Persistence of Antibodies to 2 Virus-Like Particle Norovirus Vaccine Candidate Formulations in Healthy Adults: 1-Year Follow-up With Memory Probe Vaccination

2019 ◽  
Vol 220 (4) ◽  
pp. 603-614 ◽  
Author(s):  
Robert L Atmar ◽  
Frank Baehner ◽  
Jakob P Cramer ◽  
Eric Lloyd ◽  
James Sherwood ◽  
...  
Keyword(s):  
Vaccine Candidate ◽  
Immunoglobulin A ◽  
Primary Vaccination ◽  
Immune Memory ◽  
Virus Like Particle ◽  
Memory Probe ◽  
Antibody Titers ◽  
Antibody Levels ◽  
With Memory

AbstractBackgroundWe previously reported the tolerability and immunogenicity 1 month after intramuscular administration of 2 bivalent virus-like particle (VLP)–based candidate norovirus vaccine formulations in adults. We now describe the persistence of immunity and responses to a memory probe vaccination 1 year later.MethodsA total of 454 healthy men and women aged 18–49 years in 3 equal groups received placebo (saline) or 15/50 or 50/50 vaccine formulations (ie, 15 or 50 µg of GI.1 genotype VLPs, respectively, and 50 µg of GII.4c VLPs) with MPL and Al(OH)3. Immunogenicity and safety were assessed up to day 365, when 351 participants received a memory probe vaccination of 15 µg each of GI.1 and GII.4c VLPs with Al(OH)3.ResultsNo safety signals were detected up to 1 year after the first vaccination. Pan-immunoglobulin, immunoglobulin A, and histo-blood group antigen–blocking (HBGA) antibody levels among vaccinees waned but remained higher than levels before vaccination and levels in placebo recipients on days 180 and 365. Memory probe vaccination increased all antibody titers. Levels of HBGA antibodies to GI.1 but not GII.4c were higher after the first vaccination in candidate vaccine groups, compared with those in the placebo group.ConclusionLevels of antibodies to both candidate norovirus VLP formulations persisted above baseline levels for at least 1 year after primary vaccination. HBGA-blocking responses to the memory probe for GI.1 but not GII.4c displayed characteristics of immune memory.Clinical Trials RegistrationNCT02142504.

scholarly journals Evaluation of Durability of a Single Dose of the Bivalent HPV Vaccine: The CVT Trial

2020 ◽  
Vol 112 (10) ◽  
pp. 1038-1046 ◽  
Author(s):  
Aimée R Kreimer ◽  
Joshua N Sampson ◽  
Carolina Porras ◽  
John T Schiller ◽  
Troy Kemp ◽  
...  
Keyword(s):  
Single Dose ◽  
Hpv Vaccine ◽  
Hpv Vaccination ◽  
Vaccine Trial ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Like Particle ◽  
Long Term Follow Up ◽  
Antibody Levels

Abstract Background The authors investigated the durability of vaccine efficacy (VE) against human papillomavirus (HPV)16 or 18 infections and antibody response among nonrandomly assigned women who received a single dose of the bivalent HPV vaccine compared with women who received multiple doses and unvaccinated women. Methods HPV infections were compared between HPV16 or 18-vaccinated women aged 18 to 25 years who received one (N = 112), two (N = 62), or three (N = 1365) doses, and age- and geography-matched unvaccinated women (N = 1783) in the long-term follow-up of the Costa Rica HPV Vaccine Trial. Cervical HPV infections were measured at two study visits, approximately 9 and 11 years after initial HPV vaccination, using National Cancer Institute next-generation sequencing TypeSeq1 assay. VE and 95% confidence intervals (CIs) were estimated. HPV16 or 18 antibody levels were measured in all one- and two-dose women, and a subset of three-dose women, using a virus-like particle-based enzyme-linked immunosorbent assay (n = 448). Results Median follow-up for the HPV-vaccinated group was 11.3 years (interquartile range = 10.9–11.7 years) and did not vary by dose group. VE against prevalent HPV16 or 18 infection was 80.2% (95% CI = 70.7% to 87.0%) among three-dose, 83.8% (95% CI = 19.5% to 99.2%) among two-dose, and 82.1% (95% CI = 40.2% to 97.0%) among single-dose women. HPV16 or 18 antibody levels did not qualitatively decline between years four and 11 regardless of the number of doses given, although one-dose titers continue to be statistically significantly lower compared with two- and three-dose titers. Conclusion More than a decade after HPV vaccination, single-dose VE against HPV16 or 18 infection remained high and HPV16 or 18 antibodies remained stable. A single dose of bivalent HPV vaccine may induce sufficiently durable protection that obviates the need for more doses.

