Investment in research and development largely by the pharmaceutical industry has resulted in a broad range of vaccines targeting
more than 25 infectious diseases. During the past 30 years, advances in biotechnology, genetic technology, and information
technology have resulted in acceleration in the pace of vaccine development. As a result, the vaccine industry has recently
introduced a number of new vaccines, such as those against cervical cancer, meningococcal infection, potentially pandemic
influenza, pneumococcal diseases, rotavirus diarrhea, and varicella zoster.
The manufacturing processes for vaccines have also come a long way, from using heat-inactivated cells to using recombinant
DNA technology-driven antigen production. For example, inactivated polio vaccine as developed by Salk has been changed and
improved and is currently being produced in a Vero cell line. Additionally, there are a few other examples of expression systems
that are specifically developed for use in vaccine production. These include the PER.C6 cell line, the associated AdVac/Virosome
technology (Crucell/DSM), and the avian-derived cell lines from Vivalis and ProBioGen. Another expression technology with
potential benefits is the Pfenex Expression Technology from Dow, which has been used to generate high levels of vaccine antigens.
What sets manufacturing of vaccines apart from that of other biopharmaceuticals is the risk and safety considerations related
to working with pathogens and pathogenic antigens. While removal of host cell-related contaminants (e.g., host cell proteins,
DNA) has to be demonstrated just as for other biotech therapeutics, removal or inactivation of adventitious viruses remains
a significant challenge (1). Key questions for manufacturers remain. How does one ensure that the starting materials and final
product are consistently safe and of high quality? Who can manufacture the amount of vaccine needed for clinical trials and,
eventually, commercial production?
This 27th article in the "Elements of Biopharmaceutical Production" series discusses the key technical, manufacturing, and
regulatory considerations that need to be taken into account by the manufacturers today to make safe and efficacious vaccine
products—whether manufactured in-house or outsourced.
ECONOMICS OF VACCINES
Figure 1: Distribution of products in pipelines of major biopharma companies (adapted from reference 4).
Producing a safe and effective vaccine requires about 12–15 years of research and is estimated to cost between $100 million
and $1 billion, depending on the type of vaccine being developed. It is estimated that 60% of vaccine production costs are
fixed, meaning that vaccine products require a sizable market to be profitable (2). As a result, many potentially vaccine-preventable
diseases, such as those primarily affecting the developing world, are left without large-scale research interest from multinational
vaccine manufacturers. Attempting to fill this void have been networks led by private philanthropies, governments, and public-private
partnerships (1, 2). Despite the challenges mentioned above, vaccine production has considerable lure for manufacturers. The
global vaccine market is expected to increase by more than 100%, from $24 billion in 2009 to $56 billion in 2016 (1). Multinational
vaccine companies historically have conducted much of the innovation, research, and development in the field of vaccine production.
Many factors seem to discourage vaccine research and development, including liability concerns and price limits due to bulk
purchasing. The vaccine industry is at present dominated by major players such as Merck, Sanofi-Aventis/Pasteur, GlaxoSmithKline,
Novartis, and Pfizer (3). As illustrated in Figure 1, the number of biotech products including those that are in the pipeline
indicates that there are more vaccines than recombinant proteins and monoclonal antibody products (4). The global vaccine
market has experienced robust growth over the past few years, with economically emerging countries, such as India and China
contributing effectively towards the industry's development. The governments in developing markets are spending significant
amounts of money and resources for vaccine delivery and distribution. This spending, in turn, has led to the entry of more
foreign vaccine players in these countries.