[INTERVIEW] Vaccine expert warns against premature optimism over Omicron

Jerome Kim, the director general of the International Vaccine Institute / Courtesy of International Vaccine Institute

IVI director general urges Korea to develop strategy for possible Omicron-led wave

By Lee Hyo-jin

It may be too early to take an optimistic approach to the Omicron variant of the coronavirus, says Jerome Kim, the director general of the International Vaccine Institute, calling on the Korean government to take preemptive action and come up with an in-depth strategy for a possible wave of the fast-spreading variant.

"While the coronavirus may eventually mutate toward a more rapidly spreading but truly 'flu-like' illness, Omicron is not the variant you are hoping for," Kim said in a recent e-mail interview with The Korea Times.

Citing a lack of data, he stressed that the world should be vigilant against any blind optimism surrounding the Omicron variant.

"We don't have enough data to reasonably make a proposition like that," he said. "It is true that a significant amount of tracking and sequencing information suggests that Omicron is more infectious, but we don't yet have information about the severity of illness."

According to Kim, once Omicron enters a population, it spreads "efficiently," with the ability to infect previously infected persons as well as vaccinated ones. The risk of reinfection from Omicron is 2.4 times higher than with Delta.

He also said that the early supposition that Omicron might be less severe than previous strains has been "tempered," citing preliminary data in the U.K., where investigators have found that it is not different in severity from previous waves, in addition to early data in South Africa, where it appears 20-percent more severe than Delta in children.

Unlike Kim, some overseas experts have offered optimistic views about the highly transmissible variant, as it so far seems to be less lethal than previous strains.

Angelique Coetzee, the South African doctor who first alerted the authorities on the presence of the new variant, described the symptoms of Omicron as "very mild" compared to Delta.

"While treating patients infected with Omicron, I did not see frequent COVID-19 symptoms such as loss of taste or smell, severe respiratory illnesses requiring ventilators, unlike what we've seen with Delta infections," she said during an interview with local radio TBS, Dec. 16.

Kim's warning comes as the Omicron variant is spreading rapidly across the globe since it was first detected in South Africa in November.

In just about a month, the heavily-mutated virus has arrived in nearly 90 countries, including the United States, Japan and European nations such as the U.K., Denmark and Italy, forcing governments to tighten social distancing measures and expedite rollouts of booster shots.

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After Korea reported its first cases on Dec. 1, the number of Omicron infections has grown to 376 as of Saturday.

Omicron has already become the dominant variant in several countries, including the U.S., and public health authorities here believe the same will happen in Korea in less than two months.

But regarding whether the fast-spreading variant will soon become the dominant version, Kim said it remains to be seen whether Omicron will replace Delta or if the two will coexist.

Medical workers prepare to administer COVID-19 tests at a testing center near Seoul station, Friday. Yonhap

Boosters 'a good way' to decrease disease due to Omicron

While the Korean government has been urging people to roll up their sleeves for booster shots, several breakthrough infections of Omicron, even among those who have received boosters, have raised concerns.

In Korea, five people have tested positive for the variant so far, even after being inoculated with a booster shot, leading some to question the efficacy of the vaccines against newly emerging variants.

A medical worker administers a COVID-19 booster vaccine at a community center in Jung District, Seoul, Dec. 20. Yonhap

But Kim's response to this concern was quite clear: "Boosters may be a good way, perhaps one of the few interventions, to decrease disease from Omicron."

His answers were backed by real-world evidence.

Preliminary data from South Africa suggests that vaccination with an mRNA vaccine is associated with a 70 percent reduction in hospitalization when infected with Omicron, compared to those who are unvaccinated.

"The vaccines were tested not for their ability to prevent infection, but to prevent disease, or, mild-moderate PCR positive disease," Kim explained. "If we look at the vaccine-induced protection called 'antibodies,' the levels decrease to being undetectable five months after primary vaccination. But after a booster dose, the level of protection rises much higher and most people again have detectable antibodies."

When asked how Korea should be prepared for a possible Omicron-led wave of infections in the coming months, the immunology expert said, "To use a war analogy, we need 'defense in depth.'"

In addition to fundamental virus-blocking tactics including crowd avoidance and the universal wearing of face masks, Kim stressed the importance of vaccination, saying, "While not preventing infection, it prevents the complications of infection."

The government, for its part, should prepare the medical system in advance by adding capacity, personnel and supplies, he said.

And a greater lockdown may have to be considered, Kim said, which targets high-risk transmissions initially, but becomes broader and less specific as the infections climb.