(CNN) — The US Centers for Disease Control and Prevention has added one new location to its list of "very high" risk travel destinations this week.
The ultramodern city-state of Singapore has moved up from Level 3, or "high" risk for Covid-19, to Level 4, the agency's highest risk category.
This news comes on the heels of a recent decision by Singapore to further loosen restrictions and add eight new countries, including the United Kingdom and the United States, to its Vaccinated Travel Lane program. Fully vaccinated people arriving from those nations can apply for a quarantine-free entry.
Destinations that fall into the "Covid-19 Very High" Level 4 category have had more than 500 cases per 100,000 residents in the past 28 days, according to CDC criteria.
People should avoid traveling to locations designated with a Level 4 notice, the CDC recommends. Anyone who must travel should be fully vaccinated first, the agency advises. This newest update is far cry from early August, when the CDC added 16 destinations in one week to Level 4, and Delta variant cases were rising rapidly across much of the planet. This is the first week since early August that only one nation has been added to Level 4.
Popular favorites remaining on Level 4
However, other popular international vacation spots remain at this highest level of alert, evidence of Covid-19's continuing foothold. The current list of Level 4 destinations includes the following:
• United Kingdom
In the case of the UK, it's been lodged at Level 4 since July 19, and Greece has been there since August 2.
New Level 3 locations
Budapest is the capital of Hungary, which was placed at Level 3 ("high" risk for Covid) by the CDC on October 18.
Rita Franca/NurPhoto/Getty Images
The Level 3 category applies to destinations that have had between 100 and 500 cases per 100,000 residents in the past 28 days.
Six new destinations were assigned to this "high" risk category, three of which moved up from Level 2:
The Level 3 designation was good news for people interested in the following three destinations, which previously had been at Level 4:
Some options in Level 2
Destinations carrying the "Level 2: Covid-19 Moderate" designation have seen 50 to 99 Covid-19 cases per 100,000 residents in the past 28 days.
Popular destinations in this less risky category on October 18 included the following:
• Dominican Republic
Just keep in mind the CDC list updates weekly, and your lower-risk destination of choice might move up after you begin making plans.
In the category of "Level 1: Covid-19 Low" destinations, fewer than 50 new cases per 100,000 residents have been logged over the past 28 days. New Zealand is in this category, but it has yet to open its doors to leisure travelers yet. In its broader travel guidance, the CDC has recommended avoiding all international travel until you are fully vaccinated.
"Fully vaccinated travelers are less likely to get and spread Covid-19. However, international travel poses additional risks, and even fully vaccinated travelers might be at increased risk for getting and possibly spreading some Covid-19 variants," the agency said.