WHO chief scientist names world's leading COVID-19 vaccine candidate

GENEVA: Astrazeneca’s COVID-19 vaccine candidate is probably the world’s leading candidate and most advanced in terms of development, the World Health Organization’s chief scientist said on Friday.

Soumya Swaminathan said that Moderna’s COVID-19 vaccine candidate was also “not far behind” Astrazeneca’s, among more than 200 candidates, 15 of which have entered clinical trials.

The WHO is in talks with multiple Chinese manufacturers, including Sinovac, on potential vaccines, she said.

Swaminathan, speaking to a news briefing, called for considering collaborating on COVID-19 vaccine trials, similar to the WHO’s ongoing Solidarity trial for drugs.

Effective vaccines are seen as critical to stopping a pandemic that has infected more than 9.3 million people and killed nearly 480,000 globally with little sign of letting up..

About AstraZeneca and Oxford University’s vaccine candidate

ChAdOx1 nCoV-19, now known as AZD1222, was developed by Oxford University’s Jenner Institute, working with the Oxford Vaccine Group.

It uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold (adenovirus) virus that causes infections in chimpanzees and contains the genetic material of SARS-CoV-2 spike protein.

After vaccination, the surface spike protein is produced, priming the immune system to attack COVID-19 if it later infects the body.

The recombinant adenovirus vector (ChAdOx1) was chosen to generate a strong immune response from a single dose and it is not replicating, so cannot cause an ongoing infection in the vaccinated individual. Vaccines made from the ChAdOx1 virus have been given to more than 320 people to date and have been shown to be well tolerated, although they can cause temporary side effects such as a temperature, influenza-like symptoms, headache or a sore arm.

About mRNA-1273, Moderna’s Vaccine Candidate Against COVID-19

mRNA-1273 is an mRNA vaccine candidate against COVID-19 encoding for a prefusion stabilized form of the Spike (S) protein, which was selected by Moderna in collaboration with investigators from Vaccine Research Center (VRC) at the National Institute of Allergy and Infectious Diseases (NIAID), a part of the National Institutes of Health (NIH).

On June 11, 2020, Moderna announced that enrollment of younger adults (n=300) and the sentinel group of older adults (n=50) in its Phase 2 study of mRNA-1273 was complete, and that its Phase 3 study of approximately 30,000 participants, is expected to begin in July 2020.