Measles

Measles initially presents with general flu-like symptoms, followed by more identifiable characteristics

Measles kills T and B-cells, causing severe immune suppression and further complications & secondary infections. 2010, Millennium Development Goals

Measles is caused by a negative sense ssRNA virus         The Hemagglutinin (H) and Fusion (F) proteins mediate transmission of the measles virus into host cells in the human respiratory tract (3). The virus is absorbed into the host cell when Hemagglutinin proteins bind to the CD46 and CD150 host cellular receptors (1,3). Once uncoated in the host cell, RNA polymerase transcribes the viral RNA genome into mRNA, which then undergoes translation in order to manufacture viral proteins (1). These viral proteins function to formulate new helical capsids for the replication of the virus, which eventually leaves the host cell through the process of budding (1). Although the transmission of the virus initially infects the upper respiratory tract, replication of the virus in epithelial cells can spread the virus to the lymph nodes and further replication in the lymphatic system can spread the virus to other organs including the liver, skin, kidneys and gastrointestinal tract (3). The pathogen infects human epithelial cells, endothelial cells and macrophages (3).         The virus's mode of infection is airborne droplets and can be transmitted by exposure to someone infected with this pathogen (3). The measles is exceedingly infectious and transmitted by respiratory fluid secretions most commonly from sneezing or coughing (1). 

Measles is the #1 cause of vaccine-preventable death in the world! Measles infection has its greatest incidence in children under 2 years of age, with a high mortality (10%) (malnutrition being an important factor) Measles cases from April 2015 – September 2015

The measles vaccine has a complex history 1954 – Measles virus isolated from 13 y.o. student David Edmonston in Boston, MA 1963 – First licensed vaccine from Edmonston-B strain (Enders & Peebles) 1968 – Hilleman (c/o Merck) develops more attenuated version of vaccine 1971 – Measles Mumps Rubella (MMR) combination vaccine licensed 1998 – Wakefield paper published in the Lancet linking MMR to autism 2005 – Measles Mumps Rubella Varicella (MMRV) vaccine licensed John F. Enders Dr. Thomas C. Peebles Maurice Hilleman

The vaccine drastically reduced the number of U.S. measles cases Resurgence of measles in 1989-1991 in vaccinated patients led to recommendation of second dosage of MMR

The Measles & Rubella Initiative reduced global measles deaths worldwide by 79% between 2000 and 2014.

Andrew Wakefield’s publication in The Lancet (1998) + “anti-vaxxers” hindered the progress of measles eradication

Anti-vaccine campaigns have had dramatic consequences

Since Measles is endemic and highly contagious, high vaccination rates are required to prevent outbreaks and create “herd immunity.”

Immune suppression caused by measles can last ~2 years by wiping out memory cells, leading to “immune amnesia” to nonmeasles pathogens Science, 2015

Advocating for the measles vaccine happened in the past and is still needed today American Academy of Pediatrics + Measles & Rubella Initiative, 2014 United Kingdom, 1987

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