Widespread vaccinations against the coronavirus are not expected until mid-2021, the World Health Organisations says, despite the global race to have a cure ready this year.
There are 13 experimental vaccines currently in clinical trails around the world as infections reached 26.4 million with more than 870,000 deaths.
Russia has already given regulatory approval to its Sputnik-V jab while the USA and drug company Pfizer say theirs could be ready by October which is just before the November presidential election.
The UK’s Oxford University is considered the key frontrunner, with Australia already signing a letter of intent to buy 25 million doses.
But the WHO has stressed the importance of vigorous testing and safety checks, warning that none of the candidate vaccines have yet shown a “clear signal” of efficacy of at least 50 per cent.
“We are really not expecting to see widespread vaccination until the middle of next year,” said WHO spokeswoman Margaret Harris.
“This phase three must take longer because we need to see how truly protective the vaccine is and we also need to see how safe it is,” she added, not referring to any specific vaccine candidate.
“A lot of people have been vaccinated and what we don’t know is whether the vaccine works…at this stage we do not have the clear signal of whether or not it has the level of worthwhile efficacy and safety.”
If and when we have an effective #COVID19 vaccine, we must also use it effectively.
I will repeat again: vaccine nationalism will prolong the pandemic, not shorten it. pic.twitter.com/lPlqvakkyh
— Tedros Adhanom Ghebreyesus (@DrTedros) September 4, 2020
WHO chief scientist Soumya Swaminathan said no vaccine should be approved for a worldwide roll-out until it had undergone sufficient scrutiny.
“Certainly by the middle of 2021 we should start to see some vaccines actually moving into countries and populations,” he said.
The WHO and GAVI vaccine alliance are leading a fair global vaccine allocation plan known as COVAX to deliver 2 billion doses of approved vaccines by the end of 2021.
Meanwhile, Moscow says it has faced down critics of its vaccine after the results of early stage trials were published in the The Lancet medical journal.
Russia’s Sputnik-V produced an antibody response in all participants in two early-stage trials involving 76 participants.
The trials in June-July showed 100 per cent of participants developed antibodies to the new coronavirus and had no serious side effects, The Lancet said.
Russia licensed the two-shot jab for domestic use in August, the first country to do so and before any data had been published or a large-scale trial begun.
“The two 42-day trials – including 38 healthy adults each – did not find any serious adverse effects among participants, and confirmed that the vaccine candidates elicit an antibody response,” The Lancet said.
“Large, long-term trials including a placebo comparison, and further monitoring are needed to establish the long-term safety and effectiveness of the vaccine for preventing COVID-19 infection.
Lead author Dr Naor Bar-Zeev of the International Vaccine Access Centre, Johns Hopkins Bloomberg School of Public Health, US said the studies were “encouraging but small” and that “clinical efficacy for any COVID-19 vaccine has not yet been shown”.
Some Western experts have warned against using Sputnik-V, which is named in homage to the world’s first satellite, launched by the Soviet Union, until all internationally approved testing and regulatory steps have been taken.
But a senior Russian official said accused its critics of tarnishing Russia’s success.
“With this (publication) we answer all of the questions of the West that were diligently asked over the past three weeks, frankly with the clear goal of tarnishing the Russian vaccine,” said Kirill Dmitriev, the head of the Russian Direct Investment Fund (RDIF), Russia’s sovereign wealth fund, which has backed the vaccine.
“All of the boxes are checked,” he said. “Now… we will start asking questions of some of the Western vaccines.”
Mr Dmitriev said at least 3000 people had already been recruited for the large-scale trial of the Sputnik-V vaccine launched last week, and initial results were expected in October or November this year.