The use of AstraZeneca’s vaccine against COVID-19 resumed for the under-60s Monday, except for those aged 30 and below.

South Korea suspended providing the AstraZeneca shot to people under 60 on Wednesday as Europe reviewed cases of blood clotting.

It is an inevitable decision for the authorities to resume the rollout of administering AstraZeneca vaccines, considering South Korea’s shortage of vaccine supply in the first half of this year.

The nation faces an emergency situation. It cannot sit on its hands as a fourth surge in COVID-19 infections begins. The daily number of confirmed patients has hovered around the 600s last week.

The European Medicines Agency concluded that unusual blood clots should be listed as very rare side effects of the AstraZeneca vaccine. Many countries became guarded about the rollout.

Germany, Italy, Portugal, the Netherlands, and the Philippines limited the use of the AstraZeneca vaccine to those aged 60 and above. Canada and France restricted the eligibility age to 55 and over. Australia advised those under 50 to avoid AstraZeneca. France recommended under-55s who received a first injection of the AstraZeneca vaccine to be given a jab from a different producer for their second dose. Germany made a similar recommendation for people under 60.

South Korea was shaken up by the EMA conclusion because it relies heavily on the AstraZeneca vaccine. The government reportedly secured 18 million doses for vaccination in the first half of this year, with 10.6 million of them being AstraZeneca shots.

The exclusion of those under 30 has made it inevitable for the government to revise its overall vaccination plan. Of those eligible for AstraZeneca shots in the second quarter, about 640,000 are under the age of 30 but there is no separate measure yet for them. South Korea is moving away from its goal of reaching herd immunity by November.

Those in other age groups except for the under-30s are likely to avoid AstraZeneca to receive a “safer” vaccine, even if they have to wait for it. Their choice can be influenced by many European countries that limited the use of AstraZeneca vaccines to people aged 55 or 60 and over. The government should give a persuasive answer to why South Koreans in their 30s to early 50s should take the AstraZeneca vaccine.

According to the Korea Disease Control and Prevention Agency on Monday, 1,217,776 people received at least one vaccine dose after the domestic vaccination campaign kicked off on Feb. 26. The vaccination ratio, compared with the total population of 52 million, was 2.23 percent. South Korea has still a long way to go with its vaccination campaign, but infections are spreading rather than subsiding.

As of midnight Sunday, the daily number of new COVID cases was 614, topping 600 for the fifth straight day. The figure began to rise Wednesday, fanning anxiety about a fourth wave of infections.

The government announced Friday that it would extend the current distancing levels -- Level 2 for Seoul and Gyeonggi Province and Level 1.5 for the other areas -- and the current ban on private meetings of five or more people, for three weeks to May 2. It is questionable whether it is desirable to delay adjusting distancing levels when infections show signs of a resurgence.

Last spring, advanced countries began to go all out in securing COVID vaccines, while the Moon Jae-in administration was slow to purchase them. It placed too much confidence in the so-called “K-quarantine” response to the pandemic, based on quick tracing and testing, and domestic research to develop medicines rather than vaccines. It made a strategic error, and the public is paying the price.

People have endured the inconvenience of practicing social distancing in daily life for more than a year to help the government curb the spread of COVID-19. However, the government has lagged behind in procuring vaccines, which are the key to achieving herd immunity. Some countries are expected to reach herd immunity within this year. In the meantime, South Korea may be fighting a resurgence of the virus.

The “K-quarantine” bubble has burst. It should devote all its strength to procuring more vaccines.