Vaccination against influenza
Vaccination against influenza only since 2006 is included in the National Calendar. In Europe, there is a continuous record of cases of influenza, and although it is far from complete, an inoculation against influenza has led to a decrease in the incidence.
According to WHO, with annual epidemics of influenza, 5-10% of adults and 20-30% of children fall ill, 250 000-500 000 people die from this disease, economic damage amounts to 1 to 6 mln. dollars per 100 000 population.
A vaccine against influenza should be given to patients-chroniclers, who are often ill with ARI, children of preschool age. In the countries of Europe, the elderly, patients with cardiac, pulmonary (including bronchial asthma) and renal pathology, diabetes and people with immunosuppression are vaccinated. In the USA since 2008 Inoculation against influenza is older than 6 months. introduced into the National Calendar.
Influenza vaccination in children
Vaccination against influenza should be carried out in the first year, because at this age there is a high incidence and severe course. Thus, in the 2007/08 season, the share of children 0-2 years among those who developed the flu was 38.4%, 3-6 years - 43.5%, while schoolchildren only 14%, and adults - 2.8%. Among the children hospitalized with confirmed influenza, 50% were children under the age of 6 months, 2/3 - children under 1 year and 80% - up to 2 years. In another study, it was shown that of the number of children who are sick with influenza at the age of 2-5 years, every 250th, 6-24 months is hospitalized. - every 100th. and 0-6 months. - every 10th.. According to the combined data of the American Academy of Pediatrics, the hospitalization rate for this disease is 240-720 per 100 000 children 0-6 months. and 17-45 per 10, 00 children aged 2-5 years; 37% of those hospitalized were at risk - their hospitalization rate was 500 per 100 000.
And although the death rate of children is 1/10 of the death rate of older persons (0.1 and 1.0 per 100 000), a special study in the United States of this issue in 2004-2005. showed that the children of the first half of this indicator is 0.88 per 100 000.
Symptoms of influenza in young children often differ from the classical picture - high fever + intoxication + cough and runny nose. At this age, febrile convulsions are frequent against the background of fever, the flu often causes croup, bronchiolitis, exacerbation of asthma, often complicated by otitis media, sinusitis and pneumonia. The frequency of otitis media in children with influenza is 18-40% according to different tori, much more often in children under 2 years old. Complication of myocarditis, as well as from the nervous system - is not uncommon. So, in one of the studies of 842 children with confirmed laboratory flu in 72 there were neurological complications: encephalopathy in 10 children, febrile convulsions in 27 and afebrile - in 29, meningitis 2 and cerebral stroke due to hypotension - in 4.
Who should be vaccinated?
The contingents listed in the National Calendar do not include a number of groups whose flu vaccine gives a certain effect and can be recommended; The immunoprophylaxis calendar for epidemiological indications does not decode the risk groups. The recommendations in force in the United States are presented below, the flu shot should be administered to the following categories of people:
- Healthy children over the age of 6 months.
- Asthma and other chronic lung diseases such as cystic fibrosis.
- Diseases of the heart with hemodynamic disorders.
- Conditions that are fraught with impairment of respiratory functions (aspiration, sputum stasis) - epilepsy, neuromuscular diseases, spinal cord injuries, mental retardation
- Immunodeficiencies, including HIV infection.
- Sickle cell anemia and other hemoglobinopathies.
- Chronic kidney disease, metabolism, diabetes,
- Diseases requiring long-term therapy with acetylsalicylic acid (rheumatic diseases, Kawasaki syndrome) as prevention of Reye's syndrome.
- Family members and staff caring for children under the age of 5 (especially important for children under 6 months of age).
These recommendations, although they do not include such obvious risk groups as patients with organic lesions of the central nervous system, influenza causes long-term apnea, children with malformations of the lungs and bronchopulmonary dysplasia, are quite acceptable for our conditions. Of course, we should also recommend vaccination on an individual basis to all children and adults.
Vaccination against influenza for people with chronic diseases is safe. Published enough convincing work, allowing to vaccinate these contingents.
Contraindications to the vaccination against influenza
For all vaccines - an allergy to egg hen proteins, to aminoglycosides (for vaccines containing them), allergic reactions to the administration of any vaccine. Split- and subunit vaccination against influenza can be used in persons with chronic pathology, incl. with immune defects, pregnant and lactating women, patients with immunosuppressive therapy, combine with other vaccines (in different syringes). It is not recommended to vaccinate people who have undergone Guillain-Barre syndrome.
