Vaccination against poliomyelitis

The global task set by WHO - humanity must enter the third millennium of a new era without poliomyelitis - is still not fulfilled. The poliovirus vaccine has made it possible to achieve that type 2 poliovirus has not been registered since October 1999, and poliovirus type 3 in 2005 circulated in very limited areas in only 4 countries. 

The delay with the end of vaccination in the world is associated with two main factors. Inadequate vaccination coverage in the northern states of Nigeria in 2003-2004. Led to the spread of wild type 1 poliovirus in 18 countries. In 4 more countries it was brought from India, where in 2 states with a high population density oral polio vaccine does not give the desired effect, leading to only one dose of seroconversion in 10% of children. In 1997, 1997 cases were registered in 17 countries, in 1997 - 1315 in 12 countries, in 2008 (8 months) ~ 1088 in 14 countries (372 in India, 507 in Nigeria, 37 in Pakistan, 15 in Afghanistan) .

In Russia poliomyelitis caused by wild virus has not been registered since 1997. The problem is that vaccine viruses of poliomyelitis with reversion of virulent properties during passage through the human intestine (cvDPV) are circulating in populations with insufficient vaccination coverage and causing diseases. In 2000-2005, there were 6 outbreaks, in 2006-2007. - 4 more outbreaks (a total of 134 cases in 4 countries).

The vaccine virus of poliomyelitis persists for a long time in immunodeficient individuals (iVDPV), from 1961 to 2005. 28 such individuals were registered by WHO, 6 of them allocated a vaccine virus for more than 5 years, and 2 continue to allocate it to the present; in 2006-2007. In 20 countries, another 20 cases have been identified.

After the eradication of poliomyelitis with the simultaneous termination of the oral polio vaccination, the children's population is not immune, including to the revertants, which poses a huge risk of spreading the paralytic disease. WHO estimates the period of significant risk during which outbreaks occur, at 3-5 years, these outbreaks can be localized and eliminated using monovalent vaccines (mOPV) - they are more immunogenic and do not pose a risk of isolating vaccine viruses of a different type.

Such outbreaks can be avoided by switching to the use of IPV. WHO previously did not consider it advisable after the oral polio vaccine was discontinued to switch to the routine use of IPV, the question of the use of IPV in a residual foci of poliomyelitis or a mixed vaccination scheme is now being actively discussed; the effectiveness of IPV in developing countries was even higher than OPV. The widespread use of IPV in the world will cost even less than the current cost of intensive programs using oral polio vaccination, with the routine use of IPV vaccine will cost around $ 1 per child per year, which is available for the budgets of most countries.

In Russia, since 2008, all infants will be immunized with IPV, and OPV will be used only for revaccination. To reduce the circulation of vaccine viruses, it is important to completely stop using oral polio vaccine soon.

Preparations and indications for polio vaccination

IPV is used in infants for the main series of inoculations, oral polio vaccination - for revaccination. Non-vaccinated adults are vaccinated with OPV when leaving for endemic areas (minimum 4 weeks before departure).

Vaccines against poliomyelitis, registered in Russia

Vaccine	Content, preservative	Dosage
OPV - oral types 1, 2 and Z. FGUP PIPVEim. Chumakova RAMS, Russia	In 1 dose> 1 million inf. Units type 1 and 2,> 3 million type 3 Preservative - kanamycin	1 dose of 4 drops, 10 doses in 2 ml. Store at -20 ° 2 years, at 2-8 - 6 months.
Imovax Polio - inactivated reinforced (type 1,2,3) Sanofi Pasteur, France	1 dose - 0.5 ml. Preservative 2-phenoxyethanol (up to 5 μl and formaldehyde max 0.1 mg)	V / m 0,5. Store at T 2-8 °. Shelf life 1,5 years.
Pentaxim sanofi pasteur, France	Includes IPV Imovax Polio

Post-exposure prevention of poliomyelitis

The oral polio vaccine and 3.0-6.0 ml of human immunoglobulin normal to all unvaccinated (or with unknown status) contacts are injected into the poliomyelitis focus.

Dates, doses and methods of vaccination against poliomyelitis

Vaccinations begin at the age of 3 months three times with an interval of 6 weeks IPV; Revaccination - at 18 and 20 months, as well as at 14 years - an oral vaccination against poliomyelitis. If the intervals between the first vaccinations were significantly extended, the interval between the 3rd and 4th vaccinations can be shortened to 3 months. The dose of OPV produced domestically is 4 drops (0.2 ml) of the vaccine for admission. The opened vial should be used within 2 working days (if stored at 4-8 °, tightly closed with a dropper or rubber stopper). Both vaccines are combined with all other vaccines.

[10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20]

Immunity after vaccination against poliomyelitis

The primary course of IPV forms systemic and, to a lesser extent, local immunity in 96-100% of the vaccinated after 3 injections; IPV has advantages over OPV in terms of immunogenicity to poliovirus types 1 and 3. OPV is more active in forming local immunity.

IPV rarely causes a reaction with streptomycin allergies (rashes, hives, Quincke's edema ), even more rarely they occur after OPV. Vaccinated-associated poliomyelitis (VAP) occurs in both vaccinated OPV (up to 36 days) and in persons who have come into contact with grafted OPV (up to 60 days after contact), more often in children with humoral immunodeficiency: the gamma-globulin fraction of blood proteins is below 10% decrease in the level of all classes of immunoglobulins or only IgA. Flaccid paresis develops on the 5th day of the disease. Two thirds of children had a fever at the beginning of the disease, and one-third had intestinal syndrome. 80% of children with VAP had a spinal form, 20% had a common form. Flaccid paralysis with VAP persistent - are preserved when examined after 2 months from the onset of the disease and are accompanied by characteristic electromyographic data. The risk of VAP in the recipient, according to WHO estimates - 1: 2,400,000 - 1: 3,500,000 doses of OPV, the contact - 1:14 million doses; In the world, 500 such cases are recorded annually. According to studies, the frequency of VAP is much higher - in recipients of the order of 1: 113 000 first doses, in contacts - 1: 1.6 - 1: 2 million doses. It was the fight against the VAP that caused the developed countries to switch to IPV, the reduction in the number of cases of VAP in Russia in 2007 is a probable consequence of a partial transition to IPV.

Contraindications for polio vaccination

Contraindications to IPV - a documented allergy to streptomycin, the vaccine can be administered to children from HIV-infected mothers and immunodeficient. Contraindications to OPV are suspected of immunodeficiency and CNS disorders at the previous dose; in these cases, it is replaced by IPV.

[1], [2], [3], [4], [5], [6], [7], [8], [9]