scholarly journals A survey of examining herd measles immunity in adults over 35 years old

2020 ◽  
Vol 10 (2) ◽  
pp. 381-386 ◽  
Author(s):  
L. V. Rubis
Keyword(s):  
Measles Virus ◽  
High Titer ◽  
Herd Immunity ◽  
Age Groups ◽  
High Risk Group ◽  
Protective Level ◽  
Protective Antibody ◽  
The Republic ◽  
High Level ◽  
Post Infectious

A high measles incidence rate has been registered in Russia in recent years, with adults being actively involved in the epidemic process (about 40% of patients), thereby underlying relevance of assessing herd immunity in different  age groups to measure its risk. The data on examining serum antibodies to measles virus in 402 residents of Petrozavodsk are shown: 164 and 238 subjects were born in 1948–1968 (51–71 years) and 1970–1983 (36–50 years), respectively. It was found that the second group had significantly higher percentage not only of seropositive persons (94.1±1.5 vs. 77.4±3.3%, respectively), but also frequency of detected high IgG level (5 and more IU/l) reaching 39.7±3.5 vs. 15.4±5.8%, respectively. Analysis of vaccination history showed that of 351 people with protective antibody levels, 20.9% were vaccinated once or twice, 14 of them in childhood and 63 within the 15 years prior to the study. Of the 51 people with no measles antibodies or below protective level, 13.7% were vaccinated: five in childhood, and two within the last 15 years. Among those who was born in 1948–1968, 87.1±2.2% provided no information about previous vaccinations and probably were not vaccinated. In this group, percentage of those examined with a protective antibody level was significantly higher than in the 36–50 years group — 87.1±2.2 and 62.2±4.3%, respectively. In addition, 23 subjects confirmed that they recovered after measles in childhood. Of these, antibodies were detected in 21 subjects, including 9 having serum titer at level of 5 or more IU/ml. Until 1969, the Republic of Karelia registered a high level of measles morbidity (477–2176,0 per 100 thousand). The predominance in the group born before 1969, individuals seropositive to measles mainly at high titer, indicates that intense post-infectious immunity was preserved. The lack of protective level of antibodies to measles virus in 22.6% of persons aged 36–50 years (1969–1983 year of birth), due to the low level of post-infectious and insufficient durability of post-vaccination immunity allowing to definer them as a high risk group for measles infection.

scholarly journals A herd immunity to measles and rubella viruses in the population of the Republic of Serbia

2021 ◽  
Vol 11 (1) ◽  
pp. 171-176
Author(s):  
M. A. Bichurina ◽  
S. Filipovic-Vignjevic ◽  
A. Yu. Antipova ◽  
M. Bancevic ◽  
I. N. Lavrentieva
Keyword(s):  
Measles Virus ◽  
Herd Immunity ◽  
Age Groups ◽  
Age Group ◽  
Igg Antibodies ◽  
Mmr Vaccine ◽  
Igg Antibody ◽  
Group I ◽  
Study Results ◽  
The Republic

According to the WHO Strategic Plan, measles should be eradicated in 2020 in the five WHO Regions including European Region. However, large measles outbreaks are being periodically registered in diverse European countries. In the Republic of Serbia (SRB), 5,076 measles cases were detected in 2018, among which 15 cases were fatal.Aim of the study was to examine herd immunity to measles and rubella viruses in the population of the Republic of Serbia.Materials and methods. Blood serum samples obtained in 2018 and 2019 from conditionally healthy residents of the Republic of Serbia were tested for the presence of IgG antibodies to measles and rubella viruses in five age groups: I — children from 2 to 6 years old, II — children from 8 to 14 years old, III — 15 to 24 years old, IV — 25 to 49 years old and V — over 50 years old. A total of 1000 samples were obtained, 200 sera in each group. Enzygnost® Anti-Measles virus/IgG and Enzygnost® Anti-Rubella virus/IgG ELISA test systems (Siemens Healthcare Diagnostics Products GmbH, Germany) were used according to the manufacturer's instructions.Results. Overall, around 23.0% and 33.7% of the surveyed persons had no or low level of anti-measles IgG antibody (≥ 275.0 — ≤ 1000.0 IU/1). In age group I, 60% children contained no or “low” anti-measles antibodies titer (29.5% and 30.5%, respectively). In addition, low antibody titer level was mainly detected in individuals from age group II and III (p < 0.05). A third of children under 8—14 contained high IgG-antibodies titer against measles (> 3000.0 IU/l) that might serve as an evidence that such subjects recently recovered after measles. Similar results were obtained for IgG antibodies to rubella in the same age groups.Discussion. The study results evidence about altered routine immunization against measles and rubella in children aged 12—15 months (first vaccination) and those at age of 6—7 years (revaccination) with MMR vaccine. The data obtained correlate with official data on coverage with measles and rubella vaccines in the Republic of Serbia.

