International Collaboration for Flu Vaccine Effectiveness Can Prevent Potential Pandemics

The Korean Centers for Disease Control and Prevention reported outbreaks of two types of influenza right before the 2018 Olympic Games, including H3N2, which can cause more severe symptoms than other flu strands. It was estimated during the fourth week of the United States’ 2017-18 flu season that 51 out of every 100,000 people were hospitalized due to H3N2 infections. As all strains of influenza are highly communicable and can be transmitted by a simple hand-shake, the nearly 3,000 athletes that resided in the Olympic Village during the Games were at high risk for contracting H3N2. With potentially diminished immune system functioning due to long-distance travel and extreme physical activity, vaccinations are especially crucial for ensuring athlete resistance to illness.

Influenza, also called “the seasonal flu”, is caused by several types of viruses which frequently mutate. The flu viruses can cause mild to severe symptoms in all patients, ranging from fever and vomiting to rare cases of tissue inflammation leading to life-threatening sepsis or pneumonia. The Center for Disease Control’s Advisory Committee on Immunization Practices (ACIP) highly recommends an annual flu shot, especially for those at high-risk of being in close contact with others, as the vaccine can reduce the length and severity of the illness or eliminate symptoms altogether.

Eighty-one percent of this year’s flu-related deaths have already been caused by H3N2. Vaccines contain weakened and inactive viruses, which once injected, expose the immune system to the unique exterior antigens (surface proteins) of each virus. This exposure then triggers creation of specific antibodies targeting those antigens. If active viruses containing the same surface antigens are introduced into the bloodstream, the newly created antibodies attack the foreign material and minimize a person’s risk of experiencing flu symptoms. This process takes approximately two weeks, so at-risk patients need to ensure adequate timing post-vaccination to minimize their chances of getting sick.

The International Health Regulations (IHR), created by the World Health Organization in 1951, served as the legal body responsible for international laws designed to protect against pandemics. Historically, influenza was excluded from regulation by the IHR, and instead, the World Health Organization created the Global Influenza Surveillance and Response System (GISRS). Due to multiple strains of influenza viruses and their ability to mutate, different strains are prevalent each year and it is nearly impossible to predict which will dominate any given year. The GISRS monitors influenza viruses all over the world and provides updated recommendations for vaccine compositions twice per year. International vaccine manufacturers then have the opportunity to create vaccines based on GISRS’s recommendations and submit their vaccines to their respective regulatory agencies for approval prior to flu season.

The Food and Drug Administration regulates influenza vaccines in the United States and offers expedited review and approval programs due to the nature of the seasonal flu. In 2018, the Center for Disease Control (CDC) released a quadrivalent flu vaccine, which included two inactive influenza A (H1N1 and H3N2) viruses and both common strains of influenza B. Despite containing four different types of weakened viruses, the quadrivalent vaccine was only estimated to be thirty-six percent effective against the H3N2 strains during the United States’ 2017-18 flu season, as compared to seventy-three percent estimated effectiveness against influenza B. 

In many parts of the world, there are additional and sometimes substantial to adequate influenza vaccination. Areas such as the European Union and South Africa have different regulatory regimes which do not all have expedited approval programs. Additionally, many areas only had the trivalent vaccination available for the 2017-18 flu season, which contained the two influenza A strains, but only one of Influenza B strains. Other regional policies may deter people from getting the shots, such as requiring doctors to administer the vaccine in Europe, rather than allowing convenient vaccinations at pharmacies. Availability of these vaccines can be also be a problem in low-income countries due to the manufacturing and regulatory approval cycles.

Despite reduced effectiveness against all viruses which cause influenza, getting a flu shot at any point during the flu season (October to March) will reduce transmission and prevent further outbreak of the disease. The killer strain in 2017-18’s season was H3N2. However, despite variations in international regulatory policies, it was covered by most available vaccines. While effectiveness is not 100% due to international variation in vaccine composition and the two-week period post-vaccine required for maximum effect, many cases of H3N2 arguably could have been prevented if vaccinated. International media coverage of the Olympics has raised awareness in many countries of the need for preparedness plans to prevent potential disease pandemics. The increased media attention could also lead to support to non-profit organizations which deliver vaccines to low-income countries, further preventing spreading of highly communicable viruses like the H3N2 influenza strain. Where an even moderately effective vaccination is internationally available, getting the flu shot at least two weeks prior to traveling to high-risk environments is an easy step everyone can take to reduce the likelihood of debilitating disease pandemics.

Lauren Valentor is a first-year student at DePaul University College of Law. Ms. Valentor worked as an engineer manufacturing implantable medical devices in San Diego prior to law school. She attends as many of the Health Law Institute’s events as possible and is interested in pursuing a legal career allowing the intersection of intellectual property and health law.​​