Covid-19 vaccination to realistically begin in mid-2021: WHO

While clinical trial results of the first successful covid-19 vaccines are expected as early as the end of this year, vaccination of public will, realistically, only begin in the middle of 2021 after mass manufacturing of doses starts, World Health Organization Chief scientist Soumya Swaminathan said on Friday.

“We expect results from some of the candidates which are already in phase 3 trials to come by the end of the year or by beginning of next year, following which there will be scaling of manufacturing to produce the hundreds of millions of doses that are going to be needed... Realistically speaking, probably the middle of 2021... is probably when we can see doses flowing into countries so that they can start immunising their populations,” Swaminathan said at a virtual press conference from the WHO headquarters.

As the initial supply will be limited, countries will have to prioritise who will immunised with the first tranches of vaccines, she said.

WHO director general Tedros Adhanom Ghebreyesus said that countries should first give the vaccines to healthcare and other essential workers who are on frontlines in the fight against covid-19 pandemic, as well as the elderly and immunosuppressed people who are most at risk of dying from the disease.

In a bid to assure people about the safety of any approved covid-19 vaccines, Ghebreyesus also said that the WHO will not endorse a vaccine that is not effective and safe.

“On vaccines against covid-19, we have a good number of promising ones. They will only be used when they are found to be effective and safe,” he said.

Currently, there are around three dozen covid-19 vaccine candidates in human trials, with over 100 other candidates in pre-clinical trials. While Russia’s Sputnik V vaccine is the first registered vaccine against covid-19, it is still undergoing phase 3 clinical trials.

Other vaccines that are in phase 3 clinical trials include Astrazeneca plc and University of Oxford’s jointly-developed candidate ‘Covishield’, as well as those by China-based CanSino Biological Inc, Moderna, and Pfizer.

The Oxford vaccine will also be mass-manufactured by Serum Institute of India, which is currently conducting a 1,600-participant phase 3 trial in India.

In India, Zydus Cadila’s ZyCoV-D and Bharat Biotech International Ltd’s Covaxin are also in phase I/II clinical trial.