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South Korea’s Flu Vaccine Deaths Preview COVID-19 Vaccine Distribution Challenges

The public panic over flu vaccine safety highlights the potential problems facing a COVID-19 vaccine.

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South Korea’s Flu Vaccine Deaths Preview COVID-19 Vaccine Distribution Challenges
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Already dogged by questions of safety, efficacy, and cost, a COVID-19 vaccine is coming. Actually, it is probably more accurate to say several vaccines will be coming, all of varying types and effectiveness. To compound the difficulties of bringing about an end to the pandemic, recent events in South Korea offer a sobering preview of some challenges vaccine distribution is likely to entail. Let us begin by first recapping these events, which center around a national flu vaccine drive.

Why Have a Flu Vaccine Drive During a Pandemic?

Beginning in early September, the South Korean government began an aggressive flu vaccination campaign, with the goal of inoculating as much of its population as possible in preparation for winter. A special fund was enacted to provide free inoculations for the most vulnerable segments of the population, namely: children, pregnant women, and seniors. By October 27, a little over 10 million of South Korea’s 51 million people had received a free vaccination, with the intended target being 19 million.

There are many good reasons for having a subsidized flu vaccine. On its own, the flu is already a major killer of the elderly, and responsible for around 20,000 deaths per year in South Korea. For those over the age of 70, complications from flu (of which pneumonia is most common) are responsible for around 9 percent of all deaths. Children have long been known to be significant reservoirs for viral transmission so vaccination not only protects them but also offers an indirect way to protect seniors.

Much of the South Korean calculation on flu vaccination was, of course, due to the COVID-19 pandemic. Since COVID-19 symptoms are remarkably similar to flu symptoms, it is important that the two not be confused in the event of a major outbreak. Unlike most other countries at this time, South Korea’s COVID-19 situation remains extremely stable, with an average of only 73 new cases per day over the last four weeks. Testing capacity also remains thankfully ample. Despite the calm, a large regional outbreak like the one centered on the city of Daegu in March still has the potential to stress the ability of a city or province to test thousands of people quickly. In these situations, it is important to use disease symptoms, such as fever and coughing, as secondary assessments in deciding quarantine and treatment. If many people have the flu, the reliability of symptom-checking diminishes significantly, potentially resulting in flu sufferers being treated as coronavirus patients, inadvertently diverting critical resources away.

Recent research suggests flu vaccinations may prime the immune system and impart some marginal protection against COVID-19 in the first few weeks or months after inoculation. The research is in no way decisive, but even the possibility of minor improvements merits serious consideration in the absence of a COVID-19 vaccine. This idea seems likely to have weighed positively on the South Korean government’s decision to enact the flu drive. Like for flu, children have been identified as a key reservoir for COVID-19 transmission, especially through asymptomatic cases, likely motivating the decision to subsidize vaccines for children in addition to seniors.

Accounting for South Korea’s Flu Vaccine-Related Deaths

Despite having sensible reasons for enacting the flu drive, a series of deaths have been reported shortly after vaccination. As of October 29, there had been a total of 72 deaths reported, many of them occurring within 48 hours or a week after inoculation. These reports have struck fear into the hearts of many, bringing public participation in the drive to a grinding halt.

Although some public anxiety is understandable, it is essential that misconceptions be dispelled by facts.

Fact #1: Flu vaccines are extremely common, have been in use for decades, and have shown no evidence whatsoever of increasing the odds of death. In fact, study after study has consistently shown inoculations actually decrease death, especially in seniors, by protecting them against complications like pneumonia. To fully emphasize just how conclusive this body of work is, let me describe the sheer numbers we are talking about: In the United States alone, 160 million flu vaccine doses are administered annually while, globally, around 15 billion have been administered in the last decade. Virtually all of these vaccines are made in the same way (through chicken eggs) so any miniscule relationship between inoculation and premature death would surely have been noticed.

Fact #2: Because of the large populations involved, scientists have very accurate statistics for vaccine side effects. Fever, for example, is a common side effect in about 10 percent of all cases, a natural reaction to the immune system responding to an outside invader, a response the vaccine is trying to mimic. The most severe side effects associated with flu vaccines are anaphylaxis and Guillain-Barré syndrome. The former, which happens roughly once in every million vaccinations, is usually caused by a serious, life-threatening allergic reaction, often due to chicken egg residue in the vaccine. The latter, which happens roughly once or twice in every million vaccinations, is a unique and serious condition in which the immune system mistakenly attacks nerve cells. It remains unclear why this happens, but death only occurs in 4-7 percent of such patients so long as timely treatment is administered. The recent report of spinal inflammation in AstraZeneca’s COVID-19 vaccine trial seems likely to be related to Guillain-Barré.

