Why do people still get tuberculosis after getting the BCG vaccine?

Author: Li Liang, Chief Physician, Beijing Chest Hospital, Capital Medical University

Former Chairman of the Tuberculosis Branch of the Chinese Medical Association

Reviewer: Mi Yuhong, Chief Physician, Beijing Anzhen Hospital, Capital Medical University

Relevant data show that there are approximately 1,200 new tuberculosis patients every hour in the world, of which 100 new patients appear in China. This number is very scary.

Many friends may have questions. For today's children, the first shot after birth is the BCG vaccine which can prevent tuberculosis. Why can't tuberculosis be eradicated yet?

1. Can you still get tuberculosis after getting the BCG vaccine?

BCG has been used in humans since 1921, and its history of use has exceeded 100 years. Despite this, controversy over BCG still exists because it is an imperfect vaccine, effective, but the degree of effectiveness is not satisfactory.

The generally accepted view now is:

First, BCG has a certain preventive effect on severe tuberculosis in children, but it is only a certain preventive effect, not a complete protection. Moreover, with the increase of age, the protective efficiency of the vaccine gradually decreases. When the child is over 15 years old, the effect of BCG is very limited.

Second, it offers little protection for adults.

Figure 1 Original copyright image, no permission to reprint

Of course, if you are still infected with tuberculosis after receiving the BCG vaccine, it has something to do with the body's susceptibility.

So the current BCG vaccine is an imperfect vaccine. Unfortunately, despite the efforts of scientists, no vaccine that can replace BCG has been found so far.

Theoretically speaking, if we want to eradicate tuberculosis, we need a more perfect vaccine, one that is better than BCG. For example, a vaccine that will prevent you from getting tuberculosis again after taking it would be the most perfect.

We believe that one day BCG will be replaced by a more perfect vaccine. But before that day comes, in addition to BCG, we still need to prevent tuberculosis from our daily lives.

2. How to prevent tuberculosis in daily life?

As a chronic respiratory disease, tuberculosis is very difficult to prevent. However, there are a few points that need to be emphasized:

First, improve your immunity. Because when your immunity is improved, it will protect you from not only tuberculosis but also other diseases.

Second, maintain a good attitude. With the development of the economy, many people are suffering from tuberculosis. One very important aspect is that the work pressure and life pressure are relatively high. If the attitude is not good, it is not conducive to the prevention of the disease.

Third, it is also very important to open windows for ventilation, including at home and at work. For example, although office conditions seem to be getting better and better, many places lack awareness of ventilation and air exchange is very unsatisfactory. In this case, not only tuberculosis, but also respiratory diseases such as colds and flu are easily spread, so it is very important to maintain air circulation in the surrounding environment.

In addition, for tuberculosis patients, there is another more important aspect, which is to maintain good hygiene habits.

Of course, even if we have done a lot of preventive work, we may not be able to avoid the risk of infection. Therefore, it is very important to know some symptoms of tuberculosis for early detection.

3. What are the typical symptoms of tuberculosis?

The symptoms of tuberculosis are closely related to the site of infection. The most common type of tuberculosis is tuberculosis occurring in the lungs, namely pulmonary tuberculosis, which accounts for about 85% of all tuberculosis cases.

The most common symptoms of pulmonary tuberculosis are coughing and expectoration. Severe patients may experience symptoms such as hemoptysis and chest pain. Moreover, the cough of pulmonary tuberculosis lasts for a long time. Generally, a cough lasting more than two weeks should be a warning.

However, these symptoms are not specific. Other respiratory diseases, such as colds, can also cause coughing, so we cannot judge whether it is tuberculosis simply by symptoms.

In addition to pulmonary tuberculosis, there is also extrapulmonary tuberculosis, such as bone tuberculosis, nervous system tuberculosis, brain tuberculosis, etc. These tuberculosis account for about 15% of all tuberculosis.

For bone tuberculosis, it can cause joint pain and limited mobility; if spinal tuberculosis occurs, it can also lead to paralysis of the whole body. For nerve tuberculosis and brain tuberculosis, it can cause the patient to lose consciousness, etc.

Of course, all tuberculosis diseases have some similar systemic symptoms, such as fever, fatigue, night sweats, etc.

There is a characteristic of fever, which is low fever in the afternoon, that is, low fever after noon. High fever is relatively rare. The body temperature is generally around 37.3℃-38℃.

4. How to treat tuberculosis?

Drug therapy is the most effective treatment for tuberculosis. In terms of treatment principles, we should follow the cross-principle, namely early, combined, appropriate, regular, and full-course.

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“Early stage” means early detection and early treatment;

“Combination” means that TB usually requires a combination of 3-4 drugs;

"Appropriate amount" means the dosage should be appropriate;

"Regularity" means that the medication time, dosage, and type must be taken regularly according to the doctor's instructions. You cannot stop taking the medication, reduce the dosage, or change the medication without authorization.

"Full course" means that the treatment of tuberculosis takes at least half a year. If drug resistance occurs, it may take two or even three years. During this process, patients are required to take medication throughout the whole course.

Of course, in addition to drugs, for some special tuberculosis patients, surgery, immunotherapy, traditional Chinese medicine and other treatment methods can also be chosen. As long as the treatment is adhered to, the treatment effect of most patients is still good, and the cure rate can reach more than 85%-90%.