CHEONGJU, North Chungcheong Province -- head of South Korea’s national health protection agency was vaccinated with a third dose of Moderna’s COVID-19 vaccine on Friday, having received two AstraZeneca doses more than six months ago.

Jeong Eun-kyeong, the Korea Disease Control and Prevention Agency’s commissioner, received the booster at around 11:10 a.m. at a hospital in Cheongju, North Chungcheong Province.

As immunity from vaccinations wanes over time, Jeong said she feels “safer” now that she has had the booster.

She said she is “convinced boosters will be necessary for the general adult population to keep them out of hospitals” as Korea exits pandemic restrictions. In Korea, people over 50 and vulnerable adults of all ages are currently eligible for boosters, which are administered five months after the initial series for people in their 50s. For anyone older, the interval is four months.

“The additional dose gives a significant boost in protection against infections and severe disease,” she said. “Boosters are not a matter of choice, especially for people at risk and health care workers and others who work or live in high-risk settings.”

She urged people at high risk as well as professionals in contact with vulnerable people to get boosters before winter is in full swing.

On the possibility of COVID-19 booster shots becoming routine, like seasonal flu shots, she said that globally the booster’s longevity was being studied. “We’re waiting to see the data on how long the protection would last, and how often a booster is going to be needed.”

Jeong also promised better safety monitoring for vaccines and compensation for adverse events.

People who had lost family members to suspected adverse events from vaccination were waiting for Jeong outside the hospital and pleading for an inquiry. Addressing them, she said she would meet with them at the agency’s headquarters at a later date.

Jeong received her second AstraZeneca dose April 30 in anticipation of a possible US trip. The interval between her first and second doses was only four weeks, as opposed to 11 weeks or more for the general population at the time.

In late March Korea lengthened the minimum wait between the two AstraZeneca doses to 11 to 12 weeks, from the initial eight weeks, to prioritize distribution of first doses amid a tight supply. In mid-September that gap was slashed to four weeks as the spread of delta weakened the protection from a single dose.

Korea began its rollout of boosters last month with front-line workers, people ages 60 and above and Johnson & Johnson vaccine recipients. Eligibility for an extra dose was extended Monday to anyone aged 50 and above. So far 1.6 million people in Korea have received boosters.

Since the vaccination campaign against COVID-19 kicked off Feb. 26, more than 40 million people here have been fully vaccinated with the AstraZeneca, Pfizer, Moderna or Johnson & Johnson vaccines.

By Kim Arin (arin@heraldcorp.com)