A US biotechnology company has become the latest to announce that it has started human trials of a vaccine for the coronavirus disease (Covid-19) and hopes to release a proven one this year.
Nearly dozen experimental vaccines are in early stages of testing or poised to start, mostly in China, the US and Europe for Covid-19, which has infected more than 5.49million people worldwide and killed 346,232.
Most of the shots in the pipeline aim to train the immune system to recognise the “spike” protein that studs the coronavirus’ outer surface, priming the body to react if it ever encountered the real infection.
Some candidates are made using just the genetic code for that protein, and others use a harmless virus to deliver the protein-producing information. Still other vaccine candidates are more old-fashioned, made with the killed whole virus.
As of May 24, there were at least 10 vaccines in human trials, according to the World Health Organization (WHO).
CanSino from China has non-replicating viral vector vaccine and there are inactivated vaccines from Sinovac, Wuhan Institute of Biological Products and Beijing Institute of Biological Products.
There’s a non-replicating viral vector vaccine from Oxford University and AstraZeneca (UK) and protein subunit vaccine from Novavax (US). RNA vaccine from Moderna and BioNTech and Pfizer (Germany/USA) and DNA vaccine from Inovio are also among those in the list.
Novavax human trial
Dr Gregory Glenn said, Novavax’s research chief, said the company has begun the first phase of the trial in which 131 volunteers in the cities of Melbourne and Brisbane will test the safety of the vaccine and look for early signs of the vaccine’s effectiveness.
“We are in parallel making doses, making vaccine in anticipation that we’ll be able to show it’s working and be able to start deploying it by the end of this year,” Glenn told a virtual press conference.
The Maryland-based Novavax is one of such several biotech companies racing to develop a vaccine against Sars-Cov-2, the virus that causes Covid-19.
Two other companies, Moderna and BioNTech, in a partnership with Pfizer, have already begun clinical trials of Covid-19 vaccines.
However, they are developing mRNA vaccines, a new type of vaccine that’s still unproven. There are several mRNA vaccine candidates but none have yet been approved to go to market.
Those vaccines use mRNA to stimulate the body to produce copies of the coronaviruses “spike protein” in order to stimulate an immune response.
Novavax is developing a “subunit” vaccine, which sends copies of the virus’ spike protein directly into the body to stimulate an immune response. This is an established vaccine technology currently already being used against diseases such as HPV, Hepatitis B and shingles.
Novavax adds another new kind to that list, what’s called a recombinant vaccine. Novavax used genetic engineering to grow harmless copies of the coronavirus spike protein in giant vats of insect cells in a laboratory.
Scientists extracted and purified the protein, and packaged it into virus-sized nanoparticles.
The late-stage biotechnology company in April said it identified the candidate, NVX-CoV2373, with which it planned to use its Matrix-M adjuvant to enhance immune responses.
Adjuvants are mainly used to make vaccines induce a strong immune response, including through the greater production of antibodies, and provide longer-lasting protection against viral and bacterial infection.
Novavax said it expects preliminary immunogenicity and safety results from the trial in July.
Novavax said the Phase 2 portion of the trial will be conducted in several countries, including the United States after upon the successful completion of Phase 1. It added that the Phase 2 trial will assess immunity, safety and Covid-19 reduction in a broader age range.