- How to act
- Preparation of a vaccine
- Mandatory vaccines
- Recommended vaccines
- Other vaccines
- Side Effects
In Italy the administration of vaccines , both for children and adults, is governed by agreements between the State and the Regions, in accordance with Title V of the Constitution for the protection of health; basically means that there is cooperation between the State and the Regions in determining the strategies vaccine: the National Vaccine Plan and all records relating to individual vaccinations must be approved by the State-Regions Conference, also based on the agreement on the essential levels of assistance.
Vaccines, before being introduced into the national health system, undergo a validation based on the characteristics of safety and efficacy. Currently the vaccines are divided into two categories:
- Recommended (that is recommended but not required).
The vaccines are required by law and those in the past, this approach has helped to ensure the right to health and prevention: in Italy since 1982 there is no longer any cases of polio and no cases of diphtheria since 1991.
In the first group include those for:
- ‘s hepatitis B ,
- the tetanus ,
- the diphtheria .
In the second group includes all the others, even those most recently acquired as the vaccine for human papilloma virus and varicella .
Since their discovery vaccines pose to public health tool to prevent mass: if today there is no more certain diseases (eg, smallpox) is also due to the diffusion of vaccines, interrupting the epidemiological chain, they stopped the proliferation of viruses To date eradicated.
For its part, the World Health Organization ( WHO ) periodically updates the recommendations for vaccinations and their administration times and / or recall; these elaborations are only guides for the senior national vaccination plans that are tailored to the needs and the local situation.
How to act
The term comes from the first vaccine discovered by British physicianEdward Jenner , the scientist in charge of a brave experiment, almost insane: he took the pus from cowpox infection (hence vaccine ), a less aggressive variant compared to smallpox, and inoculated in a child of 8 years (at that time were likely many people want to “lend” their child in exchange for hard cash) and then infect six weeks later with the human virus.
The child proved immune to smallpox.
The principle on which they are based all vaccines is that according to which the organism by introducing a small amount of infectious substances inactivated or weakened, that is, made less hazardous and powerful, it stimulates the activation of the immune system and the consequent production of specific antibodies (gamma globulin).Once the immune system has been activated against a specific pathogen is able to store its own defense response and thus protect the organism in an immediate way in the event of another attack by the same virus, even at a distance long time. The duration varies depending on the vaccine, for which calls are scheduled at different times.
The immune response elicited by the vaccine is the same as that induced by the virus unaltered, without, however, to follow up to the side effects of the disease itself.
Preparation of a vaccine
The vaccines can be prepared in different ways, we see the main ones.
- Some vaccines are composed of dead bacteria and viruses, but still able to provoke an immune response.
- Others, however, contain pathogens still alive but attenuated, that is modified so as to limit the aggressiveness, as with the Sabin vaccine against polio.
- In still other cases the vaccines are prepared using toxic material produced by the bacteria, as is the case for vaccines against tetanus and diphtheria.
- Some vaccines are prepared using the coating outer cell of the bacteria, is the case of vaccines for Haemophilus influenzae B and for the pneumococcus .
- The vaccines for hepatitis B and for the pertussis are instead prepared from synthetic proteins which simulate the components of the respective viruses.
Often the main matrix of the vaccine may be added as processing aids, which are usually secondary bacteria, whose presence is even more stimulating the immune response; are present because they are essential in vaccines for tetanus, and diphtheria and hepatitis B.
Vaccines can also be combined, in the case of its first pediatric vaccines which speaks of hexavalent vaccine or trivalent etc.., Ie vaccines which are different viruses and bacteria at the same time.
The dilution liquid can be constituted by
- sterile distilled water,
- a saline solution,
- A solution consisting of substances that represent the soil biological culture of the virus, such as serum proteins, antigens of cell cultures or antigens of the egg and so on.
Other substances contained in vaccines in small quantity are the preservatives and stabilizers, which are the substances most often cause of hypersensitivity reactions and that are for this at the center of much controversy. Among these, albumin, gelatin and thimerosal , a mercury-based preservative, which is not as dangerous as you would have us believe ( Deepening Thimerosal ).
As we have said for the new born in Italy are required vaccines for
- hepatitis B.
The vaccine for polio has changed since August 2002: Now is administered only the Salk vaccine, that is, the inactivated polio vaccine (IPV), noted the disappearance of the disease in Europe declared by WHO in June 2002. Before vaccination consisted in the administration of its sequential doses of Salk vaccine and two doses of oral polio vaccine (OPV).
The first three doses administered in the first year of life, however, remained unchanged, while the later recall the year of birth is a watershed: for those born before 2004, the recall was performed on the second or third year of life, while those born after January 1, 2004 the appeal must be made to the five or six years together with that of diphtheria and pertussis (DTP).
The vaccine for diphtheria consists of a diphtheria toxin original rendered harmless by biochemical treatments. Its administration is performed in three doses in the first year of life and then, as a reminder, to 5 or 6 years and to 11 or 15 years of age.
It is then recommended a booster every ten years to ensure almost complete and lasting protection.