scholarly journals Positive Result by Serology Indicates ActiveHelicobacter pylori Infection in Patients with Atrophic Gastritis

1998 ◽  
Vol 36 (6) ◽  
pp. 1808-1810 ◽  
Author(s):  
Arto Kokkola ◽  
Hilpi Rautelin ◽  
Pauli Puolakkainen ◽  
Pentti Sipponen ◽  
Martti Färkkilä ◽  
...  
Keyword(s):  
Breath Test ◽  
Eradication Therapy ◽  
Urea Breath Test ◽  
Positive Serology ◽  
Antibody Titers ◽  
H Pylori ◽  
Antibody Levels ◽  
Ongoing Infection ◽  
Corpus Gastritis

Patients with atrophic corpus gastritis and elevatedHelicobacter pylori antibody titers but13C-urea breath test (13C-UBT) and histology results negative for H. pylori were randomized into eradication therapy or follow-up only. Antibody levels decreased significantly in six out of seven patients in the eradication group, while in the follow-up group, the titers declined in only one out of eight patients. In patients with atrophic corpus gastritis, positive serology results may indicate an ongoing infection in spite of negative13C-UBT and histology results.

An AS04-containing human papillomavirus (HPV) 16/18 vaccine for prevention of cervical cancer is immunogenic and well-tolerated in women 15–55 years old

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 1008-1008 ◽  
Author(s):  
T. F. Schwarz
Keyword(s):  
Sexual Debut ◽  
Geometric Mean ◽  
Phase Iii ◽  
Cervical Lesions ◽  
Hpv 16 ◽  
Long Term Follow Up ◽  
Antibody Titers ◽  
Antibody Levels

1008 Background: Genital HPV infections can be acquired shortly after sexual debut, and the risk remains throughout a sexually active woman’s lifetime. In women 15–25 years of age, the AS04-containing HPV vaccine was highly immunogenic and conferred 100% protection against HPV-16/18 persistent infection and associated cervical lesions up to 27 months. In the long-term follow-up of this study, sustained vaccine efficacy has been observed up to 48 months. The present phase III study (580299/014) assessed immune responses to the AS04-containing HPV-16/18 vaccine in women 26–55 years old compared with women 15–25 years old. Methods: Healthy women in Germany and Poland between 15 and 55 years of age received 3 doses of HPV-16/18 AS04-containing vaccine at months 0, 1, and 6. The groups were age stratified: 15–25 (n=229), 26–45 (n=226), and 46–55 (n=211). Anti-HPV-16/18 antibody titers were assessed at months 0, 2, 7, and 12 by ELISA (EU/mL). Seropositivity rates and geometric mean antibody titers (GMTs) were calculated for all groups. Safety was assessed after each dose in all participants. Results: All initially seronegative women became seropositive for both HPV 16 and 18 at Month 2. At Month 7, HPV-16 GMTs (95% CI) were 7908.4 (6874.0–9098.5) in 15–25 year olds, 4029.2 (3402.7–4771.0) in 26–45 year olds, and 2566.8 (2181.2–3020.6) in 46–55 year olds. For HPV-18, GMTs were 3499.3 (3098.7–3951.6) in 15–25 year olds, 1837.3 (1602.1–2107.0) in 26–45 year olds, and 1313.0 (1145.6–1504.9) in 46–55 year olds. Overall the vaccine was well-tolerated, and the incidence of local symptoms (within 30 days) tended to be lower in the 46–55 year-old group (69.2% versus 81.6% [26–45] and 85.7% [15–25]). Conclusions: An AS04-containing HPV-16/18 vaccine was immunogenic and generally safe in 15–55 year-old females. As observed with other vaccines, GMTs decreased with age, however, the Month 7 postvaccination antibody levels in the oldest age group (46–55) were still 3–4 times higher than those observed during a separate long-term follow-up study where sustained efficacy has been observed up to 48 months. [Table: see text]

