American Journal of Epidemiology
ª The Author 2011. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of
Public Health. All rights reserved. For permissions, please e-mail: [email protected].
Vol. 174, No. 11
DOI: 10.1093/aje/kwr306
Original Contribution
Vaccine-preventable Diseases, Immunizations, and the Epidemic Intelligence
Service
Alan R. Hinman*, Walter A. Orenstein, and Anne Schuchat
* Correspondence to Dr. Alan R. Hinman, The Task Force for Global Health, 325 Swanton Way, Decatur, GA 30030 (e-mail:
[email protected]).
Initially submitted February 2, 2010; accepted for publication August 4, 2011.
During 1946–2005, vaccine-preventable diseases were the topic of approximately 20% of all epidemicassistance investigations by the Centers for Disease Control and Prevention. Both in the United States and
abroad, current and former Epidemic Intelligence Service officers have played a critical role in describing the
epidemiology of vaccine-preventable diseases, contributing to development of immunization policies, participating in the implementation of immunization programs, and establishing effective means for assessing adverse events following immunization. As newer vaccines are developed and introduced, they will continue to
play similar roles and most likely will be involved increasingly in investigations of the factors that affect people’s
willingness to accept vaccination for themselves or their children.
immunization; immunization programs; prevention and control; vaccines
Abbreviations: CDC, Communicable Disease Center (now the Centers for Disease Control and Prevention); DTP, diphtheria and
tetanus toxoids and pertussis vaccine; EIS, Epidemic Intelligence Service; EISOs, Epidemic Intelligence Service officers; Epi-Aids,
epidemic-assistance investigations.
Introduction and widespread use of vaccines around the
world has led to global eradication of smallpox and neareradication of poliomyelitis (polio). In the United States,
widespread use of vaccines has led to interruption of indigenous transmission (elimination) of polio, measles, rubella,
and diphtheria as well as dramatic reductions in occurrence
of other vaccine-preventable diseases. When the Communicable Disease Center (CDC; currently the Centers for Disease Control and Prevention) was established in 1946 and
the Epidemic Intelligence Service (EIS) in 1951, the only
vaccines routinely administered to children in the United
States were smallpox and combined diphtheria and tetanus
toxoids and pertussis vaccine (DTP), protecting children
against 4 diseases with a simple schedule—a single dose of
smallpox vaccine and 4–5 doses of DTP. Children now routinely receive vaccines to prevent 16 diseases according to
a complex schedule (1). Consequently, dramatic reductions
have occurred in vaccine-preventable diseases among US
children (Table 1) (2).
Since CDC’s establishment in 1946, the agency’s employees have investigated vaccine-preventable diseases, and EIS
officers (EISOs) have been involved since that program began
(3). This article summarizes CDC and EISO investigations of
vaccine-preventable diseases during 1946–2005, noting the
association between investigations into specific diseases
and introduction of vaccines for those conditions. It also
provides selected examples of individual investigations as
well as the role of current and former EISOs in developing
and implementing immunization programs throughout the
United States. Finally, it summarizes the role of EISOs in
smallpox eradication and the ongoing effort to eradicate
polio and reduce mortality caused by measles.
MATERIALS AND METHODS
CDC’s Office of Workforce and Career Development provided a line listing of all reports of epidemic-assistance investigations (Epi-Aids) by year for 1946–2005. The listing
represented an abstraction of the listings of Epi-Aids from
bound volumes. Epi-Aids typically were initiated only
for those investigations carried out by headquarters-based
S16
Am J Epidemiol. 2011;174(Suppl):S16–S22
Vaccine-preventable Disease Epi-Aids, 1946–2005
S17
Table 1. Comparison of Prevaccine With 2010 Morbidity, Vaccine-preventable Diseases, United
States
Disease
Prevaccine Era, No.a
2010, No.b
0
Reduction, %
Diphtheria
21,053
Hepatitis A
117,333
8,493c
93
Hepatitis B (acute)
66,232
c
86
Haemophilus influenzae
type b (age <5 years)
20,000
246d
99
9,419
100
Measles
530,217
63
>99
Mumps
162,344
2,612
98
Pertussis
200,752
27,550
86
All ages
63,607
44,000c
30
Age <5 years
16,069
4,700c
72
Pneumococcus (invasive)
Poliomyelitis (paralytic)
16,316
Rotavirus (hospitalizations)
62,500e
Rubella
47,745
5
>99
152
0
100
Congenital rubella syndrome
Smallpox
0
28,125c
100
55
29,005
0
100
Tetanus
580
26
96
Varicella
4,085,120
a
b
c
d
e
408,512c
90
Adapted from reference 2.
