The World Health Organization urged countries Monday to continue implementing safety measures to control the spread of the coronavirus, such as limiting public gatherings and protecting vulnerable groups as they try to reopen businesses and services. 

“The more control countries have over the virus, the more they can open up. Opening up without having control is a recipe for disaster,”WHO Director-General Tedros Adhanom Ghebreyesus said at a virtual news briefing from the United Nations health agency’s Geneva headquarters.“No country can just pretend the pandemic is over.”

Tedros outlined “four essential things that all countries, communities and individuals must focus on to take control.”He said countries should“prevent amplifying events,”which he said many countries have linked to large gatherings at stadiums, nightclubs and places of worship. He added that countries and people can find “creative ways”to be social. 

He added that countries should prevent deaths by protecting vulnerable people, including older people, people with underlying conditions and essential workers. This will help save lives and alleviate the burden on countries’health systems, Tedros said. 

Tedros also said “individuals must play their part”by wearing masks, social distancing and washing their hands frequently. He added that governments can avoid stay-at-home orders by implementing targeted responses to outbreaks through testing, contact tracing and isolating.

“If countries are serious about opening up, they must be serious about suppressing transmission and saving lives,”he said. “This may seem like an impossible balance, but it’s not. It can be done and it has been done.”

Tedros added that the WHO recently published guidance on how hotels, cargo ships and fishing vessels can safely resume operations as “part of our commitment to supporting every sector to reopen as safely as possible.”

WHO officials said the so-called new normal will include at least some mitigation measures, such as social distancing and mask wearing. The WHO has previously said that such measures will likely need to be followed in many countries even after a vaccine is eventually brought to market. 

Dozens of vaccine manufacturers have launched trials for their coronavirus vaccine candidates, according to the WHO, and at least two have started large phase three trials. Commissioner of the U.S. Food and Drug Administration Dr. Stephen Hahn said over the weekend that his agency would consider issuing an emergency use authorization for a vaccine before its phase three clinical trial is fully complete.

But Dr. Soumya Swaminathan, the World Health Organization’s chief scientist, warned Monday that authorizing a vaccine too early and with too little data could create a variety of problems. 

“The risk of approving a vaccine prematurely for us is that, first of all, it will make it very difficult to continue with randomized clinical trials,”she said. “And secondly, there’s a risk of introducing a vaccine that’s been inadequately studied and might turn out to have a low efficacy, thereby not doing the job of bringing an end to this pandemic or even worse, have a safety profile that’s not acceptable.” 

She added that the emergency use of a vaccine should be done“with a great deal of seriousness,”particularly because it could lead to adverse side effects in some parts of the population. She added that the decision should be made using as much safety and efficacy data as is possible.

“Scientists around the world are united in a call for agencies and for companies, and most companies have supported this stance, that the approval of a vaccine must be based on data from phase three clinical trials,”Swaminathan said.

Dr. Mike Ryan, executive director of the WHO’s health emergencies program, echoed Swaminathan in saying that collecting and monitoring vast amounts of data is crucial as nations start distributing vaccines to their general population. As the vaccine is introduced to larger and perhaps more diverse parts of the population, negative side effects could emerge, underscoring the importance of the collection of safety data.

“The difficulty and the the challenge with the vaccine is, at the moment, we’re moving from vaccinating tens or hundreds of people to now vaccinating thousands of people,”he said. “We need to get the safety and efficacy data from those studies. Because if you move too quickly to vaccinating millions or hundreds of millions or billions of people, we may miss certain adverse events that you won’t pick up with smaller numbers so you need to maintain monitoring.”

He added that there are strict regulations around emergency use of vaccines and drugs in the European Union and the U.S. as well as in parts of Africa and India. It’s crucial that governments are led by their regulatory agencies, he said.

(With input from agencies)