All the medical authorities in Israel, under the umbrella of the Israel Medical Association (RAI), have compiled comprehensive information about the flu for the public: the Institute for Quality in Medicine, the Israel Pediatrics Association and the Israel Infectious Diseases Association
All the medical authorities in Israel, and in particular those dealing with pediatrics, have compiled, under the umbrella of the Israel Medical Association (RAI), comprehensive information regarding the flu for the public: the Institute for Quality in Medicine, the Israel Pediatrics Association and the Israel Infectious Diseases Association. Written by: Dr. Diana Tesher, the Association for Pediatrics and the Association for Infectious Diseases at Wolfson Hospital and Prof. Eli Somech, Chairman of the Association for Pediatrics, the Association for Infectious Diseases at Wolfson Hospital and the Institute for Quality in Medicine at the Israel Medical Association.
What is the flu?
Influenza is a viral disease characterized by large seasonal outbreaks. The cause of the disease is the influenza virus that is transmitted from person to person through the respiratory tract. The virus has a number of unique characteristics that include constant seasonality and the ability to undergo changes in the structure of the proteins on the surface of the virus and thus trick the immune system.
The virus can cause illness on a large scale: during an outbreak, up to a third of children and 10% of adults are affected by the disease, this phenomenon leads to significant absences from workplaces and schools, and places a heavy burden on hospitals and clinics.
Symptoms of the flu such as fever and muscle aches and the symptoms associated with it are disturbing and unpleasant, but they pass by themselves after a few days. However, the problem of the disease (unlike other viruses that cause a flu-like picture) is mainly related to its complications. Complications include pneumonia, bronchitis, ear infections as well as complications in the nervous system and even many cases of death due to the flu and its complications.
Who is at risk for flu complications?
There are different groups in the population that have an increased tendency to suffer from the complications of the disease. These groups include: the elderly, patients with chronic diseases of the respiratory system (including asthma), heart patients, patients with kidney diseases, diabetes patients, patients suffering from obesity, patients with congenital or acquired immune deficiency, those treated with steroids and/or chemotherapy, pregnant women , and even soft babies.
Among these population groups the complication rates are high as well as the hospitalization and mortality rates due to the disease and its complications. Therefore, it is necessary to prevent or reduce as much as possible the burden of the disease among these populations.
What vaccines are available against the flu?
The killed flu vaccine contains three killed strains of the flu virus (two strains of influenza A and one strain of influenza B). Starting with the 2015-16 flu season, there is a flu vaccine in Israel that also contains 4 killed strains of the virus (two strains of influenza A and two strains of influenza B). The inactivated vaccine is given by injection. Every year, the World Health Organization predicts which viruses are likely to cause illness this coming winter, and based on this prediction, the vaccine is produced. This prediction is based on scientific data collection and is usually accurate. However, even if the forecast is not completely accurate, and even if the strains in the vaccine are only some of the strains that cause the disease, even partial protection has some benefit. It is recommended to get vaccinated with the most available preparation among the preparations suitable for the person being vaccinated and not to postpone the vaccination.
In recent years, a live attenuated vaccine has been put into use, that is, a vaccine containing live attenuated viruses. This vaccine is given as a nasal spray. This vaccine is designed to provide protection against the four strains predicted by the World Health Organization. In the last two years (2014-2016) low effectiveness of the live attenuated vaccine against swine flu (H1N1 flu) was found. Varying effectiveness rates of the vaccine were found in different countries.
In the USA no significant effectiveness was found against this strain while in Europe an effectiveness of around 50% was found. In light of this, the health authorities in various countries, including Israel and the USA, have decided to give priority to the vaccine given by injection. In various European countries, the administration of the live attenuated vaccine continues as usual, including the program to vaccinate school children in England.
What is the effectiveness of the killed flu vaccine?
The effectiveness of the vaccine was found to be very high (70%-100%) when there is a match between the vaccine strains and the disease strains in the same season. The effectiveness is lower (approximately 40%-60%) when there is no such adjustment or when the vaccinators are elderly and babies, however, even then the effectiveness against the complications of the disease remains high and it is estimated that the effectiveness of the vaccine in preventing hospitalizations due to complications of the flu in the risk groups is around 65%-70% .
Until a few years ago, it was customary to recommend vaccinating the people in the risk groups of getting complications from the flu, such as people with chronic diseases, the elderly, pregnant women, the morbidly obese, and more. In surveys published in recent years, it has been clarified that even children younger than 5 years old and even those younger than 6 years old are at high risk of suffering from the complications of the disease such as bronchitis, asthmatic attacks, stridor, lung infections and ear infections, with a high rate of hospitalizations due to flu complications in this age group. In light of these data, it is highly recommended to be careful and vaccinate the children in the risk groups, especially the asthmatic children and those suffering from chronic diseases of all kinds. Also, it is recommended to vaccinate healthy children between the ages of 6 months and five years and also school children in order to reduce as much as possible the severe morbidity of influenza. In recent years, the Ministry of Health recommends receiving a flu vaccine for the entire population, from the age of XNUMX months and older.
Is there any truth in the statement that the vaccine is ineffective and therefore there is no point in getting vaccinated?
The effectiveness of the vaccine depends on many variables, such as the age of the recipient of the vaccine, his basic state of health and the compatibility between the components of the vaccine and the virus common in the season. Under optimal conditions where the recipient of the vaccine is a healthy adult and there is a good match between the vaccine and the common virus of the season, the effectiveness of the vaccine is very good. It decreases when the recipient of the vaccine is very young or very old, when he suffers from a background illness and when there is no good match between the World Health Organization's forecast and the virus that ends up being common in the season.
