 7437-7444 ◽  
Author(s):  
Austin Vaz ◽  
Lisa Glickstein ◽  
Jodie A. Field ◽  
Gail McHugh ◽  
Vijay K. Sikand ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Immune Responses ◽  
Erythema Migrans ◽  
Antibody Responses ◽  
Humoral Immune ◽  
Convalescent Phase ◽  
Humoral Immune Responses ◽  
Antibody Reactivity ◽  
Disseminated Disease ◽  
Culture Positive

ABSTRACT We determined cellular and humoral immune responses toBorrelia burgdorferi lysate and to recombinant flagellin (FlaB), OspC, and OspA in acute- and convalescent-phase samples from 39 culture-positive patients with erythema migrans and in 20 healthy control subjects. During the acute illness, a median of 4 days after the onset of erythema migrans, 51% of the patients had proliferative cellular responses and 72% had antibody responses to at least one of the borrelial antigens tested. During convalescence, at the conclusion of antibiotic therapy, 64% of the patients had proliferative cellular reactivity and 95% had antibody reactivity with at least one of the spirochetal antigens tested. In both acute- and convalescent-phase samples, cellular immune responses were found as frequently to OspA as to OspC and FlaB. Although antibody responses were also frequently seen to OspC and FlaB, only a few patients had marginal antibody reactivity with OspA. The percentage of patients with proliferative responses was similar in those with clinical evidence of localized or disseminated infection, whereas humoral reactivity was found more often in those with disseminated disease. We conclude that cellular and humoral responses to B. burgdorferi antigens are often found among patients with early Lyme disease. In contrast with the other antigens tested, cellular but not humoral reactivity was often found with OspA.

Pathogenic and humoral immune responses to porcine reproductive and respiratory syndrome virus (PRRSV) are related to viral load in acute infection

2004 ◽  
Vol 102 (3) ◽  
pp. 233-247 ◽  
Author(s):  
Wesley Johnson ◽  
Michael Roof ◽  
Eric Vaughn ◽  
Jane Christopher-Hennings ◽  
Craig R. Johnson ◽  
...  
Keyword(s):  
Viral Load ◽  
Immune Responses ◽  
Acute Infection ◽  
Respiratory Syndrome Virus ◽  
Humoral Immune ◽  
Humoral Immune Responses

scholarly journals Antigen targeting to dendritic cells elicits long-lived T cell help for antibody responses

2006 ◽  
Vol 203 (3) ◽  
pp. 599-606 ◽  
Author(s):  
Silvia B. Boscardin ◽  
Julius C.R. Hafalla ◽  
Revati F. Masilamani ◽  
Alice O. Kamphorst ◽  
Henry A. Zebroski ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Immune Responses ◽  
Lymphoid Organs ◽  
Antibody Responses ◽  
Carrier Protein ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Maturation Stimulus ◽  
T Cell Help

Resistance to several prevalent infectious diseases requires both cellular and humoral immune responses. T cell immunity is initiated by mature dendritic cells (DCs) in lymphoid organs, whereas humoral responses to most antigens require further collaboration between primed, antigen-specific helper T cells and naive or memory B cells. To determine whether antigens delivered to DCs in lymphoid organs induce T cell help for antibody responses, we targeted a carrier protein, ovalbumin (OVA), to DCs in the presence of a maturation stimulus and assayed for antibodies to a hapten, (4-hydroxy-3-nitrophenyl) acetyl (NP), after boosting with OVA-NP. A single DC-targeted immunization elicited long-lived T cell helper responses to the carrier protein, leading to large numbers of antibody-secreting cells and high titers of high-affinity antihapten immunoglobulin Gs. Small doses of DC-targeted OVA induced higher titers and a broader spectrum of anti-NP antibody isotypes than large doses of OVA in alum adjuvant. Similar results were obtained when the circumsporozoite protein of Plasmodium yoelii was delivered to DCs. We conclude that antigen targeting to DCs combined with a maturation stimulus produces broad-based and long-lived T cell help for humoral immune responses.

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