scholarly journals Antibodies specific to infectious bronchitis in broilers in Ceará state, Brazil

2006 ◽  
Vol 58 (3) ◽  
pp. 327-332 ◽  
Author(s):  
W.M. Cardoso ◽  
L.P. Gomes ◽  
J.M. Romão ◽  
R.P.R. Salles ◽  
R.S.C. Teixeira ◽  
...  
Keyword(s):  
Antibody Response ◽  
Primary Vaccination ◽  
Maternal Antibodies ◽  
Control Group ◽  
Infectious Bronchitis ◽  
Antibody Titers ◽  
Low Levels ◽  
Different Response ◽  
Antibody Levels ◽  
Vaccinal Response

The experiment was carried out to determine the antibody levels to infectious bronchitis virus (IBV) in 1120 broilers of two broiler flocks, both from the same parental flock and free from previous vaccination. Forty chicks of each line were alloted to the control group and the sera were tested by indirect ELISA. The vaccination program consisted on the administration of commercial vaccines against IBV at 10 and 25 days of age. Chicks with low levels of maternal antibodies (Mab) did not show significant titers to the first vaccinal stimulus. They presented a vaccinal response to the second vaccinal stimulus reaching the top around GMT 1100 at 45 days. Chicks with high Mab titers did not show significant titers to the primary and secondary vaccinal stimuli, reaching peak levels of GMT 500 at 45 days. No antibody response was detected after the primary vaccination at day 10. A delayed antibody response was detected after the secondary vaccination on day 25, indicating no previous priming. The maternal antibody titers can interfere on the response to the first and second vaccinal stimulus promoting the neutralization of the first vaccination and a different response to the second one, according to high or low maternal antibodies.

scholarly journals Medical Outcomes in Women Who Became Pregnant after Vaccination with a Virus-Like Particle Experimental Vaccine against Influenza A (H1N1) 2009 Virus Tested during 2009 Pandemic Outbreak

Viruses ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 868 ◽  
Author(s):  
Arturo Cérbulo-Vázquez ◽  
Lourdes Arriaga-Pizano ◽  
Gabriela Cruz-Cureño ◽  
Ilka Boscó-Gárate ◽  
Eduardo Ferat-Osorio ◽  
...  
Keyword(s):  
Influenza A ◽  
Vaccine Trial ◽  
Immunological Response ◽  
Clinical Effects ◽  
Medical Outcomes ◽  
Virus Like Particle ◽  
Influenza A H1n1 ◽  
Antibody Titers ◽  
One Year

