A Population-Based Seroprevalence of SARS-CoV-2-Specific Antibodies Among Adults in Saint Petersburg, Russia: Longitudinal Cohort Study
Conditions: COVID19
Sponsor: European University at St. Petersburg

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 1 of 23 
 
ClinicalTrials.gov Identifier: NCT04406038 
 
Short name: Study of the spread of COVID-19 in St Petersburg, Russia  
 
Full name: Population study of SARS-CoV-2 antibodies prevalence in residents of St. 
Petersburg, Russia based on blood serum tests; socioepidemiological study.  
 
Protocol number: CDRU-001 
 
 
Study sponsors: 
Polymetal International PLC 
 
Independent 
not-for-profit 
educational 
organization of higher education “European 
University at St. Petersburg”  
 
OOO AVA-Peter 
Study sites: 
Scandinavia clinics: OOO AVA-Peter,  
Obvodny kanal branch, 
Moskovsky pr., 73, k.4 
St. Petersburg 
 
 
Protocol version: 
2 
Protocol date: 
15 Jul 2020  
Start of enrolment: 
26 May 2020  
End of enrolment: 
20 Aug 2020  
End of study: 
31 Dec 2021  
Protocol authors: 
А.А. Barchuk 
L.V. Barabanova 
V.V. Volkov 
А.А. Novkunskaya 
U.V. Raskina 
D.А. Skugarevskiy 
P.V. Talantov 
К.D. Titaev 
D.А. Shirokov 
Principal investigator: 
L.V. Barabanova 
Study coordinator: 
 
D.А. Shirokov 
 
 
 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
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Table of contents 
 
1. 
Introduction .................................................................................................. 3 
2. 
Study objectives ............................................................................................ 3 
2.1. 
Primary objective .................................................................................... 3 
2.2. 
Secondary objectives ............................................................................... 4 
3. 
Study procedures .......................................................................................... 4 
3.1. 
Study design .......................................................................................... 4 
3.2. 
Inclusion and exclusion criteria ................................................................. 5 
3.2.1. 
Study inclusion criteria: ..................................................................... 5 
3.2.2. 
Study exclusion criteria: .................................................................... 5 
3.3. 
Data collection ........................................................................................ 5 
3.4. 
Ethical and legal aspects .......................................................................... 5 
4. 
Laboratory diagnostics ................................................................................ 6 
5. 
Statistical analysis ...................................................................................... 6 
5.1. 
Sample .................................................................................................. 6 
5.2. 
Encouragement design ............................................................................ 7 
5.3. 
Data management and analysis ................................................................ 7 
5.3.1. 
Primary objective ............................................................................. 7 
5.3.2. 
Secondary objectives ........................................................................ 8 
6. 
Publication of the results ............................................................................. 8 
7. 
References ................................................................................................ 8 
 
List of Appendices  
 
Appendix 1. Questionnaire for telephonic survey. 
Appendix 2. Medical questionnaire. 
Appendix 3. SARS-CoV-2 antibody test results. 
Appendix 4. Participant Information Sheet and Informed Consent Form.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
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1. Introduction 
 
Population analysis of infection spreading is one of the key methods of new epidemics 
control1. The World Health Organization has included population serological surveys, which 
help to visualize the new virus distribution, into a list of essential assessments during the 
current epidemics, along with the vaccine development and search for effective treatments 
for severe disease2. Such studies help understand real disease spread and a real proportion 
of fatal outcomes among the patients with a disease and infected persons. Initial studies 
have shown the presence of immune response to an earlier SARS-CoV-2 infection3.  
 
Regarding the SARS-CoV-2 pandemic, the population assessment of immune response is 
recommended until the year 2024, as currently there is a discussion of a high risk of 
second and further peaks of new coronavirus epidemics4. Initial studies performed in the 
state of New York have shown that up to 14% state residents and 21.2% of New York City 
residents had had the infection and had developed antibodies5. In the states of Idaho and 
California, there were not more than 2% of such people6,7.  
 
To evaluate the proportion of people who have had the disease in a whole population (a 
city, a region, a country), the representativeness of a sample needs a strict approach. The 
methodology of a serological study is in many aspects similar to a sociological survey but 
is more complicated due to the use of serological test results. In addition, the population 
characteristics of these tests, i.e. sensitivity and specificity, are not always well-known2. 
A serological study sample should be representative for the general population (age 
groups, gender, place of living, mobility during the epidemics)8. 
 
In Russia, several studies have been performed to evaluate the proportion of antiviral 
antibody carriers, but many studies are probably biased in the direction of overestimation 
of positive results. This is caused by the selection of participants with higher probability of 
having antibodies. Thus, it is difficult to estimate how well these results reflect the real 
infection spread. In addition, such a study may help to identify objective social patterns of 
the epidemic spread in each specific region, i.e. correlation with the age, gender, 
occupation, mobility, and other factors. Also, some regions of Russia may have different 
stages of the epidemics, due to a geographical pattern of the viral spread. For example, 
in the Far East, there is high probability of viral spread from China, and in the European 
part of Russia from Europe.  
 
Several designs exist to conduct blood antibody testing with the aim of studying the 
distribution of an infection. To evaluate a proportion of people who have had the infection 
up to the current moment, it is enough to assess the results of the tests performed in a 
representative sample in a short period of time. To evaluate the dynamics of the infection 
spread, similar testing in similar samples should be performed repeatedly, with specific 
time intervals at least of 4 weeks. There is also an option of a cohort study to evaluate the 
results of repetitive tests in the same sample defined at baseline. The latter design permits 
to define how the number of infected people in the population changes in time, evaluate 
the individual immune dynamics, and identify not only the distribution but also incidence 
of the infection.  
 
2. Study objectives 
 
2.1. Primary objective 
 

 
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Pilot study: to evaluate the proportion of people in St. Petersburg, Russia who have had 
the SARS-CoV-2 infection by means of analyzing the results of the blood serum tests for 
antiviral antibodies.  
Cohort study: to evaluate the dynamics of the SARS-CoV-2 infection spread (incidence) 
by means of analyzing the results of blood serum tests for antiviral antibodies.  
 
2.2. Secondary objectives 
  
● 
To evaluate the incidence in the cohort study. 
● 
To evaluate the relation between the risk of infection and several factors (mobility, 
social characteristics). 
● 
To evaluate individual immune dynamics (seroconversion, seroreversion). 
● 
To compare the proportion of participants with positive test results between age 
(<20, 20-29, 30-39, 40-49, 50-59, 60-69, >70) and gender groups. 
 
