## Protocol Section
### Identification Module
**NCT ID:** NCT04673279

**Brief Title:** Long-term COVID-19 Immune Response in a Vulnerable Neighbourhood in Argentina

**Official Title:** Long-term Persistence of Immunoglobulin G Antibodies Against Severe Acute Respiratory Syndrome Coronavirus 2 in a Vulnerable Neighbourhood in Buenos Aires, Argentina

#### Organization Study ID Info
**ID:** 3545
#### Organization
**Class:** OTHER
**Full Name:** Hospital Italiano de Buenos Aires
### Status Module
#### Completion Date
**Date:** 2021-08-20

**Type:** ACTUAL

#### Expanded Access Info
#### Last Update Post Date
**Date:** 2021-08-25

**Type:** ACTUAL

**Last Update Submit Date:** 2021-08-23

**Overall Status:** COMPLETED

#### Primary Completion Date
**Date:** 2021-08-20

**Type:** ACTUAL

#### Start Date
**Date:** 2020-12-02

**Type:** ACTUAL

**Status Verified Date:** 2021-08

#### Study First Post Date
**Date:** 2020-12-17
**Type:** ACTUAL
**Study First Submit Date:** 2020-12-13
**Study First Submit QC Date:** 2020-12-16
### Sponsor Collaborators Module

#### Collaborators

**Class:** OTHER

**Name:** Hospital de Niños R. Gutierrez de Buenos Aires

**Class:** UNKNOWN

**Name:** Ministerio de Salud GCBA

#### Lead Sponsor

**Class:** OTHER

**Name:** Hospital Italiano de Buenos Aires

#### Responsible Party

**Investigator Affiliation:** Hospital Italiano de Buenos Aires

**Investigator Full Name:** ALICIA MISTCHENKO

**Investigator Title:** principal investigator

**Type:** PRINCIPAL_INVESTIGATOR

### Oversight Module

**Is FDA Regulated Device:** False

**Is FDA Regulated Drug:** False

### Description Module

**Brief Summary:** Between June 10t h and July 1st, a cross-sectional design study in an Argentina slum, showed a prevalence based on immunoglobuling G-class (IgG) antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) of 53.4%. It remains unanswered whether natural infection produces sustained antibodies. The aim of this study is to evaluate the presence of IgG antibodies for Coronavirus disease 2019 (COVID-19) after 5 months in inhabitants of Barrio 31 who consented the Seroprevalence Study for COVID-19.

**Detailed Description:** Background Between June 10t h and July 1st, a cross-sectional design study was carried out in an Argentina slum over people, selected from a probabilistic sample of households showed a prevalence based on IgG-class antibodies against SARS-CoV-2 of 53.4%. In regarding to the persistence of these antibodies, the early data brought hope that acquired immunity was possible. But some subsequent studies have suggested that immune protection might be short-lived. The new findings show that people who survive a COVID-19 infection continue to produce protective antibodies against key parts of the virus for at least three to four months after developing their first symptoms. In contrast, some other antibody types decline more quickly.

It remains unanswered whether natural infection produces a sustained immunity that is capable of establishing herd immunity. The other health problem that Latin America faces is dengue, whose transmission, like SARS-CoV-2, is greater in areas with high population density such as vulnerable neighborhoods. In this context, the occurrence of the two diseases implies a risk, particularly in regions with several dengue serotypes where secondary and tertiary infections have been demonstrated and dengue epidemiological surveillance has been affected by the saturation of health system.

Objectives The aim of this study is to evaluate the presence of IgG antibodies for COVID-19 after 5 months in inhabitants of this slum who consented the Seroprevalence Study for COVID-19, and to evaluate those factors associated with the persistence of positive antibodies. As a secondary objective, the presence of positive IgG for dengue will be evaluated.

