"Must Get Vaccinated"…This Winter, Possible Simultaneous Outbreak of 'Flu and Corona'

Starting from the 11th, free flu vaccinations will be available for the elderly aged 65 and over. Although the COVID-19 pandemic has subsided, concerns remain about the simultaneous spread of flu and COVID-19, known as the 'twindemic.' Therefore, experts emphasize the importance of vaccination to prevent respiratory infectious diseases such as flu and COVID-19.

Professor Song Jun-young of the Department of Infectious Diseases at Korea University Guro Hospital is being interviewed by Asia Economy about the importance of vaccination against respiratory infectious diseases.
[Photo by Lee Chun-hee]

On the 8th, Professor Song Jun-young of the Infectious Diseases Department at Korea University Guro Hospital told Asia Economy, "Unlike flu A, which has a clear epidemic season from November to February of the following year, COVID-19 circulates throughout the year." He added, "As temperatures drop and the air becomes dry, the possibility of a COVID-19 outbreak increases, so it is difficult to rule out the occurrence of a twindemic between December and January."

Regarding the decline in trust in vaccines due to increased cases of infection even after vaccination during the pandemic, Professor Song clarified, "No vaccine is 100% preventive." He explained, "The COVID-19 vaccine shows a good preventive effect of 60-80% in healthy adults and over 50% in the elderly." He also noted, "For the elderly, the flu vaccine's preventive effect is about half."

Despite this, Professor Song stressed the necessity of vaccination, saying, "The effect of preventing complications, hospitalization, and death is significant." He emphasized, "If you catch the flu, the risk of complications such as pneumonia and cardiovascular diseases increases." He added, "Overseas cases consistently show a significant rise in pneumonia patients and deaths within a month of a flu outbreak." Furthermore, since more than half of the elderly are known to suffer from chronic diseases, he warned that the risks associated with these conditions are also high. Professor Song said, "Unlike chronic diseases that can be managed well with family and friends, flu and COVID-19 are unwelcome guests." He continued, "If infected, chronic diseases that were well controlled can worsen, increasing the risk of hospitalization and death. Therefore, patients with chronic diseases are strongly recommended to receive both vaccines."

Regarding vaccine manufacturing methods, Professor Song explained that synthetic antigen vaccines, which have long been proven safe, "can be considered relatively safer vaccines." The vaccine market, which has been dominated by synthetic antigen vaccines, has recently seen rapid growth in messenger RNA (mRNA) vaccines distributed during the pandemic. mRNA vaccines are expected to be developed quickly and have higher immunogenicity. Professor Song also noted, "They have the advantage of inducing strong immunity," but added, "There are limitations for administration in clinics due to cold chain requirements for refrigerated and frozen storage, and there is a risk of myocarditis in young adults." He said, "During the pandemic, the benefits of vaccination outweighed the risks of adverse reactions, so vaccination was recommended. However, now that the outbreak has decreased, it is necessary to carefully weigh the risks and benefits before deciding to vaccinate."

Professor Song explained, "Although synthetic antigen vaccines have lower immunogenicity compared to mRNA vaccines, most people are likely to have basic immunity through natural infection and repeated vaccinations, so sufficient immunity can be induced." He added, "They also have fewer concerns about adverse reactions, making them safer vaccines." Regarding production methods, he added, "Egg-based vaccines may have reduced immune effectiveness if genetic mutations occur during the cultivation process," and "Cell culture methods do not have this problem."

Finally, Professor Song recommended that, unlike the elderly who receive free COVID-19 vaccinations, younger people should carefully consider the benefits before getting vaccinated. He emphasized, "Because the flu has a large epidemic scale and infections occur intensively within a limited period, vaccination is recommended for all age groups." He also said, "Most severe COVID-19 infections occur in the elderly, so vaccination is not actively recommended for young adults, but if there are high-risk individuals in the family or if one is a healthcare worker, vaccination is necessary."