3. Study procedures 
 
3.1. Study design 
 
This non-interventional observational socioepidemiological population study will be 
conducted in residents of St. Petersburg, Russia. Selection and invitation of participants 
will take place during telephonic survey. After giving signed informed consent, each 
participant will be subjected to a blood test for SARS-CoV-2 antibodies and will answer a 
questionnaire. The testing will be performed primarily using serological assays for serum 
IgG approved in the Russian Federation (Abbott Architect IgG and Genetico). 
 
This study involves a telephonic sociological survey during which respondents will be 
invited to undergo a blood test for SARS-CoV-2 antibodies at the participating 
investigational sites in different cities and towns of Russia. The participants will undergo 
such a test, take part in an additional survey for those who plans or have already done 
such a test, and receive the results. A part of participants will be offered to use a taxi (see 
Section 5.2). Testing and questionnaire at the clinic will be repeated several times. It is 
planned to perform up to 10 visits which will include blood sampling, testing, and collection 
of additional information.  
 
Table. Calculation of the study sample taking into account approximately 5% 
attrition at each visit 
 
First 
visit 
Week 
4 
Week 
8 
Week 
12 
Week 
16 
Week 
20 
Week 
24 
Week 
28 
Week 
32 
Week 
36 
Telephone-based 
questionnaire; medical 
hypothesis; IgG tests 
1000 
950 
902 
857 
815 
774 
735 
698 
663 
630 
  
Study participants will be asked to undergo multiple tests for SARS-CoV-2 antibodies with 
4-week intervals to assess the immune response dynamics. If a participant agrees to 
repetitive tests, they will also complete questionnaires with the objective of collecting 
epidemiological information for the period since the first test. Time of each round of survey 
and information collection will not exceed 4 weeks.  
 
If the test is not performed in the mentioned interval, delayed testing data may be used. 
If before the initial or a later test a participant shows signs of acute respiratory infection 
(see Section 3.2.2.3) or has been diagnosed with COVID-19, the study will use results of 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
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a test performed at least 2 days after all symptoms resolved, or results of the last negative 
test for the virus.  
 
3.2. Inclusion and exclusion criteria 
3.2.1. 
Study inclusion criteria: 
3.2.1.1. Residence in St. Petersburg, Russia.  
3.2.1.2. Consent to participate in a telephonic survey and personal data collection.  
3.2.1.3. Consent to an anti-SARS-CoV-2 antibodies test at an investigational site, 
and to management of the results of such a test with scientific objectives.  
3.2.1.4. Consent to second and further surveys and tests with approximately 4-week 
intervals.  
 
The participation in surveys and information collection should be based on a verbal (for 
telephonic surveys) and written (for surveys and information transfer from a clinic) 
informed consent. The participants will sign 2 copies of the informed consent form, one of 
which will be given to a participant, and another will stay at the investigational site. The 
participants will be also asked to agree to the transfer of additional medical data available 
at the clinic, for scientific analysis. The refusal to provide additional medical data is not an 
exclusion criterion.  
3.2.2. 
Study exclusion criteria:  
3.2.2.1. Refusal to take part in any of the study surveys.  
3.2.2.2. Impossibility to perform an anti-SARS-CoV-2 antibody test.  
3.2.2.3. Signs or symptoms of an acute respiratory infection at the moment of a 
survey or a test, based on the information provided by the participant or on 
the results of an examination at the investigational site. (The symptoms of an 
acute respiratory infection may include fever, cough, runny nose, loss of 
olfaction, marked weakness, dyspnea. A final decision on the presence or 
absence of the symptoms will be taken on the basis of analysis of observed and 
medical data).  
3.2.2.4. Participants younger than 18 years old cannot take part in this study. 
3.2.2.5. Residence in distant district of the city (Kronshdatsky, Kurortny, 
Petrodvortsovy, Krasnoselsky, Kolpinsky, Pushkinsky)  
 
Participation in the study is not limited by a single blood draw and anti-SARS-CoV-2 
antibody test. The consent to the information transfer maintains for similar repetitive tests 
and other medical information necessary in the frame of this study.  
 
3.3. Data collection 
During the study, the information will be collected from 3 sources: 
1. Information collected via telephonic surveys (see Appendix 1); 
2. Information collected during interviews at the clinical sites (see Appendix 2); 
 
3.4. Ethical and legal aspects 
Currently, results of the studies of SARS-CoV-2 infection prevalence in the population have 
key importance for public health in particular regions as well as at national and 
international levels. Conduction of such observational population studies is a key objective 
of scientific and practical medical institutions to be able to inform the society about the 
current epidemiological situation.  
 
This observational study will involve blood sampling for the antibodies test; this procedure 
has minimal risks for the health. Participation in the study will not affect medical decisions 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
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in any manner. The nature of participation is completely voluntary. The participants will 
be informed about the results, but it is not recommended to interpret these results from 
the point of view of protection from the infection.  
 
This study will be conducted in adherence to applicable local, regional, and national laws 
and regulations. Non-interventional epidemiological observational studies without 
investigational drugs are not directly regulated by International Council on Harmonization 
(ICH) Good Clinical Practice (GCP), but before the start of the study, an ethics committee 
will perform a review, and the GCP principles will be applied as needed.  
 
This study is being conducted at the territory of the Russian Federation, in accordance to 
the laws and regulations applicable to epidemiological observational studies. No personal 
data will be used in data analysis or transferred to the European University at St. 
Petersburg as well as to laboratories performing the tests.  
 
Participation in the study is completely voluntary and is possible only after the 
familiarization with the Information Sheet (Appendix 3), study details explanation, and 
signing correspondent Informed Consent Forms (Appendix 3). The participants can 
withdraw their consent verbally or in written form at any moment. Withdrawal of consent 
applies to personal information and results of all tests and procedures which would follow 
the moment of withdrawal, as well as other personal data. Withdrawal of consent does not 
apply to already collected and analyzed, anonymized and aggregated data, as such data 
cannot be identified.  
 
Results of this study cannot be the only reason for making decisions about the epidemics 
control measures, but they can be used in discussion of such measures.  
  