scholarly journals Pattern of resilient age-related measles immunity

2020 ◽  
Vol 10 (2) ◽  
pp. 375-380
Author(s):  
A. G. Sonis ◽  
O. A. Gusyakova ◽  
F. N. Gilmiyarova ◽  
A. A. Ereshchenko ◽  
N. K. Ignatova ◽  
...  
Keyword(s):  
Measles Virus ◽  
Age Groups ◽  
Igg Antibody ◽  
Infection Level ◽  
Age Related ◽  
Specific Igg ◽  
Young Subjects ◽  
High Level ◽  
Medical University ◽  
Igg Level

Epidemiological situation describing global measles spread is ambiguous. Along with countries succeeded in measles eradication, there are those wherein measles rate remains at quite high level. Because measles is a vaccine-preventable infection, it may then be eradicated solely by ensuring sufficient population coverage with preventive vaccination. The aim of our study was to assess level of measles immunity in medical workers at the Clinics of Samara State Medical University as well as the Samara State Medical University. There were enrolled 1503 subjects (aged 18–79 years), among which all individuals under 55 (77.58%) but not older counterparts provided with medical record on previous measles vaccination or measles infection. Level of serum measles virus-specific IgG antibodies was measured by using ELISA (VektoKor-IgG, JSC Vector-Best, Novosibirsk), with mean concentration ranging in general population within 1.02±0.02 IU/ ml. Positive results were observed in 72.52% of the examined individuals. Average vs. high measles virus-specific IgG level was detected in 52.90% (mean age — 41.4±0.5 years) and 19.62% (mean age — 54.2±0.72 years) of individuals, whereas at level below threshold — in 27.48% of subjects (mean age — 33.25±0.53 years). Thus, in 34.16% of the surveyed vaccinated individuals mostly presented by young subjects contained anti-measles virus-specific antibodies below protective level. Older age groups were shown to increase in average IgG amount with age. Interestingly, age-related measles immunity pattern was observed: percentage of subjects with high vs. low measles virus-specific IgG level increases and decreases, respectively. Taking into consideration a large percentage of subjects previously vaccinated against measles among carriers of low measles immunity, it may be concluded that measles virus-specific IgG antibody level must be monitored in young adulthood to decide of whether subsequent revaccination is necessary.

scholarly journals Detection of measles cases in the Republic of Guinea in 2017–2018

2020 ◽  
Vol 10 (3) ◽  
pp. 570-574
Author(s):  
I. N. Lavrentieva ◽  
M. A. Bichurina ◽  
A. Y. Antipova ◽  
J. Camara ◽  
N.F. Magassouba
Keyword(s):  
Antibody Level ◽  
Measles Virus ◽  
Age Groups ◽  
Cold Chain ◽  
Epidemiological Surveillance ◽  
Serum Samples ◽  
Igg Antibody ◽  
Republic Of Guinea ◽  
Measles Vaccination ◽  
The Republic