Contraindications for live vaccines - immunodeficiency states, immunosuppression, malignant neoplasms, rhinitis, pregnancy, intolerance of chicken protein. Temporary contraindications, as for inactivated vaccines, are acute diseases and exacerbations of chronic.
Vaccination reactions and complications
The live vaccine against influenza is slightly reactogenic, the temperature above 37.5 ° in the first 3 days is allowed for no more than 2% of the vaccinated. When subcutaneous injection of whole-cell vaccines, it is allowed to develop a short-term temperature above 37.5 ° or infiltrates up to 50 mm in no more than 3% of the vaccinated. With their intranasal administration, subfebrile within 1 to 3 days is allowed for no more than 2% of the vaccinated.
Subunit and split vaccines give weak short-term (48-72 hours) reactions in no more than 3% of the vaccinated. The least reactogenic according to international independent studies are subunit vaccines. Clinical experience confirms the low reactogenicity of inactivated sipit and subadynamic vaccines and in children even in the second half of life. The largest amount (about 7, 00 doses) of vaccine safety is from the United States. There are observations that the vaccine against influenza is safe in children in the first half of the year.
Rare cases of vasculitis are described. Observations in England for 34 000 vaccinated with different vaccines (of which 75% with chronic pathology) showed a low incidence of all and allergic reactions (in total, within 1-3% for different vaccines).
Rare, immediate reactions after the vaccine against influenza Grippol was introduced in 2006. in the subsequent, they were practically not repeated.
Vaccines against influenza
The vaccine against influenza is prepared from the current strains of A / H1N1 /, A / H3N2 / and B viruses, recommended annually by WHO. Vaccination against influenza is carried out in the autumn, preferably before the onset of morbidity.
Instead of the previously released anti-influenza gamma globulin, a normal human immunoglobulin is used in a doubled dosage.
Currently, a vaccine against influenza is being tested, which is based not on hemagglutinin and neuraminidase, but on the matrix protein 1 and virion nucleoprotein that do not mutate; if successful, there will be no need for an annual vaccination.
Live vaccines are made from attenuated strains of the virus (adapted to cold mutants), they are able to produce local immunity (production of IgA antibodies) with intranasal administration. In the USA, where a live vaccine has been used since 5 years, incl. in children with asthma, it is shown to be more effective than the inactivated vaccine against A / H1N1 and B.
Allantoin intranasal live flu vaccine is dry for children aged 3 years and adults (Microgen, Russia) - lyophilizate for solution preparation. The contents of the ampoule are dissolved in 0.5 ml (1 dose) of boiled water (cooled). The age-appropriate vaccine is administered once in 0.25 ml in each nasal passage to a depth of 0.5 cm. attached by the spray dispenser type RD single use.
Vaccination against influenza is weakly reactogenic. Storage of drugs at a temperature of 2 to 8. Shelf life - 1 year.
Inactivated all-virion vaccination against influenza is used in children older than 7 years and adults. It is a purified virus, cultured on chick embryos, inactivated by UV irradiation.
Grippovak (NIIVS, Russia) contains in 1 ml of 20 μg hemagglutinin subtypes A and 26 μg B. Preservative - merthiolate. Form release: 1 ml ampoules (2 doses), vials of 40 or 100 doses. Store at 2-8 °. Introduced to children from 7 years and adolescents intranasal (spray RDZH-M4) to 0.25 ml in each nasal passage twice with an interval 3-4 weeks, adults - from 18 years - intranasal in the same scheme or parenterally (SC) once in a dose of 0.5 ml.
Vaccination against influenza inactivated eluate-centrifuge liquid (Russia) - is applied according to the same scheme as Grippovac
Subunit and split vaccines are used in children older than 6 months, adolescents and Roslyh. Children vaccinated for the first time and neoblevshim influenza, as well as patients with immunodeficiency is recommended to enter 2 doses with an interval of 4 weeks, in subsequent years - once. With the introduction of 1 dose in the spring and one fall, the vaccines are less immunogenic
A vaccine against influenza is injected intramuscularly or deeply subcutaneously into the upper third of the outer surface of the shoulder. The vaccines are stored at 2-8 °. Shelf life 12-18 months.