4. Laboratory diagnostics 
 
To 
measure 
IgG 
antibodies 
titer, 
Abbott 
Architect 
SARS-CoV-2 
IgG 
(https://www.fda.gov/media/137383/download) assay will be used. According to the 
manufacturer, the sensitivity of the assay is 100%, and the specificity is 99.6%. With a 
scientific objective, Coronapass Total Ig assay (Genetico) will also be used, with the 
sensitivity of 96% and specificity of 100%, according to the manufacturer. Other point-of-
care tests can be used to immediately inform participant but not for the research analysis.  
 
5. Statistical analysis 
 
5.1. Sample 
 
In this study, a population of a region with the size of N is being looked at. Assuming that 
the number of infected (K) in the population is distributed binomially and the serological 
test is ideal, 2-sided 95% Wilson confidence interval for the prevalence (p) is:  
𝑝′ ± 𝑧
!,!#$
∗
%&'()*&')
,-.
, where 𝑝′ ≡
/-#
,-., and 𝑧
!,!#$
∗
 is the critical level of the standard normal 
distribution. In this case the sample size n, needed for the sample error to not exceed M, 
with a conservative assumption of hypothetical prevalence of 50%, is: 𝑛> *
),01×!,$
3
+
#
−4. 
For the sample error to reach 2%, at least 2397 observations are needed.  
 
If we assume that hypothetical prevalence is 10%, the sample size is less than 900 for the 
sample error of 2%. Taking into account possible attrition at the repetitive tests, it is 
planned to enroll at least 1000 participants.  
 

 
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During the study, it is planned to test at least 1000 participants with a highly sensitive 
(Se) and highly specific (Sp) test, to reach the sample error level of 2%. The calculations 
above are applicable to a cross-sectional study. In a cohort study, there is a problem of 
the sample attrition. We assume loss of 5% of participants at the repetitive blood sampling. 
It 1000 participants provide samples at the first visit, there will be 630 tested participants 
at Week 36.  
 
5.2. Encouragement design 
 
Even if random sample of potential participants (surveyed persons) is representative, the 
decision about the participation in the study may bias its results, as it is made (or rejected) 
by a potential participant. The assumption of ideal participation of all surveyed persons in 
the testing is unrealistic. The next step would be to assume self-selection based on the 
observed characteristics of the surveyed. But it is doubtful that during a telephonic 
interview all observed individual characteristics which may affect the decision about the 
participation may be identified and quantified. For this reason, the final assessment of the 
prevalence will be biased. To surpass the issue of non-observable decision about the 
voluntary participation, the encouragement design will be used in this study9,10. 
 
A randomly selected subgroup of the surveyed will be offered a benefit related to the study 
participation, free-of-charge taxi to the place of testing. This offer will be made during the 
interview. Such randomization will permit to assess the proportion of infected in the group 
of people whose decision to participate in the testing changes depending to this benefit. 
The prevalence assessed in this manner has higher external validity than the prevalence 
in the group of people who make the decision without external encouragement.  
 
5.3. Data management and analysis 
 
There are several endpoints in this study. All values will be presented with 95% confidence 
intervals which corresponds to type I error probability of 5%. Depending on the type of 
variables, correspondent statistical tests and models will be used.  
 
The prevalence will be calculated using the GJRM library for R statistical software11. The 
following parameters will be calculated: 
● 
Uncorrected prevalence; 
● 
Prevalence with a single imputation of results for non-tested participants; 
● 
Prevalence corrected by self-selection of the participants based on observed 
characteristics (Heckman model); 
● 
Prevalence corrected by self-selection of the participants based on unobserved 
characteristics; 
● 
Coefficients of regression of the relation between the observed characteristics of 
the participants and test results.  
5.3.1. Primary objective 
Cross-sectional study: the main objective of this study is to calculate the proportion of 
participants with the presence of antibodies (taking into account the threshold 
recommended by manufacturer) in the total number of tested. Crude value will be equal 
to the proportion of positive-tested persons in the total number of enrolled. Additionally, 
standardized values and values in age or gender groups will be calculated as well as an 
adjusted value based on the total population in a region.  
  
Cohort study: the main objective of the cohort study is to compare correspondent values 
of prevalence in different points in time. This comparison will be made using simple tests 
and models depending on the type of value (rough, standardized, adjusted).  

 
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5.3.2. Secondary objectives 
Cross-sectional study: 
● 
To evaluate the relation between different sociodemographic factors and presence 
of infection by means of calculation of the adjusted prevalence ratios in different 
groups12.  
Cohort study: 
● 
To evaluate the incidence (number of new cases of infection by number of 
participants and observation time, i.e. incidence rates per person-days). 
Participants with positive result at the first testing will not be included in this 
assessment.  
● 
To evaluate the relation between different sociodemographic factors and incidence 
(rate ratios).  
● 
To evaluate the dynamics of immune response:  
○ 
cumulative seropositivity, i.e. proportion of positive tests at each moment; 
○ 
cumulative seroconversion, i.e. cumulative proportion of participants at all 
moments with at least 1 positive test; 
○ 
cumulative seroreversion, i.e. cumulative proportion of participants at all 
moments with at least 1 negative test after at least 1 positive test. 
 
6. Publication of the results 
 
Results of this study will be published in forms of press-releases, preprints, and peer-
reviewed scientific publications in Russian and English. Anonymized data will be publicly 
available for use in mathematical models of the epidemic dynamics and for the exchange 
of scientific information.  
 