Is there a difference between the effectiveness of the killed vaccine and the weakened live vaccine?
In preliminary clinical studies, it was found that in children the live attenuated vaccine was found to be about 50% more effective compared to the killed vaccine given by injection. In adults, it is found to have a similar effectiveness to the inactivated vaccine. However, as written above, in the last two years variable effectiveness was found against the H1N1 influenza strain and therefore in Israel and the USA a clear and declared priority was given to the inactivated vaccine in preventing the flu in the winter of battle.
When should you get vaccinated?
It makes sense to get vaccinated for the duration of flu activity. You can be vaccinated even after this date for the duration of the influenza activity, since the peak of morbidity sometimes even lasts until the months of February - March. It should be remembered that at least two weeks pass from the administration of the vaccine to the creation of a protective level of antibodies, hence the great importance of getting vaccinated before the start of the flu season.
"I got a flu shot and as a result I was sick!"??? Are the vaccines safe? The killed vaccine does not contain live viruses and therefore cannot cause the flu. An illness that appears close to the vaccination can be due to infection with one of the winter viruses or even infection with the flu that occurred close to the administration of the vaccine when the vaccine had not yet had time to create protection.
The side effects of the killed vaccine are mild and transient. The most common side effect, similar to other vaccines, is a transient local reaction at the injection site. There may be a side effect of a bad general feeling, muscle pain, etc., this side effect can last for about 48 hours, and cannot cause complications like the disease itself.
I heard that the flu vaccine can cause death, is there any truth in this?
This accusation stemmed, among other things, from a fear that deaths in Kiryat Gat about a decade ago occurred near the administration of flu vaccines. A comprehensive inspection by the Ministry of Health that was carried out as a result refuted this fear. In fact, not only does the vaccine not cause death, but it has been found to reduce mortality, not only directly from influenza and pneumonia, but also reduces morbidity and mortality from heart attacks and cerebrovascular events.
Can people who are sensitive to eggs be vaccinated against the flu?
It is worth noting that the ban on giving the (killed and weakened) flu vaccine to people who are sensitive to eggs has been lifted. It is known today that the concentration of egg protein in the flu vaccine is extremely minimal. In recent years, data has accumulated indicating that an allergic reaction following the administration of the flu vaccine is extremely rare and is not caused by the egg protein component of the vaccine. It is recommended not to vaccinate against the flu for those who have contracted Guyana Barre syndrome within 6 weeks of receiving a flu vaccine in the past.
I was vaccinated against the flu last year. Should I get vaccinated this year as well? Does the effectiveness of the vaccine wane towards the end of the flu season?
Indeed, it is recommended to get vaccinated every year. First, flu strains sometimes change from year to year and therefore the vaccine is updated accordingly. Second, even if you were vaccinated or got sick last year against the strains that will be present this year, the level of antibodies against these strains tends to wane over the course of the year, so it is necessary to give another dose of vaccine every year in order to renew protection against the flu.
Several reports hinted at a certain decrease in antibody levels and protection towards the end of the flu season. This finding has only been demonstrated in some studies. Administering the vaccine in October constitutes an adequate balance between the need to administer an early vaccine in preparation for the flu season, and maintaining a good level of protection throughout almost the entire flu season.
How many doses of vaccine are required?
Children up to the age of 8 who receive a flu vaccine for the first time in their lives will need two doses of the vaccine with a gap of at least 4 weeks between doses. It is sufficient to give a single vaccine dose to children up to the age of 9 years who have received at least 2 vaccine doses in the past (even if they were given in different flu seasons). The vaccine doses will be given with an interval of at least 4 weeks between doses. Above the age of 9 years, only one vaccine dose is necessary.
Do flu vaccines contain mercury or an adjuvant?
No. The flu vaccines (both the killed vaccine and the live attenuated vaccine) do not contain these substances.
I am a young and healthy person, why should I get vaccinated?
Being young and healthy does not make you immune to flu complications. Preventing the disease in healthy people is important on two levels: the first is the general level, even in a year when there is a normal disease, and "only" 10-15% of the population is infected, the disease still causes 10% of the general loss of working days. During the outbreak of a pandemic flu, such as the swine flu, it is expected that 50% of the population will be infected, which of course will greatly increase the economic damage to the economy. The second aspect is personal: although in most cases it is a mild disease, in some cases, even in young adults, without underlying diseases, severe complications and even deaths may occur.
Can pregnant women get vaccinated?
Yes and even recommended! The vaccine (inactivated only) is highly recommended for women who plan to conceive, pregnant women or in the postpartum period. Pregnant women are at increased risk of complications and hospitalizations due to the flu. Vaccinating a pregnant woman makes it possible to protect both the mother and the baby at the same time, and it has been found that vaccinating pregnant women significantly reduces the risk of premature births. The live attenuated vaccine must not be administered during pregnancy.
Why are school children vaccinated against the flu?
In the winter of 2016-17 school children will be vaccinated against the flu. In the first stage, second grade children will be vaccinated. The purpose of this program is twofold: first, to protect children from the flu and its complications, and second, through the children's vaccine to prevent the spread of the flu virus to at-risk populations such as the chronically ill and the elderly, since children tend to spread the virus more efficiently than other populations. The experience of vaccinating school children in England in the last two years has shown a decrease in the incidence of influenza and its complications among children as well as an indirect effect on the older population in reducing the complications of the flu.
