Vaccine against tuberculosis (BCG)

In childhood, the main method of preventing tuberculosis is vaccination with the vaccine BCG and BCG-M. The primary vaccination with BCG vaccine is administered to all healthy newborns on the 3rd-7th day of life. Children aged 7 and 14 years with a persistently negative PM with 2 TE are subject to revaccination, and children infected with MBT are not subject to revaccination. At the age of 15 years, regardless of the results of tuberculin diagnostics, vaccination against tuberculosis is not performed. All measures for vaccination are carried out according to the calendar of vaccine prevention of childhood infections.

See also: Vaccination against tuberculosis

Vaccination, aimed at the formation of artificial immunity to various infectious diseases, has become the most massive preventive measure of medicine in the XX century. Depending on the virulence of microorganisms, the role of the immune system in the pathogenesis of infectious diseases caused by them and the specificity in some cases, vaccination prevents the occurrence of the disease (smallpox, tetanus, poliomyelitis), in others, mainly influences its course. The main criterion in determining the method of mass immunization against a disease is its biological expediency in specific epidemiological conditions. The less the specific effectiveness of the vaccine, the greater the importance attached to the negative consequences of its use (complications). As a result, the improvement of the epidemiological situation naturally leads to a revision of vaccination tactics.

The greatest debate in the literature is the problem of the protective role of BCG in the disease of tuberculosis. In the foreign literature, the spectrum of opinions about BCG vaccination has wide limits - from doubts about its individual qualities to the total denial of the effectiveness of further use of TB control.

According to research data, the efficacy of currently used vaccines is 60-90% with respect to protection against generalized forms of tuberculosis for up to 15-20 years. The published materials, despite different approaches to assessing the effectiveness of BCG, mainly reflect the trend in developed countries with a low incidence of tuberculosis to refuse mass vaccination and the transition to selective vaccination of children from high-risk groups of tuberculosis, that is, immigrants, foreign workers, arrived from countries with a high prevalence of tuberculosis infection. At the same time, most authors prove the great protective role of BCG from generalized forms of tuberculosis and the lack of influence of immunization on the prevalence of infection, that is, the infection with mycobacteria of tuberculosis. Therefore, vaccination is most indicated for young children in countries that are endemic for tuberculosis. In these cases, WHO recommends vaccinating newborns.

Among the studies conducted in our country, unlike foreign authors, there are almost no facts that question the effectiveness of anti-tuberculosis vaccinations. All authors show a high effectiveness of BCG, reducing the incidence among vaccinated, compared with the unvaccinated. And now BCG vaccination continues to have a positive impact on tuberculosis epidemiology. The improvement of the quality of vaccinations and the greater coverage of the population are still relevant. Since the early introduction of the BCG vaccine provides protection against the most dangerous clinical forms of tuberculosis (in particular, from miliary tuberculosis and tuberculosis meningitis), they believe that efforts should be directed to a wide coverage of vaccinations of children at an early age.

Method of vaccination against tuberculosis

In Russia, a mass vaccination of newborns against tuberculosis is carried out with two drugs - the tuberculosis vaccine (BCG) and the tuberculosis vaccine for sparing primary immunization (BCG-M) - with lyophilizates to prepare suspensions for intradermal administration. Vaccine preparations BCG and BCG-M are living mycobacteria of vaccine strain BCG-1 lyophilized in a 1.5% solution of sodium glutamate: a porous powdery hygroscopic mass or tablets of white or cream color. The BCG-M vaccine is a preparation with a halved weight content of BCG vaccine in the vaccine dose, mainly due to dead cells. Vaccination against tuberculosis should be carried out by specially trained medical personnel of the maternity hospital, nursing department of premature babies, a children's polyclinic and a feldsher-midwife point. Primary vaccination is performed by healthy term infants on the 3rd-7th day of life. Children aged 7 and 14 years who have a negative reaction to the Mantoux test with 2 TE PPD-L are subject to revaccination.

• I revaccinate children (vaccinated at birth) at the age of 6-7 years (1st grade students).
• II revaccination of children is carried out at the age of 14-15 years (students of 9th grades and adolescents of secondary special educational institutions in the first year of training).

Inoculation at home is prohibited. In polyclinics, a doctor (paramedic) with a mandatory thermometer on the day of vaccination, taking into account medical contraindications and anamnesis with a mandatory clinical study of blood and urine, preliminarily selects the children to be vaccinated. To avoid contamination, it is unacceptable to combine one day of vaccination against tuberculosis with other parenteral manipulations, including blood sampling for phenylketonuria and congenital hypothyroidism. If the requirements for vaccination are not met, the risk of post-vaccination complications increases. Children who have not been vaccinated in the first days of life are vaccinated for the first 2 months in a children's polyclinic or other preventive institution without prior tuberculosis diagnosis. Children older than 2 months of age before immunization need a preliminary setting of the Mantoux sample with 2 TE purified tuberculin in standard dilution. Vaccinate children with a negative reaction to tuberculin.