Methods Cross sectional study. Population of the study were inhabitants of the slum: men and women form 14 years of age or older were included. People will be invited to participated and detection of antibodies will be performed with ta serological tests, an enzyme linked immunosorbent assay (ELISA) developed and validated in Argentina which detects antibodies against two viral antigens, trimeric spike and the receptor binding domain (RBD) of the spike protein. Blood sample will be collected in a capillary tube from a finger prick taken at the doorstep of each person. Samples will be processed and analyzed at the "Hospital de Niños Doctor Ricardo Gutierrez" Virology laboratory.

Blood sample collection and epidemiological data were collected, and entered in a secure database.

Sample Size The first seroprevalence study included 426 inhabitants of 14 years or more. Considering a persistence of antibodies of 30% with a precision of 5% for a confidence interval of 95% 184 inhabitants should be included. This sample will be selected by a proportionate stratified random sampling, considering the ten sectors in which the slum is divided.

Statistical analysis Descriptive statistics of the data will be carried out according to the variables obtained. Continuous variables will be expressed as mean and standard deviation, and categorical variables as proportions. A multiple logistic regression model will be performed to evaluate the factors associated with the persistence of positive antibodies for SARS-CoV-2.

Dengue seroprevalence is determined globally and by geographic sector. R software version 4.0.2 will be used.

### Conditions Module

**Conditions:**

- Coronavirus Disease 2019

**Keywords:**

- Immunity

- serology

- antibody

- SARS-CoV-2

- COVID-19

- vulnerability

### Design Module

#### Bio Spec

**Description:** blod samples for antibodies detection against dengue

**Retention:** SAMPLES_WITHOUT_DNA

#### Design Info

**Observational Model:** COHORT

**Time Perspective:** CROSS_SECTIONAL

#### Enrollment Info

**Count:** 189

**Type:** ACTUAL

**Patient Registry:** True

**Study Type:** OBSERVATIONAL

**Target Duration:** 1 Day

### Arms Interventions Module

### Interventions

#### Intervention 1

**Description:** An enzyme linked immunosorbent assay (ELISA) developed and validated in Argentina which detects antibodies against two viral antigens, trimeric spike and the receptor binding domain (RBD) of the spike protein.

**Name:** serology

**Type:** DIAGNOSTIC_TEST

### Outcomes Module

#### Primary Outcomes

**Description:** to estimate the proportion of people with positive IgG antibodies for COVID-19 who have positive IgG antibodies after 5 month of the first measurement

**Measure:** to estimate the proportion of people with positive IgG antibodies for COVID-19 who have positive IgG antibodies after 5 month of the first measurement

**Time Frame:** up to 20 weeks

#### Secondary Outcomes

**Description:** to estimate the proportion of people with positive IgG antibodies for dengue

**Measure:** to estimate the proportion of people with positive IgG antibodies for dengue

**Time Frame:** up to 20 weeks

### Eligibility Module

**Eligibility Criteria:** Inclusion Criteria:

* Men and women form 14 years of age or older who were included in the seroprevalence study and who have positive antibodies against severe acute respiratory syndrome coronavirus 2

Exclusion Criteria:

* deny consent

**Maximum Age:** 90 Years

**Minimum Age:** 14 Years

**Sampling Method:** PROBABILITY_SAMPLE

**Sex:** ALL

**Standard Ages:**

- CHILD

- ADULT

- OLDER_ADULT

**Study Population:** inhabitants of Barrio Mugica: men and women form 14 years of age or older who were included in the first seroprevalence study carried on between Between June 10t h and July 1st, and who have positive antibodies against severe acute respiratory syndrome coronavirus 2

