Influenza, or the “flu,” is a virus that affects the respiratory tract or airways. It is spread easily through the air or when contact is made with infected surfaces. The flu can be spread by people with no symptoms who are not aware they are sick. Flu cases can be mild with little to no symptoms, but severe symptoms and serious complications may also occur. Young children, the elderly population, pregnant women, and those with conditions such as heart disease, asthma, and diabetes are more likely to experience complications.
Types of Influenza
There are 4 types of influenza viruses, but the 2 main types that impact people are influenza A and influenza B. These 2 types are responsible for most human illness and the flu strains that typically occur during the annual flu season. The currently approved seasonal flu vaccines protect against influenza A and B viruses known to cause epidemics. The CDC defines an epidemic as a sudden increase in the number of cases of a disease. This is what we observe each year during flu season. Global outbreaks spread over several countries or continents and impact a large number of people. Type A viruses are the only flu viruses known to cause outbreaks. There are clinical trials, such as the Odyssey Trial sponsored by Moderna, that are looking at investigational vaccines for global flu.
Seasonal Flu
Seasonal flu is considered an epidemic that occurs annually across the world. Flu season occurs every year during fall and winter (September through March) in the United States, with peak flu activity occurring between December and February. Seasonal flu is spread by coming in contact with an infected person. It can be spread by droplets in the air due to an infected individual coughing, sneezing, or talking. Prescription antivirals can be used for the treatment of the seasonal flu. Due to the constant exposure of new flu strains, the seasonal flu vaccine is updated every year based on scientific findings and research.
Global Flu Outbreaks
A global outbreak occurs when a new influenza A virus spreads over several countries or continents. The new virus is usually contagious with little to no immunity among people. Global flu virus strains differ from seasonal flu strains. Because fewer people will have immunity to the virus, it will likely infect more people even though it is spread in the same way as the seasonal flu.
Global flu outbreaks do not happen often. In the past 100 years, there have been 4 global flu outbreaks: the Spanish flu in 1918, the Asian flu in 1957, the Hong Kong flu in 1968, and the swine flu in 2009. The World Health Organization continually monitors flu viruses in an attempt to prepare for future flu outbreaks.
Flu viruses that have the potential to spread globally do not always result in global outbreaks. Flu viruses can mutate or transform. Scientists are able to track the evolution of flu viruses and monitor both seasonal flu strains and those with the potential to become global flu outbreaks.
Family and Community Impact
We are all familiar with the impact a global outbreak can have on our personal and collective lives. A global influenza outbreak could result in death and illness, and cause negative mental, social, and economic outcomes, especially among Black communities with higher rates of comorbidities. We can be proactive and work to potentially prevent future harm by collaborating with scientists to further investigational vaccine research by participating in clinical trials.
Help Advance Research by Joining a Clinical Trial
Consider joining a clinical trial, such as the Odyssey Trial, to help researchers study investigational vaccines that aim to prevent global influenza outbreaks.
To join the Odyssey trial, participants must:
- Be 18 years of age or older
- Have a body mass index between 18 kg/m2 and 39 kg/m2
- Not be pregnant
Visit OdysseyFluTrial.com to learn more and see if you qualify for clinical trial participation.
Reference Links:
History of influenza vaccination. World Health Organization, Types of Influenza Viruses. Centers for Disease Control and Prevention, Lesson 1: Introduction to Epidemiology. Centers for Disease Control and Prevention, How flu viruses can change: “drift” and “shift.” Centers for Disease Control and Prevention, Influenza (Flu). Centers for Disease Control and Prevention, Monitoring for Influenza Viruses. Centers for Disease Control and Prevention, Snell NJC. Pandemic Influenza — Prevention and Treatment: Past, Present and Future. Pharmaceut Med. 2010;24(1):1-6. doi:10.1007/BF0325679, Iskander J, Strikas RA, Gensheimer KF, Cox NJ, Redd SC. Pandemic influenza planning, United States, 1978-2008. Emerg Infect Dis. 2013;19(6):879-885. doi:10.3201/eid1906.121478
