Covid-19 global updates: Race between vaccines and variants tightens amid worries of Pfizer shot’s effectiveness

Here are some significant developments:

• Sydney’s lockdown has been extended by a week to July 16, New South Wales state officials confirmed. Australia’s largest city is struggling to stamp out a small outbreak of the delta variant, but only about 8 percent of the country has been fully inoculated.
• Singapore will not include people inoculated with the Sinovac shot in its national vaccine count. The city-state has not approved the Chinese-developed shot for its vaccination program, though some private clinics are allowed to administer Sinovac doses.
• The United States is dispatching 2 million Moderna vaccine doses to Vietnam, the White House said. The Southeast Asian country had been a coronavirus containment success but its vaccination rollout has been slow, and a wave of infections starting in May has not receded.
• South Korea reported 1,212 new infections on Wednesday, marking the country’s highest daily caseload since December. Seoul recently walked back its loosening of an outdoor mask mandate as infections spike. The vaccination rate has slowed.
• England’s chief medical officer warned of an increase in “long covid,” in which symptoms persist for months, among young people. While Britain’s vaccination rollout is among the world’s fastest, the youth inoculation rate is still relatively low; the country is jettisoning almost all distancing curbs later this month.