### Contacts Locations Module

#### Locations

**Location 1:**

**City:** Buenos Aires

**Country:** Argentina

**Facility:** Hospital de Niños Ricardo Gutierrez

**State:** Ciudad De Buenos Aires

**Zip:** C1425EFD

#### Overall Officials

**Official 1:**

**Affiliation:** Hospital Italiano de Buenos Aires

**Name:** Vanina Pagotto, MD MG

**Role:** STUDY_CHAIR

**Official 2:**

**Affiliation:** Hospital de Niños Ricardo Gutierrez

**Name:** Alicia Mistchenko, Phd

**Role:** PRINCIPAL_INVESTIGATOR

**Official 3:**

**Affiliation:** Hospital Italiano de Buenos Aires

**Name:** Silvana Figar, MD MG

**Role:** STUDY_CHAIR

**Official 4:**

**Affiliation:** National Council of Scientific and Technical Research, Argentina

**Name:** Andrea Gamarnick, Phd

**Role:** STUDY_CHAIR

**Official 5:**

**Affiliation:** Salud Comunitaria Ministerio de Salud del Gobierno de la Ciudad de Buenos Aires

**Name:** Ana Maria Gomez Saldaño, MD MG

**Role:** STUDY_CHAIR

**Official 6:**

**Affiliation:** Salud Comunitaria Ministerio de Salud del Gobierno de la Ciudad de Buenos Aires

**Name:** Lorena Luna

**Role:** STUDY_CHAIR

**Official 7:**

**Affiliation:** Salud Comunitaria Ministerio de Salud del Gobierno de la Ciudad de Buenos Aires

**Name:** Julieta Salto

**Role:** STUDY_CHAIR

**Official 8:**

**Affiliation:** Salud Comunitaria Ministerio de Salud del Gobierno de la Ciudad de Buenos Aires

**Name:** Magdalena Wagner Manslau

**Role:** STUDY_CHAIR

**Official 9:**

**Affiliation:** Ministerio de Salud del Gobierno de la Ciudad de Buenos Aires

**Name:** Fernan Quiroz, MD MG

**Role:** STUDY_DIRECTOR

### IPD Sharing Statement Module

**IPD Sharing:** UNDECIDED

### References Module

#### References

**Citation:** Jordan RE, Adab P, Cheng KK. Covid-19: risk factors for severe disease and death. BMJ. 2020 Mar 26;368:m1198. doi: 10.1136/bmj.m1198. No abstract available.

**PMID:** 32217618

**Citation:** Long QX, Tang XJ, Shi QL, Li Q, Deng HJ, Yuan J, Hu JL, Xu W, Zhang Y, Lv FJ, Su K, Zhang F, Gong J, Wu B, Liu XM, Li JJ, Qiu JF, Chen J, Huang AL. Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections. Nat Med. 2020 Aug;26(8):1200-1204. doi: 10.1038/s41591-020-0965-6. Epub 2020 Jun 18.

**PMID:** 32555424

**Citation:** Kellam P, Barclay W. The dynamics of humoral immune responses following SARS-CoV-2 infection and the potential for reinfection. J Gen Virol. 2020 Aug;101(8):791-797. doi: 10.1099/jgv.0.001439.

**PMID:** 32430094

**Citation:** Wilder-Smith A, Tissera H, Ooi EE, Coloma J, Scott TW, Gubler DJ. Preventing Dengue Epidemics during the COVID-19 Pandemic. Am J Trop Med Hyg. 2020 Aug;103(2):570-571. doi: 10.4269/ajtmh.20-0480. Epub 2020 Jun 15. No abstract available.

**PMID:** 32539912

**Citation:** Cardoso MR, Cousens SN, de Goes Siqueira LF, Alves FM, D'Angelo LA. Crowding: risk factor or protective factor for lower respiratory disease in young children? BMC Public Health. 2004 Jun 3;4:19. doi: 10.1186/1471-2458-4-19.

**PMID:** 15176983

#### See Also Links

**Label:** 2019 Novel Coronavirus (COVID-19) Pneumonia with Hemoptysis as the Initial Symptom: CT and Clinical Features

**URL:** http://dx.doi.org/10.3348/kjr.2020.0181

**Label:** SARS-CoV-2 infection induces sustained humoral immune responses in convalescent patients following symptomatic COVID-19

**URL:** http://dx.doi.org/10.1101/2020.07.21.20159178

**Label:** Community-level SARS-CoV-2 Seroprevalence Survey in urban slum dwellers of Buenos Aires City, Argentina: a participatory research.

