The Application of Pseudotypes to Influenza Pandemic Preparedness

Abstract

Human and animal populations are constantly exposed to multiple influenza strains due to zoonotic spillover and rapid viral evolution driven by intrinsic error-prone replication and immunological pressure. In this context, antibody responses directed against the hemagglutinin protein on the surface of the virus are of importance since they have been shown to correlate with protective immunity. Serological techniques, detecting these responses, play a critical role in influenza pandemic preparedness in particular with regard to the measurement of vaccine immunogenicity. As the recent human pandemics (H1N1) and avian influenza outbreaks (H5 and H7) have demonstrated, there is an urgent need to be better prepared to assess the contribution of the antibody response to protection against newly emerged viruses and to evaluate the extent of pre-existing heterosubtypic immunity in populations. This review compares pseudotype-based assays with wild-type and viruslike particle virus assays and discusses their place in the pandemic preparedness against the influenza virus. It additionally addresses the state-of-the-art developments of pseudotypebased assays (chimeric hemagglutinins, multiplex and post-attachment) including the development and future deployment of assay kits and approaches toward standardization to both preclinical and clinical endpoints. Progress toward the development of an influenza pseudotype library for the purposes of pandemic preparedness is also outlined and discussed.

Broadly Reactive Nanobody Targeting the H3 Hemagglutinin of the Influenza A Virus

“…The HA glycoprotein is the main immune target. A total of 18 different HA variants are known to date [ 13 , 14 ]; they form two phylogenetic groups [ 15 ]. HA consists of two subunits: HA1 and HA2; these subunits play different roles in the onset of the infectious process.…”

Studying longitudinal neutralising antibody levels against Equid herpesvirus 1 in experimentally infected horses using a novel pseudotype based assay

“…PV neutralisation assays (PVNAs) offer a potential alternative to current serological tests to detect the presence of serum antibodies that can neutralise virus particles. PVNAs have been applied to serological screening, vaccine immunogenicity testing and study of the immune host response to infection by a range of different viruses ( Carnell et al., 2015 ; Corti et al., 2011 ; Ferrara et al., 2015 ). Consequently, we utilised the functional EHV-1 PV particles generated in serological tests to measure the level of neutralising antibodies in blood serum samples which had been collected from horses over an extended time period following experimental infection with EHV-1 ( Thieulent et al., 2022 ).…”

Pseudotype Neutralization Assays: From Laboratory Bench to Data Analysis

“…For example, the use of pseudotyped lentiviral vectors as surrogate antigens in neutralization assays is extremely useful in influenza research. Influenza pseudotype neutralization assays are a safe alternative when potentially pandemic viruses need to be studied [5]. Furthermore, they have been shown to have a high sensitivity in detecting antibodies directed against the stalk of influenza envelope glycoprotein, the haemmaglutinin [6].…”