7. References 
 
1.  McBryde E. The value of early transmission dynamic studies in emerging infectious diseases. Lancet Infect 
Dis. Published online 2020. doi:10.1016/S1473-3099(20)30161-4 
2.  Organization WH. Population-based age-stratified seroepidemiological investigation protocol for COVID-19 
virus 
infection, 
17 
March 
2020. 
Published 
online 
2020. 
Accessed 
May 
4, 
2020. 
https://apps.who.int/iris/handle/10665/331656 
3.  Haveri A, Smura T, Kuivanen S, et al. Serological and molecular findings during SARS-CoV-2 infection: the 
first case study in Finland, January to February 2020. Euro Surveill Bull Eur Sur Mal Transm Eur Commun 
Dis Bull. 2020;25(11):265. doi:10.2807/1560-7917.ES.2020.25.11.2000266 
4.  Kissler SM, Tedijanto C, Goldstein E, Grad YH, Lipsitch M. Projecting the transmission dynamics of SARS-
CoV-2 
through 
the 
postpandemic 
period. 
Science. 
Published 
online 
April 
14, 
2020. 
doi:10.1126/science.abb5793 
5.  21% of NYC residents had coronavirus antibodies in study: Cuomo - Business Insider. Accessed May 7, 
2020. 
https://www.businessinsider.com/nyc-residents-coronavirus-antibodies-study-cuomo-2020-
4?r=US&IR=T 
6.  Bryan A, Pepper G, Wener MH, et al. Performance Characteristics of the Abbott Architect SARS-CoV-2 IgG 
Assay and Seroprevalence Testing in Idaho. medRxiv. Published online May 2, 2020:2020.04.27.20082362. 
doi:10.1101/2020.04.27.20082362 
7.  Bendavid E, Mulaney B, Sood N, et al. COVID-19 Antibody Seroprevalence in Santa Clara County, California. 
medRxiv. Published online April 30, 2020:2020.04.14.20062463. doi:10.1101/2020.04.14.20062463 
8.  Chen MIC, Lee VJM, Lim W-Y, et al. 2009 influenza A(H1N1) seroconversion rates and risk factors among 
distinct adult cohorts in Singapore. JAMA. 2010;303(14):1383–1391. doi:10.1001/jama.2010.404 
9.  Duflo E, Glennerster R, Kremer M. T. Schultz and John Strauss, Eds., Handbook of Development Economics. 
Vol 4. North Holland; 2008. 
10.  McGovern ME, Canning D, Bärnighausen T. Accounting for non-response bias using participation incentives 
and 
survey 
design: 
An 
application 
using 
gift 
vouchers. 
Econ 
Lett. 
2018;171:239-244. 
doi:10.1016/j.econlet.2018.07.040 
11.  Marra G, Radice R. A joint regression modeling framework for analyzing bivariate binary data in R. Depend 
Model. 2017;5(1):268-294. doi:10.1515/demo-2017-0016 
12.  Thompson ML, Myers JE, Kriebel D. Prevalence odds ratio or prevalence ratio in the analysis of cross sectional 
data: what is to be done? Occup Environ Med. 1998;55(4):272-277. doi:10.1136/oem.55.4.272 
 
 
 
 
 
 
 

 
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Appendix 1 
 
CATI: Study of the spread of COVID-19 in St Petersburg, Russia 
 
Good afternoon! My name is _______. The European University at St. Petersburg together 
with Scandinavia clinics perform a study of coronavirus spread in St. Petersburg residents. 
It is a very important study which will help to make decisions on the duration of self-
isolation, and it gives residents an opportuning of a free-of-charge test to discover if you 
have already had the infection, as it may be asymptomatic.  
Please answer several questions of this survey; it will take about 10 minutes.  
а) At the end of this survey, if you are interested in this testing, I will explain in which 
clinics you can do it and ask your contact information, for the reception contacting you 
and giving you an appointment at time which suits you.  
б) At the end of this survey, if you are interested in this testing, I will explain in which 
clinics you can do it and ask your contact information, for the reception contacting you 
and giving you an appointment at time which suits you. In this study, the testing is free-
of-charge, and the commuting to the clinic will be also covered: you will receive a personal 
promocode for a taxi.  
CLARIFICATIONS FOR AN INTERVIEWER: 
What does the test show: it’s a test for antibodies. It shows if you have had a coronavirus 
infection earlier (as this infection is often asymptomatic or similar to other diseases). It 
does not show if you are currently infected. It is free of charge.  
Results of the test will not be reported to state organizations.  
 
What are Scandinavia clinics: it’s the largest private clinics chain in St. Petersburg, one of 
the centers of urgent medical care in case of coronavirus infection.  
  
Q1001 Single choice from 'Q1001 list' 
We guarantee that your answers will be kept confidential. For the quality control of my 
work, this call will be recorded, and the record will be deleted after the end of the study. 
Do you agree to proceed to a survey? 
  
How can I refer to you? 
informationText('Respondent name: ' + Q.openValueTxt); 
 
Q1 
Sex 
(DON’T READ THE QUESTION, REGISTER THE ANSWER BASED ON EARLIER ANSWERS)
 
Single choice from 'Q1 list' 
1 
Male 
 
2 
Female 
Q2 
Please tell me, do you live in St. Petersburg? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) Single choice from 'Q2 list' 
1 
Yes 
 
2 
No 
  If Q2=2, terminate the interview 
Q3 
Single choice from 'Q3 list' 
In which district of St. Petersburg do you live? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
1 
admiraltEiskiy 
2 
vasileostrOvskiy 

 
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3 
vYborgskiy 
4 
kAlininskiy 
5 
kIrovskiy 
6 
kOlpinskiy 
7 
krasnogvardEiskiy 
8 
Krasnoselskiy 
9 
KronshtAdtskiy (KronshtAdt) 
10 
Kurortniy 
11 
Lomonosovskiy 
12 
Moskovskiy 
13 
Nevskiy 
14 
PetrogrAdskiy 
15 
PetrodvortsOviy 
16 
primOrskiy 
17 
pUshkinskiy 
18 
frUnzenskiy 
19 
Centralniy 
998 
OTHER (explain) 
 
 
OpenValueTxt 
 
  
Q4 
Numeric 
How old are you in full years? 
  If Q4(ValueInt<18), terminate the interview 
Q5 
Single choice from 'Q5 list' 
Please tell me if since the beginning of February, you have been to somewhere outside of 
St. Petersburg and Leningrad region? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
1 
Yes 
 
2 
No 
 
Q6 
Single choice from 'Q6 list' 
  Q5=1 
Have you traveled abroad since the beginning of February? 
1 
Yes 
 
2 
No 
 
Q7 
Single choice from 'Q7 list' 
Among the people who you have met after the 1st of March, are there people who have 
traveled abroad in February or later? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
1 
Yes 
 
2 
No 
 
999              (DON’T READ) Not sure 
Q8 
Have you exited your home during the last week (7 days)? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) DisableReordering Single choice from 'Q8 list' 
1 
Yes 
 
2 
No 
Q9 
Single choice from 'Q9 list' 
  Q8=1 
How often have you been outdoors during the last week (7 days)? 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
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(A SINGLE ANSWER) 
  
