What are the different stages of vaccine development?

Nine months into the COVID-19 pandemic, scientists and pharmaceutial companies around the world are racing to develop an effective vaccine against SARS-CoV-2, the coronavirus that causes COVID-19. According to the latest list of the World Health Organization (WHO), at least 200 vaccines are at various stages of development.

According to Russian State media, the first batch of Russia’s vaccine, Sputnik V, entered “civil circulation” on September 24 in capital Moscow. However, its safety and effectiveness is being looked at sceptically because the results of only the phases 1 and 2 of the trials have been published. Earlier, reports emerged that the third stage trials were ongoing in Russia and a few other countries. Phase 3 of clinical trials of the Sputnik V vaccine will begin in India in the coming weeks.

China has about 11 vaccine candidates in various stages of human testing. China has been administering experimental coronavirus vaccines to large numbers of workers deemed to be at high risk of exposure to the virus. They include frontline health workers, public service workers and border officials. A vaccine developed by CanSino Biologists and named Ad5-nCoV was approved for use within the Chinese military as early as June 2020. Four other vaccines are in the final stages of clinical trials. Chinese officials say that the country will be able to roll out a vaccine for public use by November or December. China has promised to provide doses to at least 62 countries.

Among other vaccine contenders that have drawn global attention is the one being developed by the Oxford University in partnership with phaemaceutical company AstraZeneca. Hopes were high when it successfully carried out phases 1 and 2 of the trials. But the final clinical trials had to be briefly put on hold in September after a study participant developed a suspected serious adverse reaction.

COVID-19 vaccines are also being developed by Pfizer and BioNTech in the U.S. and Germany; Johnson and Johnson in the U.S.; Sanofi along with GlaxoSmithKline in the U.K. and Franc; and Novavax in the U.S. Some of these companies have signed deals with multiple countries for trials.

Back home, in India, there are at least eight vaccine candidates under development. The phase 3 clinical trial of ‘Covishield’, being developed by Oxford University and the Serum Institute of India, is underway. Indian candidates, Covaxin, by Bharat Biotech, and ZyCoV-D, by Zydus Cadila, are currently in phase 2 trials.

Experts maintain that even at this speed a vaccine will not be ready before mid-2021.

 

Picture Credit : Google