#Hemagglutinin and #neuraminidase #antibodies are induced in an #age- and subtype- dependent manner after #influenza virus infection (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Hemagglutinin and neuraminidase antibodies are induced in an age- and subtype- dependent manner after influenza virus infection.

Sook-San Wong, Ben Waite, Jacqui Ralston, Tim Wood, G Edwin Reynolds, Ruth Seeds, E. Claire Newbern, Mark G. Thompson, Q. Sue Huang, Richard J. Webby, the SHIVERS Investigation Team

DOI: 10.1128/JVI.01385-19

 

ABSTRACT

Despite evidence that antibodies targeting the influenza virus neuraminidase (NA) protein can be protective and are broadly cross-reactive, the immune response to NA during infection is poorly understood compared to the response to hemagglutinin (HA) protein. As such, we compared the antibody profile to HA and NA in two naturally-infected human cohorts in Auckland, New Zealand; a serosurvey cohort, consisting of pre- and post-influenza season sera from PCR-confirmed influenza cases (n=50), and an immunology cohort, consisting of paired sera collected after PCR-confirmation of infection (n=94). The induction of both HA and NA-antibodies in these cohorts was influenced by age and subtype. Seroconversion to HA was more frequent in those < 20 years old (yo) for influenza A (Serosurvey, p=0.01, Immunology, p=0.02), but not influenza B virus infection. Seroconversion to NA was not influenced by age or virus type. Adults ≥ 20 yo infected with influenza A viruses were more likely to show NA-only seroconversion compared to children (56% vs 14% [5 – 19 yo] and 0% [0 – 4 yo] respectively). Conversely, children infected with influenza B viruses were more likely than adults to show NA-only seroconversion (88% [0 – 4 yo] and 75% [5 – 19 yo] vs 40% [ ≥ 20 yo]). These data indicate a potential role for immunological memory in the dynamics of HA and NA-antibody responses. A better mechanistic understanding of this phenomenon will be critical for any future vaccines aimed at eliciting NA immunity.

 

IMPORTANCE

Data on the immunologic responses to neuraminidase (NA) is lacking when compared to what is available on hemagglutinin (HA) responses, despite growing evidence that NA-immunity can be protective and broadly cross-reactive. Understanding these NA responses during natural infection is key to exploiting these properties for improving influenza vaccines. Using two community-acquired influenza cohorts, we showed that the induction of both HA and NA-antibody after infection is influenced by age and subtypes. Such response dynamics suggests the influence of immunological memory and understanding how this process is regulated will be critical to any vaccine effort targeting NA-immunity.

Copyright © 2020 Wong et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.

Keywords: Seasonal Influenza; Serology; Seroprevalence.

——-

Comparison of alpha-spending plans for near #realtime #monitoring for #GBS after #influenza #vaccination during the 2010/11 influenza season (Vaccine, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Vaccine. 2020 Jan 10. pii: S0264-410X(19)31674-3. doi: 10.1016/j.vaccine.2019.12.032. [Epub ahead of print]

Comparison of alpha-spending plans for near real-time monitoring for Guillain-Barré after influenza vaccination during the 2010/11 influenza season.

Sandhu SK1, Hua W2, MaCurdy TE3, Franks RL4, Avagyan A4, Chillarige Y4, Wernecke M4, Kelman J5, Ball R2.

Author information: 1 Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA. Electronic address: sukhminder.sandhu@fda.hhs.gov. 2 Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA. 3 Stanford University, Stanford, CA, USA; Acumen LLC, Burlingame, CA, USA. 4 Acumen LLC, Burlingame, CA, USA. 5 Centers for Medicare and Medicaid Services, Washington, DC, USA.

 

Abstract

BACKGROUND:

Near real-time surveillance of the influenza vaccine, which is administered to a large proportion of the US population every year, is essential to ensure safety of the vaccine. For efficient near real-time surveillance, it is key to select appropriate parameters such as monitoring start date, number of interim tests and a scheme for spending a pre-defined total alpha across the entire influenza season. Guillain-Barré Syndrome, shown to be associated with the 1976 influenza vaccine, is used to evaluate how choices of these parameters can affect whether or not a signal is detected and the time to signal. FDA has been monitoring for the risk of GBS after influenza vaccination for every influenza season since 2008.

