[Results of a study of collective immunity to influenza A virus (H1N1) from 1976 to 1980]. / Itogi izucheniia kollektivnogo immuniteta k virusu grippa A (H1N1) v 1976--1980 gg.

The time course of the levels of circulating antihemagglutinins to influenza A (H1N1) virus in the populations of the towns in different geographical zones of the USSR was shown to be similar. The intensity of herd immunity in some areas differed considerably, however. The population of older age groups most of whom had no clinically manifest diseases during the influenza A (H1N1) epidemic was shown to experience immunological changes upon exposure to this agent. The intensity and the rate of changes in the immunological structure of this portion of the human population exceeded similar parameters among the subjects under 20 years of age who had experienced manifest forms of infection. Some people with immunological memory to influenza A (H1N1) virus developed antibody in response to infection or immunization with influenza A (H3N2) strains.

[Influenza vaccine stimulation of antibodies to different variants of influenza A virus]. / Stimuliatsiia grippoznymi vaktsinami antitel k razlichnym variantam virusa grippa A.

The capacity of live influenza type A (H3N2) vaccines to produce antihemagglutinins and antineuraminidase antibody to drift variants of a given serosubtype emerging later than the vaccine strain was studied. For this purpose, a wider set of antigens was used to examine retrospectively by the HI and virus elution from erythrocyte inhibition tests the paired sera from the subjects immunized in 1975 and 1976 with live vaccine virus strains similar to A/Port Chalmers/1/73 (H3N2) and A/Victoria/3/75. These vaccines were shown to actively stimulate antibody production in titres of 1:40 or higher to strains forestolling the vaccine strain by 1 (antihemagglutinins) and 2 (antineuraminidase antibody) degrees of the antigenic hierarchy. The intensity of production of both kinds of antibody to similar future strains depended on the intensity of immune response to the vaccine virus. By increasing the dose and frequency of administration of the virus serosubtype A (H3N2) to animals it was possible to intensify the production of antihemagglutinins and antineuraminidase antibodies to later drift variants of this agent with respect to the virus-immunogen. Volunteers immunized in 1983 with a commercial inactivated chromatographic bivaccine prepared from the strains similar to A/Bangkok/1/79 (H3N2) and A/Brazil/14/78 (H1N1) were found to intensively produce antihemagglutinins in titres of 1:40 or higher to viruses A/Philippines/2/84 (H3N2), A/Leningrad/167/83 (H3N2), A/Leningrad/3/82 (H1N1) but not to A/Dunedin/27/83 (H1N1) virus.

[Formation, persistence period and protective role of antihemagglutinins to earlier circulating influenza A viruses]. / Formirovanie, dlitel'nost' sokhraneniia i zashchitnaia rol' antigemagliutininov k ranee tsirkulirovavshim virusam grippa A.

Surveys of the population immunity as well as blood sera from human subjects vaccinated with vaccine strains done by the HI test showed the immunity to previously prevalent influenza A viruses to be maintained by anamnestic stimulation of immunogenesis occuring during circulation of the current agent. The intensity of anamnestic immunity stimulation is determined by the degree of relationship of the current strain hemagglutinin with the similar antigen of previously prevalent viruses. Circulating antibodies have a certain protective effect only against those influenza A viruses which are antigenically related within the drift alteration of hemagglutinin.

[Regularities of formation in a general population of serum antibodies to previously circulated influenza A viruses]. / Zakonomernosti obrazovaniia u naseleniia syvorotochnykh antitel k ranee tsirkulirovavshim virusam grippa A.

The spectrum of antibody production against hemagglutinin of all known influenza A virus serotypes after influenza A (H3N2) infection in persons of all age groups (from 1 month to 72 years) was analysed to investigated the regularities of accumulation of antibodies against influenza A viruses gone out of circulation. For the same purpose, a long-term (many years) longitudinal analysis of serum anti-HA antibody levels against "old" influenza A (HSW1N1), A (H0N1), A (H1N1), A (H2N2), and A (H3N2) viruses was carried out in children and adults of various age groups in 6 cities of different geographical regions of the country. Based on the results of the study, the concept of the "original antigenic sin" is analysed critically, and a new original concept on the regularities of antibody genesis against previously prevalent influenza A viruses and the factors affecting this process has been formulated.