In 2017, WHO reported 596 confirmed measles cases in Guinea Republic connected to the 2016–2017 epidemic outbreak that was stopped after additional immunization (SIA) against measles in two provinces of the country. Improving the effectiveness of SIA is associated with the identification of epidemiologically significant groups of the population. The aim of the study was to analyze 2017–2018 measles cases and assess population immunity to measles virus in the Republic of Guinea. Materials and methods. A total of 810 blood serum samples collected from patients with maculo-papular rash and clinical diagnosis “measles?” were tested for measles virus-specific IgM-and IgG antibody level. 445 sera of conditionally healthy individuals aged 7 months to 67 years were examined for anti-measles virus IgG antibody level. Immunoglobulins of classes M and G were detected by ELISA with test systems «Anti-Measles Virus ELISA (IgM)» (Euro immun, Germany) and «Anti-Measles Virus ELISA (IgG)» (Euroimmun, Germany). Results and discussion.In 2017–2018, the epidemic process of the measles in the Republic of Guinea proceeded very intensively, being markedly prevalent in children among age groups. In 2018, more than half of the cases (61.6%) were identified in children aged 1 to 5 years old; the second most abundant age group was children under one year (18.6%), probably due to violated measles vaccination, which in GR are subject to children of nine months of age. It was found that 16.4% of patients (60 out of 366) had documented data on measles vaccination. Potentially, high proportion of measles cases among pre-vaccinated subjects was due to insufficient immune response to a single immunization in children of 9 months of age. Moreover, lowered vaccine-related properties might also be violated “cold chain” during vaccine transportation occurring in tropical climate. Analyzing 445 subjects revealed that total number of measles virus seronegative subjects was 8.3%. However, the vast majority of them were children and young adults aged 7 months to 22 years, where 52.4% of seronegative subjects were identified. Thus, the data obtained indicate that intensive measles virus circulation in human population was continued that necessitate interventions for improving epidemiological surveillance, extend routine measles vaccination coverage and conduct SIAs against measles in GR.

scholarly journals Combining serological and contact data to derive target immunity levels for achieving and maintaining measles elimination

BMC Medicine ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Sebastian Funk ◽  
Jennifer K. Knapp ◽  
Emmaculate Lebo ◽  
Susan E. Reef ◽  
Alya J. Dabbagh ◽  
...  
Keyword(s):  
Measles Virus ◽  
Herd Immunity ◽  
Age Groups ◽  
Threshold Level ◽  
Specific Immunity ◽  
Measles Elimination ◽  
Contact Patterns ◽  
Wide Range ◽  
Contact Data ◽  
Serological Studies

Abstract Background Vaccination has reduced the global incidence of measles to the lowest rates in history. However, local interruption of measles virus transmission requires sustained high levels of population immunity that can be challenging to achieve and maintain. The herd immunity threshold for measles is typically stipulated at 90–95%. This figure does not easily translate into age-specific immunity levels required to interrupt transmission. Previous estimates of such levels were based on speculative contact patterns based on historical data from high-income countries. The aim of this study was to determine age-specific immunity levels that would ensure elimination of measles when taking into account empirically observed contact patterns. Methods We combined estimated immunity levels from serological data in 17 countries with studies of age-specific mixing patterns to derive contact-adjusted immunity levels. We then compared these to case data from the 10 years following the seroprevalence studies to establish a contact-adjusted immunity threshold for elimination. We lastly combined a range of hypothetical immunity profiles with contact data from a wide range of socioeconomic and demographic settings to determine whether they would be sufficient for elimination. Results We found that contact-adjusted immunity levels were able to predict whether countries would experience outbreaks in the decade following the serological studies in about 70% of countries. The corresponding threshold level of contact-adjusted immunity was found to be 93%, corresponding to an average basic reproduction number of approximately 14. Testing different scenarios of immunity with this threshold level using contact studies from around the world, we found that 95% immunity would have to be achieved by the age of five and maintained across older age groups to guarantee elimination. This reflects a greater level of immunity required in 5–9-year-olds than established previously. Conclusions The immunity levels we found necessary for measles elimination are higher than previous guidance. The importance of achieving high immunity levels in 5–9-year-olds presents both a challenge and an opportunity. While such high levels can be difficult to achieve, school entry provides an opportunity to ensure sufficient vaccination coverage. Combined with observations of contact patterns, further national and sub-national serological studies could serve to highlight key gaps in immunity that need to be filled in order to achieve national and regional measles elimination.

