In 1776 the cry was “The British are coming! The British are coming!” This was a warning that sent chills down the backs of the colonists of America. Today, it is the vaccines that are coming, but this should bring hope to millions of Americans and other nations.
Ana Rivas, Peter Loftus, and Alberto Cervantes tell us in The Wall Street Journal that some 170 Covid-19 vaccines are under development around the world, according to the World Health Organization. While the WHO has lost much of its credibility in their response to this pandemic, this is nevertheless good news to a world eager to return to some semblance of normalcy.
In a series of graphics, these writers give us a visual display of the process of vaccine testing from preclinical development to three phases of clinical trials. They also show us the various types of vaccines in development including viral vector, genetic coded, weakened virus, and proteins.
These graphs depict the number of vaccines that began in the preclinical phase, those that began clinical trials, and finally those now in advanced Phase 3 trials. Thirty-five vaccines began clinical trials in Phase 1 and nine have advanced to Phase 3 trials.
The Front Runners
The leading candidates for a successful vaccine include the following:
- University of Oxford/AstraZeneca
- Pfizer/BioNTech SE
- CanSino Biologics
- Johnson & Johnson
- Gamaleya Research Institute
This vaccine is a viral vector vaccine that aims to deliver the into a person’s cells the genetic code for the spikes protruding from the new coronavirus. If successful, the cells then produce spike proteins which generate an immune response to fight the virus. The viral vector is a weakened, harmless version of a virus that causes the common cold in chimpanzees.
On September 8th, AstraZeneca announced they were temporarily suspending trials for its vaccine candidate after a woman in the U.K. experienced illness. At this time it isn’t clear how long this suspension will last. The trial began in late August with 30,000 expected subjects. The temporary suspension has now been removed and the trials have resumed.
This vaccine is a gene-based technology to provoke an immune response using messenger RNA. These molecular couriers take DNA instruction for making proteins. The vaccine delivers to cells mRNA for making the coronavirus’s spike protein. Moderna and the U.S. National Institute of Allergy and Infectious Diseases (NIAID) are testing a two-dose shot. It was the first candidate to enter human testing in the U.S. The vaccine produced an immune response in early-stage testing and was generally well-tolerate, with minor side effects observed in test subjects. Phase 3 trials are underway with 30,000 subjects and interim results are anticipate in the fall.
The vaccine in development by Pfizer and German partner BioNTech also uses mRNA. Phase 3 trials began in July in the U.S. enrolling 30,000 people and will expand overseas to include about 120 sites. The U.S. government has agreed to pay Pfizer and BioNTech nearly $2 billion for 100 million doses. Pfizer aims to seek regulatory approval or emergency-use authorization (EUA) soon. A spokesman recently estimated a vaccine would be ready for EUA before the end of October.
China’s state-owned Sinopharm is developing two vaccines in cooperation with the Wuhan Institute of Biological Products and Beijing Institute of Biological Products. Both vaccines area based on older vaccine-making techniques. Naturally, there is concern over the Wuhan safety record since the Covid-19 virus probably originated in Wuhan at the same institute.
Sinovac is a private Chinese company who began Phase 3 trials in July in Sao Paulo, Brazil. It is testing a vaccine to take advantage of a higher infection rate. Sinovac has also struck a deal with Indonesian state-owned pharmaceutical holding company PT Bio Farma to make up to 250 million vaccine doses each year for the Indonesian public.
This vaccine is being developed primarily for the Chinese military. It is based on a weakened virus behind the common cold. A Phase 1 study was conducted in March in Wuhan, the early epicenter of Covid-19. The government gave clearance in June for military use for one year.
The J & J vaccine is also using a weakened virus form of a common cold known as an adenovirus. A single does of this vaccine provoked a strong immune response in early animal testing. The company plans a 60,000-person global study beginning in late September, which would be the largest late-stage clinical trial of a Covid-19 vaccine. This will be carried out at nearly 180 locations in the U.S. and eight other countries.
This Russian state-owned company is developing a vaccine based on a combination of two adenoviruses which has already been tested on volunteers. Russia approved use of this vaccine in early August though the shot hadn’t gone through final stage testing. The Russian government plans for mass vaccinations to start in October, beginning with high-risk groups including healthcare workers.
This vaccine consists of two shots given 21 days apart that delivers proteins resembling the spike jutting out from the new coronavirus. Researchers hope the proteins will trigger the production of antibodies and immune cells that can fight off the coronavirus. Phase 2 testing began in August and Phase 3 trials are expected to begin later in September.
This extent of world-wide focus on vaccine development is unprecedented and marks a significant advance in the science and technology needed to battle new pandemics.