COVID-19NCT04348240
Transmissibility and Viral Load of SARS-CoV-2 in Oral Secretions
An observational study of COVID-19, run by National Institute of Dental and Craniofacial Research (NIDCR) at 1 site in United States.
Trial summary
Background: COVID-19 is a worldwide pandemic and currently there is no effective therapy or vaccine. SARS-CoV-2, the virus that causes the COVID-19 respiratory infection, appears to be very contagious however all the modes of transmission are unclear. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- COVID-19
- How many people
- 55 participants
- Where
- 1 siteUnited States
- Study dates
- 16 Apr 2020to 27 Jan 2022
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: 1) asymptomatic high-risk subjects with known history of close personal contact with a COVID-19 positive person not tested (SARS-CoV2 status unknown)2) asymptomatic or mildly symptomatic (fever withoutcough, sneezing or shortness of breath) subjects who are COVID-19 positive 3) COVID-19 positive individuals retesting negative can be enrolled to complete the electronic questionnaire(s) assessment and allow evaluation of history of symptoms. 4) COVID-19 positive individuals enrolled and admitted to the NIH Clinical Center for other protocols.
Who may be able to join
- In order to be eligible to participate in this study, an individual must meet all the following criteria:
- Willing and able to sign and date the informed consent form
- Willing to comply with all study procedures and available for study visits and calls
- Male or female, aged >= 18 years of age
- Persons who test COVID-19 positive in past 48 hours (verbal confirmation followed by documented test results, sent electronically) and are asymptomatic or have mild symptoms (e.g., fever, mild malaise, sore throat or sneezing) individuals who have re-tested and are negative may be enrolled to understand progression and resolution of disease; persons hospitalized at the NIH Clinical Center meeting Inclusion Criteria 1-3 may be enrolled on this study
- Persons considered high risk for COVID-19 due to personal contact within the past 7 days with a COVID-19 positive individual (e.g., co-habitating family member of COVID-19 positive) and has no symptoms or mild symptoms of COVID-19 - verbal confirmation followed by documented test results of positive individual, sent electronically
Who cannot join
- An individual who meets any of the following criteria will be excluded from participation in this study:
- 1. COVID-19 positive subjects with active moderate or severe symptoms of cough or shortness of breath (upper and lower respiratory symptoms) or currently requiring hospitalization at a hospital other than NIH Clinical Center (recovering COVID-19 positive patients can be enrolled).
Trial locations and contacts
1 site in 1 country.
United States1 site
National Institutes of Health Clinical Center
Bethesda, Maryland, 20892
About this study
Official title: Transmissibility and Viral Load of SARS-CoV-2 Through Oral Secretions
Background:
COVID-19 is a worldwide pandemic and currently there is no effective therapy or vaccine. SARS-CoV-2, the virus that causes the COVID-19 respiratory infection, appears to be very contagious however all the modes of transmission are unclear. Transmission may occur in up to 25 percent of cases when there are no symptoms (asymptomatic). Before there are any symptoms, droplet spray during speaking may increase transmission from person to person; most of the spray is saliva. Researchers at the NIH would like to test saliva for the virus before symptoms are reported. Additionally, they would like to examine the importance of using masks to prevent transmission. They hope to better understand how COVID-19 is spread among people and how it can be prevented. For this study they would like to collect samples from the nose (nasopharyngeal swab), mouth (spit sample), eye (conjunctival fluid) and blood to test for the virus and if it is contagious.
Read more
Objectives:
To determine if the SARS-CoV-2 virus is present in saliva in asymptomatic individuals who are COVID-19 positive. To determine if using masks can prevent transmission.
Eligibility:
People ages 18 and older without symptoms or with mild symptoms (e.g., low grade fever,
mild malaise, minor sore throat, runny nose, or sneezing) who have been in close contact (e.g. live in the same house) with someone who has tested positive for COVID-19 or people who have tested positive for COVID-19 and have mild (e.g., low grade fever, mild malaise, minor sore throat, runny nose, or sneezing) or no symptoms.