Response to the administration of the vaccine

At the site of intradermal administration of the BCG or BCG-M vaccine, a specific reaction develops in the form of an infiltrate 5-10 mm in diameter with a small knot in the center and a crusty appearance in the form of a small one, in some cases, note pustules. Sometimes in the center of the infiltrate appears a small necrosis with a slight serous discharge. In newborns a normal vaccination reaction appears after 4-6 weeks. In revaccinated local vaccination reaction develops after 1-2 weeks. The reaction site should be protected from mechanical irritation, especially during water procedures. Do not apply bandages or handle the reaction site, which parents must be warned about. The reaction is reversed within 2-3 months, sometimes even longer. 90-95% of those vaccinated at the inoculation site should have a superficial scar to 10 mm in diameter. Monitoring of vaccinated children is carried out by doctors and nurses of the general treatment network, they should check the vaccination reaction at 1.3 and 12 months after immunization with the registration of the size and nature of the local reaction:

• papule;
• pustules with crust formation (with or without separation);
• hem;
• pigmentation and the like.

Contraindications to vaccination BCG and BCG-M

There are certain contraindications to the vaccination of BCG and BCG-M.

• Acute diseases:
  • intrauterine infection;
  • purulent-septic diseases;
  • hemolytic disease of the newborn with a moderate and severe form;
  • severe lesions of the nervous system with severe neurologic symptoms;
  • generalized skin lesions.
• Primary immunodeficiency state, malignant neoplasms.
• Generalized BCG infection, found in other children in the family.
• HIV infection:
  • a child with clinical manifestations of secondary diseases;
  • the mother of the newborn, if she did not receive antiretroviral therapy during pregnancy.

The newborns are spared vaccination with BCG-M. In the appointment of immunosuppressants and radiation therapy, the vaccine is given 12 months after the end of treatment.

Persons temporarily released from vaccinations should be monitored and recorded and vaccinated after full recovery or withdrawal of contraindications. If necessary, conduct appropriate clinical and laboratory tests. In each individual case not included in this list, immunization against tuberculosis is carried out at the permission of the relevant specialist doctor. When contacting infectious patients in the family, children's institution and other institutions, vaccinations are carried out at the end of the quarantine period.

Complications after vaccination and revaccination against tuberculosis

Antituberculosis vaccine is a preparation from live attenuated BCG bacteria, so it is impossible to avoid post-vaccination complications.

Complications of vaccination BCG are known for a long time and accompany it since the beginning of its massive use.

According to the classification proposed by the International Union Against Tuberculosis of WHO in 1984, the complications arising from the vaccination of BCG are divided into four categories:

• local lesions (subcutaneous infiltrates, cold abscesses, ulcers) and regional lymphadenitis;
• persistent and disseminated BCG infection without a lethal outcome (lupus, ostitis);
• disseminated BCG infection, generalized lethal outcome, developing with congenital immunodeficiency;
• post-BCG syndrome (erythema nodosum, annular granuloma, rash).

The algorithm of the doctor's action includes the following stages of a child's examination

After the introduction of an anti-tuberculosis vaccine.

• Upon examination, the pediatrician in the conditions of the children's polyclinic should remember that every child vaccinated intradermally with a tuberculosis vaccine should be examined at the age of 1, 3.6 months before the healing of the local vaccination reaction.
• Upon examination, the pediatrician draws attention to the place of administration of the vaccine and the condition of regional (cervical, axillary, supra- and subclavian) lymph nodes.
• Significant (more than 10 mm) ulceration at the injection site, an increase of more than 10 mm in one of these peripheral lymph nodes and a prolonged (more than 6 months) non-healing of the local graft response - indications for referring the child to a consultation with the TB pediatrician.

Clinical manifestations

The analysis of the main clinical signs and the nature of the course of all the revealed complications in children showed that basically all of them developed in the form of inflammatory changes at the site of the vaccination reaction or in regional lymph nodes. Complications in the form of keloid scars arose as a result of pathological healing of the local grafting reaction. Severe complications caused by BCG are extremely rare, their risk is much lower.

Complications of the inflammatory nature are manifested, as a rule, during the development of the local grafting reaction. Much less often they occur in more distant terms - in 1-2 years, extremely rarely - 3-4 years after vaccination. In order to detect complications in a timely manner, the pediatrician informs the mother about the normal reaction to the introduction of the vaccine, and also periodically examines the child.

