In excess of 1 bn fertilised specific pathogen free (SPF) chicken eggs are used annually in vaccine manufacture, globally. SPF is the term that is used to describe eggs, which are confirmed to be free of various infectious agents e.g. bacteria and viruses. The embryo in the egg is used to grow the virus, the basis of the development and production of vaccines. Globally, there is a world shortage of ‘high grade’ eggs for vaccine manufacture and ongoing supply and contamination issues dictate a need for a superior product. Currently, all eggs used in vaccine manufacture, even those of the highest SPF grade, carry bacteria on the shell and 10-20% of eggs carry bacteria inside the shell. Internalised bacteria cannot be removed without damaging the embryo, rendering it of no use for vaccine production.
Bacterial contamination occurs because the eggshell may absorb contaminating bacteria, from external sources. An eggshell is porous to facilitate gaseous exchange by the growing embryo. The pores of the eggshell are vulnerable to bacterial ingress during laying and for approximately 5 minutes after the egg is laid. Unlike mammals, where the digestive tract is separate from the reproductive tract, in poultry, the reproductive tract merges with the digestive tract, in the cloaca, and there is a single point of exit from the hen for eggs and faeces. This results in the porous egg coming in contact with the chicken’s faeces prior to being laid and consequent contamination of 10-20% of the eggs within the shell occurs. Detection of infectious agents relies on microbiological monitoring but the 4-week lag time required to confirm the presence of infection in the SPF eggs, means that infected eggs will have already been used in vaccine production, causing rejections of batches of vaccines, delays to market and to patients. The cost of a rejected batch of vaccine can be up to $480,000 with annual losses of $35 million confirmed by one large customer visited during our extensive market research. Ovagen (OGL), in its proof of principle work, addressed this problem with its world’s first innovative disruptive patented technology of 100% bacteria-free eggs, also referred to as Germ Free (GF).
The World Health Organisation (WHO) in July 2019 set a target to make vaccination available to everyone, everywhere by 2030. Furthermore, The United Nations Transforming Our World, 2030 Agenda for Sustainable Development clearly states in goal 3.b the support for research and development of vaccines for the communicable and non-communicable diseases that primarily affect developing countries. However, in order to achieve this target of universal access to vaccines, a fundamental re-evaluation of aspects of current vaccine manufacturing processes is required. The COVID-19 global pandemic has highlighted the urgent need for access to innovative and disruptive technologies that will enable rapid manufacture of vaccines to prevent and control emerging diseases.
Societal benefits from our project are improved availability of vaccines and cost to health-services (from production efficiency and improved yield) for immunisation programmes to protect populations from disease outbreaks; clean water and vaccines are described by WHO as having the greatest impacts on human health.
An additional benefit from our project is that the use of GF eggs vs SPF eggs in vaccine production will enable vaccine manufacturers to get vaccines faster to market, at lower cost and improved quality, in greater quantities due to a lower batch rejection rate and a higher viral yield. This will bring significant benefits to populations globally by making available quality vaccines to prevent disease with the associated social and public health benefits. GF eggs will be a game-changer for vaccine health economics.
The overall objective of this project was to radically transform the way that egg based vaccines are manufactured globally and to offer an additional solution to the rapid development and manufacture of vaccines in the case of future pandemics.