METHODS:

Using Medicare administrative data and the Updating Sequential Probability Ratio Test methodology to account for claims delay, we evaluated a number of different alpha-spending plans by varying several parameters.

RESULTS:

For relative risks of 5 or greater, almost all alpha-spending plans have 100% power; however, for relative risks of 1.5 or lower, the constant and O’Brien-Fleming plans have increasingly more power. For RRs of 1.5 and greater, the Pocock plan signals earliest but would not signal at a RR of 1.25, as observed in prior influenza seasons. There were no remarkable differences across the different plans in regards to monitoring start dates defined by the number of vaccinations; reducing the number of interim tests improves performance only marginally.

CONCLUSIONS:

A constant alpha-spending plan appears to be robust, in terms of power and time to detect a signal, across a range of these parameters, including alternate monitoring start dates based on either cumulative vaccinations or GBS claims observed, frequency of monitoring, hypothetical relative risks, and vaccine uptake patterns.

Published by Elsevier Ltd.

KEYWORDS: Alpha-spending; Guillain-Barré Syndrome; Immunization; Influenza; Sequential test; Vaccine

PMID: 31932134 DOI: 10.1016/j.vaccine.2019.12.032

Keywords: Drugs safety; Seasonal Influenza; Vaccines; GBS.

——

#Safety and immunogenicity of a highly attenuated rVSVN4CT1-EBOVGP1 #Ebola virus #vaccine: a randomised, double-blind, placebo-controlled, phase 1 clinical trial (Lancet Infect Dis., abstract)

[Source: The Lancet Infectious Diseases, full page: (LINK). Abstract, edited.]

Safety and immunogenicity of a highly attenuated rVSVN4CT1-EBOVGP1 Ebola virus vaccine: a randomised, double-blind, placebo-controlled, phase 1 clinical trial

David K Clarke, PhD, Rong Xu, PhD †, Demetrius Matassov, PhD †, Theresa E Latham, MSc, Ayuko Ota-Setlik, MSc, Cheryl S Gerardi, BSc, Amara Luckay, MSc, Susan E Witko, MSc, Luz Hermida, PhD, Terry Higgins, PhD, Marc Tremblay, BSc, Susan Sciotto-Brown, MSc, Tracy Chen, PhD, Michael A Egan, PhD, Janice M Rusnak, MD, Lucy A Ward, PhD, John H Eldridge, PhD

Published: January 14, 2020 / DOI: https://doi.org/10.1016/S1473-3099(19)30614-0

 

Summary

Background

The safety and immunogenicity of a highly attenuated recombinant vesicular stomatitis virus (rVSV) expressing HIV-1 gag (rVSVN4CT1-HIV-1gag1) was shown in previous phase 1 clinical studies. An rVSV vector expressing Ebola virus glycoprotein (EBOV-GP) in place of HIV-1 gag (rVSVN4CT1-EBOVGP1) showed single-dose protection from lethal challenge with low passage Ebola virus in non-human primates. We aimed to evaluate the safety and immunogenicity of the rVSVN4CT1-EBOVGP1 vaccine in healthy adults.

Methods

We did a randomised double-blind, placebo-controlled, phase 1 dose-escalation study at a single clinical site (Optimal Research) in Melbourne, FL, USA. Eligible participants were healthy men and non-pregnant women aged 18–60 years, with a body-mass index (BMI) of less than 40 kg/m 2, no history of filovirus infection, VSV infection, or receipt of rVSV in previous studies, and who had not visited regions where Ebola virus outbreaks have occurred. Three cohorts were enrolled to assess a low (2·5 × 10 4 plaque forming units [PFU]), intermediate (2 × 10 5 PFU), or high dose (1·8 × 10 6 PFU) of the vaccine. Participants within each cohort were randomly allocated (10:3) to receive vaccine or placebo by intramuscular injection in a homologous prime and boost regimen, with 4 weeks between doses. All syringes were masked with syringe sleeves; participants and study site staff were not blinded to dose level but were blinded to active vaccine and placebo. The primary outcomes were safety and tolerability; immunogenicity, assessed as GP-specific humoral immune response (at 2 weeks after each dose) and cellular immune response (at 1 and 2 weeks after each dose), was a secondary outcome. All randomised participants were included in primary and safety analyses. This trial is registered with ClinicalTrials.gov, NCT02718469.