Subunit and split vaccines registered in Russia
|Vaccination against influenza||Composition, preservative||Doses and methods of vaccination|
5 μg of 2 strains of A and 11 μg of strain B, + polyoxidonium of 500 μg, merthiolate. Ampoules 0.5 ml
Children 6 months - 3 years 2-fold to 0.25 ml with an interval of 4 weeks. over 3 years - 0.5 ml each 1 time.
Polymer-subunit - Petrovax FC, Russia
5 μg 2 strains A and B (Solvay Biolodzh.) + Polyoxidonium 500 μg, without preservative. Syringe, amp., 0.5 ml bottles
Children over 3 years and adults at 1 dose (0.5 ml) once
Agrippal S1 - Subunit, Novartis Vaccine and Diagnostics Srl, Italy
15 mcg 3 strains, without cone. Syringe-dose.
Children older than 3 years and adults 1 dose (0.5 ml) once, up to 3 years - 1/2 dose (0.25 ml) - vaccinated for the first time and not sick of the flu - 2 times after 1 month.
Begrivak Split, New Artis Vaccine, Germany
15 mcg 3 strains, without preservative. Syringe-dose
Vaxigrip Split, sanofi pasteur, France
For 15 mcg 3 strains, no preservative. Syringe doses, amp. 0.5 ml, 10 dose vials
Children under 9 years 2-fold, 0.25 ml (up to 3 years) or 0.5 ml (3-8 years); > 9 years - 1 dose of 0.5 ml.
Subunit, Berna Biotech, Switzerland
For 15 μg 3 strains; virosomes mimic the virion. Without preservatives, formaldehyde and antibiotics
Children older than 3 years and adults - 0.5 ml IM or deeply n / k, children from 6 months. up to 3 years in 0.25 ml (previously not vaccinated with 2 doses).
Subunit, Solvay Pharma, The Netherlands
15 mcg 3 strains, free of preservatives and antibiotics. Self-destroying syringe-dose.
Persons> 14 years 0.5 ml. Children
Fluarix Split, SmithKlein Forms. GmbH, KG, Germany
15 μg 3 strains, traces of merthiolate and formaldehyde. Syringe-dose.
Children over 6 years of 0.5 ml once, 6 months - 6 years - 0.25 ml 2-fold
A cell culture-grown subunit vaccine against influenza On-taflu, Novartis Vaccine and Diagnosis GmbH, FRG and Split Vaccine FluvaxiN, ChangchukLife Science Ltd., China, is registered.
A vaccine against influenza is not active against avian influenza viruses and possible future mutants. Vaccines from "avian" strains in case of an epidemic have been created in Russia and other countries.
Is the flu vaccine effective?
The vaccination against influenza develops immunity 14 days after the injection, but in children who did not previously have contact with the virus, this requires 2 doses of the vaccine administered at intervals of 4-6 weeks. Immunity is type-specific; Vaccination against influenza should be carried out every year, since there is an antigenic drift of strains of viruses, as well as its short duration (6-12 months), even if its strain composition, in comparison with the previous season, has not changed.
Vaccination against influenza has a prophylactic efficacy against a laboratory-confirmed disease of 60-90%, although the degree of protection in children and the elderly is considered to be lower. When infected with strains of the virus, different from vaccine, the effectiveness is reduced; although the disease in vaccinated flows more easily, but the incidence of influenza and mortality remain above the epidemic threshold.
Vaccination against influenza is the most effective method of reducing the incidence of influenza and mortality from it both among the general population and at risk groups. A vaccination against influenza reduces the hospitalization of children aged 6-23 months. (who received 2 doses of the vaccine) by 75%, and mortality by 41%, and the protective effect of the vaccination, carried out for 2 years or more, is much higher than the one-time before the epidemic. Among adults with community-acquired pneumonia vaccinated against influenza, during the influenza season, mortality was lower - RR 0.3 (0.22-0.41). Especially pronounced effect among the elderly: for 10 seasons, the relative risk of pneumonia was 0.73 and death - 0.52.
Vaccination against influenza also reduces the incidence of children with acute otitis media (by 2.3-5.2%) and exudative otitis media (by 22.8-31.1%). Vaccination against influenza reduces the frequency of all ARI.
To protect children of the first half of this disease, the effect of vaccination of pregnant women is studied. Data from Bangladesh showed that this flu shot has an efficacy of 63%: up to the age of 24 weeks, 4% of children were infected with influenza, compared to 10% in controls. In addition, the frequency of febrile ARI decreased by 29%.