Q10 
Single choice from 'Q10 list' 
  Q8=1 
How much time have you spent out of your home when you went out most recently?  
(IF THE ANSWER CONTAINS INTERVAL, REGISTER THE UPPER BORDER.  
REGISTER HOURS OR MINUTES — 30 min, 20 min 
IF THE ANSWER CONTAINS HOURS AND MINUTS, REGISTER AS IT IS: 1 h 10 min, 2 h 40 
min) 
  
999 
(DON’T READ) Not sure 
Q11 
Multiple choice from 'Q11 list' 
  Q8=1 
Which of the following places have you visited during the last week? 
(ANY NUMBER OF ANSWERS) 
1 
Work  
2                   Metro and other public transport, including taxi 
 
3 
A pharmacy 
 
4 
A shop or a market  
5 
A post office, a bank, an ATM, a medical institution  
 
6                    I have not been to any of these places 
Q12 
Have you had any examination for coronavirus? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) DisableReordering, 
Blocking 
Single choice from 'Q12 list' 
1 
Yes 
 
2 
No 
Q121 Single choice from 'Q121 list' 
  Q12=1 
The result of this examination was: 
(A SINGLE ANSWER) 
1 
Positive 
 
2 
Negative 
 
3 
I don’t know  
999              (DON’T READ ANSWERS) Not sure 
Q13 
Single choice from 'Q13 list' 
Do you or do you not follow information regarding coronavirus? If you follow, do you do it 
continuously or once in a while? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
1 
Follow continuously  
2                 Follow once in a while  
  
999              (DON’T READ ANSWERS) Not sure DisableReordering 
Q15 
Single choice from 'Q15 list' 
  Q8=1 
Were you wearing a mask when leaving your home during the last week? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
1 
Yes 
 
2 
No 
 

 
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Q16 
Single choice from 'Q16 list' 
  Q8=1 and  Q15=1 
Were you wearing a mask while just outdoors? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
1 
Yes 
 
2 
No 
Q17 
Can you say that now you wash your hands more often than before the epidemics?  
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) Single choice from 'Q17 list' 
1 
Yes 
 
2 
No 
 
999 
(DON’T READ) Not sure 
Q19 
In your opinion, should the limitations for public have been stricter or not? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) DisableReordering Single choice from 'Q19 list' 
1 
Yes, they should have been  
2 
No, they should not have been 
 
999 
(DON’T READ) Not sure 
DisableReordering 
Q20 
Single choice from 'Q20 list' 
  Q19=2 
In your opinion, should the limitations for public have been less scrict or not? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
1 
Yes 
 
2 
No 
 
999 
(DON’T READ) Not sure 
Q21 
How would you evaluate your health? 
(A SINGLE ANSWER) DisableReordering Single choice from 'Q21 list' 
1                      Very good  
2                      Good 
 
3                      Satisfactory  
 
4 
Bad 
 
5                      Very bad 
Q22 
Single choice from 'Q22 list' 
Please remember how many times you have been ill since February. Answer about your 
own feelings, not only when you took a sick leave.  
(IF THE ANSWER CONTAINS AN INTERVAL, REGISTER THE UPPER BORDER) 
  
999              (DON’T READ) Not sure 
Q23 
Single choice from 'Q23 list' 
Do you seek out preventative examinations in state or private clinics? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
1 
Yes 
 
2 
No 
 
999               (DON’T READ) Not sure 
DisableReordering 
Q24 
Single choice from 'Q24 list 1' 
Do you live alone or with others?  
(DON’T READ ANSWERS) 
(A SINGLE ANSWER)  

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 13 of 23 
1 
I live alone 
 
2 
I live with other people 
 
 
Q241 Numeric 
  Q24=2 
How many people live in your household (except you)? 
Q242 Multiple choice from 'Q242 list' 
  Q24=2 
Are there following categories among the people who live with you (except you)? 
(ANY NUMBER OF ANSWERS)  
(READ ANSWERS WITH PAUSES) 
1 
Minors (younger than 18 years) 
 
2 
Elderly (older than 65 years) 
 
3 
Your husband/wife, permanent partner 
 
4 
(DON’T READ; REGISTER IF NO OTHER ANSWER HAS BEEN SELECTED) Nothing 
applies DisableReordering, Blocking 
 
Q25 
Single choice from 'Q25 list' 
How would you define your income level before the start of pandemic? 
(A SINGLE ANSWER) 
1 
It was very hard. We did not have enough money even for food 
2 
We had money for food, but buying clothes was a problem 
3 
We had money for food and clothes but buying a fridge, a TV set, furniture would 
be a problem 
  
4 
We could easily buy a fridge, a TV set, furniture, but did not have enough money 
for something bigger 
  
5 
We can easily buy a car, but we don’t have enough money for bigger things, like a 
flat or a summer house   
6 
We can afford almost everything: a car, a flat, a summer house and many other 
things  
  
Q26 
Single choice from 'Q26 list (Yes No ДРУГОЕ)' 
Tell me please if you were working at the moment of the February 1st.  
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
IF A PERSON IS ON MATERNITY LEAVE, REGISTER AS UNEMPLOYED 
  
998               Other (clarify) OpenValueTxt, 
DisableReordering 
Q27 
Single choice from 'Q26 list (Yes No ДРУГОЕ)' 
Were you studying at the moment of the February 1st? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
IF A PERSON CONSIDERS SOMETHING AS STUDYING, REGISTER ACCORDING TO THEIR 
WORDS 
(DO NOT GUIDE TO ANSWER; ASK TO ANSWER ACCORDING TO THEIR OWN OPINION 
ABOUT IF IT IS OR IT IS NOT STUDYING) 
  
998 
Other (clarify) OpenValueTxt, 
DisableReordering 
Q28 
Single choice from 'Q26 list (Yes No ДРУГОЕ)' 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 14 of 23 
At the moment of the February 1st, were you receiving a pension, a welfare, a stipend 
from the state? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
  
998 
Other (clarify) OpenValueTxt, 
DisableReordering 
Q29 
Single choice from 'Q26 list (Yes No ДРУГОЕ)' 
  Q26=2 or Q26=998 
Were you looking for a job during the last 12 months? 
(DON’T READ ANSWERS)  
(A SINGLE ANSWER) 
The question implies the last 12 months until now. 
  
