Are the sequelae of infection with Omicron serious? It's time to fight against another wave of new coronavirus rumors

Recently, the new coronavirus epidemic caused by the Omicron variant has seen a significant increase, and some rumors have begun to spread widely. These rumors include old rumors in a new guise and misunderstandings caused by new situations and information. Let's take stock of them one by one.

01

Infected with the Omicron variant,

Is it the equivalent of having a “big flu”?

Let me first state the conclusion: this is a very irresponsible and extremely misleading statement!

This statement simply means that the current Omicron variant is very harmless and can be treated as "flu", but in reality this is far from the case.

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Taking the recent data from Hong Kong as an example, according to the relevant departments of the SAR government, as of April 5, the fifth wave of the epidemic in Hong Kong has infected more than 1.16 million people, with a total of 8,136 deaths and a mortality rate of 0.70%. The death toll caused by the fifth wave of the epidemic in Hong Kong caused by Omicron is much higher than the total number of deaths caused by the previous four waves of the epidemic.

Here we need to explain the concept of "case fatality rate". The so-called case fatality rate (CFR) refers to the proportion of patients who die from a certain disease among people suffering from the disease. This value can reflect the degree of danger of a certain disease to an individual to a certain extent, but it is by no means only related to the severity of the disease itself.

Because the mortality rate depends not only on the characteristics of the disease itself, but also on the status of the infected person and medical resources. In China, where medical resources are sufficient, the epidemic is properly controlled, vaccines are widely administered, and severe cases can be detected and treated in a timely manner, the mortality rate of COVID-19 is indeed low.

However, the biggest problem is that the Omicron variant is highly transmissible, which may cause a sharp increase in the number of patients in a short period of time, while it is difficult for medical resources to increase by a corresponding amount in a short period of time, which will inevitably lead to a run on medical care, increase the mortality rate, and prevent people with other diseases from receiving timely treatment. Therefore, it is not scientific to simply use the current low mortality rate to predict the situation after the large-scale spread of Omicron.

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In addition, there is a very practical and serious problem, that is, the Omicron variant spreads very rapidly. If we must compare it with influenza, the R0 value of influenza is usually about 1-2, which means that statistically, one influenza patient can infect 1-2 unprotected people, and the R0 value of Omicron is estimated to be about 5 times that of influenza or even higher. Therefore, even if the mortality rate of Omicron is relatively low, it is more likely to cause a pandemic. Once the number of infected people is large enough, many people will still lose their lives, especially those with underlying diseases and the elderly.

Therefore, it is very misleading to equate the epidemic caused by Omicron with "big flu". In addition, the flu epidemic has a seasonality, but the new coronavirus is year-round...

02

Will infection with the Omicron variant cause serious sequelae?

There are two most common views on this issue. One side believes that the sequelae of infection with the new coronavirus (including Omicron) are not a big deal, while the other side firmly believes that the sequelae will not disappear and will bring serious consequences. So who is right?

This issue is indeed quite complicated. At present, it cannot be simply answered as "either this or that". In any article you see, if only one of the viewpoints is emphasized, it is definitely not comprehensive. Let's talk about it in detail below.

The so-called "COVID-19 sequelae", according to the definition of the World Health Organization, refers to symptoms that last for more than two months after infection with COVID-19 and cannot be explained by other diseases. According to research on the original strain of the new coronavirus and the Delta strain, the most common symptoms of this type include fatigue, shortness of breath and difficulty breathing, loss of smell and taste, etc. A small number of people have experienced amnesia, confusion, and difficulty concentrating.

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The severity of these sequelae is related to the severity of the disease and the age of the patient when he or she is suffering from COVID-19. People with severe illness and old age are more likely to suffer from sequelae. Most of the symptoms of patients with these sequelae will disappear or weaken within a few months to a year. Although the symptoms can be weakened or disappear, in this process, the lives of some patients are still greatly affected by the sequelae, and a few people are even unable to work normally for a long time. Therefore, it is wrong to underestimate these sequelae.

As for the Omicron variant, due to the short duration of its epidemic, there is currently no detailed research on its sequelae. Moreover, since the characteristics of the strains may be different, it is unscientific to simply apply the types, severity, duration, etc. of sequelae of previous strains to Omicron.

03

Will the new coronavirus become less pathogenic?

Regarding the epidemic, there is a common saying that the pathogenicity of the virus will definitely become weaker and weaker, so we can coexist with the virus. This statement is not accurate.

First, although many articles describing the evolution of the virus often give people the feeling that "the virus has actively changed", the evolution of the virus does not have a certain direction, but is random. The reason why the virus seems to be "more and more contagious and less pathogenic" is actually related to our various epidemic prevention measures - because strains with strong contagion and mild symptoms are more likely to escape the medical system's pursuit and blockade and spread on a large scale among the population, but what mutations the virus will undergo in the future is both uncontrollable and difficult to predict.

04

Will there be new coronaviruses after the Omicron Conference?

It is clear that Omicron is not over. While the epidemic mainly caused by the Omicron BA.2 strain is still ongoing, the UK has already discovered new Omicron recombinant variants XD, XE, XF, etc., some of which spread faster than BA.2.

What's worse is that the more the virus spreads, the more viruses exist at the same time, which will bring more opportunities for mutation and recombination, and new strains may spread faster, or cause the effectiveness of existing vaccines or drugs to be greatly reduced - just as the vaccine that protects better against the Delta strain is less effective in preventing Omicron infection. Therefore, it is still necessary to control the spread of the virus as much as possible.

05

If you have had COVID-19, can you still be infected with Omicron?

The reason why some people have become less vigilant about Omicron is that they think they will not be infected with Omicron again after having had COVID-19, but this view is wrong.

Current relevant studies have shown that patients who have been infected with the new coronavirus may still be infected again after recovery. Specifically for Omicron, a study on repeated infection published in the English Medical Journal at the end of March 2022 found that 314 days after infection with the new coronavirus (median), the protection rate against Omicron was only 56%. Fortunately, the severity and mortality rates of patients with repeated infections have been greatly reduced.

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In addition, even if you have been infected with Omicron, you may still be infected by other new strains. Therefore, on the one hand, you should get vaccinated in time, and on the other hand, even if you have been infected with the new coronavirus, you can still get vaccinated as needed, because this can provide additional protection.

To sum up, the current epidemic situation caused by Omicron is still serious. For each individual, the best practice is still to take good personal protection and complete immunization as soon as possible, because the vaccine is not a medicine and it takes several weeks to take effect after injection. It is often too late to get injected after the epidemic occurs.

Author | Ding Zong

Review | Tang Qin, Chief Researcher, Science Popularization Department, Chinese Medical Association

Editor | Ding Zong

Source: Science Refutes Rumors