Chulalongkorn University

COVID 19 There is still an ongoing epidemic. without an end soon

But one thing that has changed is the decrease in the severity of the disease due to many factors.

Dr. Yong Phuwarawan, Head of the Center of Excellence in Clinical Virology Department of Pediatrics Faculty of Medicine Chulalongkorn University with a message stating

COVID-19, the severity of the disease has decreased.always

COVID-19 has always tended to decrease in the severity of the disease. with many factors

1.Evolving viruses for survival The virus has evolved to become less virulent. in order to live with human beings Because if it causes violence or death, the virus itself cannot survive. The development of old vaccines such as the polio vaccine, the attenuation of the virus. Will bring the virus because it continues to spread passed many times Over time, the virus will change genetically to weaken. and then used as a vaccine

Likewise with COVID-19, when infected in humans for a long time, there will always be genetic changes to reduce the severity. The global mortality rate dropped from 3-5% to about 1% or less Figures reported by the World Health Organization. But the number of deaths and infections of the World Health Organization

It will be found that the number of infections is much lower than reality. Therefore, the actual mortality rate will be much lower. For Thailand, the death rate has decreased from 1% at first to now less than 0.1%, and even in normal people, it should not be different from influenza.

2. Infection in humans There are a lot of people who are expected to be more than 70% of the population. Just like in Thailand, we do our studies. It was found that more than 70% of the population has been infected, or about more than 50 million people, and most of the population has received at least 2 doses of vaccine, not less than 80%, resulting in hybrid immunity. which can prevent infection better than vaccine alone or infection alone and proved to reduce the severity of the disease regardless of whether it mutates to XBB.1.5

3. Vaccines alone cannot prevent infection. At the same time, vaccines induce a higher level of immunity than infection, such as mRNA vaccines, thus exerting greater pressure on the virus to escape the established antibodies for the survival of the virus itself. therefore causing mutations all along

In principle, according to evolution when there is pressure The virus tries to avoid it. Therefore, the very high immunity from the vaccine is unable to prevent infection at all. But the immune system in some systems helps to reduce the severity of the disease.

In summary, in our house More than 70% of the population has been infected and more than 80% of the 2 doses of vaccination have been given. Therefore, most of the population has hybrid immunity. That can very well reduce the severity of the disease, although the new mutant XBB.1.5 is coming (now the main strain in America)