Buccopharyngeal route administered high polyphenolic olive oil and COVID‐19: A pilot clinical trial
Authors: Rodríguez‐Argente Francisco , Alba‐Domínguez María , Díaz‐Martínez María P. , Díaz‐Vergara Cristian , Díaz‐Márques Belén , Ferrero‐Ortega Paloma , Gil‐Adrados Ana C. , Gómez‐Bernardo Lorena , Gordo‐Murillo Laura , Fuente Elsa Humanes‐de la , Jurado‐Palomo Jesús , Ortega‐González Ángel , Machado‐Gallas Juana , Moreno‐Ancillo Álvaro , Ávila‐Martín Gerardo , Marín‐Guerrero Ana C. , Álvarez‐Gregori Joaquín 
Published: October 2023

AbstractIntroductionWaning immunity after vaccination justifies the need for additional effective COVID‐19 treatments. Immunomodulation of local immune response at the oropharyngeal mucosa could hypothetically activate mucosal immunity, which can prevent SARS‐CoV‐2 main immune evasion mechanisms in early stages of the disease and send an effective warning to other components of immune system. Olive polyphenols are biologically active compounds with immunomodulatory activity. There are previous studies based on immunomodulation with olive polyphenols and respiratory infections using an enteral route, which point to potential effects on time to resolution of symptoms. The investigators sought to determine whether participants following immunomodulation with tiny quantities of high polyphenolic olive oil administered through an oromucosal route could have a better outcome in COVID‐19.SummaryThis pilot clinical trial investigated the effect of buccopharyngeal administered high polyphenolic olive oil on COVID‐19 incidence, duration, and severity.ImportanceWaning immunity after vaccination justifies the need of further research for additional effective treatments for COVID‐19.ObjectiveImmunomodulation of local immune response at the buccopharyngeal mucosa could hypothetically activate mucosal immunity, which would in turn difficult SARS‐CoV‐2 immune evasion mechanisms in early stages of the disease and send an effective warning to other components of immune system. Olive polyphenols are biologically active compounds with immunomodulatory activity. There are previous studies based on immunomodulation with olive polyphenols and respiratory infections, using an enteral route, which suggest potential shortening of time to resolution of symptoms. The investigators sought to determine whether participants following immunomodulation with tiny quantities of high polyphenolic olive oil administered through an oromucosal route could have a better outcome in COVID‐19.Design, Setting, and ParticipantsDouble blind, randomized pilot clinical trial conducted at a single site, Talavera de la Reina, Spain. Potential study participants were identified by simple random sampling from the epidemiological database of contact patients recently diagnosed of COVID‐19 during the study period. A total of 88 adult participants were enrolled and 84 completed the 3‐month study, conducted between July 1, 2021 and August 31, 2022.InterventionParticipants were randomized to receive oromucosal administered high polyphenolic olive oil, 2 mL twice a day for 3 months or no treatment.Main Outcome and MeasuresPrimary outcomes were incidence, duration, and severity of COVID‐19 after intervention.ResultsThere were no differences in incidence between both groups but there were significant differences in duration, the median time to resolution of symptoms was 3 days in the high polyphenolic olive oil group compared with 7 days in the no‐treatment group. Although time to resolution is directly related to severity, this study did not find any differences in severity.Conclusion and RelevanceAmong full‐vaccinated adults recent infected with COVID‐19, a daily intake of tiny quantities of oromucosal administered high polyphenolic olive oil before infection significantly improved the time to symptom resolution. This finding strongly support the appropriateness of further deep research on the use of oromucosal administered high polyphenolic olive oil as an effective immune strategy against COVID‐19.