Inactivated viral vaccines
Our group’s work is focused on batch release testing and developing assays and reference reagents to improve the quality control and standardisation of inactivated and recombinant viral vaccines.
These vaccines include those that protect against human papilloma virus (HPV), rabies and hepatitis B virus (HBV).
We work closely with other departments within the NIBSC and the wider Medicines and Healthcare Products Regulatory Agency.
Human papilloma virus (HPV)
Human papilloma virus (HPV) infection is the cause of nearly 100% of cervical cancers world-wide.
More than 150 HPV types have been molecularly characterised, 40 of which have been shown to infect the anogenital tract.
Of the 15 HPV types that are considered to be oncogenic, HPV types 16 and 18 account for 70% of cervical cancers while HPV types 31, 33, 35, 45, 52 and 58 are associated with an additional 15% of cervical cancer cases.
Oncogenic HPVs are also associated with a proportion of other important human diseases including cancers of the vulva, anus, penis and vagina, as well as the oral cavity, oropharynx and tonsils.
The HPV major capsid protein (L1), when expressed using recombinant DNA methods, can self-assemble to form non-infectious virus-like particles (VLPs). HPV VLPs adsorbed to adjuvant are used in current prophylactic vaccines to induce neutralising antibodies against HPV.
There are two licensed prophylactic vaccines available to prevent infection by HPV types; these are
Both protect against types 16 and 18. Gardasil also protects against non-oncogenic types 6 and 11 which cause 90% of genital warts.
Methods for detecting, quantifying and genotyping HPV DNA or antibodies in clinical samples are the primary tools used in studies to measure HPV disease burden and vaccine impact.
The accuracy and specificity of HPV tests are vital for all HPV laboratories to achieve consistent, meaningful and comparable results. This depends on the availability of well characterised biological reference standards for HPV.
Our group is actively involved in establishing WHO International Standards for HPV.
We provide guidelines in the WHO HPV LabNet Human Papillomavirus Laboratory Manual on preparing and using secondary standards calibrated against international standards for HPV DNA and antibodies.
As the UK’s National Control Laboratory, the NIBSC carries out independent batch release testing of HPV vaccines.
We carry out testing of HPV vaccines undergoing prequalification by the World Health Organisation (WHO) for procurement by UNICEF and other UN agencies.
We also test HPV vaccines submitted by other external regulatory organisations.
Production of antibody reagents for HPV vaccine quality control
Recombinant vaccines pose special problems for batch release requirements particularly where they need antigenic characterisation.
With HPV vaccines this is complicated further by the multivalent composition.
In 2015, a new 9-valent HPV vaccine will be introduced. Quality control of the vaccines must be performed with well characterised antibody reagents. Our group is working on generating such reagents for use by National Control Laboratories (NCLs) world-wide.
This work has been contracted by the WHO to generate well characterised monoclonal antibodies for types 16 and 18 in the first instance but will extend to cover all 9 types that are present in current and new vaccines.
We have used standard hybdridoma technology to produce type specific antibodies that have neutralising activity.
Characterisation of the antibodies is carried out in-house by standard antigen binding assays (ELISA) and by HPV pseudotype neutralisation assays.
We are collaborating with Dr Simon Beddows, Public Health England, to investigate the antigenic cross-reactivity of HPV neutralising epitopes to inform vaccine responses and design.
We have also created human antibody libraries from vaccinated people using ribsosome display technology to examine the immune responses generated against HPV vaccines.
Advice and training
We provide training to NCLs from developing countries undertaking HPV vaccine batch release.
There are also facilitated activities from the WHO HPV LabNet.
The IVV group is involved in revising the WHO guidelines to assure the quality, safety and efficacy of recombinant human papillomavirus virus-like particle vaccines.
We work with the wider MHRA on HPV vaccine.
The rabies virus causes acute inflammation in the brain that leads to debilitating conditions which in most cases lead to death.
It is spread to humans from other animals such as dogs through bites and scratches. Rabies causes up to 55 000 deaths a year mostly in Asia and Africa.
Treatments consist of vaccination and passive immunotherapy with rabies immunoglobulin before symptoms appear and are highly effective.
We are responsible for the 6th International Standard for rabies vaccine (Pitman Moore strain) for the standardisation of rabies vaccines in National Institutes of Health (NIH) mouse protection tests and in in vitro assays for glycoprotein content and the 2nd International Standard for, human.
Establishing pseudotype virus neutralisation assay for batch release of therapeutic immunoglobulin potency
Our Biotherapeutics group carries out the batch release of Human Rabies Immunoglobulin.
The IVV group has developed a new method for testing the neutralising potency based on a virus pseudotype assay in a collaboration with Dr Ed Wright at the University of Westminster. This method does not use wild-type rabies virus so high-cost containment facilities are not needed.
We aim to introduce the assay into the British and European Pharmacopoeia (PhEur) monographs through a multi-laboratory collaborative study which will assess its comparability to the current assays.
Replacing the rabies vaccine mouse challenge test with an ELISA method
This is part of the replacement, reduction and refinement (3Rs) drive of animal use.
The rabies vaccine potency test is an in vivo method involving vaccination and viral challenge of mice. In the context of the 3Rs concept, the EPAA (European Partnership for Alternatives Approaches to Animal Testing) is evaluating an in vitro method to replace the mouse challenge test. Our group is facilitating this collaborative study.
Hepatitis B virus (HBV)
It is estimated that more than 2 billion people world-wide have been infected with HBV.
Of these, about 600 000 people die each year from acute infections or cirrhosis and hepatocellular carcinoma caused by chronic infection.
In spite of the availability of safe and effective prophylactic vaccines, HBV infection remains a major public health problem world-wide, with chronic infection the main means of transmitting new infections.
The virus is highly contagious and is transmitted by percutaneous and permucosal exposure to infected blood and other body fluids.
The HBV surface antigen (HBsAg) included in HepB vaccines is responsible for the production of immunising antibodies. All HBV vaccines are made using recombinant DNA methods and are formulated with adjuvants.
Sensitive screening and accurate diagnostic HBsAg assays are essential to prevent and manage HBV disease and to monitor the impact of vaccination.
Laboratory diagnosis of hepatitis B infection centres on detecting HBsAg.
Clinical laboratories, blood transfusion laboratories, manufacturers of blood products and in vitro diagnostic kit manufacturers use the HBsAg IS to calibrate secondary reference materials for HBsAg and validate HBsAg assays.
We are responsible for the 3rd International Standard for the hepatitis B surface antigen HBsAg.
Our work crosses over to the standardisation, control and research of blood viral markers and blood virology. We produce CE-marked serology reference materials for HBV and Hepatitis C virus (HCV), for use as run controls. We also produce WHO serology reference materials for a number of viral targets.
We are responsible for testing HBV vaccines undergoing prequalification by WHO for procurement by UNICEF and other UN agencies. Tests for HBV vaccines are accredited under ISO17025.
Therapeutic immunoglobulin potency testing
Our group performs batch release potency testing of Hepatitis B, Hepatitis A and Varicella-zoster immunoglobulin on behalf of the Biotherapeutics group.
Investigating antibody responses in models of infectious diseases
We use various approaches to establish methods to facilitate investigations into the antibody responses to candidate vaccines and infection in models of human disease that have significant health impact.
These methods include producing hybridomas against human immunodeficiency virus (HIV) and ribosome display to generate antibody libraries against GBV-B – a model virus for HCV infection.
We use the antibody reagents to epitope-map the antigens targeted by vaccination and infection to inform vaccine design.