The first attempts to create a vaccine against hepatitis B have been made after one supervision made by Krugman with co-authors in 1971 Has been revealed that blood of chronic carriers, heated-up within 1 minute to 100 degrees protects from an infection. By such principle in 1982 in France (Gevak In) and the USA have been created the first plasma vaccines which prepared from blood (plasma) of chronic carriers of virus hepatitis of Century. And though such vaccines are still applied in some countries of the world, their distribution as a whole is insignificant and steadily decreases owing to clear fears concerning transfer with vaccines of HIV and other infectious agents.
Modern genetically engineered vaccines on the basis of technology of rekombinantny DNA have been developed in the early eighties and are applied since 1985. Advantage of such vaccines is total absence of products of blood in a production cycle, the low content of ballast substances and stable, precisely measured quantity of an active component. The main subtype of genetically engineered vaccines, so-called barmy vaccines are now in use. The vaccines of the second type preparing with use of modified cages of mammals (cellular vaccines), have essentially smaller distribution to force essentially higher prime cost.
Dosage of vaccines
Modern rekombinantny vaccines against hepatitis B consist of only one anti-gene - well-known according to very widespread analysis of "the Australian anti-gene", HBsAg. As the anti-gene is superficial, i.e. it is found on surfaces of a virus of the hepatitis B, the antibodies created by a vaccine to it, will be easily capable to attack and neutralise a virus at its hit in an organism.
Dosages of an anti-gene differ according to age of the imparted - usually it is 10 mkg for children from 0 to 15-19 years, 20 mkg for adults. For special category of patients, the patients receiving a hemodialysis, in a number of the countries vaccines with twice increased dosage - 40 mkg are available. In a number of vaccines non-standard dosages - 2,5 and 5,0 are applied to children; 10 mkg for teenagers and adults.
Features of introduction of vaccines
As well as any other vaccines containing a hydroxide of aluminium, a vaccine against hepatitis B should be entered strictly intramuscularly.
Introduction of vaccines against hepatitis B in buttock area extremely is not recommended for the reason that both at children, and at adults in this area the fatty layer is strongly expressed. In addition, much higher to injure risk large vessels and nerves. At children till 3 years an inoculation it is necessary to do a lateral surface of a leg (hip) as even at newborn children in this place the muscular layer is developed well. At children is more senior than 3 years and adults it is recommended to do an inoculation in a shoulder (a deltoid muscle) as the muscle lies directly under skin and its masses enough to enter necessary, though small (0,5 or 1,0 ml), vaccine volume.
The unique specific and absolute contra-indication for gepatitny In vaccines is the allergy to the products containing baking yeast - bread, kvass, beer, confectionery, etc. for the reason that at vaccines there can be sledovy quantities of yeast on which the anti-gen. is grown up.
In view of high cleaning, absence in preparations (even theoretically) live viruses and the minimum anti-gene loading of a vaccine against hepatitis B are not contraindicated to introduction during pregnancy and feeding by a breast.
As specific restriction to their application (in view of possible decrease in efficiency) the strong nedonoshennost (weight less than 1,5 kg) can serve. In such cases vaccination usually postpone till achievement by the child of weight of 2 kg.
All vaccines against hepatitis B are inaktivirovanny, i.e. unlike live vaccines they do not contain a live virus and consequently less, as a class, иммуногенны. The second moment - vaccines against hepatitis B consist of only one anti-gene that also is rather negative in respect of an immunogenicity a factor in comparison with inaktivirovanny vaccines on the basis of an integral virus (for example, against hepatitis A). In view of all these reasons for formation some inoculations according to the special scheme are required.
There are only two, irrespective of type gepatitny In vaccines, schemes of inoculations - standard 0-1-6 months and alternative 0-1-2 (with the first revaktsinatsiya 12 months later from the first inoculation) months. The main is the first scheme, the second is applied to the purposes of emergency prevention (for vaccination of children born from mothers carriers) and when fast protection against hepatitis B is required.
Interpretation of the standard scheme of vaccination looks so: the first inoculation in the chosen day, the second - in a month after the first, the third - in 6 months after the first or 5 months after the second.
Taking into account the minimum and maximum admissible intervals (within which total immunity does not change) between inoculations the standard scheme looks as follows: 0-1 (4)-6 (4-18) months. That is it is possible to do the second inoculation and 4 months later after the first. And a third - a minimum in four months after the second and even one and a half years later after the first.
It is necessary to make a reservation, however, that the scheme optimum and working under any circumstances remains standard - 0-1-6, to deviate from which without the need valid for that it is not necessary.
