By JAMEY KEAT­EN, RAF CASERT and MARI YA­M­AGUCHI, As­so­ci­at­ed Press

GENE­VA (AP) — The World Health Or­ga­ni­za­tion warned Mon­day that the glob­al risk from the omi­cron vari­ant is “very high” based on the ear­ly ev­i­dence, say­ing the mu­tat­ed coro­n­avirus could lead to surges with “se­vere con­se­quences.”

The as­sess­ment from the U.N. health agency, con­tained in a tech­ni­cal pa­per is­sued to mem­ber states, amount­ed to WHO’s strongest, most ex­plic­it warn­ing yet about the new ver­sion that was first iden­ti­fied days ago by re­searchers in South Africa.

It came as a widen­ing cir­cle of coun­tries around the world re­port­ed cas­es of the vari­ant and moved to slam their doors in an act-now-ask-ques­tions-lat­er ap­proach while sci­en­tists race to fig­ure out just how dan­ger­ous the mu­tant ver­sion might be.

Japan an­nounced it is bar­ring en­try to all for­eign vis­i­tors, join­ing Is­rael in do­ing so. Mo­roc­co banned all in­com­ing flights. Oth­er coun­tries, in­clud­ing the U.S. and mem­bers of the Eu­ro­pean Union, have moved to pro­hib­it trav­el­ers ar­riv­ing from south­ern Africa.

WHO said there are “con­sid­er­able un­cer­tain­ties” about the omi­cron vari­ant. But it said pre­lim­i­nary ev­i­dence rais­es the pos­si­bil­i­ty that the vari­ant has mu­ta­tions that could help it both evade an im­mune-sys­tem re­sponse and boost its abil­i­ty to spread from one per­son to an­oth­er.

“De­pend­ing on these char­ac­ter­is­tics, there could be fu­ture surges of COVID-19, which could have se­vere con­se­quences, de­pend­ing on a num­ber of fac­tors, in­clud­ing where surges may take place,” it added. “The over­all glob­al risk … is as­sessed as very high.”

The WHO stressed that while sci­en­tists are hunt­ing ev­i­dence to bet­ter un­der­stand this vari­ant, coun­tries should ac­cel­er­ate vac­ci­na­tions as quick­ly as pos­si­ble.

While no deaths linked to omi­cron have been re­port­ed so far, lit­tle is known for cer­tain about the vari­ant, in­clud­ing whether it is more con­ta­gious, more like­ly to cause se­ri­ous ill­ness or more able to evade vac­cines. Last week, a WHO ad­vi­so­ry pan­el said it might be more like­ly to re-in­fect peo­ple who have al­ready had a bout with COVID-19.

Sci­en­tists have long warned that the virus will keep find­ing new ways to ex­ploit weak­ness­es in the world’s vac­ci­na­tion dri­ve, and its dis­cov­ery in Africa oc­curred in a con­ti­nent where un­der 7% of the pop­u­la­tion is vac­ci­nat­ed.

“The emer­gence of the omi­cron vari­ant has ful­filled, in a pre­cise way, the pre­dic­tions of the sci­en­tists who warned that the el­e­vat­ed trans­mis­sion of the virus in ar­eas with lim­it­ed ac­cess to vac­cine would speed its evo­lu­tion,” said Dr. Richard Hatch­ett, head of CEPI, one of the founders of the U.N.-backed glob­al vac­cine shar­ing ini­tia­tive CO­V­AX.

Spain on Mon­day be­came one of the lat­est coun­tries to re­port its first con­firmed omi­cron case, de­tect­ed in a trav­el­er who re­turned Sun­day from South Africa af­ter mak­ing a stopover in Am­s­ter­dam.

While the ma­jor­i­ty of omi­cron in­fec­tions record­ed around the world have been in trav­el­ers ar­riv­ing from abroad, cas­es in Por­tu­gal and Scot­land have raised fears that the vari­ant may al­ready be spread­ing lo­cal­ly.

“Many of us might think we are done with COVID-19. It’s not done with us,” warned Tedros Ad­hanom Ghe­breye­sus, WHO’s di­rec­tor-gen­er­al.