  
998 
Other (clarify) OpenValueTxt, 
DisableReordering 
Q30 
Single choice from 'Q26 list (Yes No ДРУГОЕ)' 
  Q26=1 
You said that you worked at the moment of the February 1st.   
At that moment, were you managing others or no?  
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
  
998 
Other (clarify) OpenValueTxt, 
DisableReordering 
Q31 
 
Single choice from 'Q26 list (Yes No ДРУГОЕ)' 
  Q26=1 and Q27=2 and Q30=2 
Did you job at that moment involve physical work? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
  
998 
Other (clarify) OpenValueTxt, 
DisableReordering 
Q32 
Single choice from 'Q32 list' 
  Q26=1 
Currently, do you work as usual, or is your timetable/working organization different from 
those before the epidemics (remote work, coerced days off etc.)? 
(DON’T READ ANSWERS) 
 998 
OpenValueTxt, 
DisableReordering 
Q321 Single choice from 'Q321 list' 
  Q32=2 
Which of the following situations is most similar to your timetable/working organization 
during the epidemics? 
(A SINGLE ANSWER) 
1 
I work remotely 
 
2 
I am on paid leave 
 
3 
I’ve lost my job or on unpaid leave, I spend my savings or use help from friends 
and family. 
 
4 
I’ve lost my job or on unpaid leave, I have to do some casual jobs 
 
 
Q33 
Single choice from 'Q33 list' 
What is your education level? 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 15 of 23 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) 
1         Initial/ unfinished secondary education 
 
2 
Complete secondary education 
 
3        Special secondary, technical secondary, initial professional education 
 
4 
University education 
Q34 
Do you have the Russian Federation nationality? 
(DON’T READ ANSWERS) 
(A SINGLE ANSWER) Single choice from 'Q34 list' 
1 
Yes 
 
2 
No 
Q35 
Numeric 
Since what year have you been living in St. Petersburg? 
Q36 
Multiple choice from 'Q36 list' 
let code = Q8001.getCheckedCode(); let texts = {  
    1: 'Thank you for your answers. You are offered free testing for anti-coronavirus 
antibodies  
    2: 'Thank you for your answers. You are offered free testing for anti-coronavirus 
antibodies 
    3: 'Thank you for your answers. You are offered free testing for anti-coronavirus 
antibodies 4: 'Thank you for your answers. You are offered free testing for anti-coronavirus 
antibodies 
};  
  
Q.text = code in texts ? texts[code] : 'Code text not found' + code; 
 
Thank you for your answers! 
You are offered free testing for anti-coronavirus antibodies at a Scandinavia clinic; it will 
show if you have or have not had the infection (or have it now). This is needed to evaluate 
the prevalence of this infection in our city, even if some people have had in in 
asymptomatic form.  
а) If you agree, give me please your contact phone number, first and patronymic names 
(no last name). In the next 5 days, clinic representatives will contact you to discuss a 
moment for testing which suits you. Do you agree? 
b) If you agree, give me please your contact phone number, first and patronymic names 
(no last name). In the next 5 days, clinic representatives will contact you to discuss a 
moment for testing which suits you and to explain how you can call for a free taxi to go to 
the clinic as a participant of this study. Do you agree? 
 
CLARIFICATIONS FOR AN INTERVIEWER: 
Any questions related to the testing results waiting time, its medical characteristics etc. 
might be asked to a clinic representative when they contact the respondent.  
 
1 Name and patronymic name: 
OpenValueTxt 
2 Contact phone number: 
OpenValueNum 
3  No, do not agree Blocking 
 
 
 
 
 
 
 
 
 
 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 16 of 23 
 
Appendix 2 
 
Serological study of COVID-19 prevalence in St.Petersburg 
 
PARTICIPANT QUESTIONNAIRE 
  
ATTENTION! Please select most appropriate answers from your own point of view. If you 
have  any  doubt,  select  approximate  answer.  To  avoid  introducing  bias  into  the  study 
results, the clinic staff cannot give explanations. Your answers will not affect the decision 
about conducting the test and will be used in anonymized form.  
 
1. 
Your body weight (may be approximated) is ______ (kg)  
 
2. 
Your height (may be approximated) is _______ (cm)  
 
3. 
Do you smoke?   
 
 No 
 Yes 
Did you smoke before?  
At what age did you start smoking? _____ 
 No 
 Yes 
Usually, do/did you smoke cigarettes?  
Go  
to 
Question 4  
Please  answer  when  you 
quit smoking most recently 
and  answer  the  questions 
on the right  
 No 
Go  
to 
Question 4 
 Yes 
How many cigarettes per day 
do/did you usually smoke? 
 
I  quit  smoking  in  the 
year___.  
 
 Less than half a pack (10 
cigarettes) per day 
 Approximately a pack (10-
20 cigarettes) per day 
 More  than  a  pack  (20 
cigarettes) 
 
 
4. 
How often did you drink alcohol (including beer) in the last 30 days? 
 Every day    
 4-6 times per week 
 2-3 times per week    
 Once a week    
 2-3 times in the last 30 days 
 Once in the last 30 days    
 Never 
 
 
 
 
5. 
Have you visited a hospital or a clinic since the beginning of February? 
 
  
      No 
 
 
 Yes    
 
6. 
Have you had any common cold since February?   
      No 
 
 
 Yes    
 
7. 
For professional or other reasons, do you have to contact with people often? 
 
  
      No 
 
 
 Yes    
 
 
 
 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 17 of 23 
8. 
Have you used public transport in the last 2 weeks? If yes, how often?   
 
 
 At least once a day  
   
 Several  times 
per week   
 
  
  
  
  
  
 Once a week or less                
 Never  
 
9. 
Do you or your blood relatives (parents, children, siblings) have hereditary 
diseases? 
 
 I don’t know    
 No  Yes (which)  _____________________________________  
 
10. If you have any of the following chronic diseases, please, mark all 
applicable options 
 
 Diabetes. If yes, do you receive insulin?    
    No 
 
 
 Yes    
 Emphysema, chronic bronchitis, other respiratory diseases except asthma.  
 Asthma. If yes, which of the following did you use during the last month (select all 
applicable options)?  
 Manual inhalers   
 Oral medications   
 Oral steroids   
 Oral nebulizer at home    
 Other  
 Renal failure  
 Chronic hepatic diseases, for example, hepatitis or cirrhosis 
 Cardiovascular diseases 
 Hematological disorders, for example, chronic anemia   
 Other  chronic  diseases  or  disorders  not  mentioned  above.  If  yes,  describe  them: 
________________________________________________________  
What treatment do you receive? __________________________________________  
 
