[Interview] Measles comeback exposes gaps in vaccine uptake, expert warns

Walter Orenstein, a recipient of this year’s IVI–SK bioscience Park MahnHoon Award, in an interview last Friday at the International Vaccine Institute (IVI) in Seoul. (Credit: IVI)

Measles outbreaks and weak adult vaccination show countries are still falling short on getting people vaccinated, Walter Orenstein, one of this year’s IVI–SK bioscience Park MahnHoon Award recipients, said, warning that governments still do not invest enough in delivery, public confidence and follow-up as vaccine programs expand.

Orenstein, the former head of the U.S. National Immunization Program at the Centers for Disease Control and Prevention, said countries often focus on adding vaccines and issuing recommendations without doing enough to make sure people actually receive them.

“Vaccines don’t save lives -- vaccinations save lives,” he said in an interview with Korea Biomedical Review last Friday, using a line he has repeated for years to make the same point: policy matters, but coverage is what changes disease outcomes.

He pointed first to measles, which can return quickly when immunity gaps open and national coverage figures fail to capture under-vaccinated groups in particular communities or age bands.

“Country-level immunization coverage could be misleading if there are pockets of susceptibles,” he said. Korea reported 78 measles cases in 2025, according to a January update from the Korea Disease Control and Prevention Agency (KDCA), even though the country still holds World Health Organization (WHO) certification for measles and rubella elimination and polio eradication.

Orenstein said he had visited Korea about 20 years ago to talk about measles and implementation and returned to many of the same issues in this interview.

Korea, he said, has “done a very, very good job,” but remains exposed when outbreaks spread in nearby countries because imported infections can still cross borders through travel and trade.

He said Korea should keep pushing for stronger vaccination coverage beyond its own borders because “when these pathogens circulate in other countries, they’re not only putting themselves at risk, they’re putting Korea at risk.”

When uptake falls, he said, officials need to find out why instead of treating every shortfall the same way. The cause may be cost, distance, missed opportunities in clinics, or hesitancy.

On hesitancy, he was direct. “We don’t have the education systems in place to overcome hesitancy,” he said, later adding that vaccines are “victims of their own success” because younger generations no longer see many of the diseases they prevent.

He said governments need stronger advocacy, coalitions with political influence, and outside support to keep vaccine investment on the agenda. “We need advocacy, we need coalitions that have influence with politicians,” he said, along with donor groups and charitable organizations willing to invest.

He connected that problem to adult vaccination, which he said remains far weaker than childhood immunization in many countries.

Vaccines don’t save lives — vaccinations save lives,” Orenstein said. (Credit: IVI)

“Adult immunization is really a global problem,” he said. “The hope was Covid-19 would help do that, and it didn’t.” He added that the political fallout around Covid-19 vaccination made the problem worse. “The Covid-19 vaccine turned out to be a backfire.”

He mentioned influenza several times, both as the most likely source of the next pandemic and as an example of how urgency fades when a disease becomes familiar or less visible.

The issue has practical relevance in Korea, which is still expanding its vaccine program. Free PCV20 for children was added from October 2025, and free HPV shots for 12-year-old boys are due to start in May.

KDCA’s 2024 annual report said the vaccination rate among 6-year-olds rose for a third straight year, while Korea’s national influenza program reached 69.5 percent of children and 82.5 percent of older adults in the 2023–2024 season.

Asked which countries were setting useful examples, Orenstein pointed to regional cooperation and cited Singapore and Thailand. The International Vaccine Institute (IVI) made a similar point, saying experts from Thailand and Japan would join related discussions on vaccination and that the forum would look at collaboration, data sharing and information sharing.

The Park MahnHoon Award, launched in 2022 by IVI, a nonprofit global vaccine organization, and SK bioscience, recognizes contributions to vaccine access and public health. This year’s other recipient was the Developing Countries Vaccine Manufacturers Network.

In materials released after the ceremony and in the interview, Orenstein described the award as one of the highlights of his life.

Kim Ji-hye