Design and Procedures:
For screening, interested participants will contact a study team member. The interested participant will be asked to provide documentation of COVID-19 positive status, their symptoms, or their contact to a COVID-19 positive person.
Participants will be asked to come to the NIH drive-up COVID-19 testing site or NIH Clinical Center (Bethesda, MD) for 2 or more visits in 15 days for the following procedures: nasal swab for COVID-19 and viral load, verbal symptom assessment, saliva collection, and speaking exercise to capture oral fluid. During this time, participants will also be asked to participate in phone calls with the study staff and to complete questionnaires electronically. Participants will have weekly telephone calls to discuss their symptoms and 2-5 drive-up visits to the NIH within 28 days. If visits are scheduled at the Clinical Center, participants will have the option to participate in providing blood sample(s), a conjunctival swab and 1-2 salivary gland biopsies.
If a participant has tested positive, they may be asked to return to the NIH after they have recovered from COVID-19 for additional sampling.
The following procedures are part of this research:
- Speaking exercise - participants will be asked to read a short script with and without wearing a mask. The droplets they produce while they speak will be collected.
- Saliva collection - participants will spit into a cup and have saliva collected from different areas of the mouth. They should not eat 90 minutes before this but drinking water or juice is acceptable. They may have their tongue painted with a sour liquid to increase their saliva.
- Nasal swab- participants will have a swab rubbed inside their nose.
- Nasopharyngeal swab - participants that are close contacts of COVID-19 positive individual(s) and need a COVID-19 test, will have a swab inserted through the nose to rub the back of their throat.
- Questionnaires - participants will complete questionnaires about their symptoms electronically at home.
The following procedures are optional for participants to agree to participate in and will be performed in the Clinical Center:
- Blood sample(s) - participants will have blood collection via venipuncture.
- Conjunctival swab - participants will have the inner lower eyelid wiped with swab.
- Minor salivary gland biopsy - participants will have tiny glands in mouth removed. Procedure will be done in the hospital.
Participants will be paid up to a total of $300 for the study, based on the number of visits to NIH and the types of procedures performed. Payment will be: $50 on Day 1, Day 15 and at the recovery visit. Participants who agree to the optional conjunctival swab and/or biopsy will be paid $50 for each conjunctival swab (up to 1) and/or $50 for each salivary biopsy (up to 2).
If at any time the participants start to have moderate or severe respiratory symptoms, their participation in the study will end and they should seek care with their local provider.
Read the detailed description
COVID-19 is a worldwide pandemic without an effective therapy. A series of reports have implicated that asymptomatic transmission occurs in at least 25% SARS-CoV-2 cases. We hypothesize that droplet emission from oral fluids generated during speaking could be an important and actionable factor driving asymptomatic transmission. We aim to collect oral and nasal secretions, conjunctival fluid and blood to test for viral load and viral infectivity in 1) asymptomatic or mildly symptomatic high-risk subjects with unknown SARS-CoV-2 status, but with a history of close personal contact with a SARS-CoV-2 positive person and 2) asymptomatic or mildly symptomatic subjects who are SARS-CoV-2 positive. 3) COVID-19 positive individuals retesting as negative can be enrolled to complete the electronic questionnaire(s) assessment and allow for evaluation of history of symptoms. 4) COVID-19 positive individuals admitted to the NIH Clinical Center can be enrolled as a symptomatic comparison cohort.
