A rapid increase in coronavirus cases in the United States and elsewhere is fueling fears of a pandemic resurgence, sending shockwaves through the stock market on Monday as the highly contagious Delta variant takes hold – and Joe Biden urged Americans to “please, please get vaccinated.”

The number of new cases, hospitalizations, and deaths caused by Covid-19 has risen alarmingly in recent days, largely due to outbreaks in areas of the country with low vaccination rates, as officials have warned of a “pandemic of the unvaccinated.” US stock indexes fell as investors worried about the impact of the coronavirus on the economic recovery, and the president begged more people to get the shot even as he delivered an economic speech in which he dismissed predictions of “doom and gloom” that electing him would bring about depression and the death of capitalism.

Biden stated that capitalism was alive and well.

“Six months into my administration, the US economy has experienced the highest economic growth rate in nearly 40 years,” he said. Forecasters have doubled their growth projections to 7% or higher… The United States is the only developed country with growth projections that are higher today than they were before the pandemic.”

However, the stock market fell on Monday as the Delta variant of the coronavirus spread across the United States and around the world.

Covid cases are now on the rise in all 50 US states, and some cities are considering or have already imposed mask mandates.

After losing 946 points earlier in the day, the Dow Jones Industrial Average closed down 725 points, or 2.1 percent. The S&P 500 index fell 1.6 percent, while the Nasdaq Composite fell 1.1 percent. The available vaccines are effective against the Delta variant, but lab tests have revealed that they are less effective than against the original form of coronavirus.

And Biden warned that getting the pandemic under control was critical to the US’s recovery, noting that four states with low vaccination rates accounted for 40% of all new coronavirus infections last week.

According to data analysis, the average number of new Covid-19 cases per day in the United States has tripled in the last 30 days. It increased from 12,004 to 32,136 in the month of June 18 to Sunday.

In addition, the average number of people hospitalized with Covid-19 has increased by 21% in the last 30 days to over 19,000, up from 16,000. Deaths, which can lag weeks behind an increase in cases, increased by 25% last week compared to the previous seven days, with an average of 250 people dying per day.

Meanwhile, as the situation in the United Kingdom deteriorated, US citizens were advised not to travel there.

On Monday, the United Kingdom was upgraded to the highest level of travel warning in the United States, “Level 4: Very High,” warning that even fully vaccinated travelers could be at risk.

The Centers for Disease Control and Prevention (CDC) in the United States issued the update on the same day that British Prime Minister Boris Johnson repealed mask-wearing and social distancing laws, reopening nightclubs. The decision will be a setback for Johnson, who had been working with Biden to find a way to reopen UK-US travel.

Americans were advised to “avoid travel to the United Kingdom,” but to ensure they are fully vaccinated if they must travel.

“Because of the current situation in the United Kingdom, even fully vaccinated travelers may be at risk of contracting and spreading Covid-19 variants,” according to the US guidance.

Level 4 countries include the United Kingdom, Brazil, South Africa, and the Netherlands.

India, Iran, and Italy are among the countries that have been severely impacted by the coronavirus but are rated lower than the United States. In Canada, officials announced that the US-Canadian border will reopen to fully vaccinated American citizens and permanent residents on August 9 for the first time since the pandemic began.

There was no word on when Canadians might be allowed to enter the US for non-essential travel.