Household Transmission and Immunity to SARS-CoV-2 among Paediatric Clients of a Primary Care Center in a Low-resource Community in Rio de Janeiro

Lead Research Organisation: London School of Hygiene & Tropical Medicine
Department Name: Infectious and Tropical Diseases

Abstract

Our aim is to study the household transmission dynamics of SARS-CoV-2 in a slum in Rio de Janeiro, Brazil and to estimate the immunity of the study population against the new virus. We will examine and test a sample of children and their families for SARS-CoV-2.
Recruitment will take place at a primary health clinic, located in one of the poorest neighbourhoods of the city. We will recruit children 0 to 13 years of age who are brought to the clinic to receive free vaccinations. With the written informed consent from the child's guardian, we will collect the study samples. Afterwards we will visit the child's home to collect samples of all residents, with four follow-up visits in the first month, every three months during the first year and twice in the second year. We hope to uncover the role of children in the disease transmission.

Technical Summary

This project aims to characterise household transmission dynamics in Manguinhos, an urban slum (favela), which has one of the lowest Human Development Index (HDI) scores of Rio de Janeiro/Brazil. We will also estimate the immunity of the study population against SARS-CoV-2. This will be a prospective study of household contacts of
laboratory-confirmed SARS-CoV-2 infected and non-infected children and their families, following the WHO Household Transmission Investigation Protocol for COVID-19. We will recruit children 0 to 13 years of age who are brought to the local health care centre to receive free vaccinations. The clinic provides primary care to 4,300 children in this age group per month. After obtaining written informed consent from the child's guardian, samples will be collected at the clinic (oral fluid, nasopharyngeal and rectal swabs, and serum). The child's home will then be visited to collect samples from contacts. All samples will be screened for SARS-CoV-2 by PCR following the Charité protocol, and serum for IgG antibodies by ELISA or CLIA and for neutralising antibodies by FRNT.

At the household we will collect samples at Days 1 (first visit), 14 and 28, every three months during the first year and twice in the second year. Clinical follow up will be done through telephone calls and video conferences by nurses and paediatricians from Day 0 to Day 28.

Publications

10 25 50

 
Description Our study characterized the clinical, virological, and immunological characteristics of SARS-CoV-2 infection in a low-resource urban community by following the members of 842 households during study visits at regular intervals over two years. We collected clinical samples from the participants and performed a total of 7,500 RT-PCR tests for SARS-CoV-2 and 5,500 serological tests for COVID-19 antibodies.

Our analysis demonstrated that the direction of COVID-19 transmission is predominately from adults and adolescents to children. We showed that there was a benefit of vaccination as preventing onward transmission to household contacts. Outreach activities included edutainment workshops for children in the community about COVID-19 prevention and the importance of vaccination in general.

The objective of the proposal was "to gain an understanding of the transmission dynamics of COVI19 to household contacts of children, as well as rapid and early information on key clinical, epidemiological, virological characteristics of SARS-CoV-2 infection, and immunity". We believe that all the components of this objective have been met. We developed a REDCap database for the collection and analysis of clinical and epidemiological data. In collaboration with the Measles and Respiratory Viruses Reference Laboratory at the Oswaldo Cruz Foundation, we sequenced the virus over five waves of transmission: pre-variants of concern, as well as during the periods of predominance of the Zeta, Gamma, Delta, and Omicron variants. The dynamics of humoral immunity were characterized following natural infection and vaccination. We showed that neutralizing antibody responses against Omicron were reduced compared to prior variants and that the anamnestic response to the first boost was more pronounced than after the second boost.
Exploitation Route Our results indicated that the vaccination of the adults in a household, especially mothers, significantly reduced the onward transmission of SARS-CoV-2. This could incentivize vaccine uptake, which is a critical aspect of efforts to control COVID-19. Our findings were taken forward by the Technical Committee of the Regional Medical Association of Rio de Janeiro, of which Dr. Brasil is a member. In this capacity, Dr. Brasil participated in decision-making such as vaccination requirements and both pharmacological and non-pharmacological interventions against COVID-19. The outreach component of the project included edutainment workshops in which children in the community learned about vaccination. Recordings of the workshop were edited to create brief, educational videos that are being made available to a wider audience on social media to ensure maximum accessibility and possibility of further sharing. The dissemination of our results might impact the adherence of the population to the recommended health policies to the control of COVID-19, especially immunization and non-pharmacological interventions.
Sectors Healthcare

