Meningitis: the ten things to know according to the Higher Institute of Health

The succession of alarming news about cases of meningitis has considerably raised the level of public attention to this infection.

According to the experts of the Higher Institute of Health (ISS) there is actually no public health emergency in Italy. However, given the spread of information that is not always precise and correct, there is a need to clarify, not only on the current epidemiological situation in our country, but also on which categories are most at risk and vaccines available.

To this end, the ISS has drawn up a document entitled “Meningitis. What you need to know”, with which he takes stock of meningitis in Italy, especially on the most aggressive form, that of a bacterial nature, and on vaccinations to prevent it.

1. Is there a meningitis emergency today?

There is currently no epidemic of meningitis. According to ISS data, in 2015 and 2016 there were almost 200 cases per year of invasive meningococcal disease in Italy, most of which were caused by serogroup B and C. The trend follows the trend of recent years. In general, lethality concerns 10% of cases.

The vaccine should be administered only to recommended population groups and at-risk groups, in order to maintain high collective and individual protection from the disease. The prevalence of meningitis in general is low and has remained constant over the past five years.

The only epidemiological variation in the last two years concerns the outbreak of meningococcal C present in Tuscany, which is however limited to a specific area, in which the Region has immediately prepared the free offer of vaccination to a large share of the population.

2. What bacteria cause meningitis?

Among the bacterial agents that cause meningitis the most feared is Neisseria meningitidis (meningococcus), as well as Streptococcus pneumoniae (pneumococcus) and Haemophilus influenzae. There are several serogroups of meningococcus: the most common are A, B, C, Y, W135, X. Among these, the most aggressive is meningococcal serogroup C, which together with B is also the most frequent in Italy and Europe.

3. What are the categories most at risk of contracting the infection caused by the different types of meningococcus?

Young children (under 5 years of age) and adolescents, but also young adults, are at higher risk of contracting the infection and disease. With regard to serogroup B, most cases concern younger children, under one year of age.

4. What vaccines are available against meningitis and which strains do they protect against?

There are three types of meningococcal vaccine:

• the meningococcal serogroup C (MenC) conjugate vaccine: it is the most frequently used and protects only against serogroup C.
• tetravalent conjugate vaccine: protects against serogroups A, C, W and Y.
• the vaccine against meningococcal type B: protects exclusively against this serogroup.

5. Are vaccines mandatory or recommended?

Some vaccines have long been recommended and offered free of charge, while others come into force with the 2017-2019 National Vaccination Prevention Plan.

The vaccination card currently provides for anti-meningococcal C vaccination in children who have reached one year of age, while a booster with tetravalent vaccine is recommended in adolescents. The tetravalent conjugate vaccine is also recommended for adolescents who were not vaccinated as children and should still be administered to those who travel to countries where the meningococcal serogroups contained in the vaccine (A, C, W and Y) are present.

Outside the two age groups mentioned above, the vaccine is strongly recommended in people at risk or suffering from certain diseases (thalassemia, diabetes, severe chronic liver disease, congenital or acquired immunodeficiencies, asplenia, etc.), and is also recommended in the presence of particular conditions (infants attending nurseries, boys living in boarding schools, sleeping in dormitories, military recruits, and, as mentioned above, for anyone who has to travel to countries of the world where meningococcal disease is common, such as some areas of Africa).

The meningococcal B vaccine is now offered free of charge to children during the first year of life only in some regions of Italy, but it will soon be also at national level.

6. Which vaccines are free and which are paid for by the citizen?

Vaccination against meningococcal C is free of charge and the national calendar provides for the administration of only one dose at 13 months. The vaccine is also free for adolescents and recommended both for those who have never been vaccinated in childhood, and for those who have already received the expected dose at 13 months. For the rest, the vaccination offer varies from region to region: for example, some regions, instead of the monovalent vaccine against meningococcal C have included in the calendar, in childhood and / or adolescence, the tetravalent vaccine.

Vaccination against meningococcal B involves different dosages depending on the age at which you start vaccinating, although the vaccine is indicated especially under one year of age. With the National Vaccine Prevention Plan 2017-2019 this vaccine is offered free of charge at national level. In particular, 3 doses are expected to be administered during the first year of life, to which is added a booster after one year of age. For the rest, the vaccination offer varies from region to region.

As for vaccines against other bacterial agents of meningitis, vaccination against Haemophilus Influenzae B (hemophilic type B) is usually carried out, free of charge, together with tetanus, diphtheria, pertussis, polio and hepatitis B, at the 3rd, 5th and 11th month of life of the child, as per the Italian vaccination calendar. No further recalls are required.

Vaccination against Streptococcus pneumoniae (pneumococcus) is offered free of charge and the national calendar provides for the administration of 3 doses, at the 3rd, 5th and 11th month of life of the child. In some regions, the free offer of pneumococcal vaccination has also been extended to the elderly. The National Vaccination Prevention Plan 2017-2019 provides for the active and free offer to subjects of 65 years of age.

7. How long does the effect of vaccine protection last?

Generally, the duration of protection depends on the type of vaccine and the age at which it is administered. In fact, while some vaccines, such as the anti-hepatitis B vaccine, confer lasting protection throughout life, others, such as those against diphtheria and tetanus, require ten-year boosters.

With regard to meningococcal vaccines, the data currently available in the literature do not allow to establish the need for a booster. In Italy, with the National Vaccination Prevention Plan 2017-2019, however, a booster dose in adolescence was included to strengthen the immune response to a possible infection. In this age group, in fact, there is a risk that, although it remains very low, is greater than the rest of the population.

8. What is the value of the vaccination booster?

The recall of a vaccination allows to maintain high individual immune protection against a specific infectious disease and to guarantee, if the levels of vaccination coverage are high even in the general population, the establishment of the so-called herd immunity, a sort of protection shield, essential to limit the circulation of a given microbe and to avoid the re-emergence of diseases now under control, thus defending even the most vulnerable population groups such as the elderly, very young children still not fully vaccinated and at risk.

9. Do adolescents need to be vaccinated? And if they were vaccinated at one year of age, should a booster be administered?

Vaccination against meningococcal C, or rather the tetravalent vaccine, is certainly advisable for adolescents, as they fall among the categories at greatest risk of contagion, although it is still limited compared to other much more contagious infectious diseases, such as influenza and measles.

For those who were vaccinated as a child, there is currently no booster, although it is still advisable to do so. In some regions the booster in adolescence has already been included in the calendar and the vaccine is offered free of charge. The National Vaccination Prevention Plan 2017-2019 also introduces a booster dose in adolescence to strengthen the immune response to a possible infection.

10. Is vaccination recommended for adults who have not been vaccinated against meningococcal disease in childhood?

Vaccination in adults is not recommended unless the above risk factors or conditions are present. In case of doubt, it is advisable to contact the ASL or your general practitioner.