NCT04348240

Transmissibility and Viral Load of SARS-CoV-2 in Oral Secretions

Completed Last updated 26 January 2026

What this trial tests

trial in COVID-19 in 55 participants. Completed in 27 January 2022.

Timeline

16 April 2020

Primary endpoint
15 December 2021

27 January 2022

Quick facts

Lead sponsor	National Institute of Dental and Craniofacial Research (NIDCR)
Status	Completed
Study type	OBSERVATIONAL
Enrollment	55
Start date	16 April 2020
Primary completion	15 December 2021
Estimated completion	27 January 2022
Sites	1 location across United States

Conditions studied

• COVID-19 — all drugs for COVID-19 →

Sponsor

National Institute of Dental and Craniofacial Research (NIDCR)

Who can join

18 and older, any sex, with COVID-19. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

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.

Publications & conference data

8 peer-reviewed publications reference this trial (live from Europe PMC):

1. SARS-CoV-2 infection of the oral cavity and saliva.
   Huang N, Pérez P, Kato T, Mikami Y, et al · · 2021 · cited 596× · PMID 33767405 · DOI 10.1038/s41591-021-01296-8
2. The "oral" history of COVID-19: Primary infection, salivary transmission, and post-acute implications.
   Marchesan JT, Warner BM, Byrd KM. · · 2021 · cited 23× · PMID 34390597 · DOI 10.1002/jper.21-0277
3. Evidence of a Sjögren's disease-like phenotype following COVID-19 in mice and humans.
   Shen Y, Voigt A, Goranova L, Abed M, et al · · 2023 · cited 12× · PMID 37676726 · DOI 10.1172/jci.insight.166540
4. Sensitive extraction-free SARS-CoV-2 RNA virus detection using a chelating resin.
   Guan B, Frank KM, Maldonado JO, Beach M, et al · · 2021 · cited 10× · PMID 34396082 · DOI 10.1016/j.isci.2021.102960
5. SARS-CoV-2 infection of salivary glands compromises the production of a secreted antifungal peptide with potential implications for development of oral candidiasis.
   Alfaifi AA, Wang TW, Perez P, Sultan AS, et al · · 2024 · cited 4× · PMID 39666753 · DOI 10.1371/journal.ppat.1012375
6. Antiviral innate immunity is diminished in the upper respiratory tract of severe COVID-19 patients
   Ramos-Benitez MJ, Strich JR, Alehashemi S, Stein S, et al · · 2022 · DOI 10.1101/2022.11.08.22281846
7. Evidence of a Sjögren’s disease-like phenotype following COVID-19
   Shen Y, Voigt A, Goranova L, Abed M, et al · · 2022 · DOI 10.1101/2022.10.20.22281265
8. 40 Weeks In: A Look at How One NIH Institute Handled the Unimaginable.
   D'Souza RN, Lee JS, Shum L, Hoffman M. · · 2021 · PMID 33906484 · DOI 10.1177/00220345211013305