The clinical effects and immunological response to the influenza vaccine in women who later become pregnant remain to be thoroughly studied. Here, we report the medical outcomes of 40 women volunteers who became pregnant after vaccination with an experimental virus-like particle (VLP) vaccine against pandemic influenza A(H1N1)2009 (influenza A(H1N1)pdm09) and their infants. When included in the VLP vaccine trial, none of the women were pregnant and were randomly assigned to one of the following groups: (1) placebo, (2) 15 μg dose of VLP vaccine, or (3) 45 μg dose of VLP vaccine. These 40 women reported becoming pregnant during the follow-up phase after receiving the placebo or VLP vaccine. Women were monitored throughout pregnancy and their infants were monitored until one year after birth. Antibody titers against VLP were measured in the mothers and infants at delivery and at six months and one year after birth. The incidence of preeclampsia, fetal death, preterm delivery, and premature rupture of membranes was similar among groups. All vaccinated women and their infants elicited antibody titers (≥1:40). Women vaccinated prior to pregnancy had no adverse events that were different from the nonvaccinated population. Even though this study is limited by the sample size, the results suggest that the anti-influenza A(H1N1)pdm09 VLP experimental vaccine applied before pregnancy is safe for both mothers and their infants.

scholarly journals SARS-CoV-2-directed antibodies persist for more than six months in a cohort with mild to moderate COVID-19

Infection ◽  
2021 ◽  
Author(s):  
Vivian Glück ◽  
Sonja Grobecker ◽  
Leonid Tydykov ◽  
Bernd Salzberger ◽  
Thomas Glück ◽  
...  
Keyword(s):  
Immune Responses ◽  
Time Course ◽  
Individual Variability ◽  
Igg Antibody ◽  
Severity Of Disease ◽  
Antibody Titers ◽  
Specific Igg ◽  
Antibody Levels ◽  
Specific Symptoms

Abstract Objective To follow serological immune responses of front-line healthcare workers after PCR-confirmed COVID-19 for a mean of 30 weeks, describe the time-course of SARS-CoV-2 spike protein-specific IgG, IgA and IgM levels and to identify associations of the immune response with symptoms, demographic parameters and severity of disease. Methods Anti-SARS-CoV-2 S protein-specific IgG, IgA and IgM antibodies were measured at three time points during the 30-week follow-up. COVID-19-specific symptoms were assessed with standardized questionnaires. Results 95% of the participants mounted an IgG response with only modest decline after week 12. IgG-type antibodies were still detectable in almost 90% of the subjects at 30 weeks. IgA and IgM responses were less robust and antibody titers decreased more rapidly. At 30 weeks, only 25% still had detectable IgA-type and none had IgM-type antibodies. Higher age and higher disease severity were independently associated with higher IgG antibody levels, albeit with wide variations. Conclusion Serological immune responses after COVID-19 show considerable inter-individual variability, but show an association with increasing age and higher severity of disease. IgG-type anti-SARS-CoV-2 antibodies remain positive in 90% of the individuals 30 weeks after onset of symptoms.

scholarly journals Longitudinal Serological Analysis and Neutralizing Antibody Levels in Coronavirus Disease 2019 Convalescent Patients

2020 ◽  
Author(s):  
Frauke Muecksch ◽  
Helen Wise ◽  
Becky Batchelor ◽  
Maria Squires ◽  
Elizabeth Semple ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Neutralization Titer ◽  
Serological Assay ◽  
Antibody Assays ◽  
Antibody Titers ◽  
Binding Antibody ◽  
Antibody Levels ◽  
Prior Infection ◽  
Commercial Platform

Abstract Background Understanding the longitudinal trajectory of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies is crucial for diagnosis of prior infection and predicting future immunity. Methods We conducted a longitudinal analysis of coronavirus disease 2019 convalescent patients, with neutralizing antibody assays and SARS-CoV-2 serological assay platforms using SARS-CoV-2 spike (S) or nucleocapsid (N) antigens. Results Sensitivities of serological assays in diagnosing prior SARS-CoV-2 infection changed with time. One widely used commercial platform that had an initial sensitivity of >95% declined to 71% at 81–100 days after diagnosis. The trajectories of median binding antibody titers measured over approximately 3–4 months were not dependent on the use of SARS-CoV-2 N or S proteins as antigen. The median neutralization titer decreased by approximately 45% per month. Each serological assay gave quantitative antibody titers that were correlated with SARS-CoV-2 neutralization titers, but S-based serological assay measurements better predicted neutralization potency. Correlation between S-binding and neutralization titers deteriorated with time, and decreases in neutralization titers were not predicted by changes in S-binding antibody titers. Conclusions Different SARS-CoV-2 serological assays are more or less well suited for surveillance versus prediction of serum neutralization potency. Extended follow-up should facilitate the establishment of appropriate serological correlates of protection against SARS-CoV-2 reinfection.

