COVID-19 Vaccine Clinical Development: An Unprecedented Challenge
One third of humanity is under some form of containment to slow the spread of COVID-19. Whilst governments across the world have taken different approaches to control the outbreak, it is universally accepted that the deployment of an effective vaccine against SARS-CoV-2 is imperative.
A global effort involving cross-disciplinary experts is currently underway, with the aim of mass producing clinically tested COVID-19 vaccines within the next 18 months. Vaccine development is a complex process that typically takes over 10 years, with a market entry probability as low as 6%. Significant acceleration of clinical development and regulatory pathways are therefore required to address the current global health threat.
Partnerships have been established with the goal of sharing expertise and resources to increase the speed of vaccine development, manufacture and regulation. Joint ventures between GSK and Sanofi, as well as Pfizer and BioNTech are underway, and licensed adjuvants have been made available for the cause.
Ten vaccine technology platforms are under research and development with clinical trials currently underway for at least seven candidates. Next-generation approaches that reduce preclinical development time are at the forefront; Moderna’s mRNA-based vaccine (mRNA-1273) was first dosed in humans just 63 days following publication of the SARS-CoV-2 sequence. Phase I and I/II studies of Inovio’s DNA vaccine (INO-4800), similar to their promising Middle East Respiratory Syndrome (MERS) vaccine currently in development, will be run in parallel in the US and South Korea. Whilst DNA and mRNA-based platforms are relatively straight forward to develop and produce, their long-term effectiveness is relatively untested and neither technology has previously been approved.
Progress is also being made with well-established technologies:
- A phase III trial is underway to assess the effectiveness of the BCG (tuberculosis) vaccine on prevention of COVID-19 in Australian health workers, since preliminary evidence suggests that countries with BCG vaccination programs are less severely affected by COVID-19.
- Two adenovirus-based vaccines are also in development.
- A phase I/II trial has begun in Oxford using replication-deficient adenovirus vector technology (ChAdOx1) that has previously shown promise for MERS.
- In addition, data from a phase I study of CanSino Biologics’ adenovirus type 5 vector vaccine (AdS-nCoV) have supported plans for a phase II trial in China.
A major challenge for researchers is to run consolidated clinical studies under extremely reduced timeframes without compromising vital immunogenicity and safety assessments. To this end, the World Health Organization has published a Research and Development Blueprint of the SOLIDARITY vaccine trial; an international, controlled, randomised trial in adults at high risk of SARS-CoV-2 exposure that will evaluate benefit and risks of candidate vaccines made available to the trial within 6 months. SOLIDARITY will generate robust data while overcoming the challenge of comparisons between multiple small trials with different methodologies.
The clinical development of vaccines for COVID-19 is at the centre of the global effort to overcome the current health crisis. Despite the constraints on time, overwhelming scientific and medical evidence of the highest quality is required before widespread administration of a COVID-19 vaccine. Bioscript are evaluating how we – as a medical communications agency with key expertise in the vaccines field – can contribute to this effort and support our industry partners at this important time.
See Regulatory Focus’s tracker for more information and weekly updates on COVID-19 candidate vaccines in development.