Dr Tedros Adhanom Ghebreyesus said that while work on an “effective” vaccine is underway in several countries, a perfect vaccine to end the pandemic may never be found.
Around the world, 690,624 people have died with COVID-19[feminine[feminine and more than 18.1 million have been infected with the disease, according to figures compiled by Johns Hopkins University.
Of these, 46,295 deaths and 307,251 infections have been recorded in the UK.
Although some countries have eliminated their first waves, there are fears of a resurgence.
The British government warns a the second peak could come from Europe, as the number of cases – when it was at its lowest point since mid-March – has stopped dropping significantly.
England’s chief medical officer Professor Chris Whitty also warned last week that the country may have reached the limit of restrictions that can be relaxed.
In order to stop the virus Exploding again, Dr Tedros called on countries to rigorously enforce measures such as wearing masks, social distancing, hand washing and testing.
“The message to citizens and governments is clear: do it all,” he told a press conference at WHO headquarters in Geneva.
“There are a number of vaccines currently in phase three clinical trials and we all hope to have a number of effective vaccines that can help prevent infection.
“However, there is no quick fix at the moment – and there may never be. ”
“There is concern that we don’t have a vaccine that can work or that its protection lasts only a few months, not more.
“But until we finish the clinical trials, we won’t know. ”
WHO emergency chief Mike Ryan said at the same event that countries with high transmission rates, like Brazil and India, need to prepare for a big battle and “reset” their approaches.
“Some countries are really going to have to take a step back now and really look at how they cope with the pandemic within their national borders,” he warned.
There are only five vaccines in what’s called phase three – which means they are being tested for efficacy on a large scale.
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Sky News is follow the race for a vaccine, which currently seems to be driven by the UK group from the University of Oxford and AstraZeneca.
If successful, it will then be reviewed by the Medicines and Health Products Regulatory Agency to see if it should be used by the general public.
Several countries, including the United Kingdom, have spent millions to pre-order vaccine supplies. It is based on previous work to produce a vaccine against MERS, another deadly respiratory virus.