scholarly journals Immune Memory Response After a Booster Injection of mRNA-1273 for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2)

2021 ◽  
Author(s):  
Laurence Chu ◽  
David Montefiori ◽  
Wenmei Huang ◽  
Biliana Nestorova ◽  
Ying Chang ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Primary Vaccination ◽  
Immune Memory ◽  
Serious Adverse Events ◽  
Booster Injection ◽  
Memory Response ◽  
Primary Series ◽  
The One ◽  
Study Participants ◽  
Antibody Levels

Rising breakthrough infections of coronavirus-2 (SARS-CoV-2) in previously immunized individuals has raised concerns for a potential booster to combat suspected waning immunity and new variants. In this study, participants immunized 6-8 months earlier with a primary series of two doses of 50 or 100 μg of mRNA-1273 were administered a booster injection of 50 μg of mRNA-1273. Neutralizing antibody levels at one month after the booster were 1.7-fold higher than those one-month post primary series second injection meeting the prespecified criteria for noninferiority, and indicating an immune memory response. The reactogenicity after the booster dose was similar to that after the second dose in the primary series of two doses of mRNA-1273 (50 or 100 μg) with no serious adverse events reported in the one-month follow-up period. These results demonstrate that a booster injection of mRNA-1273 in previously immunized individuals stimulated an immune response greater than the primary vaccination series.

scholarly journals Potential of Artesunate in the treatment of visceral leishmaniasis in dogs naturally infected by Leishmania infantum: Efficacy evidence from a randomized field trial

2020 ◽  
Vol 14 (12) ◽  
pp. e0008947
Author(s):  
Hacène Medkour ◽  
Idir Bitam ◽  
Younes Laidoudi ◽  
Ismail Lafri ◽  
Abdelaziz Lounas ◽  
...  
Keyword(s):  
Field Trial ◽  
Leishmania Infantum ◽  
Test Group ◽  
Public Health Problem ◽  
Control Group ◽  
Neglected Diseases ◽  
Meglumine Antimoniate ◽  
Antibody Titers ◽  
Antibody Levels

Leishmaniasis is among the world’s most neglected diseases. Dogs are the main reservoirs/hosts of Leishmania infantum, causative agent of both canine and human visceral leishmaniosis. Canine leishmaniasis (CanL) represents a public health problem as one of the most prevalent zoonotic diseases worldwide. Current therapeutics present drawbacks; thus, there is a need for more effective, safer, and cheaper drugs. The aim of this study was to evaluate and to compare the efficacy of oral administration of artesunate or meglumine antimoniate/allopurinol in dogs with clinical leishmaniasis. Forty-two dogs with naturally occurring clinical leishmaniasis were included in this open-label, simple randomized positive-control clinical field trial with 6 months of follow-up. Dogs received meglumine antimoniate 100 mg/kg/day and allopurinol 30 mg/kg/day for 28 days (control group, n = 26) or artesunate 25 mg/kg/day for 6 days (test group, n = 16). The animals were evaluated for their clinical evolution, parasite load (by qPCR) and humoral response at different time points: 0, 30, 90, and 180 days after treatment. Data analyses showed a significant improvement in both groups in clinical scores, parasitemia and antibody titers after treatment. Compared to the control group, the artesunate group showed significantly lower clinical score (P = 0.0001), lower parasitemia (P = 0.0001) and antibody titers after 6 months of follow-up. Compared to baseline values, a rapid, significant reduction (P < 0.012) in antibody levels, 2.28- versus 3.04-fold for the control versus artesunate groups, respectively, was observed 30 days after treatment. Antibody levels continued to decrease further in the artesunate group, where 58% of cases became seronegative at the 6-month follow-up. All qPCR-positive dogs were negative after treatment with artesunate, while 14.3% remained positive with the appearance of two new cases in the control group. Artesunate was well tolerated, and no side effects were recorded. Treatment failures were similar in both groups with 27.27% (6/22), including 18.18% (4/22) mortality in the control group, versus 26.66% (4/15), including 13.33% (2/15) mortality in the artesunate group. This is the first report showing the potential of artesunate in the treatment of dogs with clinical leishmaniasis. Artesunate showed higher efficacy than the current first-line treatment for CanL without any adverse effects. It could be a good alternative chemotherapy for CanL, and may be considered for further studies in human leishmaniases. Further clinical trials are needed to confirm these findings, to determine if there are relapses after treatment and if dogs remain infective to sandflies, to define the ideal therapeutic dosage and duration of treatment with artesunate.