The formulations of the vaccine are different for children and adults. The former are used to recall six years, from this time forward instead are then used formulations for adults that contain a reduced dose of diphtheria toxoid than in children.
The vaccine for tetanus toxoid consists dall’anatossina, that provides protection from viruses very long, up to ten years, then that is even longer if the calls are made. A difference of diphtheria and tetanus polio is not eradicated and is not debellabile, in the sense that the spores tetanic can be everywhere and the contamination does not occur from person to person, but for direct infection. The goal of vaccination in this case is therefore geared to keep under control the casuistry.
Hepatitis B vaccine
The vaccine for hepatitis B is constituted by a surface antigen of the virus that is administered is in the form monovalent that in hexavalent form, the second is that used in pediatric age: three doses in the first year of life to achieve a protection of the 90% without any additional calls.
For infants from infected mother doses administered in the first year of life and are four with the first dose, performed within 24 hours after birth, are injected too specific immunoglobulins hepatitis.
Vaccination against hepatitis B since 1998, is subject to numerous controversies especially in relation to the fact that France has stopped using after a study on the adult population, which would link the development of multiple sclerosis with administration of the vaccine.It ‘also found the risk for the adult population of contracting Guillain-Barré syndrome , an acute polyneuritis which is manifested by a progressive paralysis of the limbs.
At the moment, there is too unequivocal evidence, such as to advise against its use.
Vaccination in children decreases the chance of contracting hepatitis B and its complications, including liver cancer, cancer that can be triggered in overt cirrhosis, and whose infections hepatitis Cand B would be predisposing factors.
Since 2003, the vaccination is no longer compulsory for teenagers because twelve years old, starting in 2003, have already been vaccinated in the first year of life.
In Italy, for the new born, the following vaccines are recommended:
- measles , mumps and rubella (MMR);
- Haemophilus influenzae (Hib);
- pertussis ;
- meningitis C;
- pneumococcus ;
- chickenpox ;
- papilloma virus.
MMR is the combined vaccine used since the early nineties and is administered in an initial dose around 15 months of age, and you can also do it in conjunction with the third dose as the other mandatory vaccines. A call is then made to 5/6 years. Vaccination especially against measles and rubella was recommended back in the seventies, when many studies and cases have already shown the danger of these diseases in pregnant women: these infections, when transmitted to the fetus in early pregnancy can lead to severe heart defects, mental retardation and motor or other complications.
Vaccination in recent years has spread, even if these diseases are not yet widespread in the area.
The MMR vaccine has been the subject of great controversy, since in 1998 its use has been reported in twelve cases of full-blown autism, in which case the evidence clearly show the unfounded fears (vaccines and autism, the great bluff )
The Haemophilus influenzae B or Hib is effective in the prevention of more serious infections such as meningitis and at the same time reduces the number of carriers that are home to the bacteria in the nasal cavities. There is a monovalent that the chromium, the latter used on newborns and administered in three doses with the mandatory vaccines.
The pertussis vaccine is usually included in the hexavalent vaccine and is administered in three doses during the first year of life, and it requires two calls, one to 5/6 years and one for 11/15 years. For the calls is now used as a vaccine consisting only some components of the virus which provide fewer side effects while maintaining unchanged the effectiveness.
The disease itself and the vaccination does not allow unfortunately lifelong immunity to the virus.
The meningococcal vaccine type C is always recommended in the first year of age, the period at risk for contracting this type of infection. The meningococcal naturally inhabit the nose and throat, but only under certain conditions may be activated and cause severe infection with a high mortality rate of up to 10-15% of cases. This vaccine is available in several versions and used mainly in pediatrics, because the result safest and most effective, is married, it contains the C polysaccharide conjugated to other infectious agents such as tetanus toxoid or diphtheria. For children under one year of age is given in two doses, while for older children and adults is given as one dose.
Also with regard to the pneumococcus is to be noted that Streptococcus pneumoniae normally lives in the mucous membranes of the oral and nasal cavity without causing any damage normally, while in some conditions may activate and spread giving rise to pneumoniaand meningitis. His heptavalent conjugate vaccine is that it has a high degree of safety and effectiveness; is administered in two doses during the first year of life. Among all vaccines recommended that pneumococcal turns out to be the safest and most effective for fighting infections less weight as the ear , without counting the more serious infections such as meningitis, pneumonia and sepsis. Its administration reduces at the same time the use of antibiotics. The social and economic benefits of this vaccine has unfortunately prevented that occur disparities between different regions, adoption and modes of administration.
Chickenpox is a rash illness that mostly affects the pediatric population; cases in our country seem to be twice those of other European countries. Chickenpox, in the majority of cases, namely in healthy children without special affections, resolves without leaving traces; may instead give the serious side effects in subjects at risk or immunosuppressed: mortality in these cases may also arrive to a 14%; go up to 20% in the newborn.
Infants who are infected in early pregnancy can lead to changes permanent serious: skin lesions and eye up to even get to cerebral atrophy with mental retardation.