Lymphadenitis. With complications of inflammatory nature, lymph nodes of the axillary region, which are detected mainly in young children, are more likely to suffer. Axillary lymphadenitis is the most severe type of complication. Occurrence of them is different in time, more often - during the development of the local vaccination reaction, that is, from 1 to 4 months after the introduction of the vaccine. There may be a later increase and suppuration of the lymph nodes. The disease begins gradually. Mother, bathing a child, pays attention to the enlargement of the lymph node in the left axillary region, sometimes in the supra- or subclavian area. Gradually, the lymph node continues to grow. At the time of going to the doctor, the node reaches the size of a bean or hazelnut. The consistency of the affected lymph node is soft, elastic, and later dense. Palpation of the lymph node is painless, the skin over it is not changed or slightly pinkish in color, the local temperature is normal. These signs allow the doctor, especially with a late complication, to correctly determine the etiology of the disease.

The smaller the child, the faster the development of clinical manifestations: after 1-2 months the size of the lymph node reaches the walnut. In the absence of treatment in the center of the node, a softening occurs, which quickly leads to total caseization of the lymph node, the breakout of caseous masses, and the formation of a fistula with a mild or abundant purulent discharge. As a rule, even with fistulous forms, especially in the first month of the disease, there are no complaints from the child; later, in the absence of treatment, symptoms of intoxication may develop (subfebrile body temperature, loss of appetite, lethargy, irritability, poor weight gain, anemia, liver enlargement). With the appointment of treatment, the complaints disappear quickly: after 2-2.5 weeks.

To exclude errors in diagnosis, despite the characteristic clinical picture of postvaccinal lymphadenitis, laboratory methods of investigation are used. In the center of the pathological focus, that is, in the place of the most pronounced softening of the lymph node, the puncture is performed, its contents are extracted. Prepared smears are necessary for cytological and bacterioscopic studies. In addition, punctate in a sterile test tube is examined bacteriologically (seeding on nonspecific flora and on mycobacterium tuberculosis).

• In the cytological examination of the punctate, leukocytes, destroyed neutrophils and lumps of caseoze are determined in the field of vision. The latter confirm the correctness of the diagnosis. Epithelioid cells are rare.
• Bacteriographic examination of the smear by the method of luminescence microscopy often reveals a few acid-resistant mycobacteria (BCG) in the field of vision. Sowing on nonspecific flora after 5-6 days gives a negative result.
• Sowing on MBT in 2-3 months is accompanied by growth of mycobacterium. When typing, they confirm their belonging to BCG.

The infiltrate is formed at the site of injection of the vaccine with suppuration in the center or its absence, the size of the formation is from 15 to 30 mm. Extremely rare infiltrates are larger. The appearance of an infiltrate can be combined with the reaction of regional lymph nodes: they increase to 10 mm, their consistency is soft-elastic. With a favorable course of 2 weeks from the start of treatment, the reaction of the lymph nodes subsides: they either cease to be determined, or decrease in size. The diagnosis is not difficult, as infiltrates occur during the first or second month after vaccination.

Cold abscess (scrofuloderma) is a tumor-like formation, the skin over it is not changed or has a pale pink color, the local temperature is not increased, palpation is painless, in the center is determined fluctuation (softening). A cold abscess is often combined with the reaction of the axillary lymph nodes to the left: they increase to 10 mm, become a testate of consistency. Along with clinical manifestations, the correctness of the diagnosis is confirmed by laboratory methods using the punctate obtained from the site of the greatest softening of the abscess.

According to our data, in children with complications after vaccination in the maternity hospital, lymphadenitis was registered in 77.1% of cases, and cold abscesses - in 19.1%. In children with complications after vaccination in the clinic, cold abscesses were found in 63% of cases, and lymphadenitis - in 37%. Thus, it was revealed that complications in the form of cold abscesses in children vaccinated in the polyclinic, compared with those vaccinated in maternity hospitals, are 3.3 times more common. Speaking of cold abscesses, we mean a violation of the technique of introducing the vaccine, which indicates a lower training of medical staff in polyclinics.

In case of untimely diagnosis of a cold abscess, the latter is spontaneously opened, and an ulcer is formed in its place.

The ulcer as a type of complication is characterized by considerable dimensions (from 10 to 20-30 mm in diameter), its edges are undercut, infiltration around is poorly expressed, which distinguishes it from the infiltrate with ulceration in the center, the bottom is covered with abundant purulent discharge. And in this case the diagnosis is not difficult. Studies on the above scheme confirm the association of the occurrence of an ulcer with the introduction of a vaccine. Sowing the contents of an ulcer on a nonspecific flora often gives a negative result, also confirming the etiology of the disease.