11. 
Do you regularly (continuously) receive any medications not mentioned 
above?   
 
 No 
 Yes  (please list all medications that you remember of) 
________________________________________________________________  
_______________________________________________________________________
_  
 
12. Were you ever diagnosed with a cancer?    No  Yes   
If yes, did you receive oncological treatment during the last year?   No 
 Yes   
 
13. Do you have any known allergies?   
  
   No  Yes   
 
 
QUESTIONS FOR WOMEN 
 
14. Are you currently pregnant?   No  Yes  (how many weeks) 
______________________  
 
15. Did you give birth during the last year?    No 
 Yes  (when) ________  
 
Completion date ____ May/June (underline the applicable option) 2020  
 
 
 
 
 
 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 18 of 23 
Appendix 3 
 
Subject Information Sheet and Informed Consent Form 
 
Dear________________________________________________________,  
 
You are being offered to take part in the study named « Population study of SARS-CoV-2 
antibodies prevalence in residents of St. Petersburg, Russia based on blood serum tests; 
socioepidemiological study», directed to the evaluation of prevalence of the novel 
coronavirus in St. Petersburg, Russia as well as to the assessment of immune reaction to 
this infection.  
 
The main objective of this study conducted by the European University at St. Petersburg 
with the support of Polymetal International PLC, is to evaluate the scale of novel 
coronavirus infection. Results of this study will help to make conclusions about the stage 
of the epidemics. This study may also help to make rational decisions about the scale and 
duration of controlling measures needed to manage the epidemics. For this study, we need 
some information which will be collected by means of special questionnaires, as well as 
the results of anti-SARS-CoV-2 antibodies testing.  
 
The study is dedicated to the assessment of the spread of novel SARS-CoV-2 coronavirus. 
Main symptoms of infection are usually mild and resemble those of common cold. 
Nevertheless, this virus may cause serious life-threatening complications related to 
respiratory organs damage. The novel virus has provoked a pandemic, and many countries 
has reacted with the introduction of different measures of infection control.  
 
This invitation is directed to you personally. All participants have been selected randomly, 
so that results would reflect the objective image of the infection prevalence in residents of 
St. Petersburg. No other person may take part in this study in your place. Participation in 
the study is completely voluntary. To take part in the study, you will have to provide your 
written consent for data transfer. You have full right to refuse participation at any moment, 
without explaining the reason.  
 
Please, read this Information Sheet thoroughly; it contains detailed information about the 
study and participation. In addition to this Information Sheet, we provide you with the 
Informed Consent Form. You can sign it at the clinic after receiving full information about 
the study, if you decide to take part.  
 
You can always clarify any detail by asking study coordinators and investigators at the 
European University at St. Petersburg.  
 
Study coordinator at the clinical site: 
Name: _________________________________ 
Phone: __________________________________ 
 
Study coordinator, an employee of the European University at St. Petersburg: 
Name: _________________________________ 
Phone: __________________________________ 
 
 
 
 
 
 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 19 of 23 
 
Why is this study being conducted? 
The main objective of this study is to evaluate the scale of novel coronavirus infection. 
Results of this study will help to make conclusions about the stage of the epidemics. 
Presence of antibodies in blood permits to make a conclusion about a past SARS-CoV-2 
infection with some certainty. Based on the number of people who have had the infection 
in a small investigative sample, we could evaluate its prevalence in a region. There is no 
vaccine or effective treatment for this disease yet, so it is very important to obtain 
information about its spread and presence of immunity. To make decisions on the scale 
and duration of controlling measures needed to manage the infection, it is essential to 
evaluate the scale of the epidemics and understand which stage of the infection spread is 
ongoing in each region.  
 
How does the test for anti-novel coronavirus antibodies differ from other tests? 
Unlike tests which detect presence of the virus in the body, this test permits to evaluate if 
a person has had SARS-CoV-2 infection before, and how their immune system has reacted. 
Thus, the antibody test does not provide information about the current presence of the 
virus in the body, and it cannot be used for diagnostics. As human body needs some time 
to develop antibodies, this test may rather reflect a past infection, symptomatic or 
asymptomatic.  
 
If I have a positive result of the antibody test, does it mean that the novel 
coronavirus is not dangerous for me anymore? 
Unfortunately, we don’t know yet how much the immunity detected by this test is able to 
protect a person from a repeated infection with the same virus. One of additional 
objectives of this study is to attempt to answer this question exactly. Based on the 
experience of studying other infectious diseases, we know that such protection is possible, 
but there are still no exact data for the novel coronavirus. Thus, even a positive result of 
the antibody test cannot be a reason of refusing to use means of individual protection, 
which include personal hygiene and physical distancing.  
 
Can anyone take part in the study instead of me? 
A person I know has done a test already; can they be offered the study 
participation in my place? 
All potential participants of this study have been selected randomly, using methods which 
are being used, for example, in sociological surveys. By means of these methods, the 
investigators will be able to make conclusions about the infection spread in the whole 
region while having information only for a small amount of antibody tests. Participation of 
any other person who would like to or has already done the test may bias the results of 
this study, so that the result would not reflect the real spread of infection.  
 
Does it make sense to repeat the test in case of positive result? 
Currently, we don’t know for how long the anti-novel coronavirus immunity maintains. To 
obtain this information, it is necessary to evaluate repeated testing results in same 
participants. Several persons are not enough to conclude about the immunity maintenance 
with certainty, but if there are enough people who agree to provide information about the 
repeated testing results, the investigators will be able to answer the question about the 
immunity durability.  
 
Can this test give erroneous results? 
Any test can give erroneous results. There is a small probability that a positive result will 
be obtained in a person who does not have antibodies, and vice versa, sometimes the test 
does not detect antibodies while a person has them. Errors in the anti-novel coronavirus 
antibody detection may be in part explained by the fact that these tests are pretty new. If 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 20 of 23 
possible, tests made by different manufacturers will be used to detect antibodies; this will 
help to identify the most precise test.  
 
I have symptoms of cold; can I participate in the study? 
For safety reasons, to protect you and others, people with signs and symptoms possibly 
related to respiratory infections cannot take part in the study. If this is the case, you need 
to follow medical recommendations and self-isolation instructions if applicable. 
Nevertheless, if you have received this invitation, you will be able to take part in the study 
after your condition resolves, taking into account medical recommendations. Only results 
of the tests performed after your disease resolution will be collected in this study.  
 
