Health authorities in the United States have raised their risk assessment of the COVID-19 situation in Mexico to Level 4 “very high” and are advising U.S. citizens not to travel here.

The Centers for Disease Control and Prevention (CDC) raised its warning level from Level 3 “high” on Monday.

“Avoid travel to Mexico. If you must travel to Mexico, make sure you are vaccinated and up to date with your COVID-19 vaccines before travel,” the CDC said in its updated advisory.

“Even if you are up to date with your COVID-19 vaccines, you may still be at risk for getting and spreading COVID-19. … Follow all requirements and recommendations in Mexico,” the agency said.

Its warning to avoid travel to Mexico – which doesn’t require incoming travelers to be vaccinated, show a negative COVID-19 test result or go into quarantine – comes as Mexico nears the end of its worst month of the pandemic in terms of new case numbers.

The Health Ministry reported 950,446 confirmed cases in the first 30 days of January. Even before Monday’s case tally is announced, the figure exceeds the previous monthly record – set last August – by 89%.

Mexico’s accumulated tally currently stands at 4.93 million, while there are just under 268,000 estimated active cases.

An additional 6,465 COVID-19 deaths have been reported this month, a 25% increase compared to December but well below the pandemic high of almost 33,000 last January. The official death toll rose by 131 on Sunday to 305,893.

With case numbers surging as the highly contagious omicron strain continues to spread rapidly, the Mexican Social Security Institute (IMSS) issued a statement calling on citizens not to drop their guard and continue wearing face masks in all public places, including schools and workplaces.

It also recommended that people wear masks in their own homes if a family member is ill with COVID or they suspect they have been in contact with someone who had the virus.

“With face masks we can breathe. Without face masks there is a risk that some people will require the use of nasal cannulas, oxygen masks or even artificial ventilators,” said the statement issued by IMSS nursing official María Isabel López.

With reports from Milenio