If time of the next inoculation has been passed, and all maximum intervals have been also exceeded, all other doses are entered with usual intervals, despite of the admission though in this case for confirmation of efficiency of vaccination on end of a course of inoculations the analysis of concentration of antibodies can be demanded.
Revaktsinatsiya (i.e. repeated inoculations through certain time after end of a course of inoculations) at the moment is not recommended for all imparted. However it can be demanded to persons with violations of immunity and to the patients receiving a hemodialysis, in view of fast loss of the antibodies created by an inoculation.
Modern vaccines against hepatitis B are characterised by exclusively high extent of cleaning, to 95 % of their volume is presented by an anti-gene. In addition, vaccines consist of only one anti-gene which contents is measured in micrograms. Both these a factor define that in practice of a vaccine against hepatitis B are one of the safest, "soft", easily being transferred.
The most typical collateral reactions to introduction of vaccines against hepatitis B are local reactions (i.e. arising in a prick place). Their frequency is rather standard for all available vaccines - to 10 % (at most) imparted note such reactions, as reddening, insignificant consolidation, discomfort at active movements. The prevalence of local reactions speaks action of a hydroxide of aluminium, substance which is specially intended to strengthen inflammatory reaction in a place of introduction of a preparation as much as possible immune cages проконтактировало with the entered anti-gene.
Essentially less often, with frequency about 1 % (at most - 5 %), at imparted are noted so-called general reactions, i.e. mentioning an organism as a whole - slight increase of body temperature, an easy indisposition, etc.
All listed reactions are normal (expected), are shown within 1-2 days from the moment of an inoculation and pass without treatment within 1-2 days.
llateral reactions and complications to inoculations against hepatitis B are extremely rare. In medical literature cases of the small tortoiseshell (1 on 100 thousand inoculations) are described, rashes (1 on 30 thousand), are even more rare - muscular or articulate pain and knotty эритемы.
Recently, according to recommendations of WHO and other foreign institutes all producers of vaccines against hepatitis B gradually pass to use of the lowered dosages (or complete refusal from) preservative in preparations that will allow to reduce even more risk of collateral reactions to inoculations.
Usual complications which can arise on any other inoculation anafilaktichesky shock, the small tortoiseshell (1 on 100 thousand inoculations), allergic rash (1:30000 inoculations). Persons with food allergy on yeast dough have (bread), its aggravation is possible.
Until recently discussions about communication of inoculations against hepatitis B and multiple sclerosis proceeded. In the final statement of WHO it is on this matter said that certificates of such communication are absent(!), as in one of the researches carried out under the aegis of WHO, the increased frequency of reactions it has not been revealed - frequency of multiple sclerosis among imparted did not exceed usual levels (1 on 300 thousand adults and on 1 million children). As a source for fears concerning multiple sclerosis the incorrect logic calculation according to which observed growth of relative number of a sclerosis among the imparted has been caused simply by increase in number of inoculations in the developed countries has served.
Real two ways of improvement of vaccines against hepatitis B - improvement of the vaccine and creation of the new combined vaccines on its basis are at the moment represented.
The first direction has had development still in the eighties when researchers of the company "Aventis Pasteur" have created essentially new gennoinzhenerny vaccine of Genhevac B ("женевак Б" or Gengevak In) which besides the "Australian" S-antigena, contains to two additional, related basic of an anti-gene - pre-S1 and S2 of a squirrel. Such strengthening of a preparation by additional proteins has allowed to increase essentially efficiency of vaccination and to reduce percent of those who does not answer with immunity formation standard vaccines. In addition, efficiency of a vaccine Gengevak In at its application in treatment of a chronic nositelstvo of a virus of hepatitis of V.Odnako in view of complexity of the technologies used at its creation has been shown, to limited capacity of production and, as a result, high cost of this vaccine, she has not received a wide circulation, having given way to more economic and rather effective barmy vaccines. Later, the English company Medeva has created analogue of a vaccine Gengevak In, but also this vaccine still has very limited distribution. Most likely, improvement of similar vaccines demands the solution of a question of decrease in expenses for their production and further studying of their efficiency in respect of hepatitis B treatment.
The second direction - creation of the combined preparations on the basis of vaccines against hepatitis B develops much more successfully. The last 10 years tens combined preparations on the basis of acellular and tselnokletochny AKDS-vaktsin and ADS - M-vaccines have been created. Their founders had to overcome a lot of hidden before the difficulties arising at a combination of various components - in particular mutual negative influence of a combination in one preparation koklyushny and gepatitny In vaccines. Undoubtedly, the best and most demanded achievement in this area was creation of 6-componental vaccines on the basis of acellular AAKDS-preparatov for vaccination of children at the age from 2 months till 6 years, in particular the French vaccine Geksavak (АаКДС+ХИБ+ИПВ+ГепВ).
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