Findings

Between Dec 22, 2015, and Sept 15, 2016, 39 individuals (18 [46%] men and 21 [54%] women, mean age 51 years [SD 10]) were enrolled, with ten participants receiving the vaccine and three participants receiving placebo in each of three cohorts. One participant in the intermediate dose cohort was withdrawn from the study because of a diagnosis of invasive ductal breast carcinoma 24 days after the first vaccination, which was considered unrelated to the vaccine. No severe adverse events were observed. Solicited local adverse events occurred in ten (26%) of 39 participants after the first dose and nine (24%) of 38 participants after the second dose; the events lasted 3 days or less, were predominantly injection site tenderness (17 events) and injection site pain (ten events), and were either mild (19 events) or moderate (ten events) in intensity. Systemic adverse events occurred in 13 (33%) of 39 participants after the first dose and eight (21%) of 38 participants after the second dose; the events were mild (45 events) or moderate (11 events) in severity, and the most common events were malaise or fatigue (13 events) and headache (12 events). Arthritis and maculopapular, vesicular, or purpuric rash distal to the vaccination site(s) were not reported. A GP-specific IgG response was detected in all vaccine recipients after two doses (and IgG response frequency was 100% after a single high dose), and an Ebola virus neutralising response was detected in 100% of participants in the high-dose cohort.

Interpretation

The rVSVN4CT1-EBOVGP1 vaccine was well tolerated at all dose levels tested and was immunogenic despite a high degree of attenuation. The combined safety and immunogenicity profile of the rVSVN4CT1-EBOVGP1 vaccine vector support phase 1–2 clinical evaluation.

Funding

US Department of Defense Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense: Joint Project Manager for Chemical, Biological, Radiological and Nuclear Medical.

Keywords: Ebola; Vaccines.

——-

Modification of neutralizing epitopes of #hemagglutinin for the #development of broadly protective #H9N2 #vaccine (Vaccine, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Vaccine. 2020 Jan 7. pii: S0264-410X(19)31634-2. doi: 10.1016/j.vaccine.2019.11.080. [Epub ahead of print]

Modification of neutralizing epitopes of hemagglutinin for the development of broadly protective H9N2 vaccine.

Poh ZW1, Wang Z1, Kumar SR1, Yong HY1, Prabakaran M2.

Author information: 1 Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore. 2 Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore. Electronic address: prabakar@tll.org.sg.

 

Abstract

The H9N2 avian influenza viruses cause significant economic losses in poultry worldwide and could potentially cause human pandemic. Currently, the available vaccines have limited efficacy due to antigenic drift of H9N2. To improve vaccine efficacy, we developed monovalent vaccine strain via the modification of neutralizing epitopes on hemagglutinin (HA) to broaden the protection against H9N2 viruses. In this study, single and multiple mutation were introduced to amino acid at position 148, 150 (site I) and 183, 186, 188 (site II) on the full-length HA gene of H9N2 strain (A/Hong Kong/33982/2009). These mutant HA constructs were displayed on the baculovirus surface (BacH9), and evaluated for their cross-protective efficacy against H9N2 viruses in a mouse model. Our findings indicate that mice immunized with multiple BacH9 mutant constructs (148-150 183 and 186) induced cross-protective immunity against circulating H9N2 in the viral challenge study and prove to be a promising vaccine candidate for H9N2.

Copyright © 2019 Elsevier Ltd. All rights reserved.

KEYWORDS: Baculoviral display HA; H9N2; Monovalent vaccine strain; Neutralizing epitope

PMID: 31924429 DOI: 10.1016/j.vaccine.2019.11.080

Keywords: Avian Influenza; H9N2; Vaccines; Animal models.