scholarly journals High Titers of Circulating Maternal Antibodies Suppress Effector and Memory B-Cell Responses Induced by an Attenuated Rotavirus Priming and Rotavirus-Like Particle-Immunostimulating Complex Boosting Vaccine Regimen

2006 ◽  
Vol 13 (4) ◽  
pp. 475-485 ◽  
Author(s):  
Trang V. Nguyen ◽  
Lijuan Yuan ◽  
Marli S. P. Azevedo ◽  
Kwang-il Jeong ◽  
Ana M. Gonzalez ◽  
...  
Keyword(s):  
B Cell ◽  
Immunoglobulin A ◽  
Lymphoid Tissues ◽  
Memory B Cell ◽  
Antibody Secreting Cell ◽  
Cell Responses ◽  
Rotavirus Vaccines ◽  
Virus Like Particle ◽  
Antibody Titers ◽  
B Cell Responses

ABSTRACT We investigated maternal antibody (MatAb) effects on protection and immune responses to rotavirus vaccines. Gnotobiotic pigs were injected intraperitoneally at birth with pooled serum from sows hyperimmunized with human rotavirus (HRV); control pigs received no sow serum. Pigs with or without MatAbs received either sequential attenuated HRV (AttHRV) oral priming and intranasal boosting with VP2/VP6 virus-like particle (VLP)-immunostimulating complex (ISCOM) (AttHRV/VLP) or intranasal VLP-ISCOM prime/boost (VLP) vaccines at 3 to 5 days of age. Subsets of pigs were challenged at 28 or 42 days postinoculation with virulent Wa HRV to assess protection. Isotype-specific antibody-secreting cell (ASC) responses to HRV were quantitated by enzyme-linked immunospot assay to measure effector and memory B-cell responses in intestinal and systemic lymphoid tissues pre- and/or postchallenge. Protection rates against HRV challenge (contributed by active immunity and passive circulating MatAbs) were consistently (but not significantly) lower in the MatAb-AttHRV/VLP groups than in the corresponding groups without MatAbs. Intestinal B-cell responses in the MatAb-AttHRV/VLP group were most suppressed with significantly reduced or no intestinal immunoglobulin A (IgA) and IgG effector and memory B-cell responses or antibody titers pre- and postchallenge. This suppression was not alleviated but was enhanced after extending vaccination/challenge from 28 to 42 days. In pigs vaccinated with nonreplicating VLP alone that failed to induce protection, MatAb effects differed, with intestinal and systemic IgG ASCs and prechallenge memory B cells suppressed but the low intestinal IgA and IgM ASC responses unaffected. Thus, we demonstrate that MatAbs differentially affect both replicating and nonreplicating HRV vaccines and suggest mechanisms of MatAb interference. This information should facilitate vaccine design to overcome MatAb suppression.

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