scholarly journals 2019–2020 measles in the Republic of Guinea: epidemic features and herd immunity

2021 ◽  
Vol 11 (6) ◽  
pp. 1179-1184
Author(s):  
I. N. Lavrentieva ◽  
M. A. Bichurina ◽  
A. Yu. Antipova ◽  
J. Camara ◽  
N’F. Magassouba ◽  
...  
Keyword(s):  
Measles Virus ◽  
Herd Immunity ◽  
Global Scale ◽  
Elisa Test ◽  
Seroprevalence Rate ◽  
Serum Samples ◽  
African Countries ◽  
Republic Of Guinea ◽  
Number Of Patients ◽  
The Republic

 Introduction. In connection with the Ebola epidemic in the West African countries, including the Republic of Guinea, a failure in implementing measles immunization program was noted. A proportion of measles seronegative subjects in 2017 was 52.4% of total examined individuals. In 2018, a high proportion of measles cases among children aged 1–5 years (61.6%) was identified. In order to stop the 2018 outbreak, the Supplemental Immunization Campaign was conducted in the Konakri and Nzerekore prefectures in the Republic of Guinea. The aim of this study was to examine the 2019–2020 measles epidemic situation and assess the measles population immunity in the Republic of Guinea. Materials and methods. Measles-specific antibodies were examined in 1697 blood serum samples collected from residents of different regions of the Republic of Guinea, aged from 7 months to 76 years, obtained in 2019–2020, and tested retrospectively. The ELISA test systems Anti-Measles Virus ELISA (IgM) Euroimmun and Anti-Measles Virus ELISA (IgG) Euroimmun (Germany) were used. The presence of serum IgM measles antibodies was considered as acute measles infection. Statistical analysis was performed using the software package Statistica 6.0. Results. Blood sera (n = 638) were tested for IgM-measles, and in 46.6% of cases the diagnosis was confirmed by laboratory tests. The biggest proportion of the total cases (61.6%) was found in children aged 1–4 years. The second most important age group was 5–9 years of age, the third is children under 1 year: 18.5% and 11.8% of the total number of patients, respectively. Measles infection was registered in vaccinated patients in 7.4% of the total number of laboratory-confirmed cases. 1059 subjects were examined for IgG measles antibody. The lowest seroprevalence rate was found among children under 4 years of age (47.8%). The highest (85.5%) was found among subjects of 40 years old and older. Conclusion. Measles in GR remains a poorly controlled infection. As in the previous years of observation (2017–2018), children under 5 years of age are the most vulnerable cohort of the population, despite the 2018 DI campaign conducted in a number of GR territories. More problems with the measles control in the Republic of Guinea are expected in the period from 2021, as along with the COVID-19 epidemic, Ebola is repeatedly registered in the country. The Republic of Guinea particularly requires assistance from the international community to implement the WHO measles elimination program on a global scale.

scholarly journals Combining serological and contact data to derive target immunity levels for achieving and maintaining measles elimination

2017 ◽  
Author(s):  
Sebastian Funk ◽  
Jennifer K. Knapp ◽  
Emmaculate Lebo ◽  
Susan E. Reef ◽  
Alya J. Dabbagh ◽  
...  
Keyword(s):  
Measles Virus ◽  
Herd Immunity ◽  
Age Groups ◽  
Threshold Level ◽  
Specific Immunity ◽  
Measles Elimination ◽  
Contact Patterns ◽  
Wide Range ◽  
Contact Data ◽  
Serological Studies