The problem of bird flu
The highly pathogenic avian influenza virus (H5N1) multiplies in the intestines of birds - its neuraminidase N1 is resistant to acidic medium, and haemagglutinin H5 recognizes epithelial receptors containing sialic acids characteristic of birds. There are few such receptors (therefore people rarely get sick), but the trachea of pigs contains both types of sialic acids, which makes them the main "mixer" of viruses. Mass transmission from a person to a person is possible only if the specificity of the hemagglutinin of the avian virus changes.
Vaccination against influenza should be performed before the beginning of the cold season. During the epidemic, interferon-a-nasal drops of Alfaron, Grippferon (1, 00 U / ml) and in aeozoles are used: children 0-1 years, 1 drop (, 00 ME); 1-14 years old - 2 each, older than 14 years and adults - 3 drops 2 times a day for 5-7 days (in contact with a sick person) or an age-related dose in the morning every 1-2 days (during the epidemic season). The same scheme uses Viferon 1 candles. Interferon-gamma (Ingaron - 100 000 ME in a vial, diluted in 5 liters of water) for children over 7 years and adults for 2 drops in the nose: in contact with a sick flu - once, in the season of epidemics - 2-3 drops 30 minutes before meals after the toilet of the nose 1 time every other day 10 days (repeated course if necessary - after 2 weeks).
For prevention in adults and children older than 1 year, use rimantadine (tablets 50 mg, 2% syrup for children Algeria with sodium alginate), although the virus A1 has become resistant to it. Doses of rimantadine: 100 mg / day (children 7-10 years), 150 mg / day (children over 10 years and adults); Algirem: children 1-3 years 10 ml (20 mg) children 3-7 years - 15 ml: (30 mg) - once a day for 10-15 days. Similar effect in Arbidol - according to the same scheme: children 2-6 years - 0.05, 6-12 years - 0.1, over 12 years - 0.2 g.
The neuraminidase inhibitor oseltamivir (Tamiflu) is approved for the treatment and prevention of influenza A and B from 1 g. When administered within 36 hours after contact with the patient, warns of influenza in 80%, is active with avian flu (but not with ARVI). Prophylactic dose for children 1-2 mg / kg / day, for adults - 75-150 mg / day - 7 days after contact or up to 6 weeks during the epidemic. Zanamivir (Relenza in an aerosol is used from the age of 5 years for 2 inhalations 2 times a day (total 10 mg / day) treatment and prevention.
Vaccination against influenza in people with chronic diseases
Vaccination against influenza in the form of split and subunit vaccines has shown its effectiveness and safety when administered to patients with severe pathology (asthma, leukemia, liver transplant recipients, diabetes, multiple sclerosis, etc.). Clinical experience of vaccination of more than , 00 children, 31 of them with various pathologies, showed its safety and effectiveness.
Vaccination against influenza - contraindications
The flu epidemic has become habitual for a long time, and preparation for it has turned into something self-evident. Even children know how important prevention is. It is also well known that one of the best means for preventing influenza is vaccination. And only those who directly faced the problem know that the flu vaccine is not universal - it has contraindications. That is, not everyone can protect themselves from the disease with the help of a vaccine. More details about the negative aspects of vaccination against influenza will be described in the article.
Side effects of vaccination against influenza
Vaccines against influenza are of different types:
- Injection is more popular. There are no live viruses, but it gets into the body thanks to a shot.
- The second type of vaccine is aerosol. This means contains live viruses. Weakened, they do not pose a threat to the body, but contribute to the development of strong immunity.
Like any other vaccine, a flu shot can cause side effects. Different organisms perceive vaccination in their own way. The most frequent negative manifestations of vaccination are the following:
- Immediately after vaccination a person can feel weakness, fatigue, drowsiness. Sometimes the patient is tormented by fever and fever.
- Many people get a headache after the vaccination.
- One of the most unpleasant consequences of vaccination is a runny nose or a pharyngitis.
- The most serious and harmful complication of vaccination against influenza is anaphylactic shock. Fortunately, this side effect is extremely rare.
- A fairly frequent unpleasant consequence of vaccination is pain, swelling and redness at the injection site.