[Indicators of collective immunity to influenza depending on the blood group and sex of the population]. / Pokazateli kollektivnogo immuniteta k grippu v zavisimosti ot gruppi krovi i pola obsleduemogo naseleniia.

Immunological investigations of the time course of serum anti-HA and anti-NA antibodies against influenza A and B viruses in the female and male population with blood groups 0(I), A(II), B(III), and AB(IV) were carried out for several months. The persons with the blood group AB (IV) were shown to be most sensitive to influenza A and B. They were affected by the epidemic virus earlier and more severely than those with the other blood groups. A special method is proposed for prediction of the etiology of the forthcoming epidemic. A correlation between blood groups and titres of anti-HA but not anti-NA antibodies was observed. The view on the lack of the genetic factor influence on the affliction with influenza and antibody response in persons of different sexes is substantiated.

[The role of antibody functional activity in the protection of people against influenza]. / Rol' funktsional'noi aktivnosti antitel v zashchishchennosti liudei ot grippa.

Indices of the functional activity of specific serum antibodies (IFAA) before and after outbreaks of influenza A (H3N2) and B were determined in 164 subjects of 18-20 years of age from the military communities observed in 1987-1988. The IFAA were calculated on the basis of kinetic HI tests followed by computer processing according to the program developed by the authors. The IFAA were found to indicate the protection of human subjects against influenza, reflecting the state of resistance to influenza more exactly than antibody titres. High initial IFAA correlated with lower severity of influenza infection. The IFAA to the same strain may differ significantly in individual subjects. In patients with influenza the time course of antibody titres did not coincide with dynamic changes in IFAA.

[Antibody functional activity in immunization with influenza vaccines]. / Funktsional'naia aktivnost' antitel pri immunizatsii grippoznymi vaktsinami.

The functional activity of serum antibody had been shown previously to reflect the state of resistance to influenza more accurately than antibody concentration. The functional activity of antibodies in the vaccination process was studied. The immune response to influenza antigens was found to be accompanied by an increase in the functional activity of antibodies, the intensity of this increase was the highest in natural influenza infection, moderate after administration of live vaccines and the least after immunization with inactivated preparations. The vaccine strains may differ significantly in their capacity to stimulate antibody with high functional activity. The quantitative parameters of the functional activity of antibody are directly related to the antigen dose and frequency of antigenic stimulation.

[The use of saliva for study in the immunoenzyme analysis of postvaccinal and postinfectious immunity to influenza]. / Ispol'zovanie sliuny dlia izucheniia v immunofermentnom analize postvaktsinal'nogo i postinfektsionnogo immuniteta k grippu.

Paired specimens of blood sera, upper respiratory tract secretions, and saliva from healthy, influenza-infected, and live influenza trivaccine-immunized humans were tested in parallel by HI tests and enzyme immunoassay (EIA). The resulting comparative data suggest that determination by EIA of specific secretory IgA in the saliva may be recommended as an independent test for large-scale influenza diagnosis, evaluation of the immune status of people, and trials of influenza vaccines. By immunologic parameters, this method is not inferior to the standard ones. At the same time its advantages include simplicity and readily available large volumes of saliva even from children as well as no necessity to bleed subjects to be examined.