- Conditions
- COVID-19
- Keywords
- Saliva, Coronavirus, SARS-CoV-2, Symptoms, COVID19, Natural History
- Medical subject headings
- COVID-19, Coronavirus Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Group 1 | asymptomatic or mildly symptomatic high-risk subjects with unknown SARS-CoV-2 status but with known history of close personal contact with a COVID-19 positive person. | |
| Group 2 | asymptomatic or mildly symptomatic (e.g., low grade fever, mild malaise, minor sore throat, runny nose, or sneezing) subjects who are COVID-19 positive. | |
| Group 3 | COVID-19 positive individuals retesting negative can be enrolled to complete the electronic questionnaire(s) and allow evaluation of history of symptoms. | |
| Group 4 | COVID-19 positive individuals enrolled and admitted to the NIH Clinical Center for other protocols. |
What is being measured
The primary outcome is the main question the study is designed to answer.
To determine SARS-CoV-2 viral load and infectivity insaliva that may contribute to asymptomatic transmission
detection of virus in saliva, blood and conjunctival fluid
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Apr 2020
- Study start16 Apr 2020
- Primary completion15 Dec 2021
- Study completion27 Jan 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for COVID-19Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 55 participants (actual)
Sponsor and investigators
- Lead sponsor
- National Institute of Dental and Craniofacial Research (NIDCR)
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Blake M Warner, D.D.S., Principal investigator, National Institute of Dental and Craniofacial Research (NIDCR)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04348240
- Sponsor's protocol ID
- 200094
- Other IDs
- 20-D-0094
- Status last verified
- 22 Jan 2026
- First submitted
- 15 Apr 2020
- Last updated
- 26 Jan 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
To KK, Tsang OT, Leung WS, Tam AR, Wu TC, Lung DC, Yip CC, Cai JP, Chan JM, Chik TS, Lau DP, Choi CY, Chen LL, Chan WM, Chan KH, Ip JD, Ng AC, Poon RW, Luo CT, Cheng VC, Chan JF, Hung IF, Chen Z, Chen H, Yuen KY. Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study. Lancet Infect Dis. 2020 May;20(5):565-574. doi: 10.1016/S1473-3099(20)30196-1. Epub 2020 Mar 23.
PubMed 32213337Rubin EJ, Baden LR, Morrissey S. Audio Interview: Lessons from Covid-19 Hotspots. N Engl J Med. 2020 Apr 2;382(14):e35. doi: 10.1056/NEJMe2007783. No abstract available.
PubMed 32242382Fauci AS, Lane HC, Redfield RR. Covid-19 - Navigating the Uncharted. N Engl J Med. 2020 Mar 26;382(13):1268-1269. doi: 10.1056/NEJMe2002387. Epub 2020 Feb 28. No abstract available.
PubMed 32109011
Study at a glance
From the registry record, last updated by the sponsor on 26 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Transmissibility and Viral Load of SARS-CoV-2 Through Oral Secretions
- ClinicalTrials.gov ID
- NCT04348240
- Acronym / sponsor ID
- 200094
- Conditions
- COVID-19
- Keywords
- Saliva, Coronavirus, SARS-CoV-2, Symptoms, COVID19, Natural History
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 55 participants (actual)
- Lead sponsor
- National Institute of Dental and Craniofacial Research (NIDCR)US National Institutes of Health
- Study start
- 16 Apr 2020 (actual)
- Primary completion
- 15 Dec 2021 (actual)
- Study completion
- 27 Jan 2022 (actual)
- First posted
- 16 Apr 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background:
COVID-19 is a worldwide pandemic and currently there is no effective therapy or vaccine. SARS-CoV-2, the virus that causes the COVID-19 respiratory infection, appears to be very contagious however all the modes of transmission are unclear. Transmission may occur in up to 25 percent of cases when there are no symptoms (asymptomatic). Before there are any symptoms, droplet spray during speaking may increase transmission from person to person; most of the spray is saliva. Researchers at the NIH would like to test saliva for the virus before symptoms are reported. Additionally, they would like to examine the importance of using masks to prevent transmission. They hope to better understand how COVID-19 is spread among people and how it can be prevented. For this study they would like to collect samples from the nose (nasopharyngeal swab), mouth (spit sample), eye (conjunctival fluid) and blood to test for the virus and if it is contagious.
