'BA.5 mutation' more risk of reinfection... The high-risk group doubles the mortality rate.

<Anchor> The number of

corona patients is increasing again.

In particular, BA.5, a sub-mutation of Omicron, is spreading rapidly, and this mutation does not have a great effect on the existing immunity, so it is easy to re-infect people who have had Corona before.

In particular, research results have also found that reinfection with this mutation in high-risk groups is more at risk than when previously confirmed.

Let's have a look at the report by Dong-Chan Cho, a medical professional reporter, and talk more.

<Reporter>

BA.5, which is rapidly spreading in Korea, is already the dominant species in the United States.

In a study of 257,000 confirmed cases in the United States in the past six months, 15% were reinfected, and most were BA.5 mutations.

Compared to the reinfection rate of the delta and omicron mutations of less than 1.5%, this is more than 10 times, because BA.5 has the greatest ability to evade the existing immunity.

In addition, a study from the University of Washington in the United States found that healthy people were mildly ill even after being re-infected with BA.

Reinfection was more than twice as likely to cause pneumonia, heart and bleeding complications as the initial infection, and for this reason the hospitalization rate was three times higher and the fatality rate was 2.14 times higher.

It overturns the conventional wisdom that symptoms will be weak in the case of secondary or tertiary infections because immunity is acquired after infection.

The research team estimated that the high-risk group was severely ill at the time of the first infection and was reinfected in a state in which health was compromised, resulting in a higher fatality rate.

The characteristic of BA.5 penetrating into the lungs and heart better than the conventional Omicron was also prominent in the high-risk group.

The risk of reinfection in the high-risk group was similar regardless of the number of vaccinations.

[Bang Ji-hwan/Professor of Infectious Diseases, Seoul National University Boramae Hospital: Healthy people pass very lightly even if they do not have re-infection.

High -risk groups do not have long immunity even if they receive a vaccine or are naturally infected.]

With the spread of BA.5 mutations, more special prevention measures are needed for high-risk groups.

(Video editing: Park Ji-in, CG: Kim Jong-un)

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<Anchor>

Medical reporter Cho Dong-chan is here.

[Cho Dong-chan / Medical reporter (specialist): Let's look at the results of the study in the Journal of the American Medical Association.

After the 3rd or 4th inoculation, 5,783 units of neutralizing antibodies that catch the Wuhan virus in the early stages of Corona were generated.

Omicron produces only 900 units and BA.5 only produces 275 units.

However, if you only get 2 shots, you will get less than 20 units of neutralizing antibody that catches BA.

The effect of the 4th vaccination is lower than expected, but it is better than not being right, so the quarantine authorities are encouraging the 4th vaccination.]

Enlarging an image

[Cho Dong-chan/medical reporter (specialist): It has been about three months since my mother had the 4th vaccination.

It is difficult to say with certainty that the vaccine remains effective.

However, there are no studies showing that the 5th vaccination with the existing vaccine is better.

I'll have to be careful not to get infected with BA.5.

Early diagnosis and prompt medication should be taken care of.

The quarantine authorities plan to administer Eveshield, an antibody treatment that comes in from this month, for the highest-risk groups, such as dialysis patients and blood cancer patients.]

[Cho Dong-chan / Medical reporter (specialist): For now, it is.

Moderna said that it would announce the clinical results of a new bivalent vaccine, which is a mixture of Wuhan and Omicron, on the 19th, but BA.5 is also known to have a good preventive effect.

In addition, Stanford University in the US and Oxford University in the UK jointly developed a new vaccine in which only the core parts of the eight mutations of Corona were cut out like a mosaic, and it was successfully tested on animals.

The quarantine authorities are preparing a vaccine strategy while watching the spread and development of new vaccines.]

(Video editing: Park Ji-in, CG: Kang Kyung-rim)