By ZEKE MILLER, As­so­ci­at­ed Press

(AP)—Pres­i­dent Joe Biden an­nounced Wednes­day that the Unit­ed States is dou­bling its pur­chase of Pfiz­er’s COVID-19 shots to share with the world to 1 bil­lion dos­es as he em­braces the goal of vac­ci­nat­ing 70% of the glob­al pop­u­la­tion with­in the next year.

The stepped-up U.S. com­mit­ment marks the cor­ner­stone of the glob­al vac­ci­na­tion sum­mit Biden con­vened vir­tu­al­ly on the side­lines of the U.N. Gen­er­al As­sem­bly, where he en­cour­aged well-off na­tions to do more to get the coro­n­avirus un­der con­trol.

World lead­ers, aid groups and glob­al health or­ga­ni­za­tions are grow­ing in­creas­ing­ly vo­cal about the slow pace of glob­al vac­ci­na­tions and the in­equity of ac­cess to shots be­tween res­i­dents of wealth­i­er and poor­er na­tions.

The U.S. pur­chase of an­oth­er 500 mil­lion shots brings the to­tal U.S. vac­ci­na­tion com­mit­ment to more than 1.1 bil­lion dos­es through 2022. About 160 mil­lion shots sup­plied by the U.S. have al­ready been dis­trib­uted to more than 100 coun­tries, rep­re­sent­ing more do­na­tions than the rest of the world com­bined. The re­main­ing Amer­i­can dos­es will be dis­trib­uted over the com­ing year.

“To beat the pan­dem­ic here, we need to beat it every­where,” Biden said. He added that with the new com­mit­ments, “For every one shot we’ve ad­min­is­tered to date in Amer­i­ca, we have now com­mit­ted to do three shots to the rest of the world.”

The lat­est pur­chase re­flects on­ly a frac­tion of what will be nec­es­sary to meet a goal of vac­ci­nat­ing 70% of the glob­al pop­u­la­tion — and 70% of the cit­i­zens of each na­tion — by next Sep­tem­ber’s U.N. meet­ing. It’s a tar­get pushed by glob­al aid groups that Biden threw his weight be­hind.

Biden is press­ing oth­er coun­tries to do more in their vac­cine shar­ing plans.

“We need oth­er high in­come coun­tries to de­liv­er on their own am­bi­tious vac­cine do­na­tions and pledges,” Biden said. He called on wealthy coun­tries to com­mit to do­nat­ing, rather than sell­ing the shots to poor­er na­tions, and to pro­vide them “with no po­lit­i­cal strings at­tached.”

Biden said the U.S. would al­so in­crease its fund­ing to glob­al aid groups that are ad­min­is­ter­ing shots

The Amer­i­can re­sponse has come un­der crit­i­cism for be­ing too mod­est, par­tic­u­lar­ly as the ad­min­is­tra­tion ad­vo­cates for pro­vid­ing boost­er shots to tens of mil­lions of Amer­i­cans be­fore vul­ner­a­ble peo­ple in poor­er na­tions have re­ceived even a first dose.

“We have ob­served fail­ures of mul­ti­lat­er­al­ism to re­spond in an eq­ui­table, co­or­di­nat­ed way to the most acute mo­ments. The ex­ist­ing gaps be­tween na­tions with re­gard to the vac­ci­na­tion process are un­heard of,” Colom­bian Pres­i­dent Iván Duque said Tues­day at the Unit­ed Na­tions.

More than 5.9 bil­lion COVID-19 dos­es have been ad­min­is­tered glob­al­ly over the past year, rep­re­sent­ing about 43% of the glob­al pop­u­la­tion. But there are vast dis­par­i­ties in dis­tri­b­u­tion, with many low­er-in­come na­tions strug­gling to vac­ci­nate even the most vul­ner­a­ble share of their pop­u­la­tions, and some yet to ex­ceed 2% to 3% vac­ci­na­tion rates.

Chilean Pres­i­dent Se­bas­t­ian Piñera said the “tri­umph” of speedy vac­cine de­vel­op­ment was off­set by po­lit­i­cal “fail­ure” that pro­duced in­equitable dis­tri­b­u­tion. “In sci­ence, co­op­er­a­tion pre­vailed; in pol­i­tics, in­di­vid­u­al­ism. In sci­ence, shared in­for­ma­tion reigned; in pol­i­tics, re­serve. In sci­ence, team­work pre­dom­i­nat­ed; in pol­i­tics, iso­lat­ed ef­fort,” Piñera said.

The World Health Or­ga­ni­za­tion says on­ly 15% of promised do­na­tions of vac­cines — from rich coun­tries that have ac­cess to large quan­ti­ties of them — have been de­liv­ered. The U.N. health agency has said it wants coun­tries to ful­fill their dose-shar­ing pledges “im­me­di­ate­ly” and make shots avail­able for pro­grams that ben­e­fit poor coun­tries and Africa in par­tic­u­lar.

CO­V­AX, the U.N.-backed pro­gram to ship vac­cines to all coun­tries has strug­gled with pro­duc­tion is­sues, sup­ply short­ages and a near-cor­ner­ing of the mar­ket for vac­cines by wealthy na­tions.

The WHO has urged com­pa­nies that pro­duce vac­cines to pri­or­i­tize CO­V­AX and make pub­lic their sup­ply sched­ules. It al­so has ap­pealed to wealthy coun­tries to avoid broad roll­outs of boost­er shots so dos­es can be made avail­able to health care work­ers and vul­ner­a­ble peo­ple in the de­vel­op­ing world. Such calls have large­ly gone ig­nored.

CO­V­AX has missed near­ly all of its vac­cine-shar­ing tar­gets. Its man­agers al­so have low­ered their am­bi­tions to ship vac­cines by the end of this year, from an orig­i­nal tar­get of some 2 bil­lion dos­es world­wide to hopes for 1.4 bil­lion now. Even that mark could be missed.

As of Tues­day, CO­V­AX had shipped more than 296 mil­lion dos­es to 141 coun­tries.

The 70% glob­al tar­get is am­bi­tious, not least be­cause of the U.S. ex­pe­ri­ence.

Biden had set a goal of vac­ci­nat­ing 70% of the U.S. adult pop­u­la­tion by Ju­ly 4, but per­sis­tent vac­cine hes­i­tance con­tributed to the na­tion not meet­ing that tar­get un­til a month lat­er. Near­ly 64% of the en­tire U.S. pop­u­la­tion has re­ceived at least one dose and less than 55% is ful­ly vac­ci­nat­ed, ac­cord­ing to da­ta from the Cen­ters for Dis­ease Con­trol and Pre­ven­tion.