Recent blunders with flu shots should serve as a lesson that clear communication backed by science is key to bolstering the public’s embrace of the coming COVID-19 vaccines and offsetting mistrust, experts say.

Earlier in the fall, more than 1 million doses of flu vaccine were recalled over suspected contamination or exposure to temperatures outside their safe range. Public health authorities were accused of withholding information on the mishandling for at least three days -- during which nearly 65,000 people received vaccines that were later declared unusable.

Reports of post-vaccination side effects and deaths came rushing in. As of Dec. 4, the count of reported side effects and deaths reached had 2,002 and 108, respectively. Although investigations found no link between the events and the vaccine, the situation fed fears and vaccination rates fell across all age groups compared to last year.

Virologist Dr. Paik Soon-young of Catholic University of Korea said what happened with the flu vaccines this year may have been a “taste of things to come” for when COVID-19 vaccines reach communities.

“Look how easy it was for the time-tested flu vaccines to lose credibility with people from the missteps,” he said. “Public hesitancy toward COVID-19 vaccines, which are brand new, can be even more easily triggered.”

As AstraZeneca -- the only vaccine producer that Korea has finalized a purchasing deal with -- is facing delays in late-stage clinical trials of its vaccine, and subsequently is pushing back its timeline for approval from the US Food and Drug Administration, local regulatory authorities may have to OK the vaccine first if inoculations were to go ahead as planned.

While Korean authorities have said delays in authorizations overseas will not affect the vaccine’s rollout here, some reports say granting approval locally before getting the nod from other regulatory agencies, such as the US FDA and the European Medicines Authority, could pose potential credibility challenges.

“Theoretically, it shouldn’t be a problem,” Paik said. The delays were not due to safety issues, but questions over dosages. “AstraZeneca vaccine’s protection reached the same levels as was seen with the mRNA vaccines due to a lower-strength dose in one of the batches of vaccine. This wasn’t planned.”

Dr. Jerome H. Kim of the International Vaccine Institute said in an email response that safety -- or perceptions about safety -- were very important in prompting public acceptance of a vaccine. If not properly addressed, they “could have a significant and detrimental impact, not only around the vaccine itself, but around vaccines and vaccination in general.”

“The Korean government should lead with honesty, transparency, and empathy -- a strong scientific basis for vaccination, with efficacy and safety well documented is the enabling context,” he said. “Leadership by example -- enlisting leading figures -- helps. Consistent messaging, ease of service, and prompt, factual handling of issues will be very helpful.”

Experts agree that building trust in vaccines is best achieved through transparent communication coupled with scientific data.

“We need to convince people and we need to persuade and we need to dialogue on this issue,” Dr. Michael Ryan, executive director of the World Health Organization’s health emergencies program, told a virtual news conference earlier this week.

“I think we are much better served to present people with the data, to present people with the benefits and let people make up their own minds.”

While experts are optimistic about the COVID-19 vaccine front-runners, they are also cautious to note the limits of available data as of the present.

Kim of the IVI said vaccines from AstraZeneca, Pfizer and Moderna appear to have no safety issues based on the press releases.

“But could the assessment change when we have data from month six rather than month two? Yes,” he said. “It is important to remember that we only have 2 months of safety data, and the approvals being issued are an emergency use authorization, not a general approval for sale.”

Dr. Kim Woo-joo, a professor of medicine at Korea University, said the vaccines against COVID-19 were turning out to be “much more effective than previously anticipated,” but that questions remained.

“It’s yet to be determined how long the protection these vaccines provide will last, or whether they will be able to defend against mutated versions of the virus,” he said.

He said when the vaccines are rolled out to millions of people, a large number may well report side effects.

“Then the government should move quickly to investigate and relay the findings in a transparent manner in order to give people assurance in the process,” he said.

Highlighting the merits of vaccinations was one way to solicit public acceptance and participation, according to bioethics professor Dr. Lee Il-hak at Yonsei University. “Vaccines are our chances of returning to some degree of pre-pandemic normal,” he said.

By Kim Arin (arin@heraldcorp.com)