How much time will I spend in the study and what does it involve? 
This study includes at least 2 questionnaires and at least 1 blood sampling for the testing. 
You can complete 1 questionnaire by phone, and the other at a clinical site. General 
duration of answering questions will be about 15 to 30 minutes. Answers are critically 
important to define if the study participants reflect a whole region population well enough, 
and which adjustments should be done during the calculation of the infection spread in 
this population. Some questions are needed to evaluate factors which may influence the 
probability of infection. A blood sampling is also planned in this study with the objective 
of performing a test.  
 
The blood sampling will be performed as a service provided by the clinical sites, but for 
the participants of the study it will be free of charge. Laboratory tests will be performed 
later and do not require your presence. Blood sampling may be partly performed by means 
of a catheter which is a thin plastic tube, or a needle inserted in a vein on your forearm. 
During the blood sampling you may feel weakness or mild pain; at the place of the 
puncture, a bruise, irritation, or redness may appear. In very rare cases, an infection may 
develop. To perform tests, we will need 2 tubes of blood, 5 ml each. For another test, we 
will need several drops of blood collected by means of a fingertip puncture with a special 
thin needle; this procedure may bring minimal discomfort.  
 
What tests will be used? 
In this study, at the first stage we plan to use 1 or 2 types of coronavirus tests. They will 
be performed in laboratories and will answer the question about the presence of anti-
coronavirus antibodies in blood. You will receive only results of the first test.  
 
What personal benefits will participation in the study give me? 
Participation in this study will not give you any personal benefits from the point of view of 
your health, except receiving information about a possible past infection. This information 
does not imply protection from the virus in the future. Nevertheless, by taking part in this 
study you will help to obtain information about the disease spread and characteristics of 
the immunity against the novel coronavirus at the population level. In the future, this may 
indirectly influence you, as means of epidemic control effect all aspects of life of a country 
population. No monetary compensation for the participation in this study is planned. But, 
in the frame of the second and later study stages, your transport expenses for commuting 
to the clinic may be compensated; we may also plan a compensation in the form of gift 
cards.  
 
Personal data? 
To perform analysis, the investigators do not need your personal data (like your name, 
contact phone number, address, passport data), so they will not be transferred from 
clinical sites. The alignment of completed questionnaires and test results will be performed 
at clinical sites, and later anonymized data will be used for analyses. Laboratory testing 
will not involve transfer of personal data to any other laboratories.  

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 21 of 23 
 
Where will I be able to see the study results? 
Results of the study will be published in the form of press-releases and scientific articles 
in Russian and English. Detailed information may be followed at the European University 
at St. Petersburg webpage. All information about this sociological epidemiological study is 
open for general public. 
 
When will the study end? 
Timing of the study completion depends on its initial results. It is very important that the 
study continues while there are unanswered questions about the disease spread and 
immune system reaction with time. It is possible that the study will last at least for 1 year. 
For this reason, we cannot currently say how many times testing will be needed. We would 
like to perform at least 10 testing visits. We will be able to inform you about the timing 
and interval between the tests after your first visit. You have a right to refuse to take part 
in repeated tests when you decide.  
 
May I be invited for blood sampling again? 
This study includes several stages, and most probably we will ask you to come for testing 
again. It is necessary to answer the questions about the durability of immunity, its 
dynamics and changes in the disease spread. All these issues are very important to 
understand this novel disease, and this information can radically change our understanding 
of its nature and characteristics of the virus. In the Informed Consent Form, we have 
included a possibility of multiple testing.  
 
 
 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 22 of 23 
Consent for the study participation 
 
I have been offered to take part in the study « Population study of SARS-CoV-2 antibodies 
prevalence in residents of St. Petersburg, Russia based on blood serum tests; 
socioepidemiological study» (short name: Serological study of COVID-19 prevalence in St. 
Petersburg).  
 
I have familiarized myself with clarifications and received exhaustive information about 
the study and related blood sampling, testing, data collection, management, and transfer. 
I have had enough time to consider my participation in this study. I understand that 
participation in this study is voluntary. I have a right to withdraw my consent to the study 
participation at any moment, without explaining the reasons. Withdrawal of consent will 
not have any negative consequences for me and will not affect my medical care at the 
clinical sites where the study is being conducted or at other medical institutions. Two 
copies of this Consent Form will be signed: one will be retained at the clinical site, and the 
other is intended for me.  
 
By signing below, I confirm the following: 
 
• 
I have read and understood the information provided in the Patient Information 
Sheet; 
• 
I have had an opportunity to ask questions, and I have received exhaustive answers 
to all my questions;  
• 
I voluntary agree to take part in this study; 
• 
I do not waive my legal rights by signing this document; 
• 
My signature on this document means that I agree to take part in this study; 
• 
I am aware that I may terminate my participation in the study at any moment; 
• 
I voluntary agree that my data collected during the study may be used with 
scientific objectives and published with the condition of confidentiality maintained;  
• 
I agree that in case if I provide consent I will receive a signed and dated copy of 
this document; 
• 
My signature on this document means that I agree to take part in the study 
described in the attached Information Sheet, and voluntary give my consent to a 
single blood sampling, testing, using of the data provided by me during study-
related surveys, and data collected by clinical site staff, including the results of 
testing for anti-SARS-CoV-2 antibodies.  
 
First, second, last name (full) __________________________________________  
 
Date: _______ /______ / 2020  
Signature: _________________________ 
 
Место: _____________________ 
 
My signature below means that I give my consent to multiple (up to 10 times) blood 
sampling, testing for anti-SARS-CoV-2 antibodies and transfer of the results of repeated 
tests for analysis within the objectives of this study.  
 
First, second, last name (full) __________________________________________  
 
Date: _______ /______ / 2020  
Signature: _________________________ 
 
Place: _____________________ 
 
I give my consent to contacting me again in relation to coronavirus epidemics studies: 
 
Phone number: _______________________  
 

 
[Study Protocol CDRU-001. Edition 2 dated 15 Jul 2020]             
 
 
Page 23 of 23 
email: _____________________@_____________  
 
Signature:_____________ 
 
Study coordinator signature: 
 
First, second, last name (full) __________________________________________  
 
Date: _______ /______ / 2020  
Signature: _________________________ 
 
Place: _____________________