Page 1253 - Clinical Immunology_ Principles and Practice ( PDFDrive )

1214 Part ten Prevention and Therapy of Immunological Diseases

TABLE 90.1 Stages of reduction of Army’s A/H1N1 vaccine, which had been successfully used for
Infectious Disease Incidence by Vaccination several years, became significantly less effective in 1947 as a result
and Other Preventive Interventions of antigenic drift. In 1958, the type A virus, which was circulating
at that time, entirely changed its HA and NA proteins to new
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Control. The reduction of disease incidence and prevalence to a subtypes, a process termed antigenic shift. With increased
locally acceptable level as a result of vaccination and/or other recognition that it was necessary to regularly update the vaccine
interventions; continued interventions are needed to maintain the composition to match the changing circulating strains, in 1973,
reduction. Example: diarrheal diseases.
elimination of disease. Reduction to zero of the incidence of a the World Health Organization (WHO) began providing annual
specified disease in a defined geographical area as a result recommendations for the composition of the seasonal influenza
vaccination and/or other interventions; continued measures are vaccine based on the current circulating subtypes and strains.
required. Example: neonatal tetanus. In 1978, the first trivalent vaccine was licensed (two influenza
elimination of infection. Reduction to zero of the incidence of A strains and one influenza B strain). Beginning in 2013, the
infectious disease in a defined geographical area as a result of WHO began including a second type B strain and recommended
vaccination and/or other interventions; continued measures to
prevent reestablishment of transmission are required. Example: four vaccine strains annually (A/H3N2, A/H1N1, B/Victoria,
poliomyelitis elimination from North America. and B/Yamagata), which enabled production and licensure of
eradication. Permanent reduction to zero of the worldwide incidence the new quadrivalent influenza vaccines.
of infection caused by a specific agent as a result of vaccination Several other live, attenuated viral vaccines, such as measles,
and/or other prevention efforts; interventions are no longer needed. mumps, and rubella vaccine (MMR), were developed in the
Example: smallpox. second half of the twentieth century and became staples of
extinction. An infectious agent no longer exists in nature or in the childhood vaccination programs both in the United States and
laboratory. Example: none.
globally. Serial passages of wild-type viruses led to viral adaptation
(Adapted from Dowdle WR. The principles of disease elimination and eradication. Bull for growth in cell cultures and a diminished ability to cause
W H O 1998;76 Suppl 2:22–5.) disease in humans. Importantly, the cell culture–passaged viruses
that were useful as vaccines were not only well tolerated and
to grow in cultures of various types of tissue,” John Enders, safe in humans, but they retained the ability to produce protective
Thomas Weller, and Frederick Robbins jointly received the Nobel immune responses. Later in the twentieth century, the develop-
Prize in Physiology or Medicine in 1954. 29 ment of the Oka strain of the varicella-zoster virus led to live
Recognition and subsequent exploitation in vaccines of key attenuated vaccines for both chicken pox in children and herpes
antigenic substructures rather than whole microbes was another zoster in seniors.
technical advance. For example, the studies of Oswald Avery
(1877–1955), Rebecca Lancefield (1895–1981), and others of the KeY COnCePtS
polysaccharide capsules of Streptococcus pneumoniae 30,31 and the
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M proteins of the Streptococcus species, respectively, led to the Historical Highlights
characterization, isolation, and serotyping of these bacterial • Edward Jenner promotes use of the smallpox vaccine in 1798.
structures and their recognition as key antigens in immunity to • “Morbid matter of various kinds, when absorbed into the system,
streptococcal diseases. Such observations eventually led to safer may produce effects in some degree similar; but what renders the
vaccination with components (subunits) of pathogens, as opposed cow-pox virus so extremely singular is that the person who has
to entire microbes (e.g., the bacterial polysaccharide capsules been thus affected is forever after secure from the infection of the
from S. pneumoniae or Neisseria meningitidis, or the viral surface small-pox; neither exposure to the variolous effluvia, nor the insertion
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of the matter into the skin, producing this distemper.”
antigens [hemagglutinins, or HA] in influenza split-virus vac- • World Health Organization certifies eradication of smallpox from the
cines). When delivered as vaccines, these isolated microbial world in 1980.
components produced protective antibodies and cellular immune • “The world and its peoples have won freedom from smallpox,
responses in vaccinated hosts but did not cause the disease induced which was a most devastating disease sweeping in epidemic form
by the complete wild-type organisms. through many countries since earliest time, leaving death, blindness
The great influenza A/H1N1 pandemic of 1918 (“Spanish and disfigurement in its wake and which only a decade ago was
rampant in Africa, Asia and South America.”
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flu”) caused an estimated 50 million deaths globally. This led to
efforts to develop vaccines against influenza, and in 1933, the
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virus that causes influenza was identified. That discovery quickly The decades following World War II have been described as
led to the first-generation live attenuated and killed monovalent a golden age for vaccinology. Maurice Hilleman (1919–1985)
influenza vaccines. A bivalent vaccine was produced in 1942 developed a number of vaccines against viruses while working
after the discovery of a second influenza type, type B. The ability for large pharmaceutical companies during the middle of the
to grow influenza viruses in embryonated hen’s eggs facilitated twentieth century. His highly productive career included inventions
vaccine production and provided the basis for killed and split- of vaccines against measles, mumps, and rubella; Haemophilus
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virus influenza virus vaccines that came into use in the 1940s. influenzae type b; hepatitis A; hepatitis B; and chickenpox. 34
Over the following years that followed, there was increasing The polysaccharide vaccines developed for the prevention of
awareness of the multiple types of influenza (A, B, and C), bacterial diseases caused by H. influenzae, N. meningitidis, and
subtypes of influenza A (e.g., A/H1N1, A/H3N2), and lineages S. pneumoniae were welcome advances. Over time it was recog-
of influenza B (Victoria and Yamagata). In addition, recognition nized that these polysaccharide antigens were T-cell independent
that influenza virus antigen drift (caused by changes in the two because they contained no peptide/protein antigens. Furthermore,
surface proteins HA and neuraminidase [NA]) could lead to unlike T cell–dependent protein antigens, these carbohydrate
vaccine mismatch with an altered circulating strain and thus antigens failed to produce B-cell memory responses. The polysac-
decreased vaccine effectiveness was first described when the US charide vaccines could not be used in neonates because infants