Source: reference 27.
Source: reference 29.
23 type b and 223 of unknown serotype (age <5 years).
Source: reference 20.
EISOs. Investigations conducted by state-based officers usually did not result in issuance of a formal Epi-Aid unless the
officers were deployed to another state or out of the country.
In addition, EISOs working within the Division of Immunization at CDC sometimes undertook investigations of
vaccine-preventable diseases as part of program assistance
to state and local immunization programs and did so without
issuance of Epi-Aids.
The listing describes the topic of each investigation as of
the time it was initiated. One of the authors (A. R. H.) reviewed the line listing of the 4,485 Epi-Aids for which an
investigation was initiated and, on the basis of the subject
line of each one, identified Epi-Aids related to the following conditions now preventable by vaccines—smallpox, influenza or pneumonia, polio, diphtheria, tetanus, pertussis,
measles, mumps, rubella, hepatitis, Haemophilus influenzae
type b, varicella, and rotavirus—and other vaccine-preventabledisease-related topics. The listing was reviewed twice (by
the same person) to ensure complete ascertainment. The
conditions influenza and pneumonia were combined because many of the investigations related to ‘‘acute respiratory disease,’’ ‘‘suspected influenza,’’ ‘‘pneumonia,’’ and
so forth, but the final reports of certain investigations
were unavailable. We also reviewed published and unpublished reports regarding the history of CDC’s involvement in
vaccine-preventable disease prevention and control and
vaccination efforts.
Am J Epidemiol. 2011;174(Suppl):S16–S22
RESULTS
During the 60-year period, vaccine-preventable disease
investigations accounted for 901 (approximately 20%) of
all of CDC’s epidemic investigations (Table 2). After the
EIS Program was established, virtually all investigations
included EISOs (often along with other CDC staff). Hepatitis was, by far, the most commonly investigated condition,
with 338 investigations. Many were conducted before specific diagnostic tests were available; therefore, all forms
of hepatitis are included. Influenza, pneumonia, and acute
respiratory disease were second, with 159 investigations,
followed by measles (n ¼ 108), polio (n ¼ 102), and
smallpox/vaccinia (n ¼ 54). As might be expected, temporal
changes occurred in the types of vaccine-preventable diseases
investigated, often related to development and introduction
of a new vaccine (Table 3). Investigations into smallpox
ended during 1971–1975 but reappeared during 2001–
2005, when 5 investigations examined suspected adverse
events among smallpox vaccine recipients or their contacts.
Polio investigations were most common during the 1950s
and early 1960s.
The relative decline in the number of Epi-Aids after 1975
might have resulted from decreased incidence of vaccinepreventable diseases because of immunization, development of ongoing population-based surveillance systems to
answer questions regarding vaccine-preventable diseases
S18 Hinman et al.
Table 2. Number of Epi-Aids for Vaccine-preventable Diseases, United States, 1946–2005
Period
Influenza/
VPDs
Polio Diphtheria Pertussis Measles Mumps Rubella Hepatitis Hib Varicella Rotavirus Other
Smallpox
Pneumonia
(Total)
1946–1950
9
2
5
1
1951–1955
44
3
3
18
2
1956–1960
74
7
13
19
7
1961–1965a
128
23
19
31
7
1966–1970
143
13
17
14
5
2
30
1971–1975
110
3
10
6
4
2
17
1976–1980
89
24
3
2
12
1981–1985
69
11
3
5
14
1986–1990
72
21
3
8
1991–1995
55
13
4
1996–2000
58
12
7
2
2000–2005b
50
1
4
5
29
35
108
Total
901
5c
52
102
16
1
28
1
1
1
14
159
1
1
1
44
4
6
2
51
2
6
57
3
40
2
1
2
2
3
24
2
1
3
14
5
1
19
13
1
3
19
5
25
1
3
1
1
2
14
16
24
338
2
7
2
1
2
6
1
1
16
4
12
Abbreviations: Epi-Aids, epidemic-assistance investigations; Hib, Haemophilus influenzae type b; polio, poliomyelitis; VPDs, vaccine-preventable
diseases.
a
Two investigations involved 2 diseases.
b
One investigation involved 2 diseases.
c
Five investigations relating to vaccination.
that typically occur in endemic rather than epidemic patterns,
undertaking of formal research efforts to address critical vaccine and program questions, investigations performed as
part of immunization program assistance, or increased state
capacity for investigation.