——

Heterologous viral protein #interactions within licensed seasonal #influenza virus #vaccines (npj Vaccines, abstract)

[Source: npj Vaccines, full page: (LINK). Abstract, edited.]

Heterologous viral protein interactions within licensed seasonal influenza virus vaccines

Marina Koroleva, Frances Batarse, Savannah Moritzky, Carole Henry, Francisco Chaves, Patrick Wilson, Florian Krammer, Katherine Richards & Andrea J. Sant

npj Vaccines volume 5, Article number: 3 (2020)

 

Abstract

Currently, licensed influenza virus vaccines are designed and tested only for their ability to elicit hemagglutinin (HA)-reactive, neutralizing antibodies. Despite this, the purification process in vaccine manufacturing often does not completely remove other virion components. In the studies reported here, we have examined the viral protein composition of a panel of licensed vaccines from different manufacturers and licensed in different years. Using western blotting, we found that, beyond HA proteins, there are detectable quantities of neuraminidase (NA), nucleoprotein (NP), and matrix proteins (M1) from both influenza A and influenza B viruses in the vaccines but that the composition differed by source and method of vaccine preparation. We also found that disparities in viral protein composition were associated with distinct patterns of elicited antibody specificities. Strikingly, our studies also revealed that many viral proteins contained in the vaccine form heterologous complexes. When H1 proteins were isolated by immunoprecipitation, NA (N1), M1 (M1-A), H3, and HA-B proteins were co-isolated with the H1. Further biochemical studies suggest that these interactions persist for at least 4 h at 37 °C and that the membrane/intracytoplasmic domains in the intact HA proteins are important for the intermolecular interactions detected. These studies indicate that, if such interactions persist after vaccines reach the draining lymph node, both dendritic cells and HA-specific B cells may take up multiple viral proteins simultaneously. Whether these interactions are beneficial or harmful to the developing immune response will depend on the functional potential of the elicited virus-specific CD4 T cells.

Keywords: Influenza A; Vaccines.

——

#Development of an #EV71 #vaccine efficacy #test using human scavenger receptor B2 transgenic mice (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Development of an enterovirus 71 vaccine efficacy test using human scavenger receptor B2 transgenic mice

Ayumi Imura, Yui Sudaka, Ayako Takashino, Kanami Tamura, Kyousuke Kobayashi, Noriyo Nagata, Hidekazu Nishimura, Katsumi Mizuta, Satoshi Koike

DOI: 10.1128/JVI.01921-19

 

ABSTRACT

Enterovirus 71 (EV71) is a causative agent of hand-foot-mouth disease, and it sometimes causes severe neurological disease. Development of effective vaccines and animal models to evaluate vaccine candidates are needed. However, the animal models currently used for vaccine efficacy testing, monkeys and neonatal mice, have economic, ethical, and practical drawbacks. In addition, EV71 strains prepared for lethal challenge often develop decreased virulence during propagation in cell culture. To overcome these problems, we used a mouse model expressing human scavenger receptor B2 (hSCARB2) that showed life-long susceptibility to EV71. We selected virulent EV71 strains belonging to the subgenogroups B4, B5, C1, C2, and C4 and propagated them using a culture method for EV71 without an apparent reduction in virulence. Here, we describe a novel EV71 vaccine efficacy test based on these hSCARB2 transgenic (Tg) mice and these virulent viruses. Adult Tg mice were immunized subcutaneously with formalin-inactivated EV71. The vaccine elicited sufficient levels of neutralizing antibodies in the immunized mice. The mice were subjected to lethal challenge with virulent viruses via intravenous injection. Survival, clinical signs, and body weight changes were observed for 2 weeks. Most immunized mice survived without clinical signs or histopathological lesions. The viral replication in immunized mice was much lower than that in nonimmunized mice. Mice immunized with the EV71 vaccine were only partially protected against lethal challenge with coxsackievirus A16. These results indicate that this new model is useful for in vivo EV71 vaccine efficacy testing.