Days af­ter the vari­ant sent a shud­der through the fi­nan­cial world near­ly two years in­to the pan­dem­ic that has killed over 5 mil­lion peo­ple, mar­kets had a mixed re­ac­tion Mon­day. Eu­ro­pean stocks re­bound­ed and Wall Street stead­ied it­self, while Asian mar­kets fell fur­ther.

U.S. Pres­i­dent Joe Biden called the omi­cron vari­ant a cause for con­cern but “not a cause for pan­ic.” He said he is not con­sid­er­ing any wide­spread U.S. lock­down and in­stead urged mask-wear­ing and vac­ci­na­tions, even as a fed­er­al judge blocked his ad­min­is­tra­tion from en­forc­ing a re­quire­ment that thou­sands of health care work­ers in 10 states get the shot.

Dr. Rochelle Walen­sky, di­rec­tor of the U.S. Cen­ters for Dis­ease Con­trol and Pre­ven­tion, re­act­ed to the po­ten­tial threat by urg­ing every­one 18 and old­er to get boost­er shots, be­cause “strong im­mu­ni­ty will like­ly pre­vent se­ri­ous ill­ness.” Ear­li­er this month, the U.S. opened boost­ers to all adults but rec­om­mend­ed them on­ly for those 50 and old­er or peo­ple in long-term care.

The omi­cron in­fec­tions have un­der­scored the dif­fi­cul­ty in keep­ing the virus in check in a glob­al­ized world of jet trav­el and open bor­ders. Yet many coun­tries are try­ing to do just that, against the urg­ing of the WHO, which not­ed that bor­der clos­ings of­ten have lim­it­ed ef­fect and can wreak hav­oc on lives and liveli­hoods.

Some have ar­gued that such re­stric­tions can buy valu­able time to an­a­lyze the new vari­ant.

While the ini­tial glob­al re­sponse to COVID-19 was crit­i­cized as slow and hap­haz­ard, the re­ac­tion to the omi­cron vari­ant came quick­ly.

“This time the world showed it is learn­ing,” said EU Com­mis­sion Pres­i­dent Ur­su­la von der Leyen, sin­gling out South African Pres­i­dent Cyril Ramaphosa for praise. “South Africa’s an­a­lyt­ic work and trans­paren­cy and shar­ing its re­sults was in­dis­pens­able in al­low­ing a swift glob­al re­sponse.”

Late last week, von der Leyen suc­cess­ful­ly pushed the 27-na­tion EU to agree to ban flights from sev­en south­ern African na­tions, sim­i­lar to what many oth­er coun­tries are do­ing.

Cas­es have been re­port­ed in such places as Cana­da, Ger­many, Britain, Bel­gium, Den­mark, the Nether­lands and Por­tu­gal, where au­thor­i­ties iden­ti­fied 13 omi­cron in­fec­tions among mem­bers of the Be­le­nens­es pro­fes­sion­al soc­cer team.

Tak­ing no chances, Japan, which has yet to de­tect any omi­cron cas­es, reim­posed bor­der con­trols that it had eased ear­li­er this month.

“We are tak­ing the step as an emer­gency pre­cau­tion to pre­vent a worst-case sce­nario in Japan,” Prime Min­is­ter Fu­mio Kishi­da said.

Is­rael like­wise de­cid­ed to bar en­try to for­eign­ers, and Mo­roc­co said it would sus­pend all in­com­ing flights for two weeks.

Britain re­act­ed by ex­pand­ing its COVID-19 boost­er pro­gram to every­one 18 and old­er, mak­ing mil­lions more peo­ple el­i­gi­ble. Up un­til now, boost­er shots were avail­able on­ly to those 40 and over and peo­ple par­tic­u­lar­ly vul­ner­a­ble to the virus. The U.K. has re­port­ed about a dozen omi­cron cas­es.

De­spite the glob­al wor­ry, doc­tors in South Africa are re­port­ing pa­tients are suf­fer­ing most­ly mild symp­toms so far. But they warn that it is ear­ly. Al­so, most of the new cas­es are in peo­ple in their 20s and 30s, who gen­er­al­ly do not get as sick from COVID-19 as old­er pa­tients.

Ya­m­aguchi re­port­ed from Tokyo, Casert from Brus­sels. As­so­ci­at­ed Press jour­nal­ists from around the world con­tributed to this re­port.