**URL:** https://www.medrxiv.org/content/10.1101/2020.07.14.20153858v2.full.pdf

**Label:** Reductions in commuting mobility correlate with geographic differences in SARS-CoV-2 prevalence in New York City

**URL:** https://doi.org/10.1038/s41467-020-18271-5

**Label:** The COVID-19 pandemic should not jeopardize dengue control

**URL:** https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0008716

## Derived Section

### Condition Browse Module - Ancestors

- ID: D000003333

- Term: Coronaviridae Infections

- ID: D000030341

- Term: Nidovirales Infections

- ID: D000012327

- Term: RNA Virus Infections

- ID: D000014777

- Term: Virus Diseases

- ID: D000007239

- Term: Infections

- ID: D000011024

- Term: Pneumonia, Viral

- ID: D000011014

- Term: Pneumonia

- ID: D000012141

- Term: Respiratory Tract Infections

- ID: D000008171

- Term: Lung Diseases

- ID: D000012140

- Term: Respiratory Tract Diseases

### Condition Browse Module - Browse Branches

- Abbrev: BC01

- Name: Infections

- Abbrev: BC08

- Name: Respiratory Tract (Lung and Bronchial) Diseases

- Abbrev: All

- Name: All Conditions

- Abbrev: BC23

- Name: Symptoms and General Pathology

- Abbrev: Rare

- Name: Rare Diseases

### Condition Browse Module - Browse Leaves

- ID: M2561

- Name: COVID-19

- Relevance: HIGH

- As Found: Coronavirus Disease 2019

- ID: M16355

- Name: Syndrome

- Relevance: LOW

- As Found: Unknown

- ID: M20490

- Name: Coronavirus Infections

- Relevance: HIGH

- As Found: Coronavirus

- ID: M25445

- Name: Severe Acute Respiratory Syndrome

- Relevance: LOW

- As Found: Unknown

- ID: M10283

- Name: Infections

- Relevance: LOW

- As Found: Unknown

- ID: M6368

- Name: Communicable Diseases

- Relevance: LOW

- As Found: Unknown

- ID: M6555

- Name: Coronaviridae Infections

- Relevance: LOW

- As Found: Unknown

- ID: M23685

- Name: Nidovirales Infections

- Relevance: LOW

- As Found: Unknown

- ID: M17522

- Name: Virus Diseases

- Relevance: LOW

- As Found: Unknown

- ID: M15149

- Name: RNA Virus Infections

- Relevance: LOW

- As Found: Unknown

- ID: M13904

- Name: Pneumonia

- Relevance: LOW

- As Found: Unknown

- ID: M13914

- Name: Pneumonia, Viral

- Relevance: LOW

- As Found: Unknown

- ID: M14978

- Name: Respiratory Tract Infections

- Relevance: LOW

- As Found: Unknown

- ID: M11168

- Name: Lung Diseases

- Relevance: LOW

- As Found: Unknown

- ID: M14977

- Name: Respiratory Tract Diseases

- Relevance: LOW

- As Found: Unknown

- ID: T170

- Name: Acute Graft Versus Host Disease

- Relevance: LOW

- As Found: Unknown

- ID: T5186

- Name: Severe Acute Respiratory Syndrome

- Relevance: LOW

- As Found: Unknown

### Condition Browse Module - Meshes

- ID: D000018352

- Term: Coronavirus Infections

- ID: D000086382

- Term: COVID-19

### Intervention Browse Module - Browse Branches

- Abbrev: All

- Name: All Drugs and Chemicals

### Intervention Browse Module - Browse Leaves

- ID: M4225

- Name: Antibodies

- Relevance: LOW

- As Found: Unknown

- ID: M10184

- Name: Immunoglobulins

- Relevance: LOW

- As Found: Unknown

- ID: M10122

- Name: Immunoglobulin G

- Relevance: LOW

- As Found: Unknown

- ID: M19117

- Name: Immunoglobulins, Intravenous

- Relevance: LOW

- As Found: Unknown

- ID: M12147

- Name: Myeloma Proteins

- Relevance: LOW

- As Found: Unknown

- ID: M13179

- Name: Paraproteins

- Relevance: LOW

- As Found: Unknown

### Misc Info Module

- Version Holder: 2024-05-24
