Remember at the start of the pandemic when South Korea and Vietnam were almost untouched? When Africa seemed to be largely unscathed? These places are now being swamped by covid-19 infections, underscoring the most important lesson of the pandemic: The virus knows no walls, no borders and no seasons.

While those vaccinated in the United States can feel safer, no one can be sanguine about the world as a whole. In a weekly report, the World Health Organization noted that after nine consecutive weeks of declines around the globe, deaths due to covid began to rise last week and new cases jumped 10 percent. There are now four major “variants of concern” circulating with a “strong likelihood for the emergence and global spread of new and possibly more dangerous variants of concern” that could be even more difficult to control, the WHO’s emergency committee said Thursday. This is the relentless dynamic: As long as the pandemic rages out of control, it can incubate new variants to pose a threat to everyone.

Once again, the world has cleaved in two. The wealthy, vaccinated nations are opening up. But those with few vaccine doses are facing fresh waves of infection, “erosion of public trust and growing resistance” to mitigation measures, as well as “growing economic hardship, and, in some instances, increasing social unrest,” the WHO committee declared.

Africa’s situation is alarming. Cases are up for eight straight weeks, a surge faster than anything the continent has seen. Deaths rose 43 percent week-on-week. The delta variant has already spread widely. Matshidiso Moeti, WHO regional director for Africa, reported that nations face “dire shortages of the health workers, supplies, equipment and infrastructure needed to provide care to severely ill COVID-19 patients.” In six countries, just 27 percent of the medical oxygen needed is being produced, the WHO said. South Africa’s vaccination program was disrupted by days of unrest after the jailing of former president Jacob Zuma, which came amid a new wave of covid infections that will probably be exacerbated by the riots.

In Asia, Indonesia is the epicenter of an outbreak, and only 5.8 percent of the country’s population is vaccinated. South Korea, which was praised for its testing and contact tracing early in the pandemic, now is in the midst of a steep climb in cases, and only about 30 percent of the population has received at least one shot. A wave of cases has hit Ho Chi Minh City in Vietnam; only about 4 percent of the country has received at least one dose. In Australia, authorities extended a lockdown in Sydney by at least two weeks.

Vaccines are the most important exit from the pandemic misery, but doses are still too scarce. Only 18 million people in Africa, or 1.5 percent of the population, have been fully vaccinated. The United States has stepped up in sharing vaccines, but far more must be done to help stand up vaccine factories and ensure that everyone in the world can be protected. Until that happens, no one is truly protected.

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