The deaths were mounting, and so were the public's fears. South Korea had vastly expanded its flu vaccine programme to cover millions more people, to prevent a one-two punch to its health system as the coronavirus spread globally. But as the injections got under way, reports of deaths started popping up.
South Korean scientists quickly determined that the deaths were unrelated to the flu shots. But they worried that if they didn’t stop the panic, the public might shun the vaccines altogether. So health officials doubled down – and, in the process, gave the world a game plan for when coronavirus vaccines become widely available.
They ramped up efforts to communicate with the public. They disclosed data on what was found. And they quickly got the vaccination campaign back on track, at a time when scientists dealing with Covid-19 are increasingly worried about the rise of the anti-vaccine movement.
"South Korea is doing everything right," said Dr Noel T Brewer, a professor in the health behaviour department at the Gillings School of Global Public Health at the University of North Carolina. "The government is gathering data, giving information to the public quickly and standing up for their vaccination programme. That will ensure public trust, and help the programme."
As pharmaceutical makers rush to get a coronavirus vaccine approved, countries around the world are grappling with how to safely and quickly distribute hundreds of millions of doses. Already, the pandemic has created confusion and distrust in an era when misinformation can spread rapidly – all of which could complicate the global effort toward immunity.
If a long-proven, extensively tested flu shot can spark uncertainty and concern, it could portend challenges for mass inoculations of a brand-new coronavirus vaccine.
Pitfalls
The potential pitfalls played out on a small scale in South Korea. The country’s ambitious flu vaccine campaign began on September 8th, a month earlier than usual. Health officials announced plans to inoculate 30 million people, 10 million more than last year.
But in their haste, problems arose. A company hired to transport millions of doses of the vaccine had never carried such large quantities of cargo before. The flu vaccines need to stay refrigerated, at between 2 and 8 degrees Celsius. On September 21st, photos began circulating online showing boxes of vaccines stacked outdoors, in a car park.
Out of an abundance of caution, the government temporarily suspended the programme to investigate. On October 6th, it concluded that the vaccines were still safe, but nevertheless recalled the 480,000 doses that had been left outside long enough to potentially become ineffective.
Three days later, 615,000 doses of a vaccine shipped by another company were also recalled, after white particles were found inside. The government concluded they were harmless protein particles.
South Korea’s flu vaccine campaign was up and running again on October 13th. But the public was still wary. The following week, a family reported that a 17-year-old high school student had died after receiving a flu vaccine. More reports of deaths came rushing in, most involving patients in their 70s and older.
By October 22nd, the reported death count had reached 28 and it was rising by the day. Singapore briefly suspended the use of a South Korean vaccine after the deaths were reported.
Pushback
As Dr Jung Jae-hun, a professor of preventive medicine at Gachon University near Seoul, read the news, he felt an urgent need to push back. Flu vaccines had been tested and safely used for decades in South Korea. If the credibility of the programme could be so easily undermined by unsubstantiated claims, he wondered what would happen once millions of people started taking coronavirus vaccines.
“I think this extreme situation was created because we are living through this unusual time of Covid-19 and people are overly sensitive about vaccines,” Jung wrote on October 22nd, in the first of a series of Facebook posts criticising the news reports.
He warned that reporting on “post-vaccination deaths” when there was no scientific evidence establishing a connection was like counting how many people had died after eating breakfast.
“If people don’t understand this, it could lead to the proliferation of anti-vaxxers here, like the ones in the West,” he said.
While the government stood by the safety of the vaccines, it also launched an investigation into the deaths, hoping to use science to counter misinformation. If, for instance, all the cases were linked to a particular vaccine or clinic, or if all the deaths were similar, it would raise red flags. Multiple deaths from anaphylaxis, a severe allergic reaction, would also implicate the vaccine.
But the government’s forensic investigations, which would eventually rule out such connections, didn’t move as quickly as the panic spread.
"Elderly people die every day, of a stroke, of heart attack, but the media reported these deaths as if none of them died on a normal day," said Dr Ki Mo-ran, a public health researcher at the National Cancer Center who sat on the government's vaccination supervisory group. "As the people waited for the results, anxiety grew, trust fell and the vaccination programme suffered."
To help quell some of the public’s concerns, Jung published an opinion piece in the Journal of Korean Medical Science pointing out that it’s not unusual for some people to die coincidentally from unrelated causes, after receiving a vaccine. He cited a study published in 2013 that showed 23 out of every 100,000 Americans aged between 75 and 84 had died from a variety of causes within a week of taking their vaccines.
Days after Jung’s essay was published, the South Korean government released corresponding national figures. Last year, it said, 1,500 South Koreans 65 or older had died within a week of taking a flu vaccine. None of the deaths were linked to the vaccines. As influenza usually kills 3,000 people each year in South Korea, health officials insisted that the benefits of vaccination far outweighed any risks.
Disclosing causes
In the weeks since South Korea’s vaccination campaign started, the government has received more than 100 reports of people dying after receiving a flu vaccine. Officials have promptly disclosed the causes, which were unrelated to the inoculations.
Autopsies concluded that the patients often suffered cardiovascular and other diseases, and that all of them died of causes unrelated to vaccines, such as aortic dissection, acute myocardial infarction and cerebral haemorrhage. A medical examiner found poison in the body of the 17-year-old, and the police suspected suicide, although his family insists that he had no reason to take his own life.
"If you just blindly say, 'oh no, these are not related', you'll build a lot of distrust," said Dr Vanessa Raabe, an expert on vaccines and infectious diseases at NYU Langone Health who praised South Korea's response. "You need to do the science before you say they are not related."
The flu panic has subsided in South Korea, but only 19 million people have so far received their shots, far short of the government's target of 30 million. Jung said that, as in the United States, political polarisation in South Korea had likely contributed to some of the confusion over the safety of flu vaccines.
“Rather than being divided, we must learn to fight together against the common enemy,” he said. “If we want to reclaim our pre-Covid-19 life, going out to eat and drink and travelling abroad, vaccines are our best chance.” – New York Times