Most of the side effects the patient forgets about a couple of days after the vaccination. And in order to avoid more serious and complex consequences, it is necessary to get acquainted with the list of contraindications before vaccination.
Who is against the flu vaccine?
Despite the large number of benefits, some groups of patients may not be vaccinated against influenza. An alternative method of protection against a disease is recommended in the following cases:
- First, it is strictly forbidden to get a flu shot from people suffering from colds or ARVI. Vaccination is allowed at least a month after recovery.
- Secondly, an inoculation against influenza is contraindicated to people with an allergy to chicken protein.
- Specialists are in no hurry to vaccinate patients who did not have a good previous vaccination.
- This method of preventing influenza is not recommended for people with diseases of the nervous and endocrine systems.
- Additionally, patients suffering from kidney and adrenal problems should consult.
- Vaccination against influenza Grippol and its analogs are contraindicated for chronic diseases of the lungs, bronchi and upper respiratory tract.
- You can not vaccinate babies.
- Asthma, anemia, hypertension and general cardiacInsufficiency can also serve as a contraindication to vaccination.
As you can see, there are a lot of contraindications to vaccination against influenza for adults. Therefore, in order to really benefit the vaccination, the procedure must necessarily be consulted with specialists and with understanding to treat their detailed inquiries about the state of health and the transferred diseases.
Do not forget that the vaccine is not a panacea. To completely protect yourself against the flu, you need to lead a healthy lifestyle, for the time of the epidemic, to supplement your diet with nutritious foods, fruits and vegetables.
Is it worth it for an adult to get a flu shot?
The protective effect of vaccinations persists for at least one year, and after two to three years of consistent vaccination - for two years or more. However, there is one "but" - the flu virus easily mutates, and now there are several of its varieties. The introduced vaccine creates immunity only against one particular species. In addition, a person may well become infected not dominant in this season, but another kind of infection. Which also spreads, albeit in smaller numbers, and is looking for a "victim." Therefore, the effectiveness of vaccination, according to various estimates, does not exceed 50-60%.
Do not forget about the adverse reactions that may occur with the use of vaccines: Local reactions are the most common effects. They are expressed in the form of redness at the injection site. These are short-term events that usually take place within 1-2 days. Nonspecific systemic reactions include fever, chills, malaise and myalgia. Usually occur 6-12 hours after vaccination and last no more than 1-2 days. Hypersensitivity is a rare reaction, which is supposedly allergic in nature.
Serious contraindications for vaccinations are the following:
allergy to chicken protein;
diffuse connective tissue diseases;
adrenal gland diseases;
diseases of the nervous system;
chronic diseases of the lungs and upper respiratory tract;
cardiovascular insufficiency and hypertension II and III stages;
disease of the endocrine system;
Risk groups: small children and the elderly, as well as patients with chronic cardiovascular and broncho-pulmonary diseases. These patients often exacerbate their chronic diseases: rheumatism, tuberculosis, bronchitis and others. Of course, complications can occur in any other person. But, as a rule, in the event that he does not comply with bed rest and recommendations of a doctor. In order to decide whether or not to be vaccinated against influenza, the first thing to objectively assess the likelihood of infection with the flu is you. If you are at risk and the danger is high enough, you should consider whether there are any possible complications in your case. If they are very likely, go straight to your doctor about whether you can inject a flu vaccine. In the case of a negative answer, you will not have to think about anything. In the case of a positive doctor's answer, weigh all the pros and cons and make a decision.
Well, if you do not belong to the risk group, and complications are unlikely - do not overtake fear. And then you can and "get scared" get sick.
at your discretion.
it's your decision. My mother-in-law does every year, says she is less sick. Daughters do at school, sick for the whole school. year about 2-3 times. I never did myself, but if I start to get sick, then the cold usually shows up. I have not yet had the choice to do or not, but I think that I will try, when they offer and compare before and after
* MAD *
I never did, because I think this shit is crap.. Those who at least once did or made it was pleasant to a flu (I about those whom I know)
not worth it
Here the question is ambiguous. If you can know exactly what kind of vaccination. whose production, as in what terms and under what conditions they will do, it certainly stands. Provided that you do not abuse them now and do not feel well. In this state, the vaccine can not be done, and even there are many contraindications, you should explain everything. Because when we get vaccinated, it seems like nothing terrible, made a shot and went, and it's not. When we were with children abroad, we had to get them vaccinated, so they pre-donated a lot of tests, watched us for almost a week, for our well-being, and these vaccinations are of different production, and there are kotorey calculated for 4 doses, that is, as soon as the ampoule is opened, should be immediately used, and not so keep open until the next patient. If you can control all this, then of course it is worth doing, the flu is now such that it is not so scary as the consequences after it ...