 

Importance

The development of new vaccines for EV71 relies on the availability of small animal models suitable for in vivo efficacy testing. Monkeys and neonatal mice have been used, but the use of these animals has several drawbacks, including high costs, limited susceptibility, and poor experimental reproducibility. In addition, the related ethical issues are considerable. The new efficacy test based on hSCARB2 Tg mice and virulent EV71 strains propagated in genetically modified cell lines presented here can overcome these disadvantages and is expected to accelerate the development of new EV71 vaccines.

Copyright © 2020 American Society for Microbiology. All Rights Reserved.

Keywords: EV-71; Vaccines; Coxsackievirus A16; Animal models.

——

Association between #vaccine #adjuvant effect and pre-seasonal #immunity. Systematic review and meta-analysis of randomised immunogenicity trials comparing squalene-adjuvanted and aqueous inactivated #influenza vaccines (Vaccine, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Vaccine. 2019 Dec 23. pii: S0264-410X(19)31679-2. doi: 10.1016/j.vaccine.2019.12.037. [Epub ahead of print]

Association between vaccine adjuvant effect and pre-seasonal immunity. Systematic review and meta-analysis of randomised immunogenicity trials comparing squalene-adjuvanted and aqueous inactivated influenza vaccines.

Beyer WEP1, Palache AM2, Reperant LA3, Boulfich M4, Osterhaus ADME5.

Author information: 1 Artemis One Health, Utrecht, the Netherlands; Erasmus Medical Center, Department of Viroscience, Rotterdam, the Netherlands. 2 FluPal Consultancy, Amstelveen, the Netherlands. 3 Artemis One Health, Utrecht, the Netherlands. 4 University of Amsterdam, the Netherlands. 5 Artemis One Health, Utrecht, the Netherlands; University of Veterinary Medicine, Hannover, Germany. Electronic address: Albert.Osterhaus@tiho-hannover.de.

 

Abstract

The immunogenicity benefit of inactivated influenza vaccine (IIV) adjuvanted by squalene over non-adjuvanted aqueous IIV was explored in a meta-analysis involving 49 randomised trials published between 1999 and 2017, and 22,470 eligible persons of all age classes. Most vaccines contained 15 μg viral haemagglutinin per strain. Adjuvanted IIV mostly contained 9.75 mg squalene per dose. Homologous pre- and post-vaccination geometric mean titres (GMTs) of haemagglutination-inhibition (HI) antibody were recorded for 290 single influenza (sub-)type arms. The adjuvant effect was expressed as the ratio of post-vaccination GMTs between squalene-IIV and aqueous IIV (GMTR, 145 estimates). GMTRs > 1.0 favoured squalene-IIV over aqueous IIV. For all influenza (sub-)types, the adjuvant effect proved negatively associated with pre-vaccination GMT and mean age. The adjuvant effect appeared most pronounced in young children (mean age < 2.5 years) showing an average GMTR of 3.7 (95% CI: 2.5 to 5.5). With increasing age, GMTR values gradually decreased towards 1.4 (95% CI: 1.0 to 1.9) in older adults. Heterologous antibody titrations simulating mismatch between vaccine and circulating virus (30 GMTR estimates) again showed a larger adjuvant effect at young age. GMT values and their variances were converted to antibody-predicted protection rates using an evidence-based clinical protection curve. The adjuvant effect was expressed as the protection rate differences, which showed similar age patterns as corresponding GMTR values. However for influenza B, the adjuvant effect lasted longer than for influenza A, possibly due to a generally later influenza B virus exposure. Collectively, this meta-analysis indicates the highest benefit of squalene-IIV over aqueous IIV in young children and decreasing benefit with progressing age. This trend is similar for seasonal influenza (sub-)types and the 2009 pandemic strain, by both homologous and heterologous titration. The impact of pre-seasonal immunity on vaccine effectiveness, and its implications for age-specific vaccination recommendations, are discussed.

Copyright © 2019 Elsevier Ltd. All rights reserved.

KEYWORDS: Adjuvant; Immunogenicity; Influenza vaccine; Meta-analysis; Pre-seasonal immunity; Squalene

PMID: 31879122 DOI: 10.1016/j.vaccine.2019.12.037

Keywords: Seasonal Influenza; Vaccines.

—–