Vaccination against meningococcal infection

The causative agent of meningococcal infection - meningococci - Neisseria meningitidis serogroups: A, B, C, H, I, K, L, W-135, X, Y, Z or 29E (Z), more common A, B, C, Y and W-135. In Russia, Asia, Africa, meningococcus group A prevails, in Zap. Europe and North America — Groups C. Meningococci of group B cause endemic diseases and local outbreaks; in New Zealand, they caused an epidemic lasting from 1991 with an incidence of 400–500 cases per year (per 4 million people). Vaccination against meningococcal infection in the form of polysaccharide meningococcal vaccines types A and C in persons older than 2 years is immunogenic and provides protection for at least 3 years (at least 2 years in children); their epidemiological effectiveness is 85-95%.

The decrease in the incidence caused by the causative agents of serogroups A and C is often replaced by an increase in the incidence caused by meningococcus B. Every year more than 300,000 cases of meningitis with 30,000 deaths are recorded worldwide. In connection with the cases of pilgrims delivering meningococci of the serogroup W 135 from Mecca, now the hajj requires a vaccination that includes it (in Russia Mentsevax ACWY of GlaxoSmithKline has been registered).

Patients with meningitis are contagious in the prodrome, they stop secreting the pathogen 24 hours after the start of treatment. Carriage of meningococci is the main source of infection, in the interepidemic period, its frequency is less than 5%, increasing during epidemics in foci to 50% or more. It is usually short-term — less than 1 week, so treatment of carriers is impractical. Most often sick children under the age of 5 years.

In Russia, in 2007, meningococcal infection was registered in 2,680 people (1,779 of them were children aged 0–14 years), 1.87 per 100,000 (children - 8.25).

Objectives of meningococcal vaccination programs

Although the vaccine of group A can be used on epidemiological indications in children after 12 months, but it is not suitable for routine immunization at the age of 2 years; Type C vaccine is even less immunogenic at this age.

WHO recommends polysaccharide vaccines A and C for people older than 2 years from risk groups, as well as for mass vaccination during an epidemic, both for individual protection and for creating collective immunity and reducing carrier life. In Canada, the universal (6 months old - 20 years old) vaccination of 1.6 million people in 1992 led to a decrease in the incidence of C meningitis from 1.4 to 0.3 (per 100,000) in 1993-1998, preventing 48 cases of meningitis in vaccinated and 26 cases due to collective immunity. Its effectiveness was 41% at the age of 2–9 years, 75% at 10–14 years and 83% at 15–20 years, but this indicator was zero in children aged 0–2 years.

Vaccination against meningococcal infection according to epidemiological indications is carried out in risk groups. Mass immunization with the A + C vaccine (with coverage of at least 85%) is carried out with an increase in the incidence rate above 20.0 per 100,000 population. Vaccination is also carried out in the foci of infection. Children with asplenia or distant spleenias, with liquorrhea, after surgery for cochlear implantation, as well as with a number of forms of primary immunodeficiency (deficiency of C3-9 complement components) are at particular risk.

Conjugated type C vaccine (scheme - 2-3-4 months, along with other vaccines) was created and used in Europe, which led to a sharp decrease in the incidence of meningitis C, and this vaccine included England, Holland and Spain on the calendars.

In the United States, the 4-valent Menactra ™ conjugated vaccine (serotypes A, C, Y, W-135) from sanofi pasteur has been used since the age of 11; her goal is to reduce the incidence of adolescents, especially freshmen in colleges giving meningitis outbreaks. The vaccine is not enough immunogen in infancy, the new vaccine version - MenACWY, however, showed 80% immunogenicity after 3 vaccinations, starting at 3 months old and 85% after revaccination at 1 year old.

Type B polysaccharide vaccines have common antigenic determinants with brain tissue, provoking complications. Group B vaccines have been created based on meningococcal outer membrane proteins; these vaccines are immunogenic, but only against the strains of the pathogen used in its production. Such vaccines from local strains are used in Norway and New Zealand.

[1], [2], [3], [4], [5], [6], [7], [8], [9], [10]

Vaccination against meningococcal infection: characteristics of drugs

The following meningococcal vaccines have been registered in Russia:

Meningococcal vaccines registered in Russia

Vaccine	Composition	Dosage
Meningococcal A vaccine, Russia;	Serogroup A Polysaccharides	1 dose - 25 mcg (0.25 ml) for children 1-8 years old and 50 mcg (0.5 ml) for persons 9 years and older.
Meningo A + C Sanofi Pasteur, France	Lyophilized polysaccharides of serogroups A IC	1 dose - 50 mcg (0.5 ml) for children from 18 (according to indications from 3) months. And adults
Mentsevax ACWY polysaccharide - GlaxoSmithKline, Belgium	In 1 dose (0.5 ml), 50 µg of polysaccharides of types A, CW-135.Y.	1 dose - 0.5 ml for children over 2 years old and adults
Menugate Novartis Vaccine and Diagnostics GmbH & Co., KG, Germany (in the registration phase)	At 1 dose (0.5 ml) 10 μg of type C oligosaccharides conjugated to 197 C protein. Diphteriae. Without preservatives.	For children 2 months. And older and adults, administered in / m, in contrast to non-conjugated vaccines, creates immunological memory.

Vaccines are issued in a dry form complete with a solvent do not contain preservatives and antibiotics, they are stored at a temperature from 2 to 8 °.

Mentsevax ACWY. Children, young children, going to the endemic zone, should be inoculated subcutaneously no later than 2 weeks before departure, children under 2 years old should be administered the 2nd dose after 3 months. Children over 6 years old and adults can be vaccinated before leaving.

Immunity

Immunization with a polysaccharide vaccine leads to a rapid (from 5th to 14th day) increase of antibodies, immunity persists in children for at least 2 years; in adults, antibodies remain vaccinated after vaccination for up to 10 years. Re-vaccination is carried out no earlier than 3 years.

Conjugated vaccines are immunogenic in children older than 2 months, adolescents and adults, they create a significantly more intense immune response in children and adolescents. In addition, unlike non-conjugated vaccines, they induce the development of immunological memory.

[11], [12], [13], [14]

Vaccination reactions and contraindications for meningococcal infection

Vaccination against meningococcal infections A and Meningo A + C is little reactogenic. The local reaction - pain and hyperemia of the skin - is noted in 25% of the vaccinated, less frequent subfebrile temperature occurs with normalization in 24-36 hours. Mentsevax ACWY rarely causes a temperature for 1 day, local - redness, soreness at the injection site.

Contraindications common to inactivated vaccines. The risk for pregnant women is not established, they are vaccinated only when there is a high risk of the disease.

Post-exposure prophylaxis of meningococcal infection

The introduction of normal human immunoglobulin once for children from the foci of meningitis under the age of 7 years is recommended no later than 7 days after contact in doses of 1.5 (children under 2 years old) and 3.0 ml (over 2 years old). Carriers in the focus carry out chemoprophylaxis with amoxicillin for 4 days, and in closed adult groups, with rifampicin, 0.3 g 2 times a day. Abroad, rifampicin prophylaxis has been taken for 2 days for all closely contacted children (5–10 mg / kg / day for children under 1 year, 10 mg / kg / day for children 1–12 years old) or ceftriaxone intramuscularly once.

Since secondary cases of meningitis occur within a few weeks, chemoprophylaxis is complemented by vaccination in the first 5 days after contact.

[15], [16], [17], [18], [19], [20]