Many countries are closing their borders as health experts continue to study the latest version of the coronavirus , the Omicron variant .
On Monday , Japan became the latest country to ban all foreigners from entering the country .
Over the weekend , Israel and Morocco announced that the countries are closed to all international travelers .
Israeli citizens can come back to the country .
But they will have to quarantine , even if fully vaccinated .
Australia said it would delay reopening the country to international students and workers for two weeks .
The move came after the country reported its first cases of the Omicron variant of the new coronavirus .
Across the world , the United States , Brazil , Britain and the European Union announced travel restrictions from eight African countries where the variant was first identified .
The countries are South Africa , Botswana , Zimbabwe , Namibia , Lesotho , Eswatini , Mozambique , and Malawi .
New cases of Omicron infection have since been identified in Hong Kong , Australia , Canada , and several European countries .
We'll have to face this new threat just as we face those that come before it .”
Variant of concern
The health organization said Omicron “has a large number of mutations , some of which are concerning .”
A mutation is a change in the genetic material of a virus .
The WHO added that early evidence suggests “an increased risk of reinfection with this variant , as compared to other VOCs .”
Scientists still do not know whether the mutated versions could make it more dangerous .
But the WHO said , “There is currently no information to suggest that symptoms associated with Omicron are different from those from other variants .”
Dr . Angelique Coetzee , a South African doctor who was one of the first to identify Omicron , spoke to Reuters .
She said that symptoms of the variant were not severe and could be treated at home .
It is also unknown whether currently approved vaccines or treatments will protect against the variant .
Dr . Francis Collins is head of the U.S . National Institutes of Health .
But we don't know that ."
The companies said , if necessary , they expect to be able to ship a new vaccine against Omicron in about 100 days .
The Pfizer vaccine uses mRNA technology which uses RNA genetic material to change cells .
Moderna is the maker of the other highly effective mRNA vaccine .
It said it is working on a booster designed to protect against several variants .
And Johnson & Johnson stated that it was already testing their vaccine against Omicron .
Vaccines , however , are still not widely available in poor and developing countries .
In Africa , where Omicron was first reported , only seven percent of the continent's 1.2 billion people have received the shots so far .