Measles vaccine was licensed in 1963, and, in 1966, a federally funded effort was initiated to eradicate measles from
the United States (4). This effort was aided by a substantial
increase in the size of the EIS Program and a corresponding
emphasis on investigating and containing measles outbreaks, as reflected in reports of 30 investigations of measles during 1966–1970. The first investigations of pertussis
and varicella occurred during 1951–1955, rubella during
1961–1965, mumps and H. influenzae type b during 1966–
1970, rotavirus during 1986–1990, and human papillomavirus
during 1996–2000. In 1977, one investigation of suspected
neonatal tetanus occurred. Additional investigations included
4 general immunization assistance events during 1961–1965,
a polio vaccination campaign (2001), and failure to vaccinate
(2000). In addition, 4 special investigations were conducted
into aspects of DTP use: concern regarding the association
of DTP and sudden infant death syndrome (1979), abscesses
related to DTP vaccination (1982), a field trial of acellular
pertussis vaccine-containing DTP (1983), and a mass DTP
vaccination campaign (1983).
children, the focus of the program has historically been on
childhood immunization.
Introduction of new vaccines, expansion of immunization
recommendations for children, enactment of the Vaccines
For Children Program (which entitles uninsured, Medicaideligible, and American Indian/Alaska Native children aged
less than 19 years (and underinsured children who seek
care at federally qualified health centers) free vaccine at
any participating provider), and the increasing price of
newer vaccines have resulted in immunization activities
accounting for more than $3.5 billion in costs in 2010
(approximately one-third of the total CDC annual budget).
The vast majority of this money supports state, local, and
tribal health departments with either operational support or
access to vaccines for their populations.
Four of the 5 directors of this activity (the late John J.
Witte and the authors of this paper) started their public
health careers as EISOs. Since establishment of the Division
of Immunization, current and former EISOs have made major
contributions to the understanding of vaccine-preventable
disease epidemiology in the United States and the development of appropriate strategies to address these diseases. The
following examples illustrate the role of EISOs in different
aspects of the immunization enterprise.
Immunization activities at CDC
Investigations by EISOs into vaccine-preventable
disease epidemiology
After the Vaccination Assistance Act was enacted in 1962,
CDC formed a Division of Immunization, which subsequently became the National Immunization Program (1993)
and later the National Center for Immunization and Respiratory Diseases (2006). Although the Vaccination Assistance
Act allowed for supporting immunizations for adults as well
EISOs have been involved in investigating the entire spectrum of vaccine-preventable diseases. Selected examples are
described briefly in chronological order.
A 1960 epidemic of polio in Rhode Island demonstrated
the changing epidemiology of this disease as a result of use
of inactivated poliovirus vaccine and also enabled
Am J Epidemiol. 2011;174(Suppl):S16–S22
Vaccine-preventable Disease Epi-Aids, 1946–2005
Table 3. Timeline of Introduction of Selected Vaccines, United
Statesa
Year
Vaccine
1903
Smallpox vaccine
1926
Diphtheria toxoid
1933
Tetanus toxoid
1945
Influenza vaccine (inactivated)
1948
Diphtheria and tetanus toxoids and pertussis vaccine
1955
Inactivated polio vaccine
1961
Oral polio vaccine, monovalent strains
1963
Trivalent oral polio vaccine
1963
Measles vaccine
1967
Mumps vaccine
1969
Rubella vaccine
1971
Measles-mumps-rubella vaccine
1981
Hepatitis B vaccine—plasma derived
1981
Meningococcal polysaccharide vaccine—A, C, Y, W135
1983
Pneumococcal polysaccharide vaccine—23 valent
1985
Haemophilus influenza type b polysaccharide vaccine
1987
Hepatitis B vaccine—recombinant
1987
Haemophilus influenzae type b conjugate vaccine
1987
Inactivated polio vaccine—enhanced potency
1995
Hepatitis A vaccine
1995
Varicella vaccine
1996
DTaP (diphtheria and tetanus toxoids and acellular
pertussis) vaccine
1998
Rotavirus vaccine (withdrawn in 1999)
2000
Pneumococcal conjugate vaccine—7 valent
2003
Influenza vaccine—live intranasal
2005
Meningococcal conjugate vaccine—A, C, Y, W135
2006
Rotavirus vaccine
2006
Zoster vaccine
2006
Human papillomavirus vaccine
a
Adapted from reference 28.
estimation of vaccine effectiveness. Whereas previous epidemics had been widespread, during this epidemic (with
121 diagnosed or suspected cases), ‘‘cases were remarkably
concentrated within lower socio-economic census tracts and
housing projects within the metropolitan Providence area’’
(5, p. 342). These areas were also the ones with the lowest
vaccination coverage. Estimated vaccine effectiveness was
81%. This investigation demonstrated that striking differences
existed in vaccine coverage among lower socioeconomic status
areas and reinforced the need for extra efforts in such areas.
