It’s 2022, why are people still spreading these COVID-19 rumors?

Recently, with the recurrence of the COVID-19 pandemic and the invasion of new mutant strains, many COVID-related rumors have resurfaced and reappeared before our eyes. There are even rumors like the one below that make hospitals cry, CDC officials want to beat people, and leave people speechless...

Screenshot from WeChat group

If this nephew is studying medicine, I suggest he tear up his degree certificate and graduation certificate. He really can't afford to lose face...

Although this set of rumors is extremely speechless, it has one good thing, that is, it is very comprehensive and representative, so we can catch them all in one fell swoop. Next, let's refute all the statements mentioned here one by one.

Will the only symptoms of COVID-19 be dry cough and fever?

According to the eighth edition of the Diagnosis and Treatment Plan for Novel Coronavirus Pneumonia, although the main symptoms of COVID-19 are fever, dry cough, fatigue, and decreased or lost sense of smell and taste, a small number of patients also have symptoms such as nasal congestion, runny nose, and sore throat. Therefore, you should not judge yourself based on symptoms alone. If you suspect you are infected, you should take precautions and get a nucleic acid test.

The new coronavirus is not heat-resistant and will be killed in an environment with a temperature of 26-27 degrees, so we should drink more hot water to prevent the virus?

In fact, 26-27℃ is probably quite limited in its effect on the new coronavirus, because heating at 56℃ for 30 minutes or 92℃ for 15 minutes can effectively inactivate the new coronavirus. The hot water we can drink directly at ordinary times will not exceed 60℃, and it only "passes" through our mouths, so it is nonsense to rely on drinking hot water to prevent virus infection.

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When we are infected by the virus, we will have symptoms of fever, which helps mobilize the immune system and reduce the rate of viral reproduction. However, our measured body temperature when we have a fever usually does not exceed 40°C, so it is difficult to kill the virus directly.

Drink plenty of water to keep your throat moist and flush away the new coronavirus?

The new coronavirus is transmitted in the form of droplets. The virus is inhaled through the nasal cavity, nasopharynx, and throat, enters the trachea and lungs, and causes damage to the lungs. Although the pharynx is a common passage for breathing and swallowing, its functions in breathing and swallowing are completely different. When breathing, the pharynx only serves as a passage, and the virus carried by the airflow hardly stays in the pharynx, but enters the trachea and then the lungs.

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When we drink water, a swallowing movement occurs in the pharynx, and the pharyngeal constrictor muscles quickly send the water to the pharynx, blocking the throat and preventing the water from entering the trachea. Instead, the water is sent directly to the esophagus and into the stomach.

Moreover, the mucous membranes of the mouth and throat are not smooth tubes, they have wrinkles on the surface, and the tongue also has uneven taste buds of different sizes and functions. The swallowing action of drinking water only takes 1 to 2 seconds, which is almost no time to "wash" the uneven taste buds and the wrinkled mucous membranes, and there is no water to stay between the wrinkles, and it is impossible to "wash" the entire throat.

It can be seen that the paths and destinations of viruses and water in the human body are completely different, and the frequency of drinking water every 15 minutes cannot be matched with the breathing frequency of 16-20 times per minute, let alone "relying on drinking water to flush out viruses and prevent invasion."

Can eating more garlic kill bacteria and viruses and prevent COVID-19?

In in vitro experiments, allicin and related nutrients do show a certain inhibitory effect on pathogenic microorganisms, but it should be noted that these are mostly the results of in vitro cell tests on isolated and extracted allicin or alliin and other components, which is different from eating garlic on a daily basis.

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Judging from the current epidemic situation, there is no evidence that eating more garlic can prevent people from contracting COVID-19. Garlic has many health benefits, and moderate intake is good for health, but it is indeed "too much for garlic" to prevent COVID-19. The same is true for other onions, ginger, chili peppers, and peppers, so I will not go into details here.

Will the virus completely disappear as long as it is exposed to the sun?

Although the new coronavirus is sensitive to ultraviolet rays, on the one hand, since light travels in a straight line, the surface of many daily necessities is uneven and has gaps, so the virus cannot be killed in places where it cannot be exposed; on the other hand, it is difficult to control the intensity and angle of sunlight in different seasons and at different times, so the actual disinfection effect is difficult to guarantee. Therefore, relying on sun exposure is not a sufficiently reliable disinfection method.

Can drinking tea prevent COVID-19?

This misunderstanding comes from a scientific research result based on COVID-19, which believes that tea can inhibit the replication of the new coronavirus at the cellular level. However, the "intracellular inhibition" in the information cannot be directly equated with "in vivo inhibition."

The research is roughly like this: a group of experimenters wearing protective clothing used the new coronavirus to infect human cells in the laboratory, and then added the tea we drink (both green tea and black tea) to them. The results showed that the virus's self-replication was inhibited in the human cells added with tea, so the above conclusion was drawn.

However, the human body is very complex and is not a simple superposition of trillions of cells. Before any antiviral substance can take effect, it must go through processes such as digestion, absorption, circulation, and liver metabolism, which are not necessary at the in vitro cellular level. Many drugs work at the in vitro cellular level, but may not work in vivo, or the effects may be inconsistent.

Therefore, although in vitro studies have shown that tea has an inhibitory effect on the replication of the new coronavirus, based on current evidence, it cannot be shown that drinking tea can prevent the occurrence of new coronary pneumonia. Some interpretations of this conclusion are generally confused with the conclusion, which is wrong. Saying that drinking tea can prevent new coronary pneumonia is a rumor.

If you exercise more, you won’t be infected with the new coronavirus?

Exercise cannot ensure that we will not be infected with the new coronavirus. However, exercise can help people strengthen their bodies, regulate the immune system, relieve stress, and better resist the invasion of diseases, so we should still develop the good habit of regular exercise. It should be noted that studies have shown that if the intensity of exercise is too high, it may suppress the function of the immune system and make people more susceptible to upper respiratory tract infections. For most people, exercising 3-4 times a week for about half an hour each time is more appropriate.

After fighting the new coronavirus for so long, we actually already understand its transmission methods and weaknesses. Wearing masks correctly, washing hands frequently, ventilating more, avoiding gatherings, etc. are all very effective prevention methods. Doing these is enough. There is no need to believe in rumors and make yourself anxious.

Compiled by Ding Zong from the Science Rumor Refutation Public Account

Review | Jin Dong, Associate Researcher, Institute of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention

Editor | Ding Zong

Scientific rumor refutation