AbstractBackgroundVaccination has reduced the global incidence of measles to the lowest rates in history. However, local interruption of measles virus transmission requires sustained high levels of population immunity that can be challenging to achieve and maintain. The herd immunity threshold for measles is typically stipulated at 90–95%. This figure does not easily translate into age-specific immunity levels required to interrupt transmission. Previous estimates of such levels were based on speculative contact patterns based on historical data from high-income countries. The aim of this study was to determine age-specific immunity levels that would ensure elimination of measles when taking into account empirically observed contact patterns.MethodsWe combined estimated immunity levels from serological data in 17 countries with studies of age-specific mixing patterns to derive contact-adjusted immunity levels. We then compared these to case data from the 10 years following the seroprevalence studies to establish a contact-adjusted immunity threshold for elimination. We lastly combined a range of hypothetical immunity profiles with contact data from a wide range of socioeconomic and demographic settings to determine whether they would be sufficient for elimination.ResultsWe found that contact-adjusted immunity levels were able to predict whether countries would experience outbreaks in the decade following the serological studies in about 70% of countries. The corresponding threshold level of contact-adjusted immunity was found to be 93%, corresponding to an average basic reproduction number of approximately 14. Testing different scenarios of immunity with this threshold level using contact studies from around the world, we found that 95% immunity would have to be achieved by the age of five and maintained across older age groups to guarantee elimination. This reflects a greater level of immunity required in 5–9 year olds than established previously.ConclusionsThe immunity levels we found necessary for measles elimination are higher than previous guidance. The importance of achieving high immunity levels in 5–9 year olds presents both a challenge and an opportunity. While such high levels can be difficult to achieve, school entry provides an opportunity to ensure sufficient vaccination coverage. Combined with observations of contact patterns, further national and sub-national serological studies could serve to highlight key gaps in immunity that need to be filled in order to achieve national and regional measles elimination.

scholarly journals Assessment of Population Immunity to SARS-CoV-2 Virus in the Rostov Region

2021 ◽  
pp. 117-124
Author(s):  
A. Yu. Popova ◽  
E. B. Ezhlova ◽  
A. A. Mel’nikova ◽  
A. K. Noskov ◽  
E. V. Kovalev ◽  
...  
Keyword(s):  
Herd Immunity ◽  
Age Groups ◽  
Incidence Rates ◽  
The State ◽  
Scientific Center ◽  
Education Professionals ◽  
Humoral Immune ◽  
Population Immunity ◽  
Rostov Region ◽  
High Level

By August 2020, more than 850000 cases of new coronavirus infection (COVID-19) caused by SARSCoV-2 were confirmed in the Russian Federation, with the Rostov Region as one of the ten most affected regions in Russia. The spread of the disease is largely determined by the state of population immunity in a certain area. Our research focuses on specific humoral immune response and estimates the level of herd immunity to SARS-CoV-2 virus among the population of the Rostov Region.Materials and methods. The study involved 3,048 people; the volunteers participating in the study were divided into seven age groups. The content of antibodies to SARS-CoV-2 was determined applying ELISA using a kit for the analysis of human serum or blood plasma for the presence of specific IgG to the nucleocapsid of the SARS-CoV-2 virus, manufactured by the State Scientific Center of Applied Microbiology and Biotechnology (Obolensk) in accordance with the instructions for use.Results and discussion. The assessment of seroprevalence to SARS-CoV-2 in the Rostov Region showed that the proportion of people positive for IgG to the new coronavirus was 16.5 %, the range of seropositive individuals in the general population was between 13.9 % and 19.1 % (p<0.05). There were no significant gender differences in the degree of seroprevalence with a positive result registered in 16.6 % of women and 16.5 % of men. A high level of humoral immunity to SARS-CoV-2 was established in individuals aged 1–17 against the background of low incidence rates, which may indicate the dominance of asymptomatic forms of the disease in this age group. The highest level of seropositivity was found in preschool children (33.6 %), students (29.3 %), employees (17.3 %), and education professionals (15.3 %). 

