I thought it was the flu... Why is COVID-19, which is resurging in the summer, spreading again?

Now perceptions have changed a lot... I didn't worry much about COVID-19...

There are quite a few confirmed COVID-19 cases around as well...

Be careful because they say a pandemic is coming again.

COVID-19 was not even a seasonal trend in winter;;;

 

 

 

Amid the summer surge of COVID-19, there are concerns that COVID-19 does not exhibit seasonality like influenza, which only spreads in winter, and therefore requires periodic preparedness for outbreaks.

According to the Korea Disease Control and Prevention Agency on the 13th, the number of COVID-19 hospitalized patients in the first week of August was 861, reaching the highest level in six months since the first week of February. Compared to the first week of July, one month earlier, it increased by as much as 9.5 times.

Influenza, a respiratory infection virus like COVID-19, exhibits seasonality. Typically, viruses tend to be more resilient at lower temperatures and humidity levels, which is why they tend to spread during the winter season.

However, in the case of COVID-19, there has been no significant seasonality observed since it was introduced domestically in 2020. The outbreaks, referred to as the second wave in August 2020, the fourth wave in June 2021, and the sixth wave in June 2022, all began before the winter season.

Experts agree that the idea that COVID-19 has seasonality is a misconception.

Professor Kim Woo-joo of the Department of Infectious Diseases at Korea University Guro Hospital said, "It is wrong to mistake COVID-19 for the flu and think it will only spread during the winter."

The reason for the repeated outbreaks of COVID-19 is attributed to mutations. COVID-19 is an RNA virus, and it is known to have a higher likelihood of mutations occurring during the process of cell replication.

As a result, various COVID-19 variants have emerged worldwide, and domestically, Delta, Omicron, and sub-variants of Omicron have continued to appear. Currently, a variant called KP.3 is on the rise.

When a new mutation occurs, it can evade the antibodies formed from previous mutations or neutralize the resistance of vaccines based on the existing virus. Additionally, immunity acquired through natural infection or vaccination also weakens over time, making individuals more vulnerable to infection when new mutations emerge.

Professor Jeong Jae-hoon of Korea University College of Medicine, Department of Preventive Medicine, said, "The COVID-19 pandemic occurs due to a complex phenomenon where new variants emerge and immunity levels decrease."

This summer, which is considered an unprecedented heatwave, the frequent use of air conditioning and other cooling devices indoors, along with crowded, close-contact, and enclosed environments, is also being cited as one of the causes of infection transmission.

There are also opinions that the relaxed perception of COVID-19 over time has contributed to the spread of the outbreak. In our country, since May, the COVID-19 infection crisis level has been lowered from the 'alert' stage to the lowest stage, 'interest.'

Professor Kim said, "The most serious issue is COVID-19 complacency," and "High-risk groups should be advised to wear masks."

<Source Newsis>