L’influenza is a viral respiratory disease and affects approx a billion people in the world. Although it is very common, its impact should not be underestimated: in fact, the flu can present itself with different forms of severity, sometimes hospitalization may be necessary and in some cases it can even have fatal consequences.
What are the virus dell’influenza and how prevent it? We talk about it with Dr. Michele LagioiaHealth Medical Director of Humanitas.
How do you get the flu?
Influence is one viral respiratory diseasethe virus passes from person to person:
- through the droplets (droplets) that are spread when coughing, sneezing or talking (particularly in crowded and closed environments);
- because of the direct contact with infected people (for example through contaminated hands on the eyes, nose or mouth);
- through theuse of tools and objectssince the flu virus can resist for a long time and reach the organism through the mucous membranes.
Influenza: How contagious is it?
Seasonal flu typically has a incubation period two days, but can vary from one to four. Adults can spread the flu from the day before symptoms start to about five days after the flu symptoms start, while children and people with weakened immune systems can be more contagious.
What are the symptoms of the flu?
Sudden high fever, cough (usually dry) e muscle aches are the characteristic symptoms of the flu. Other common symptoms are:
In children, the flu can also go along with nausea, vomiting and diarrhea.
The flu typically lasts from one week to ten days.
Influenza can present in different forms of severity, and certain population groups, such as younger children and older people, are at greater risk of developing serious influenza complications such as viral pneumonia, secondary bacterial pneumonia, and worsening of underlying medical conditions.
How to prevent the flu?
To prevent the flu, as well as to prevent colds, the same indications are valid that are adopted to contain the COVID-19 pandemic:
- Wash your hands often and well with soap and water, for at least 40-60 seconds, especially after coughing or sneezing. Alcohol-based sanitizers reduce the amount of influenza virus from contaminated hands and represent a valid alternative;
- Cover your nose and mouth when sneezing or coughingwith disposable handkerchiefs to be thrown away immediately;
- Wear the surgical masks in the presence of symptoms such as cough and cold, it can reduce infections between close contacts;
- Staying home with symptomsespecially in the initial phase;
- Avoid close contact with sick peoplefor example by keeping a distance of at least one meter from someone with flu symptoms and wearing a mask;
- Avoid touching your eyes, nose or mouth. Viruses can spread when a person touches any surface contaminated with the virus and then touches their eyes, nose or mouth.
The flu vaccine
Vaccination is the most effective way to prevent the flu and every year the vaccine is available for the current flu season. Flu vaccines contain only inactivated viruses o parti di questitherefore, they cannot cause influenza virus infections.
Do the flu shot significantly increases the probability of don’t get the flu and even if you get sick, the flu would be less severe and generally without complications.
Furthermore, vaccination it also protects others, thus reducing the burden on the healthcare system. Given that the COVID-19 pandemic is still ongoing, extensive vaccination coverage is very important because it helps to not weaken one’s immune defenses, to reduce complications in people at risk and to avoid an overload of patients in hospitals.
Especially in the cold season, many bacterial and viral agents circulate, which can cause respiratory infections and flu-like syndromes: however, since they are not flu viruses, the flu vaccine is not effective for these agents.
What Are Influenza Viruses?
In humans, the main viruses responsible for influenza are types A and B.
I virus dell’influenza A (circulating in humans and other animal species) are classified into subtypes according to two surface proteins: hemagglutinin (HA) e neuraminidasi (THAT). Two subtypes of HA (H1 and H3) and two subtypes of NA (N1 to N2) are recognized among the influenza A viruses as responsible for human disease in recent decades. Immunity to HA and NA proteins reduces the likelihood of infection and, together with immunity to internal viral proteins, decreases the severity of disease in case of infection. To date, 16 HA and 9 NA subtypes have been identified.
I virus dell’influenza B (present only in humans) have no distinct subtypes within their HA and NA surface proteins.
Influenza viruses undergo mutations at the level of surface proteins: these physiological changes allow viruses to evade the immunity barrier present in people who have had the flu or who have been vaccinated against the flu the previous year, thus favoring a broad and rapid spread of infection.
In fact, every year composition of influenza vaccines it must be updated. To do this, the surveillance activity is fundamental, which allows you to select which strains to include in the vaccine, depending on the degree of epidemiological and serological difference compared to what has circulated in the previous flu seasons.
In Italy the use of vaccines is approved by theItalian Medicines Agency (AIFA), the national regulatory authority for medicines. Vaccines are approved starting at a proven efficacy of 60%.
Who should get vaccinated?
The flu vaccine is indicated in all people from 6 months of age, provided they do not have any contraindications to vaccination. L’influenza in fact he is serious public health problem and a considerable cost for the management of cases, complications of the disease and for the implementation of control measures (in Italy the InfluNet surveillance network deals with this). Just think that in Italy flu and pneumonia are classified among the top ten main causes of death.
Vaccination is strongly recommended to the following categories:
- people leaving from 60 years of age;
- people who are in close contact with the elderly;
- people at risk complications that have chronic diseases (diabetes, hypertension, HIV / AIDS, asthma and other chronic heart or lung diseases);
- pregnant women;
- children from 6 months to 6 yearsgiven the ongoing COVID-19 pandemic, in order to reduce the circulation of the flu virus between adults and the elderly;
- healthcare personnel.
In the circular of the Ministry of Health “Prevention and control of influenza: recommendations for the 2022-2023 season” of 6 July 2022, it is possible to consult in Table 1 all the categories for which seasonal influenza vaccination is recommended and offered free of charge.
When to get vaccinated against the flu?
The vaccination is given from the beginning of October to the end of December and the vaccine begins to be effective two weeks after the injection; the immunity thus obtained declines within 6-8 months. Being vaccinated the previous year does not protect in the flu season of the following year, precisely because of the mutations of the flu viruses.
The vaccine is given in a single dose intramuscularly in the deltoid of the arm chosen, while in young children the injection is preferably carried out in the anterolateral thigh muscle or the vaccine is administered intranasally.
After the vaccine they could occur symptoms Which:
- pain, erythema, swelling at the injection site;
- general malaise;
- fever;
- muscle pain (myalgia).
Can the flu vaccine and the COVID-19 vaccine be made together?
Yes, there is no contraindication. The flu vaccine does not interfere with the immune response to other inactivated or live attenuated vaccines and there are no side effects other than those already known.
The flu vaccine in Humanitas Medical Care
The flu shot is available (from 15 years of age) no medical center Humanitas Medical Care and you can book it online by clicking here.
Vaccination of Humanitas staff
Humanitas has always believed in vaccination as an important prevention tool and the influenza vaccination campaign for healthcare professionals is ongoing.
All the more so with the COVID-19 pandemic still ongoing, vaccinating even against the flu is the best way to protect yourself, your family and patients.
The numbers of Humanitas