Crossing the road while playing a mobile game app – effects of age, environmental load and game complexity

2017 ◽  
Vol 61 (1) ◽  
pp. 880-880
Author(s):  
Rokni Danielle ◽  
Tapiro Hagai ◽  
Parmet Yisrael ◽  
Oron-Gilad Tal
Keyword(s):  
Mobile Phone ◽  
Motor Vehicle ◽  
Age Groups ◽  
High Risk Group ◽  
Point Of View ◽  
Environmental Load ◽  
The Road ◽  
Appearance Rate ◽  
High Level ◽  
Motor Vehicle Injuries

Children are a high-risk group for motor vehicle injuries, and characterized also by extensive use of mobile phones. We investigated the influence of playing a mobile phone game on crossing behavior of children relative to adults. Our hypotheses were that: a) game use will affect pedestrian’s crossing behavior for all age groups; and b) increase in the complexity of the game will cause greater impact on crossing behavior. Twenty-seven children and twenty-one adults (mean=25.3, sd=1.5) participated. Children were divided into two ages; nine children aged 9-10 (mean=9.2, sd=0.4), and eighteen children aged 11-13 (mean=11.9, sd=0.6). The experiment took place in our Dome pedestrian simulator. Twelve simulated street-crossing scenarios, each lasting for 60-90 seconds; six in each environmental load (high/low clutter). Scenarios were presented from a pedestrian point of view, as if they were standing on the curb on one side of the road facing to the other side of a two lane street with two-way traffic. Street surround sounds were embedded in the scene. A dedicated smartphone game was built. The aim of the game was to identify as many dots in a predefined color specified for the participant at the beginning of the game. Identification is implemented by clicking on the desired color dot. The complexity of the game depended on the dots’ appearance rate on the screen, the dots’ growing rate, and the allowed overlap between different dots. Participants were asked to decide when to cross the virtual road, and indicate their decision by pressing a foot pedal. Each pedal step and its time of occurrence was recorded and the scenario was then stopped. In eight out of the twelve scenarios (four in each load), participants were asked to play the game while attempting to cross the road. Safety gap was significantly shorter when the complexity of the game was high and the visual load was low, for all age groups. No change in safety gap was found while using the mobile phone in a high load environment for 11-13 year-olds and adults. Hence, they maintained the same performance, with or without the use of the phone and regardless of game complexity. This was not the case for those aged 9-10, whose performance suffered as a result of the use of the phone, especially in the high level of game complexity. Possibly, in loaded environments the 11-13 and adults balanced their attention between the crossing environment and the game, something they have not done in cases of low environmental load. It seems that, only when the environment was more complex, these two age groups ‘put their phone aside’ and turned their attention on the crossing task, which they may have regarded as more difficult under these conditions. However, children aged 9-10 have not been able to do so. Presumably, the environmental load did not change their behavior.

scholarly journals Herd immunity to SARS-CoV-2 among the population of the Republic of Belarus amid the COVID-19 pandemic

2021 ◽  
Vol 11 (5) ◽  
pp. 887-904
Author(s):  
A. Yu. Popova ◽  
A. A. Tarasenko ◽  
V. Yu. Smolensky ◽  
S. A. Egorova ◽  
V. S. Smirnov ◽  
...  
Keyword(s):  
Herd Immunity ◽  
Age Groups ◽  
Statistical Processing ◽  
Threshold Level ◽  
Test System ◽  
Elisa Test ◽  
Surface Glycoprotein ◽  
Pasteur Institute ◽  
The Republic ◽  
Questionnaire Method

