Department: Editor's Memo
As flu season approaches, many people worry about how severe the illness will be this year and whether the vaccine is going to be effective in preventing the flu. On the other hand, public health officials have a larger, global population-focused concern: prevention and control of influenza and whether this year will be when the next influenza pandemic strikes.
Saunders-Hastings and Krewski wrote a review on the history of influenza, highlighting previous pandemics and recounting the four most destructive: the Spanish flu in 1918–1920 with the H1N1 strain, the Asian flu in 1957–1958 with the H2N2 strain, the Hong Kong flu in 1968–1970 with the H3N2 strain, and the Swine flu in 2009–2010 with a new H1N1 strain.1
The first three pandemics originated in China based on discoverable evidence, and the fourth was traced to Mexico. With an estimated 40–50 million deaths worldwide, the Spanish flu was one of the greatest public health disasters in recorded history.
In the past, pandemics spread along dominant lines of movement and communication, primarily via military and trade routes. Today, globalization has made it easier for novel viruses to travel swiftly around the world and spread new influenza viruses within populations for which few individuals have developed an immunity. These situations create outbreaks that are difficult and often impossible to contain. However, a positive outcome of globalization is that it has facilitated common efforts from different public health agencies in research and surveillance, resulting in more effective preparation and control of influenza.
From global to local
Each year, the Global Influenza Surveillance and Response System of the World Health Organization meets to review surveillance data about circulating flu viruses worldwide. This committee recommends which viruses should be included in the next season's influenza vaccine for the Northern Hemisphere and other areas of the world. The FDA's Vaccines and Related Biological Products Advisory Committee reviews similar data and makes the final determination of vaccine composition for the US.
Vaccine manufacturers are informed of the viruses chosen before production begins. The CDC's Advisory Committee on Immunization Practices Influenza Work Group then develops recommendations and creates an immunization schedule for the upcoming flu season, considering age, formulation, dosage, and administration timing, including provisions for special populations, which are available to healthcare professionals.2 The full process of identifying important influenza viruses, approval, vaccine production and distribution, vaccine administration, and surveillance is complex and depends on the cooperation of multiple government agencies.
Are you vaccinated?
The 2019–2020 trivalent influenza vaccine contains A/Brisbane/02/2018-like (H1N1) virus, A/Kansas/14/2017-like (H3N2) virus, and B/Colorado/06/2017-like (Victoria lineage) virus. The quadrivalent influenza virus contains the aforementioned three viruses plus B/Phuket/3073/2013-like (Yamagata lineage) virus.2 The CDC recommends routine annual vaccination for all individuals age 6 months or older who do not have contraindications. Pandemics are inherently uncertain. The manufacturing process for vaccines has been greatly purified, and surveillance measures are more sophisticated. However, public health agencies must maintain policies that are flexible in responding to outbreaks as they develop. Get your flu shot and make sure to wash your hands often.
Jamesetta A. Newland, PhD, FNP-BC, FAANP, DPNAP, FAAN
1. Saunders-Hastings PR, Krewski D. Reviewing the history of pandemic influenza: understanding patterns of emergence and transmission. Pathogens
2. Grohskopf LA, Alyanak E, Broder KR, Walter EB, Fry AM, Jernigan DB. Prevention and control of seasonal influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices—United States, 2019-20 influenza season. MMWR Recomm Rep
. 2019;68(No. RR-3):1–21.