Various observational studies have reported an association between influenza vaccination and lower rates of infection with SARS-Cov-2 and less COVID-19 disease severity have been reported in large epidemiological studies in US, Brazil and Italy. Observational studies from the Netherlands showed also strongly reduced COVID-19 infection rates among influenza-vaccinated healthcare workers, with ORs of 0.61 and 0.49 for the first and second wave of COVID-19, respectively. In addition, in-vitro immunological analyses showed that the quadrivalent inactivated influenza vaccine can induce a trained immunity program against SARS-CoV-2 (2). In-vivo vaccination against influenza was also shown to induce improved interferon responses against SARS-CoV-2, with modulation of hyperinflammatory responses. Trained immunity could be the underlying mechanism for the potential protective effect of influenza vaccine, a mechanism that has also been proven for BCG vaccination, and epidemiological evidence suggests similar non-specific effects of MMR and OPV vaccination. Currently, various clinical trials are being conducted to study the impact of BCG, MMR and OPV vaccination on COVID-19, but prospective clinical data on influenza vaccination are lacking. Although specific COVID-19 vaccines have been developed and are proven effective, there are important reasons for assessing in a controlled randomized trial the effect of influenza and MMR vaccine on COVID19: * Specific COVID-19 vaccines are still not yet available for all segments of the population, and especially not for the majority of the population in developing countries. * The emergence of new SARS-CoV-2 variants, especially the P1 variant from Brazil, may very well be associated with reduced response to vaccines. An immunomodulatory protective vaccine that protects in an antigen-independent manner would be of great importance. * It would also be conceptually important to know whether influenza and the MMR vaccine can induce heterologous protection against another viral infection, in the context of future pandemics.
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Cumulative incidence of SARS-CoV-2 infection during 1 year follow up
Timeframe: 3 months after inclusion
Cumulative incidence of SARS-CoV-2 infection
Timeframe: 6 months after inclusion
Cumulative incidence of SARS-CoV-2 infection
Timeframe: 12 months after inclusion