Objective was to investigate the SARS-CoV-2 collective immunity status of the population of Belarus within the context of the COVID-19 pandemic. Materials and methods. The work was carried out according to the methodology for assessing SARS-CoV-2 population immunity, developed by Rospotrebnadzor Russia and the Ministry of Health of Belarus with the participation of the St. Petersburg Pasteur Institute, taking into account WHO recommendations. The Bioethics Committee of Belarus and the local ethics committee of the St. Petersburg Pasteur Institute approved the study. Selection of participants was carried out using a questionnaire method and online technology (internet, cloud server). Volunteers were randomized into seven age groups (years of age): 1–17; 18–29; 30–39; 40–49; 50–59; 60–69; and 70+. Regional randomization ensured proportional representation of volunteers from each region, and no more than 30 people were included from one enterprise. In accordance with manufacturer instructions, blood plasma samples were analyzed for: IgG antibodies (Abs) to the SARS-CoV-2 nucleocapsid (Nc) using a quantitative ELISA test system; and IgG Abs to the receptor binding domain (RBD) of the SARS-CoV-2 S (spike) surface glycoprotein using a qualitative ELISA test system. Statistical processing was carried out using Excel 2010 and other software. Statistical differences were designated as significant when p < 0.05, unless otherwise indicated. Results. The level of seroprevalence, in terms of Abs to Nc among the Belarusian population, was 38.4% (95% CI 37.6–45.4). The highest Ab levels were found among individuals in older age groups (50-70+ years old). The lowest were found in children 1–17 years old and in young people 18–39 years old The distribution of seroprevalence across Belarusian regions was relatively homogeneous, with the exception of the Minsk Region, where a statistically significant decrease in the indicator was noted. In terms of profession, the largest share of seropositive individuals was found among transportation workers; the smallest was found in business. The moderate COVID-19 incidence has not led to a dramatic increase in the number of contacts. The base reproduction number (R0) was 1.3. In the Republic of Belarus, there was a moderate level of asymptomatic COVID-19 among seropositive individuals (45.3% [95% CI 44.0–46.7]). This form of infection was observed most often among children aged 1–17 years old (65.0% [95% CI 61.3–68.6]). In parallel with seroprevalence assessment, SARS-CoV-2 vaccination was carried out. We used two vaccines: Gam-COVID-Vac (also known as Sputnik V, developed by Gamaleya National Center for Epidemiology and Microbiology, Russia); and BBIBP-CorV (Sinopharm, PRC). Vaccination against SARS-CoV-2 was accompanied by an increase in the level of anti-RBD Abs (95% [95% CI 94.7–96.7]). Taking into account the vaccination of a subset of the population with BBIBP-CorV, the overall herd immunity, inferred from the analyzed indicators (presence of anti-Nc or anti-RBD Abs), was 47.1% (95% CI 46.3–48.0). Conclusion. COVID-19 in Belarus was characterized by a moderately pronounced course of the epidemic process. The threshold level of herd immunity to SARS-CoV-2 has not yet been reached, as a result of which the conditions for progression of the epidemic remain.

scholarly journals Evaluation of an immunity status against measles of health workers in Kharkiv city

2019 ◽  
Keyword(s):  
Blood Serum ◽  
Measles Virus ◽  
Health Workers ◽  
Risk Group ◽  
Age Groups ◽  
Age Group ◽  
Protective Level ◽  
Minimum Number

Objectives. The purpose of this article was to determine the intensity of immunity against measles among health workers in Kharkov to identify and vaccinate susceptible individuals. Materials and methods. ELISA levels of specific measles IgG in blood serum of health workers were studied. Results. It was shown that the largest number of measles-susceptible individuals is observed in the age group of 18 to 27 years (9 % do not have a protective level of antibodies (AT); 7.7 % have a dubious level of protection). In the age groups from 28 to 37 years old and from 38 to 47 years old, a rather large number of measles-sensitive health workers was also detected (6.9 % and 6.1 % - with the absence of a protective level of AT and 6.9 % and 5.1 % - with a dubious level of protection, respectively). The minimum number of measles unprotected health workers was determined in the group aged 48 to 57 years (0.9 % of negative and doubtful results), and among physicians older than 57 years, there were no individuals with a lack of protective levels of antibodies to measles virus. Conclusions. Possible reasons for the prevalence of measles-unprotected health workers in the age groups from 18 to 47 years and the absence of unprotected people in the group of people over 57 are discussed. Doctors are a professional risk group for contracting infections (including measles). The article argues that there is no need for vaccination against measles for medical workers over 57 years old and vaccination of representatives of other age groups is recommended only after determining the strength of measles immunity, since more than 90 % of medical workers have protective levels of IgG.

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