 
Description • Details of emerging economic and societal impact arising from the award The project has made it possible for children in the community to have much more frequent access to specialized care by pediatricians. The project also has an educational component that contributes to reducing transmission of respiratory viruses and increasing vaccination. In addition, the project provides follow-up care to the participating families. With respect to economic impacts, most of the project's research team are residents of the community where the project is being conducted. To this extent, the project has provided work and training opportunities to the community. • Impacting on the public, private or third/voluntary sectors, and elsewhere The impact of the project on the public sector is that it provides data that support the Brazilian Ministry of Health's recommendations about COVID-19 prevention. This includes the recent decision to make COVID-19 vaccines available to all children 2-5 years of age free of charge. • Challenges overcome to achieve impact Armed conflicts in the community posed a challenge to conducting our study. When study visits were delayed due to street violence, we resumed them promptly as soon as it was safe. It was only possible to enroll and follow a COVID-19 cohort in this community because of the team's expertise in follow-up and experience working in challenging conditions. Another challenge was that the evolution of variants of concern made it more difficult to develop live virus neutralization assays. • Impact within academia This project resulted in our group undertaking research in the new area of Long COVID-19, a syndrome that has generated considerable interest due to its health and economic impacts.
First Year Of Impact 2022
Sector Healthcare
Impact Types Societal,Policy & public services

 
Description Dr. Brasil was elected to the Technical Committee of the Regional Medical Association of Rio de Janeiro (Camara Tecnica do Conselho Regional de Medicina do Rio de Janeiro)
Geographic Reach Local/Municipal/Regional 
Policy Influence Type Participation in a guidance/advisory committee
Impact Dr. Brasil's participation in the advisory committee has contributed to improved vaccination policies that have reduced the incidence of COVID-19 in Brazil.
 
Description Covid Mother Infant Pairs (COMP) Study
Amount $250,000 (USD)
Organisation Simons Foundation 
Sector Charity/Non Profit
Country United States
Start 06/2021 
End 05/2024
 
Description Infant Immunologic & Neurologic Development following Maternal Infection in Pregnancy during Recent Epidemics
Amount $250,000 (USD)
Funding ID AI172252-01 
Organisation National Institute of Allergy and Infectious Diseases (NIAID) 
Sector Public
Country United States
Start 02/2023 
End 03/2024
 
Description LSHTM and Oswaldo Cruz Foundation's Collaborative Research on Household Clusters of COVID-19 
Organisation Oswaldo Cruz Foundation (Fiocruz)
Country Brazil 
Sector Public 
PI Contribution The LSHTM team has contributed to study design, data interpretation, and the writing of the first manuscript.
Collaborator Contribution Our partners at the Oswaldo Cruz Foundation (FIOCRUZ) have led the recruitment of study participants in Rio de Janeiro Brazil. They have also been responsible for testing of samples for SARS-CoV-2 by RT-PCR and ELISA.
Impact This collaboration has generated a paper that was published in Pediatrics. Our research partnership involves the disciplines of epidemiology, virology, immunology, and statistical analysis.
Start Year 2020
 
Description Brazilian Public Health Association Guidance on Chloroquine 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Dr. Brasil authored a technical note on COVID-19 treatments published by the Brazilian Public Health Association. The note discouraged the use of chloroquine as COVID-19 treatment or prophylaxis. The report included a review of the literature demonstrating that chloroquine is not an effective treatment or prophylaxis for COVID-19.
Year(s) Of Engagement Activity 2020
URL https://www.abrasco.org.br/site/wp-content/uploads/2020/05/Nota-CQ-HCQ-20-05-2020-01h00.pdf
 
Description Dissemination: Children's theater production and workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact We produced a play for children about COVID-19 explaining how infection occurs and emphasizing the importance of individual preventative measures such as mask use and the value of vaccination in general. There were two performances of the play at the local community centre. Each performance was followed by an interactive session run by actor educators with hands-on activities to reinforce the public health information in the play. An audiovisual production company filmed the play and interactive session. The recording was edited to create brief, educational videos that are being made available to a wider audience on social media to ensure maximum accessibility and possibility of further sharing. The dissemination of our results might impact the adherence of the population to the recommended health policies to the control of COVID, especially immunization and non-pharmacological interventions.
Year(s) Of Engagement Activity 2023
 
Description Editorial in the largest Brazilian newspaper 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Dr. Brasil wrote an editorial published in Folha de São Paulo, which is the newspaper with the highest daily circulation in Brazil. The subject of the editorial, entitled "Doctors Should Have Autonomy, but They Must Also Respect Science", was the practice of prescribing hydroxychloroquine as COVID-19 prophylaxis. Dr. Brasil's editorial explained to the general public that this practice has been investigated and discredited by numerous randomized controlled trials conducted around the world. It is hoped that the editorial will discourage this off-label use of hydroxychloroquine.
Year(s) Of Engagement Activity 2021
URL https://www1.folha.uol.com.br/opiniao/2021/01/autonomia-do-medico-deve-respeitar-a-ciencia.shtml
 
Description Report on the Use of Chloroquine and Hydrochloroquine for the Treatment of COVID-19 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Dr. Brasil was a member of a panel of experts from learned societies in Brazil including the Brazil's National Academy of Medicine that drafted a technical report on the use of chloroquine during the COVID-19 pandemic. The report reviewed the literature on COVID-19 treatments and explained that chloroquine provided no clinical benefits. The report influenced the formulation of public policies on COVID-19 treatments in Brazil.
Year(s) Of Engagement Activity 2021
URL https://iqc.org.br/ciencia/uploads/2020/12/Nota-CQ-HCQ-20-05-2020.pdf