Important introduction
Until 2017, in Italy, vaccination against meningococcus was not mandatory, although it was recommended for health workers and highly recommended for newborns, conscripts, for pilgrims going to Mecca and for all those traveling in high-risk areas, such as sub-Saharan Africa.
What changes since 2017
With the decree law on the prevention of vaccination for minors from zero to 16 years, approved on 07/28/2017 the vaccine against meningitis ( Haemophilus Influenzae type b vaccine) has become mandatory for those born since 2001 .
As far as vaccinations against meningococcus C and meningococcus B are concerned, although they are not mandatory, they are offered by the Regions and Autonomous Provinces, based on the indications of the vaccination calendar for the year of birth:
- those born between 2012 and 2016 are offered free antimeningococcal vaccinations C
- those born in 2017 are offered free antimeningococcal B, anti-meningococcal C and pneumococcal vaccinations.
For more information on mandatory vaccines in children, see this article.
What is Meningitis
Meningitis is an inflammation of the membranes (meninges) that surround the brain and spinal cord. The disease is generally of infectious origin and can be viral, bacterial or caused by fungus.
The viral form (called aseptic) is the most common, but also the least severe.
Bacterial forms, on the other hand, can be fatal or even result in very serious complications (permanent neurological damage).
There are several types of pathogenic bacteria that can cause meningitis, including Neisseria meningitidis ( meningocco ), Streptococcus pneumoniae ( pneumococcus ) and Haemophilus influenzae type b ( hemophilic B or Hib ).
To learn more, read: Vaccine Meningitis ยป
The Meningococcus ..
As we know, meningococcus - scientifically known as Neisseria meningitidis - is a pathogen involved in serious, potentially fatal diseases, such as meningitis and meningococcal sepsis.
There are several meningococcal serotypes (currently, if we know 13, but only 5 - A, B, C, Y, W135 and X - are relevant from a clinical point of view, as they can cause epidemics and diseases that are dangerous for humans) . In Italy, meningococcus C is the most aggressive serotype and is found most frequently along with strain B.
Why get vaccinated
Vaccination provides the body with an effective defense weapon against pathogenic microorganisms, whose infection could trigger exaggerated and deadly reactions. However, it should be emphasized that vaccination is not simply a prophylactic measure towards oneself, but also towards others: the antimeningococcal vaccine (in this specific case) limits the spread of Neisseria meningitidis, reducing the number of victims to a minimum.
Another fundamental premise is the collaboration of the population: when meningococcal infection is suspected, it is the moral duty of the patient to immediately report to the public health department, in compliance with the methods currently in use for the rapid reporting of meningococcal infection.
The antimeningococcica vaccination gave surprising results: in fact, a clear reduction in the number of healthy carriers of meningococcus type C was observed and, at the same time, a marked decrease in the frequency of meningitis in subjects who were NOT vaccinated, a clear expression that the vaccine is in able to limit the spread of the pathogenic microorganism.
Vaccination or Prophylaxis?
All subjects exposed to a high risk of meningococcal infection, such as a family member of a patient, should undergo chemoprophylaxis *, since the risk of infection is extremely high on days when the symptoms of the disease occur.
Who Should Get Vaccinated?
There are three types of menngococcus vaccines:
- The conjugated vaccine against meningococcus C (it is the most frequently used and protects only from serotype C): it consists of the polysaccharide of the capsule of the "conjugated" bacterium on a protein that allows the induction of immune memory prolonged over time, in addition to the development of short-term antibodies. The Ministry of Health recommends its administration to all newborns between the 13th and 15th month of life; this vaccine is also indicated for all adolescents not previously vaccinated.
- The tetravalent vaccine that protects against ACY-W135 serotypes : it is recommended for adolescents and people traveling in regions where the infection is circulating. The conjugate version of this vaccine can be administered starting from 12 months of life, while the polysaccharide version (containing only the polysaccharides of the serotype capsule A, C, Y and W135) is indicated beyond two years of age.
- The conjugate vaccine against meningococcus type B (protects only against this serotype): it can be used starting from two months of age, but currently there is no recommendation for vaccination of all children in the national territory.
Conjugated vaccine for group C meningococcus
Medical statistics show that patients at risk of meningococcal meningitis are less than 25 years old; over this period, in fact, the risk of contracting the disease decreases.
- Vaccination against Neisseria meningitidis C ( meningococcus C ) is free and requires a single dose at 13 months. It is also recommended for susceptible teenagers. For those who have been vaccinated as children, the need for a recall in adolescence is being studied.
