There might never be a "silver bullet" treatment for the coronavirus pandemic, according to the director general of the World Health Organisation (WHO).
Dr Tedros Adhanom Ghebreyesus told a media briefing on Monday: "A number of vaccines are now in phase three clinical trials and we all hope to have a number of effective vaccines that can help prevent people from infection."
"However, there's no silver bullet at the moment, and there might never be."
His remarks came following a meeting of the WHO-convened emergency committee of international experts on Friday.
He also said that wearing a face mask sends a message of solidarity, as he urged countries to continue with the “basics” of public health to bring the pandemic to an end.
He said he carried a mask and hand sanitiser with him at all times.
“By wearing a mask, you’re sending a powerful message to those around you that we’re all in this together,” he said.
“Wear a mask when appropriate, keep your physical distance from others, and avoid crowded places. Observe coughing etiquette, clean your hands frequently, and you’ll be protecting yourself and others,” he said.
Dr Tedros’s warning came as the world recorded more than 18 million cases of the disease, with the US, Brazil and India continuing to report high numbers of new infections. Other countries, such as Australia and Vietnam, are also seeing a resurgence in cases.
Dr Tedros urged countries to continue with the basics of testing, isolating and treating patients and tracing and quarantining their contacts.
"We learn every day about this virus and I'm pleased that the world has made progress in identifying treatments that can help people with the most serious forms of Covid-19 recover.
"Over the past week we've seen several countries that appeared as though they were past the worst now contending with fresh spikes in cases.
"However, we've also seen how some countries, regions or localities that had a high number of cases are now bringing the outbreak under control."
He added: “The message to people and governments is clear: do it all. And when Covid-19 is under control keep going. Keep strengthening the health system. Keep improving surveillance, contract tracing and ensure disrupted health services are restarted as quickly as possible,” he said.
And Dr Mike Ryan, WHO’s head of emergencies, warned that countries with high transmission rates, including Brazil and India, needed to be prepared for a long journey ahead. "The way out is long and requires a sustained commitment,” he said.
Dr Tedros also announced that a WHO-led team of Chinese and international experts would be set up to study the origins of the virus in the city of Wuhan, although the timing and composition of the team is not yet clear.
A smaller, advance team is currently in the city, where the virus first originated last year.
Dr Tedros said epidemiological studies will begin soon to identify the potential source of infection of the early Covid-19 cases, which were linked to a seafood market in Wuhan.
Dr Ryan added: “There are gaps in the epidemiological landscape and there are going to be much more extensive studies to fully understand the link between these [early] cases so we can determine at what point the animal-human species barrier was breached.”