auto soldering machine，auto soldering machine，auto soldering machine，auto soldering machine，The 2021 summer travel season started out full of hope and promise, but by the day, two words are threatening to dismantle it all.Delta variant.This more transmissible variation of the coronavirus was first detected in India in February, just when the United States and some other places around the world were starting to really gear up their vaccination efforts. It turned out to be a race against time: vaccines vs. Delta. And just like all other waves of the pandemic, travel feels the Covid impact quick and hard.From new travel advisories issued this week to Google searches on the topic in the past 24 hours, it's clear the Delta variant is causing increasing worry and disruptions for governments and would-be travelers.On Monday, the US State Department and Centers for Disease Control and Prevention issued new advisories for five nations, citing the rise in Covid-19 cases:-- Cyprus (Level 4: Do not travel)-- Israel (Level 3: Reconsider travel)-- Kyrgyzstan (Level 4: Do not travel)-- Portugal (Level 4: Do not travel)-- Spain (Level 4: Do not travel)The warning against travel to Spain is particularly significant as it is one of the most popular destinations in the world. As of Tuesday, however, all five of those places were still allowing US tourists to enter if they meet certain restrictions, according to the State Department's listings. This comes even as the United States is grappling with its own Delta variant outbreak.Spain and Portugal join a growing list of popular travel destinations in the "Level 4: Do not travel" category, which is the highest on the State Department's scale. Level 4 is also the highest alert for the CDC.Some of the other places on Level 4 as of Tuesday that are traditionally popular with travelers around the world:-- Argentina (which has been closed to most international tourism during the pandemic)-- Brazil (which has had a liberal visitation policy despite being one of the hardest-hit countries by the pandemic)-- Maldives (these tourism-dependent Indian Ocean islands are allowing most visitors minus some South Asian countries)-- The Netherlands (which opened its doors to US travelers on June 24 and is welcoming the bulk of Europe; check a full list of the Netherlands' "safe countries" here.)-- South Africa (many nations will not allow visitors to enter if they have recently been to South Africa)-- United Kingdom (the CDC warns that even if you're fully vaccinated, you may be at risk for getting and spreading Covid-19 variants).You can see the full lists of State Department and CDC advisories from Level 4 to Level 1 (low risk) here.White House: Existing restrictions will stay for nowMore evidence of the mounting concern and its effect on travel:On Monday, the White House decided to keep existing coronavirus travel restrictions in place, press secretary Jen Psaki said."We will maintain existing travel restrictions at this point for a few reasons. The more transmissible Delta variant is spreading both here and around the world," Psaki told reporters. "Driven by the Delta variant, cases are rising here at home, particularly among those who are unvaccinated and appear likely to continue in the weeks ahead."