- Vaccination against Neisseria meningitidis B ( meningococcus B ) includes different vaccination schedules according to the number of doses, depending on the age at which vaccination begins. For example, before the 6 months of the child's life, a 4-dose schedule is generally followed (3rd, 4th, 6th and 13th month of life). At the moment the vaccine is offered for free only in some regions. The new National Vaccine Prevention Plan is expected to be approved after summer 2016 and will extend the offer to all regions, with the 4-dose schedule described.
- The quadrivalent vaccination against meningococcus ACY-W135 confers protection against meningitis and sepsis caused by 4 different meningococcal serogroups; consists of the administration of a single dose starting at 12 months of age. At the moment the vaccine is offered for free to teenagers only in some regions. The new National Vaccine Prevention Plan is expected to be approved after the summer, which will extend the offer to all regions.
The drug "Menveo" - obtainable only after medical prescription - is a vaccine formulated with powder + solution: by mixing, an injectable solution is obtained. The vaccine consists of parts of the bacterium Neisseria meningitidis, and is active against meningococcal groups A, C, W135 and Y.
More precisely, the vaccine consists of oligosaccharides extracted from the 4 groups of meningococcus; after purifying (before) and conjugating these sugars to a protein from the bacterium Corynebacterium diphtheria (after), the vaccine is ready to be injected.
Deepening: how the vaccine works
The drug stimulates the immune system to develop antibodies against the particles of the bacterium, inoculated by injection. Following a possible exposure to meningococcus, antibodies and other components of the immune system destroy the bacterial particles, protecting the individual from infection.
Among the vaccines available for the prophylaxis of meningitis, we also recall Menjugate (active ingredient: meningococcal group C vaccine conjugated with Corynebacterium diphteriae CRM 197).
Vaccination and side effects
It is not uncommon for the patient, after vaccination, to observe side effects, almost always mild and solvable in a very short time; hardening of the skin at the injection site, pain, erythema, headache and nausea are some of the most common symptoms. High fever or low-grade fever are also common symptoms following vaccination, especially in young children.
Vaccine prophylaxis and chemoprophylaxis
The terms "vaccinoprophylaxis" and "chemoprophylaxis" should not be confused: let us clarify the two different concepts.
VACCINOPROPHILASSIS is performed by administering a vaccine in order to develop an immune status towards meningococcus (in this specific case). In addition to recruits, those traveling in areas with a high risk of infection and healthcare personnel, antimeningococcal vaccination is also recommended for asplenics, for patients with deficit of complement complement components, factor D or properdin (protein plasma involved in the complement factor 3 activation).
Meningococcal vaccination is NOT recommended for patients allergic to the vaccine (or to some of its components).
chemoprophylaxis
* CHEMIOPROFILASSI is taken into consideration in the eventuality of a presumed (and not yet ascertained) bacterial infection: this medical practice consists in the administration of antibiotic drugs able to act actively against meningococcus. In general, the most widely used drugs are rifampicin, ceftriaxone and ciprofloxacin.
For example, in the category of subjects to whom it is recommended to undergo chemoprophylaxis, there are family members and roommates of the patient, people exposed to oral secretions of the patient, asylum companions / class of the patient, patients who have long stayed with the patient within 7 days before the onset of symptoms.
Vaccination and AIDS
Severe immunocompromised patients, such as AIDS patients, are clearly more at risk of infections, including those sustained by meningococcus. In the presence of endemic outbreaks, antimeningococcal vaccination is highly recommended for HIV-positive patients: in fact, it is reasonable to assume that the immunogenicity rendered by this vaccine is almost equivalent to that ensured by analogous vaccines (anti-Heamophilus influenzae etc.). ).
Future expectations
Recently, a new antimeningococcal vaccine has been developed: it is a tetravalent conjugate vaccine, containing meningococcus type C, AY and W-135, indicated for children over the age of 11, up to adults within the age of 55 . Current studies are aimed at studying the efficacy of the vaccine also for children aged between 2 and 10 years.
A problem that should not be underestimated is the unknown duration of the immunity conferred by the conjugated antimeningococo vaccine, an indispensable parameter for the compilation of the so-called vaccination schedules.
Unfortunately, especially the poor inhabited areas of the Western world are faced with a new obstacle, the meningococcus N. meningitis type B ; however, researchers are already experimenting with innovative vaccines against this new serogroup.
