Dr Tedros Adhanom Ghebreyesus said the length of the global Spanish flu outbreak in the years after the First World War was a good comparison.
“Our situation now with more technology, of course with more connectiveness, the virus has a better chance of spreading, it can move fast,” he said.
“At the same time we have the technology and knowledge to stop it.”
Nearly 800,000 people have died since the start of the outbreak at the end of last year, while about 22 million people are confirmed to have been infected with the virus.
Some countries, like South Korea and Vietnam, have had some success in keeping Covid-19 largely at bay through a combination of extensive testing, contact tracing and lockdown measures.
But Mr Ghebreyesus warned that “progress does not mean victory” pointing out that some countries like New Zealand appeared to have conquered the virus, before a fresh outbreak struck.
He said: “These countries are a cautionary tale for those that are now seeing a downward trend in cases.”
And while some countries are seeing progress towards a vaccine, the WHO boss said that this would not solve all problems related to the virus.
“We must all learn to control and manage this virus using the tools we have now, and to make the adjustments to our daily lives that are needed to keep ourselves and each other safe,” he added.
WHO officials also warned that more research needs to be done into coronavirus mutations, which can drastically change the severity of the symptoms a sufferer experiences.
Epidemiologist Maria Van Kerkhove said: “A special working group has been formed to identify mutations… and we’re looking at how we can better understand what the mutation means and how they behave.”