The introduction of the chickenpox vaccine is very recent and therefore also the route of administration and timing may vary from region to region. The varicella vaccine can be given along with MPR or other attenuated vaccines, such as polio, antidifetrite, whooping cough, Hib vaccine, and inoculated in different areas of the skin.
There are specific contraindications to varicella vaccine:
- strong immunosuppression acquired or congenital;
- acute in progress;
- Tuberculosis active untreated;
- people taking high doses of corticosteroids;
- allergic reactions by one component of the vaccine.
Vaccination against the human papilloma virus, HPV, is an acquisition rather recent (2008) and was included in the immunization schedule for children twelve years old. The vaccine is given in three doses (first dose and two subsequent calls to be made within six months) and allows to protect against ulcers and precancerous cervical cancer.
The choice of the age group of 12 years is given by a study on the risks and benefits indicated in this range an excellent response of the immune system, this approach is also important to administer the vaccine before they are tested the first sexual intercourse, responsible for any transmission of the HPV virus.
Currently, the HPV vaccine is available in two versions: the Gardasil and Cervarix R R, the first seems to be also active to the strains responsible for 90% of genital warts as well as those that cause cervical cancer, the second one is active only two strains of HPV.
Finally, we recall influenza vaccines: in Italy it were authorized only some, including the split vaccines that are made up of protein from the cell surface of the virus and disrupted by parts of the virus itself.These vaccines are generally well tolerated even by people who are particularly sensitive to protein synthetic and alien. However, many still lack data on the efficacy of the vaccine in children, due to the fact the high mutability of strains from year to year.
Vaccination against rotavirus , viral agent that causes gastroenteritissevere especially in children, has not yet entered in the National Vaccine because there are still some data regarding the safety and efficacy of the two vaccines on the market: the RotaTeq, a pentavalent vaccine , and the Rotarix. It ‘s true that rotavirus infection often lead to hospitalization of children, however, the cost / benefit ratio resulting from the administration of the vaccine is not yet satisfactory. The first vaccine produced in 1999 (RotaShield) was immediately withdrawn from the market because procured intestinal intussusception.
The mortality related to infection of rotavirus occur only in the countries in the developing world.
Even tuberculosis infection continues to be important, especially in developing countries. In Italy, where the series is very low (7 cases per 100 thousand inhabitants) but is constantly increasing, no steps were taken vaccine. In countries at risk is given the vaccine against Mycobacterium bovis (live attenuated vaccine) in the first few days of life with good results in terms of safety. The WHO has set itself the goal of halving by 2015 the cases and mortality due to TB.
The most common and least dangerous are those that occur within a few hours of administration:
- slight fever,
- pain and swelling at the injection site,
- general malaise,
Then there are the adverse reactions that may occur just after the injection until days later.
- The first are allergic-type reactions, that is attributable to IgE antibodies that attack components of the vaccine, these reactions can manifest as urticaria , angioedema , and more rarely as nasal congestion, vomiting, diarrhea , cough , respiratory spasms and abdominal pain. A reaction that can take place in a short time is anaphylaxis, tamto rare as dangerous, which leads to a cardiorespiratory and neurological symptoms from severe clinical picture.
- The reactions occur rather than after several hours or days are related to the formation of immune complexes and causing skin rash, maculopapular rash, …
The incidence of allergic reactions is statistically very low, we are talking about one case in fifty thousand for the DTP (diphtheria, tetanus and polio) and 1 case of five hundred thousand / one million for all other vaccines.
Contraindications exist temporary concerning the state of health of the child at the time; such vaccinations are not recommended in case of acute illness with fever high, in case of current therapy with drugs that act on the immune system or with high-dose corticosteroids . In addition, the vaccination with vaccines in vivo, as the MPR, must not be carried out if in the previous month has already been introduced another vaccine of the same characteristics.
Then there are the so-called false contraindications concerning alleged allergies already present in the child, such as allergy to egg, meat, medications (excluding the components of the vaccine). The egg allergy in itself is not a contraindication to MMR vaccination (measles, mumps, rubella) whose adverse reactions are usually due to gelatin present and not the egg. On the other hand blown egg allergy can be an obstacle for influenza vaccination , they are used culture media protein derived from the egg.
Other false contraindications are atopic dermatitis , a family history of allergies, previous febrile seizures, the diabetes , the cystic fibrosis, neurological diseases stabilized, malnutrition, antibiotic therapy during the febrile reaction or discomfort to the previous vaccination, …
Then there are contraindications true that the vaccine would cause more harm than good:
- advanced neurological diseases, such as pertussis vaccination should be postponed until it has stabilized the disease. The onset of encephalopathy after the first dose not recommended automatically a second administration;
- in the case in which the child has manifested severe allergic reactions, such as anaphylaxis, after the first dose. If the reaction is not clearly attributable to the vaccine then the subsequent doses should be administered under close medical supervision;
- full-blown allergy to antibiotics contained in some vaccines such as streptomycin;
- in primary immunodeficiency.
By Romina Brown
Scientific review and correction by Dr. Guido Distemper (pharmacist)
The information contained in this article should in no way replace the doctor-patient relationship, it is recommended as opposed to seek the advice of your doctor before you implement any advice or direction given.