Keloid scar (from the Greek words keleis - tumor, eidos - type, similarity). According to the morphological and histochemical properties of the keloid scar, developed after BCG, does not differ from a keloid tissue that appeared spontaneously or for other reasons (more often after trauma). The leading cellular form in the connective tissue of keloid scars is functionally active fibroblasts with a well-developed granular endoplasmic reticulum and lamellar complex. The causes of the development of keloid tissue in general and at the site of post-vaccination scar in particular are not known until now. However, there are factors predisposing to the occurrence of a keloid scar: the period of prepubescent and puberty development of the child, hereditary predisposition (insufficient consistency of the development of connective tissue), trauma that does not heal the local vaccination reaction for a long time. It is impossible to exclude the influence of the vaccine itself, BCG, reintroduced with revaccinations.

As a rule, keloid scars are found in children of school age after revaccination, and also (extremely rarely) after primary vaccination. The keloid scar is a tumor-like formation of various sizes, which rises above the skin level, a dense, sometimes cartilaginous consistency. The main feature - the presence of capillaries in the thickness of the keloid, which are clearly visible during its examination. The shape of the scar is rounded, elliptical, sometimes stellate. The surface of the scar is smooth (glossy). Color varies: from pale pink, intensely pink with a bluish tinge to brownish. When diagnosing keloid scars, they should be differentiated with hypertrophic scars. The latter almost do not rise above the level of the skin, white or slightly pinkish in color, their surface is uneven, the capillary network is never visible in the thickness. In addition, the dynamics of development helps to correctly diagnose.

• Keloid scar, as a rule, slowly but continuously increases. Accompanied by itching in his surroundings.
• Hypertrophic scar does not cause itching and gradually resolves.

During the observation, the doctor should find out whether the keloid scar is growing or not growing, as in 2-5% of cases the growth of keloids ceases on its own. The size of these scars does not exceed 10 mm in diameter. The answer to this question can only be given to the observation of the child and adolescent within 2 years after the revaccination of BCG. When diagnosing a non-growing keloid scar, the patient is not removed from the dispensary register at least 2 years after the detection. The growth of keloids is slow. For a year the scar is increased by 2-5 mm. Gradually there is a feeling of itching in his area. The longer there is a keloid scar, not diagnosed in time, the stronger the itching sensation. In the future, unpleasant painful sensations that extend to the shoulder join the itch.

BCG-ostites. Lameness and unwillingness to walk are the earliest manifestations of the disease. An acute beginning is associated with the breakthrough of an asymptomatic bone focus in the joint cavity. When the joint is affected, swelling, smoothed contours, local skin temperature increase without hyperemia ("white tumor") with rigidity and atrophy of the limb muscles, increasing local soreness with palpation and axial load, limiting the volume of movements are revealed. It is possible to exudate into the joint cavity (determined by the presence of fluctuations, the balloting of the patella, the forced position of the limb), as well as gait disturbance. With far-gone defeat, contracture of the joints, abscesses, fistulas develop. The general condition worsens, and a moderate increase in body temperature is noted.

If BCG-ostitis is suspected, X-ray examinations of the affected department are performed in two projections or a CT scan to identify the characteristic signs of pathology: regional osteoporosis, bone atrophy, foci of destruction in epimetaphyseal sections of long tubular bones with shadows of dense inclusions, sequesters, contact destruction of articular surfaces, narrowing of the joint gap, tightening of the shadows of the soft tissues of the joints. It is also necessary to conduct a radiographic examination of all family members, including not only the mother and father of the patient, but also grandmothers, grandfathers and other relatives who have been in contact with the child.

Generalized BCG-iti is the most severe complication of BCG vaccination, which occurs in newborns with immunodeficiency states. Foreign authors give the frequency of generalized BCG-it 0,06-1,56 per 1 million grafted. These rare post-vaccination complications associated with dissemination and generalization of BCG infection and accompanied by the defeat of various groups of lymph nodes, skin, osteoarticular system, proceed according to the type of severe general disease with polymorphic clinical symptoms caused by tuberculous lesion of various organs and systems. At autopsy, miliary tubercles and foci of caseous necrosis are found, from which it is possible to isolate mycobacteria of the vaccine strain of BCG, as well as purulent foci in the liver and other organs. It is proved that such complications are met in children with immunodeficiency conditions.

Treatment of postvaccinal complications (with the exception of generalized ones) is recommended to be performed on an outpatient basis under the supervision of a phthisiatrician. Hospitalization of a child both in the tuberculosis and in the obscheomatic hospital is undesirable. In the absence of a child phthisiatrician (a child from a village or an area where there is no specialist), the child can be hospitalized, preferably in boxing at a general hospital. Regardless of the type of complication, the doctor should prescribe anti-tuberculosis antibacterial drugs. However, the number of drugs, their dose, combination, duration of admission can be individual and depend on the severity of manifestation of the type of complication, the age of the child, taking into account the tolerability of drugs. All children with complications after vaccination against tuberculosis are observed in the dispensary for the V group of patients.