Coronavirus vaccine: Which companies are the frontrunners?

There is a huge rush among nations across the globe to immunise their citizens against coronavirus. According to the World Health Organisation, around 170 coronavirus vaccines are currently under development around the world. However, only a handful are nearing the final stage of testing.

Vaccines mimic the virus - or part of the virus - they protect against, stimulating the immune system to develop antibodies against the disease.

HOW ARE VACCINES TESTED?

1. Pre-clinical stage: This is the earliest stage in which researchers test the vaccine on animals to check if it triggers an immune response.
2. Phase-1: In this phase of clinical testing, a vaccine is given to a small group of people to understand whether it is safe, and to learn about the immune response.
3. Phase-2: At this stage of the clinical trial, the vaccine is given to hundreds of people to gain an understanding of the safety and correct dosage of it.
4. Phase-3: This is the final phase of vaccine development, wherein thousands of people get a dosage of the vaccine. In this phase, scientists and researchers try to determine the rare side-effects and effectiveness of the vaccine. This trial involves a control group that is given a placebo.

Coronavirus vaccine - The Frontrunners:

1. University of Oxford/AstraZeneca: The University of Oxford and AstraZeneca PLC has developed the first vaccine candidate to start the final round of testing of the coronavirus vaccine. India's Serum Institute of India (SII)  has signed an agreement with AstraZeneca to manufacture a COVID-19 vaccine candidate for India and low-and-middle-income countries. The SII has selected 17 sites in India to conduct the Phase 2 trial of the Oxford COVID-19 vaccine.

Moreover, the Oxford vaccine's Phase 3 trials are underway in the US, UK, Brazil, and South Africa.

AstraZeneca aims to make two billion doses available worldwide and said one billion doses of the vaccine will be available this year.

2. Moderna Vaccine:  American biotech company Moderna is developing a vaccine candidate using messenger RNA (or mRNA for short) to trick the body into producing viral proteins itself. Moderna and US National Institute of Allergy and Infectious Disease are testing two-dose shot. Moderna's candidate was the first one to enter human trials in the US. Moderna's final-stage testing is underway with 30,000 human trials that might yield interim results by the end of 2020. It must be noted that the mRNA vaccine has never been approved for any disease. Moderna has promised to supply between 500 million to 1 billion doses a year starting 2021.

3. Pfizer: US Biotech firm Pfizer is also developing a coronavirus vaccine using mRNA. Pfizer and its German partner BioNTech SE have begun enrolling 30,000 people in 120 different sites. The US government has approved to pay $2 billlion to Pfizer and BioNTech for 100 million doses. It is estimated that Pfizer will distribute 1.3 billion doses by the end of 2021.

4.Sinopharm: China's biotechnology firm Sinopharm is developing two coronavirus vaccines with the government agencies Wuhan Institute of Biological Products and Beijing Institute of Biological Products.

At present, Sinopharma has entered into an agreement to conduct testing in several countries, including Pakistan and the United Arab Emirates. Chinese officials have said they aim to make a vaccine available to the public before the end of the year with a production capacity of 220 million doses a year.

5. Sinovac: This is a private Chinese company that began the final-stage trial in Brazil in July. Sinovac has also struck a deal with an Indonesian pharmaceutical firm called PT Bio farma to make up to 250 million vaccine doses each year for Indonesians.

6. Johnson & Johnson: A single dose of the J&J vaccine triggered a strong immune response in early animal testing.  Johnson & Johnson has used a weakened form of a common cold virus, called adenovirus to develop the coronavirus vaccine. The US-based company will conducted a trial on 60,000 persons, which could be the largest late-stage clinical trial of a coronavirus vaccine. J&J said that it will carry out the study at nearly 180 locations in the US and eight other locations where the transmission rate is high.

Johnson & Johnson is expected to produce one billion doses of the COVID-19 vaccine by the end of 2021, including 100 million doses for the US.

7. Novavax Inc: US-based Novavax is making a vaccine that consists of two shots given 21 days apart. The vaccine delivers proteins resembling the spike of SARS-CoV-2. Researchers are hoping that the protein will trigger the production of antibodies and immune cells that can fight off the coronavirus. Novavax has planned to provide 100 million doses for use in the US.

8. Gamaleya Research Institute: Russia's Gamaleya Research Institute is developing a coronavirus vaccine based on the combination of two adenoviruses. Although Russia has already approved the use of the vaccine in early August, the shot hadn't gone through final-stage testing. The Russian government is planning for mass vaccination in October.

Also read: AstraZeneca's coronavirus vaccine enters phase 3 trials in US

Also read: Coronavirus update: India reports 69,921 in 24 hours; caseload nears 37 lakh