At least 11 countries have reinstated COVID-19 restrictions over fears of a second wave of infections.
Dr Hans Kluge, the director for the World Health Organization (WHO) European region, has warned countries to brace themselves for a new increase in cases and deaths which could be more deadly than the first.
Many countries have been easing restrictions worldwide in an attempt to minimise the impact on the economy, including New Zealand which has decreased from Alert level 4 to 2 over the past month and a half.
But the increased freedom comes at the risk of increasing case numbers and more deaths.
Japan, China, South Korea, Lebanon, Germany, Iran, Saudi Arabia, El Salvador, Iraq, Sri Lanka and Pakistan have all been forced to bring back quarantines or shutdowns, the Telegraph reported.
Japan was the first country to experience a second wave after lifting lockdown restrictions in mid-March.
By April 12, the country had declared a second state of emergency, ordering the closure of schools, stopping large gatherings and asking residents to stay at home.
In May Germany brought in an "emergency brake" meaning that former restrictions were reintroduced at a local level in areas where coronavirus cases rose above a threshold of 50 people per 100,000, Business Insider reported.
Lebanon had a four-day shutdown in the middle of May after cases began to increase two months after the government started easing restrictions.
Prime Minister Hassan Diab accused some citizens of "negligence and lack of responsibility" for ignoring guidelines on social distancing on Monday 12.
Iran saw an increase of 3574 confirmed new infections in 24 hours after easing restrictions, an increase of 440 on the previous day.
As schools, mosques, offices, shops and borders reopened the infection rate began to rise, prompting authorities to reinstate restrictions.
And last weekend, Iraq reimposed total lockdown as COVID-19 cases began rising again. Sri Lanka, El Salvador, Saudi Arabia and Pakistan have also reintroduced some measures.
Professor Mark Woolhouse, of the University of Edinburgh, told The Telegraph that a second wave is a "clear and present danger".
"The lockdown was never intended to be permanent – it's clearly not possible," Woolhouse said.
"So ideally we would like to get 'R' down by using a vaccine, and we call that herd immunity. We don't have a vaccine and we're quite far from natural herd immunity, and it doesn't look like we can eliminate it.
He says countries should be looking at containment.
"That is a possible new normal – and if we don't like it we're going to have to find other ways of living with COVID-19 because it's not going away any time soon."
There are over 6.6 million cases of COVID-19 confirmed worldwide and 391,000 deaths.