During November–December 1961, a total of 22 officers
stationed at a naval air base in Florida experienced signs
and symptoms of hepatitis. Clustering of cases indicated
a common-source outbreak. The summary of the article
describing the investigation stated the following:
It was concluded that the disease was primarily spread
through potato salad. A salad handler with minor illness
Am J Epidemiol. 2011;174(Suppl):S16–S22
S19
in October, perhaps anicteric hepatitis, who evidenced
unusual behavior relating to urination, was considered
to be the likely source of the contamination. The mechanics of contamination are obscure although fragmentary
evidence suggests that salad dressing, perhaps contaminated by urine, may have been the specific responsible
ingredient (6, p. 194).
Subsequent Epi-Aids related to hepatitis helped to further
elucidate risk factors for hepatitis A. They also contributed
to formulation of immunization policies with respect to both
hepatitis A and hepatitis B.
EISOs were also involved in measles vaccination programs. In 1966, a mass vaccination program was conducted
in Rhode Island, sponsored by the state medical society.
At the invitation of the state health officer, CDC provided
EISOs, other CDC staff, and 11 jet injector vaccination guns.
A total of 36 clinic sites were selected, each staffed by
volunteer physicians, nurses, and lay community members.
In total, 30,647 children aged 1–12 years were vaccinated
on Sunday, January 23, 1966 (7). Follow-up approximately
2 years later showed that the campaign had apparently
interrupted measles transmission, one of the first demonstrations that transmission could be interrupted by a mass
campaign (8).
A 1970 outbreak of measles in Texarkana, Texas and
Arkansas provided a dramatic example of the impact of
measles vaccination campaigns and school immunization
requirements. A total of 606 cases of measles occurred in
the city, which is bisected by the Texas-Arkansas state
line. Approximately 95% of cases occurred in Texarkana,
Texas, which had never had a measles vaccination campaign and where only 57% of children aged 1–9 years had
been vaccinated. In contrast, a limited number of cases
occurred in Texarkana, Arkansas, where a school immunization requirement was in effect and more than 95% of
children aged 1–9 years had been vaccinated; vaccine efficacy was 95.9% (9).
In 1979, EISOs played prominent roles in investigating
what was recognized later to be the last outbreak of polio
in the United States (10). The outbreak of 15 cases occurred among unvaccinated Amish persons living in Iowa,
Missouri, Pennsylvania, and Wisconsin. Because of preexisting high levels of vaccination in the surrounding communities,
no cases of illness were reported among non-Amish persons.
Epidemiologic and virologic evidence indicated this outbreak
resulted from importation of poliovirus from the Netherlands
through Ontario, Canada, where outbreaks had occurred during 1978 among members of religious groups with objections
to vaccination. Vaccination efforts involved extensive contacts with Amish groups in the 21 states with Amish populations and ultimately resulted in vaccination of approximately
one-half of Amish populations in the United States (11).
During 1988–1989, measles outbreaks in Los Angeles,
California, and Houston, Texas, affected predominantly unvaccinated preschool-aged children within low socioeconomic
groups. Approximately one-fourth of the cases occurred
among children aged less than 16 months (too young to be
protected by vaccination at the then-recommended age of
15 months). A substantial proportion of cases—23% in Los
S20 Hinman et al.
Angeles and 39% in Houston—were reported by single
emergency departments, raising the question whether transmission might be occurring in the emergency departments.
A case-control study was conducted to determine whether
cases were more likely to have visited the emergency department during the period of potential measles exposure
(10–18 days before rash onset). Odds ratios of 5.2 (Los
Angeles) and 8.4 (Houston) were identified, leading the investigators to conclude that
measles transmission in pediatric emergency rooms
played a prominent role in perpetuating these outbreaks.
Measles transmission in emergency rooms can be reduced
by triage and isolation of suspected cases and by vaccination of eligible patients. Vaccination in emergency
rooms provides postexposure prophylaxis and may increase vaccination coverage in the community (12, p. 74).
Although vaccination in emergency departments can prevent
this type of transmission, efforts to introduce immunizations
as a part of emergency department practice generally have
not been successful.
