Routes of vaccine administration

Comparative injection techniques

Correct selection of the needle insertion plane ensures that the biological product reaches the target anatomical structure and prevents complications.

During intravenous procedures, exceeding an angle of 15° increases the risk of puncturing the opposite wall of the vein.

Features of intradermal and subcutaneous administration

Intradermal method:

• Aiming to administer a minimal volume of the drug using a fine needle with the bevel facing up.
• Accompanied by local separation of the epidermis, destruction of capillaries, and formation of a distinct papule.
• Used for diagnostic allergy testing (on the outer surface of the shoulder with readings at 2 hours and 24 hours), tuberculin skin testing (Mantoux test in the middle third of the forearm), and local anesthesia.

Subcutaneous method:

• Performed with a standard 2 ml syringe at a 45° angle to two-thirds of the needle length.
• Used for immunization, heparin injections, anesthetics, and insulin (for which specialized syringes with an ultra-thin, short needle are used).

Immunization in hemophilia and bleeding disorders

Patients with hemophilia and rare bleeding disorders (RBD) must undergo vaccination, where protection against hepatitis B has the highest priority.

• Choice of access: oral and subcutaneous (SC) routes are recognized as preferred. Intradermal (ID) and intramuscular (IM) administrations are considered undesirable due to the risk of deep hematoma formation.
• Regulations for forced IM administration: if alternative routes are unavailable, the procedure is performed strictly against the background of hemostatic replacement therapy with clotting factors.
• Timing of hemotherapy: replacement products are administered the day before vaccination; their use on the day of the injection itself is not recommended.
• Absolute contraindication: presence of active bleeding at the time of the procedure.

Serotherapy and diphtheria prevention

The administration of specific antibodies and toxoids has strict temporal and methodological frameworks:

1. Scheduled active immunization: starts from the age of 3 months with toxoid-containing preparations (DTP, DT), and in children over 6 years of age, it continues with a reduced antigen load vaccine (DT-M). The first 48 hours require monitoring for post-vaccination reactions.
2. Emergency serotherapy: diphtheria antitoxin (DAT) is prescribed immediately for toxic and localized forms via intramuscular or intravenous routes.
3. Besredka's test (prevention of anaphylaxis to equine protein):
4. Stage 1: intradermally 0.1 ml of serum at a 1:100 dilution (evaluated after 20 minutes; negative if papule < 0.9 cm);
5. Stage 2: subcutaneously 0.1 ml of native serum (evaluated after 1 hour);
6. Stage 3: administration of the full course dose intramuscularly.

Class and exam questions

What else to study on this topic

• Dosing regimens of diphtheria antitoxin for localized and toxic forms (from 10–15 thousand to 450 thousand IU)
• Etiotropic therapy of diphtheria with macrolides and penicillins
• Differentiated tactics for isolation and sanitation of carriers of toxigenic and non-toxigenic strains of corynebacteria
• Antiepidemic measures in the focus of infection: 7-day observation and twice-repeated swabs
• Pathogenetic treatment of severe forms of diphtheria: detoxification, glucocorticoids, and prevention of asphyxia

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