Who should not get a flu shot
Opponents of the vaccination believe that it is possible to get rid of it from the flu. But this is just an absurd delusion. The vaccine itself can neither provoke its outbreak nor aggravate the disease if the vaccinated person is still clotted. On the contrary, it is transferred easier, passes faster and does not end with complications. True, vaccination would be the best protection against influenza, if not for some contraindications that limit its use.
Contra-indications for adults
If, for example, you transferred the flu vaccine last year badly, then it is clearly contraindicated to you. And it is better not to experiment, making repeated attempts.
All types of influenza vaccines are made on the basis of chicken protein. If you do not eat eggs of chickens, because they cause you to have allergic reactions, you will have to refuse vaccinations once and for all.
Some vaccines include antibiotics such as "Polymyxin" or "Gentamicin", "Neomycin" (and others of this series), as well as formaldehyde, octoxynol-9. They can cause the strongest allergy. These drugs, of course, are absolutely contraindicated to such a category of patients.
As for allergies, if the painful reactions occurred earlier on vaccinations against any other diseases, this type of prevention will have to be excluded.
The vaccine "Grippovac" has its own contraindications. These are immunodeficient conditions, cancerous tumors, diffuse connective tissue diseases (lupus erythematosus, scleroderma, etc.), severe diseases of the nervous system, adrenal lesions. Live vaccines that are introduced into the nasal cavity, in addition to all this, are contraindicated in pregnancy.
The patient at the time of vaccination should feel relatively healthy. You can not do it, if you experience malaise, the temperature is slightly increased, there are signs of a cold, even a slight rhinitis. Of course, vaccination is out of the question for acute infection.
Exacerbation of chronic diseases is also a contraindication, but temporary. Vaccination can be started as soon as it subsides or recuperation occurs. The vaccine should be determined only by a doctor.
Very rarely after the introduction of the vaccine, Guillain-Barre syndrome develops. This is an acute polyradiculitis with a partial loss of muscle sensitivity and restriction of movements. If it does not pass for a month and a half, vaccination should not be done.
There are diseases in which the issue of influenza vaccination in each case must be addressed with a doctor. Much depends on the stage of the disease, the severity of its course, complications. This bronchial asthma, hypertension, heart failure, kidney damage, diabetes, blood diseases.
Contraindications for children
You can not vaccinate against the flu of babies who have not turned six months old. But babies from 6 months to 2 years should be vaccinated, because at this age they do not yet have a stable immunity against viruses.
As adults, children are not allowed to be vaccinated for allergies to chicken protein, as well as for pseudo-allergy to cold. The introduction of the vaccine is excluded and with Guillain-Barre syndrome. Do not vaccinate children if they have had adverse reactions after previous vaccinations, even if they are very poorly expressed.
Check with your doctor
To vaccinate has only benefited, before doing it, consult your therapist. Did you have a good vaccination last year? But in a year a lot can change. And it is better to make sure that you do not have contraindications.
Can I get cold after flu vaccination?
you can do different things
Yeah you can get sick, but not deadly, but you can
as a rule, it happens
I was sick after a recent vaccination. so it should be like
read) the vaccine contains a strain of influenza, that is, contains antibodies that your body perceives as strangers and begins to destroy, and then if the flu does not progressively mutate (not a fact yet) you will not have the flu, so the catarrhal condition is the very fight of your body's antibodies with influenza antigens, thereby developing artificial immunity to influenza
Yes, you can get sick not only with a cold, but also with the flu.
The strains of the influenza virus about 200, in the vaccine contain about 15.
But even if you become infected with a species that is not included in the vaccine, it is easier to transfer.
Easily. Even the flu can get sick, -gave immunity to viruses that cause a certain form of flu. And in nature, the human influenza virus is prone to transformation, and new forms are emerging. However, vaccination is more reliable, before vaccination, scientists calculate what form of the virus threatens us at a particular time. Forgive me, which I explained simply and in a philistine way. Do not be ill!!!
You can, of course, can even pick up the flu and it will be with complications.
of course it is possible