Fact #3: It is indeed possible that the body’s natural reaction to a flu vaccine can push a very sick or weak person over the edge. There is no delicate way to say it but some elderly are already precariously close to death, no matter how happy or healthy they may appear before the unfortunate fact. Of South Korea’s 72 vaccine-related deaths, all but 10 occurred in people aged 70 and over. Of the 20 post-mortem examinations completed so far, at least 13 were revealed to have had preexisting conditions such as cardiovascular disease, potentially putting them at higher risk for sudden death even from a minor stressing event. It is for this reason that severely ill or hospitalized patients are generally not given vaccines and why seniors are always asked to report preexisting conditions before inoculation.

Fact #4: The probability of people dying shortly after a flu vaccine is not higher than the probability of people dying without one. It gives me absolutely no pleasure to say this, but numbers are important for putting flu vaccine deaths into perspective. Seventy-two might seem like a large number on a headline, but it actually isn’t when you consider the larger trends of death that are constantly at work. In South Korea, an average of 200,000 people over the age of 70 and 40,000 aged 60-69 die each year. Given that the country has roughly 5 million people over 70 and 6 million aged 60-69, this means that an average of 4 percent in the former age group and 0.7 percent in the latter die annually. Since September, about 70 percent of all eligible South Koreans over 70 (a total of 4 million) and 20 percent of those between 60 and 69 (5 million) have received a flu vaccine. If these numbers are used to extrapolate the odds of someone dying within a week of inoculation, one finds that the estimated value is in the hundreds, indicating the 72 deaths we have observed so far are easily explainable by normal patterns of age-specific death.

Fact #5: Scientists have long been keeping track of the number of people who die within a week after receiving a flu vaccination. In 2013, for example, a U.S. study found that 0.011 percent and 0.023 percent of all recipients aged 65-74 and over 74 died, respectively. In 2019, the South Korean government reported that 0.023 percent of those over 65 died. The latter number would, therefore, predict about 900 of the 4 million vaccine recipients over 70 to die within a week after inoculation. Luckily, we are a full order of magnitude below this, again suggesting the deaths are, for lack of better phrasing, following predictable trends of normal death.

Given the data, it would seem exceedingly likely the deaths, despite their appearance, are not actually related to the flu vaccine. The South Korean Ministry of Health agreed with this line of reasoning, ruling out 26 cases as “unrelated” and 45 cases as “highly unlikely” to be related. Clearly, the government has more detailed information than I do, but it is nevertheless reassuring to see them reaching similar conclusions. So far, no case has yet been decisively linked to vaccination, with investigations in the remaining 46 cases still pending. One of these cases that was particularly troubling was the death of a 17-year-old teenager. Here too, however, recent evidence suggests the death had nothing to do with vaccines but was, in fact, a suicide due to overdose on sodium nitrite.

Implications for COVID-19 Vaccine Distribution

In recent years, vaccines have come under the most unfortunate public scrutiny. Anti-vaxxers in the United States and across Europe have become more vocal and prevalent despite the fact that vaccines research has been ongoing in some fashion for over 200 years, making them one of the most reliable and consistent medical implements ever invented. Beginning with Edward Jenner’s use of cowpox puss in 1797 to grant immunity to smallpox, 14 diseases that once ravaged the human race have either been eradicated or brought under near-complete control. It is true vaccines don’t work for every disease and do take some time to develop, test, and distribute, but they are, otherwise, extremely safe with stringent safety guidelines governing their use. Throughout their history, vaccines have rarely been recalled and, even when they were, they were usually recalled because of suboptimal efficacy or manufacturing error, not because they caused sudden, unexpected deaths.

As a nation with high regard for science and a high level of faith in government institutions, the South Korean public’s willingness to embrace COVID-19 mitigation early in the pandemic is a testament to its ability to channel scientific recommendations into collective action. Nevertheless, recent events appear to have shaken this confidence, obliterating flu vaccine waiting lines that were once 10 to 30 minutes long. Despite the vast majority of experts consistently saying the benefits of vaccinations far outweigh the risks, the South Korean media has curiously exercised a more critical tone, perhaps inadvertently breathing life into unnecessary doubts and suspicion.

Whether South Koreans will recover their confidence and resume vaccinations remains to be seen but the episode should function as an important warning for the future distribution of COVID-19 vaccines, both in South Korea and other countries. Just as we are observing now with South Korea’s flu drive, many people, especially seniors, will die within a week after receiving a COVID-19 vaccine, even if there is no causation at play. Unfortunately, this propinquity will likely be interpreted the wrong way, fueling concerns about vaccine safety even if the cause of death is found to be completely unrelated. As has been the case for virus mitigation, the South Korean experience highlights the critical importance of having consistent public messaging about COVID-19, including vaccine drives. Absent this consistency, the public will again be put at risk of being swamped in an ocean of misinformation, malintent, and political weaponization of the pandemic, leaving large sections of the population anxious, doubtful, and unwilling to be inoculated even if a perfectly safe and effective vaccine does become available.

Justin Fendos is a professor at Dongseo University in South Korea.