[Immunological efficacy of smallpox vaccination in children with relative contraindications to vaccination]. / Izuchenie immunologicheskoi éffektivnosti protivoospennoi vaktsinatsii detei s otnositel'nymi protivopokazaniiami k privivkam

Children (aged from 3 to 9 years) vaccinated against smallpox by multiple puncture (3 punctures by bifurcation needle), by a single cut and with vaccine diluted with a double dose of the solvent were observed. Vaccination by the methods tested considerably diminished the vaccinal reactions and failed to influence appreciably the formation of a full-value humoral immunity; only dilution of the vaccination material reduced the dynamics of the immunogenesis at the early periods after the vaccination. In children aged 3--5 and 6--9 years general vaccinal reactions were of the same character, whereas local reactions and immunological response were more pronounced in older children. A method of multiple puncture is recommended for mass vaccinations and also for vaccination of children with relative contraindications to the vaccinations.

[Complex study of population immunity to 3 influenza A virus antigens]. / Kompleksnoe izuchenie populiatsionnogo immuniteta k trem antigenam virusa grippa A.

In 5 large cities of the USSR a four-year study of the population immunity to 3 antigens of influenza A virus (hemagglutinin, neuraminidase and ribonucleoprotein antigens) was carried out. The time course of immunity to these antigens had a similar character. The high level of population immunity to actual hemagglutinin and neuraminidase, observed for 2 years, in succession, indicated the possibility of shift-life changes in these surface antigens. Population immunity to ribonucleoproteid antigen had no influence on the epidemic process in influenza A. A method for the study of population immunity, based on the analysis of pooled serum samples from healthy persons, is proposed. This method considerably reduces the time of the test and the number of ingredients.

[Antigenic anachronism of the influenza A(H2N2) viruses in Leningrad in 1980. I. The epidemiological and serological characteristics of the influenzal infection caused by A/Leningrad/80 (H2N2) viruses]. / Antigennyi anakhronizm virusov grippa A(H2N2) v Leningrade v 1980 g. Soobshchenie I. Epidemiologicheskaia i serologicheskaia kharakteristika grippoznoi infektsii, vyzvannoi virusami A/Leningrad/80 (H2N2).

In April-May 1980 a number of unrelated outbreaks of influenza-like diseases were registered in Leningrad in an infant home (50 out of 68 children under observation, aged 3 months to 2 years, were affected) and among the pupils of a boarding school (13 out of 50 adolescents under observation, aged 15-17 years, were affected). 5 strains of influenza A virus were isolated from 3 sick children and 1 clinically healthy child. A similar virus was isolated from a sick adolescent in a boarding school, as well as from a female patient aged 24 years at a domiciliary focus of infection (a sporadic case). In the subsequent laboratory investigation all these 7 strains were identified as viruses A/H2N2. Isolated cases of seroconversion to hemagglutinin H2 were definitely registered in 6 patients during February--May 1980. In 3 cases, including the 24-year old female patient with an acute respiratory disease, seroconversion to hemagglutinin H2 was observed in combination with the release of influenza viruses A/H2N2 from these patients. 2 influenza virus strains with this antigenic characteristic were isolated from a young female patient at an interval of 3 days. Among the patients admitted to the clinics of the Research Institute of Influenza in Leningrad on account of acute respiratory diseases isolated cases of diagnostically significant seroconversion to hemagglutinin H2 constituted 3.5% among children and 4.5% among adults. The study of the level of antihemagglutinins in the population revealed that in 1980 persons aged 18-50 years showed a high level of antihemagglutinins.(ABSTRACT TRUNCATED AT 250 WORDS)

[Characteristics of the state the population's immunity in the influenza epidemic of 1977-1978]. / Kharakteristika sostoianiia populiatsionnogo immuniteta v épidemiiu grippa 1977--1978 gg.

During the influenza epidemic of 1977--1978, as well as during the epidemics of 1968 and 1972, the levels of population immunity proved to be a factor which led to the disappearance of the old antigenic variants of group A influenza virus from circulation. At the same time this factor had no influence on the regulating action affecting the selection of new strains. The appearance of the new antigenic variants of group A influenza virus in circulation seemed to depend mainly on the biological properties of the infective agent. The analysis of morbidity among different age groups suggests that immunity against influenza virus A (H1N1), which developed among the population in 1949--1956, determined to a certain extent, resistance to infection during the epidemic of 1977--1978.