March 2021
How close are we to the end of the COVID-19 pandemic?
By Thais Langer, PhD
What the data say about the vaccines developed so far.
A comparative analysis made by Novateur Ventures (a well-established global healthcare consulting company) published this February provides an early – and good – perspective for 2021. Novateur evaluated twelve COVID-19 vaccine platforms (the technology – delivery method, mechanism – of the vaccine) that reached Phase III clinical trials.
With a great balance between safety, reactogenicity and efficacy, the novel messenger RNA (mRNA) vaccine seems promising, according to new research. Its main hurdle, say the researchers, is the cold-chain requirements for storage, diminishing the vaccine’s shelf life. Protein-subunit platforms (vaccines that use only a fragment of the virus) also ranked well but showed less efficacy than mRNA vaccines.
“A novel vaccine platform (mRNA) has been established that will likely alter the course of vaccine development in perpetuity. This will pave the way for the use of the platform in cancer therapeutics and other biomedical applications,” the authors concluded.
Which vaccines were compared and how?
The researchers analysed the following platforms: mRNA (Moderna and Pfizer/BioNTech), viral vector (Astra Zeneca/University of Oxford, CanSino Biologics, Gamaleya and Johnson & Johnson/Janssen), recombinant protein-based (Novavax and Medicago) and inactivated virus (Bharat Biontec, Sinopharm (Wuhan), Sinopharm (Beijing) and Sinovac).
The harmonized Target Product Profile (TPP – outlines the desired profile of a product ) analyses how each vaccine reaches minimally acceptable targets in different categories. The team ranked each platform according to the following parameters using a weighing scale (in parentheses):
- Safety/Reactogenicity (30): benefits versus risks, including adverse effects.
- Efficacy (50): percentage of tested individuals that generated enough immunity during Phase III (immunogenicity).
- Logistics (10): storage requirements to maintain product stability.
- Cost of goods (COGS) (10): scale-up manufacturing potential at a cost/dose that allows broad use.
The mRNA vaccines scored best overall (82 – maximum is 100) due to high efficacy (50) and safety/reactogenicity (24).
Inactivated virus vaccines scored high for safety/reactogenicity (30) but lacked efficacy (25). Viral-vector vaccines scored second last due to lower safety/reactogenicity (21) and efficacy (35). Inactivated-virus platform scored the least overall.
“The clear winners in this category are the mRNA vaccines with efficacy in the 95% range across a spectrum of ages and ethnicities followed by the protein subunit platform,” researchers wrote.
What to expect in the near future
The study was limited due to incomplete data sets from Phase III trials from some vaccines and relied on data from Phase II for some parameters. “Nonetheless, the successes should be praised and hope should reign that the global pandemic will end soon or at least be held in check so that we can return to a world unhampered by restrictions and to global prosperity,” the authors concluded.
Antibody levels induced by natural infection with SARS-CoV-2 last several months, but we do not know yet how long vaccine efficacy lasts. The next question is whether we will need annual immunizations.
Data from vaccination campaigns so far are promising: “Vaccine rollout has begun in massive campaigns, in Israel, UAE, and across the United States (…). Early success is emerging in Israel where half the population has been vaccinated, with cases of COVID-19 and hospitalization falling dramatically,” the authors described.