Objectives:
To determine if the SARS-CoV-2 virus is present in saliva in asymptomatic individuals who are COVID-19 positive. To determine if using masks can prevent transmission.
Eligibility:
People ages 18 and older without symptoms or with mild symptoms (e.g., low grade fever,
mild malaise, minor sore throat, runny nose, or sneezing) who have been in close contact (e.g. live in the same house) with someone who has tested positive for COVID-19 or people who have tested positive for COVID-19 and have mild (e.g., low grade fever, mild malaise, minor sore throat, runny nose, or sneezing) or no symptoms.
Design and Procedures:
For screening, interested participants will contact a study team member. The interested participant will be asked to provide documentation of COVID-19 positive status, their symptoms, or their contact to a COVID-19 positive person.
Participants will be asked to come to the NIH drive-up COVID-19 testing site or NIH Clinical Center (Bethesda, MD) for 2 or more visits in 15 days for the following procedures: nasal swab for COVID-19 and viral load, verbal symptom assessment, saliva collection, and speaking exercise to capture oral fluid. During this time, participants will also be asked to participate in phone calls with the study staff and to complete questionnaires electronically. Participants will have weekly telephone calls to discuss their symptoms and 2-5 drive-up visits to the NIH within 28 days. If visits are scheduled at the Clinical Center, participants will have the option to participate in providing blood sample(s), a conjunctival swab and 1-2 salivary gland biopsies.
If a participant has tested positive, they may be asked to return to the NIH after they have recovered from COVID-19 for additional sampling.
The following procedures are part of this research:
- Speaking exercise - participants will be asked to read a short script with and without wearing a mask. The droplets they produce while they speak will be collected.
- Saliva collection - participants will spit into a cup and have saliva collected from different areas of the mouth. They should not eat 90 minutes before this but drinking water or juice is acceptable. They may have their tongue painted with a sour liquid to increase their saliva.
- Nasal swab- participants will have a swab rubbed inside their nose.
- Nasopharyngeal swab - participants that are close contacts of COVID-19 positive individual(s) and need a COVID-19 test, will have a swab inserted through the nose to rub the back of their throat.
- Questionnaires - participants will complete questionnaires about their symptoms electronically at home.
The following procedures are optional for participants to agree to participate in and will be performed in the Clinical Center:
- Blood sample(s) - participants will have blood collection via venipuncture.
- Conjunctival swab - participants will have the inner lower eyelid wiped with swab.
- Minor salivary gland biopsy - participants will have tiny glands in mouth removed. Procedure will be done in the hospital.
Participants will be paid up to a total of $300 for the study, based on the number of visits to NIH and the types of procedures performed. Payment will be: $50 on Day 1, Day 15 and at the recovery visit. Participants who agree to the optional conjunctival swab and/or biopsy will be paid $50 for each conjunctival swab (up to 1) and/or $50 for each salivary biopsy (up to 2).
If at any time the participants start to have moderate or severe respiratory symptoms, their participation in the study will end and they should seek care with their local provider.
Detailed description
COVID-19 is a worldwide pandemic without an effective therapy. A series of reports have implicated that asymptomatic transmission occurs in at least 25% SARS-CoV-2 cases. We hypothesize that droplet emission from oral fluids generated during speaking could be an important and actionable factor driving asymptomatic transmission. We aim to collect oral and nasal secretions, conjunctival fluid and blood to test for viral load and viral infectivity in 1) asymptomatic or mildly symptomatic high-risk subjects with unknown SARS-CoV-2 status, but with a history of close personal contact with a SARS-CoV-2 positive person and 2) asymptomatic or mildly symptomatic subjects who are SARS-CoV-2 positive. 3) COVID-19 positive individuals retesting as negative can be enrolled to complete the electronic questionnaire(s) assessment and allow for evaluation of history of symptoms. 4) COVID-19 positive individuals admitted to the NIH Clinical Center can be enrolled as a symptomatic comparison cohort.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Group 1 | – | –asymptomatic or mildly symptomatic high-risk subjects with unknown SARS-CoV-2 status but with known history of close personal contact with a COVID-19 positive person. |
| Group 2 | – | –asymptomatic or mildly symptomatic (e.g., low grade fever, mild malaise, minor sore throat, runny nose, or sneezing) subjects who are COVID-19 positive. |
| Group 3 | – | –COVID-19 positive individuals retesting negative can be enrolled to complete the electronic questionnaire(s) and allow evaluation of history of symptoms. |
| Group 4 | – | –COVID-19 positive individuals enrolled and admitted to the NIH Clinical Center for other protocols. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- 1) asymptomatic high-risk subjects with known history of close personal contact with a COVID-19 positive person not tested (SARS-CoV2 status unknown)2) asymptomatic or mildly symptomatic (fever withoutcough, sneezing or shortness of breath) subjects who are COVID-19 positive 3) COVID-19 positive individuals retesting negative can be enrolled to complete the electronic questionnaire(s) assessment and allow evaluation of history of symptoms. 4) COVID-19 positive individuals enrolled and admitted to the NIH Clinical Center for other protocols.
Key inclusion criteria (6 listed)
- In order to be eligible to participate in this study, an individual must meet all the following criteria:
- Willing and able to sign and date the informed consent form
- Willing to comply with all study procedures and available for study visits and calls
- Male or female, aged >= 18 years of age
- Persons who test COVID-19 positive in past 48 hours (verbal confirmation followed by documented test results, sent electronically) and are asymptomatic or have mild symptoms (e.g., fever, mild malaise, sore throat or sneezing) individuals who have re-tested and are negative may be enrolled to understand progression and resolution of disease; persons hospitalized at the NIH Clinical Center meeting Inclusion Criteria 1-3 may be enrolled on this study
Key exclusion criteria (2 listed)
- An individual who meets any of the following criteria will be excluded from participation in this study:
- 1. COVID-19 positive subjects with active moderate or severe symptoms of cough or shortness of breath (upper and lower respiratory symptoms) or currently requiring hospitalization at a hospital other than NIH Clinical Center (recovering COVID-19 positive patients can be enrolled).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
To determine SARS-CoV-2 viral load and infectivity insaliva that may contribute to asymptomatic transmission
detection of virus in saliva, blood and conjunctival fluid
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Jan 2026.
- Background: PubMed 32213337To KK, Tsang OT, Leung WS, Tam AR, Wu TC, Lung DC, Yip CC, Cai JP, Chan JM, Chik TS, Lau DP, Choi CY, Chen LL, Chan WM, Chan KH, Ip JD, Ng AC, Poon RW, Luo CT, Cheng VC, Chan JF, Hung IF, Chen Z, Chen H, Yuen KY. Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study. Lancet Infect Dis. 2020 May;20(5):565-574. doi: 10.1016/S1473-3099(20)30196-1. Epub 2020 Mar 23.
- Background: PubMed 32242382Rubin EJ, Baden LR, Morrissey S. Audio Interview: Lessons from Covid-19 Hotspots. N Engl J Med. 2020 Apr 2;382(14):e35. doi: 10.1056/NEJMe2007783. No abstract available.
- Background: PubMed 32109011Fauci AS, Lane HC, Redfield RR. Covid-19 - Navigating the Uncharted. N Engl J Med. 2020 Mar 26;382(13):1268-1269. doi: 10.1056/NEJMe2002387. Epub 2020 Feb 28. No abstract available.
- NIH Clinical Center Detailed Web PageLink provided by the sponsor.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Blake M Warner, D.D.S. principal investigator
National Institute of Dental and Craniofacial Research (NIDCR)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of COVID-19, run by National Institute of Dental and Craniofacial Research (NIDCR) at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 26 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To determine SARS-CoV-2 viral load and infectivity insaliva that may contribute to asymptomatic transmission. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04348240, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Jan 2026.