In 1988, a statewide pertussis outbreak of 522 reported
cases occurred in Arizona, providing an opportunity to
study the effectiveness of erythromycin therapy and prophylaxis for pertussis. Seventeen households with 1 or more
secondary cases were compared with 20 households without secondary cases in Maricopa County. Groups were
similar in age distribution, size, crowding, race/ethnicity,
immunization status, and medical care of patients who
were primary cases. However, the median interval from
onset of illness in the patient who was a primary case and
initiation of erythromycin prophylaxis among contacts
was significantly longer in households with secondary
cases (22 days) compared with households with no secondary transmission (16 days). Investigators concluded that
‘‘these results provide additional evidence that erythromycin is effective in the medical management of pertussis and
should be initiated promptly to minimize secondary spread’’
(13, p. 177).
Epi-Aids sometimes lead to legal approaches to ending
outbreaks. An extreme example occurred in Philadelphia,
Pennsylvania. During November 4, 1990–March 24, 1991,
approximately 1,300 measles cases and 9 measles-associated
deaths were reported to the Philadelphia Health Department.
Approximately one-third of the cases and 6 of the deaths
occurred among members of 2 religious groups who did
not accept vaccination or conventional medical treatment.
Five children were hospitalized by court order.
Because voluntary immunization was not accepted by
church member families, on March 4, 1991, the city obtained a court order to immunize preschool age children
of church members who did not have school age siblings
and who were not believed to have been exposed to
measles. All eight of these children were vaccinated
with measles-mumps-rubella vaccine by court order
(14, p. 291).
Investigations were not limited to the United States. In
1991, epidemic diphtheria appeared in the former Soviet
Union and, during the following years, resulted in more than
150,000 cases of the disease. The majority of cases occurring throughout the Russian Federation and Ukraine were
among adults. Serologic surveys in both countries indicated
that a majority of adults lacked protective levels of circulating antitoxin. Other factors contributing to the epidemic
included a lengthy list of contraindications to use of DTP
vaccine and widespread use of reduced-strength diphtheria
toxoid in vaccinating children before school entry (15).
Investigations into vaccine safety
Since the earliest years of the EIS Program, EISOs have
played major roles in evaluating adverse events after vaccine administration, beginning with the Cutter incident in
1955, in which 192 inactivated poliovirus vaccine recipients
or their close contacts experienced paralysis as a result of
inadequate inactivation of the wild poliovirus in the vaccine
(16). This investigation involved at least 11 of 43 EISOs on
duty at the time, and most of the field investigation was
accomplished in less than 6 weeks after the initial report
(17). The investigation revealed that almost all cases were
associated with a single lot of inactivated poliovirus vaccine
manufactured by Cutter Laboratories (originally located in
Berkeley, California) and that the inactivation procedure
used by Cutter allowed some viable viral particles to survive. The overall impact of the Cutter incident was summarized in a history of CDC, as follows:
In retrospect, it was apparent that the Cutter incident was
a turning point in the history of [CDC]. . . . The extensive
surveillance program required a bigger budget, always
a help in achieving recognition, and the value of the Epidemic Intelligence Service was apparent. The importance of competent viral diagnostic services in the
public health movement was clearly demonstrated and
CDC led the way to accomplish this (18, pp. 79–80).
Subsequently, EISOs were involved in assessing the risk
of vaccine-associated paralysis related to oral polio vaccine,
sudden infant death syndrome and DTP, localized abscesses
and DTP, Guillain-Barré syndrome and swine influenza vaccine, and rotavirus vaccine and intussusceptions (refer to the
following discussion).
In addition, EISOs established the Monitoring System for
Adverse Events Following Immunization, the Vaccine Adverse Event Monitoring System, and the Vaccine Safety
Datalink. The Vaccine Adverse Event Monitoring System,
which succeeded the Monitoring System for Adverse Events
Following Immunization, is a passive reporting system obtaining reports on adverse events occurring after vaccination
but is usually not able to determine whether vaccine plays a
causal or coincidental role in the adverse event. By contrast,
the Vaccine Safety Datalink obtains data from 8 different
health maintenance organizations throughout the United
States containing approximately 3% of the US population
and can conduct investigations rapidly to assess the possible
causal roles of vaccines in a variety of adverse events.
One of the largest recent vaccine safety investigations conducted by EISOs was on intussusception among recipients
of rotavirus vaccine in the United States during 1998–1999
Am J Epidemiol. 2011;174(Suppl):S16–S22
Vaccine-preventable Disease Epi-Aids, 1946–2005
(19). During the 11 months after licensure of a tetravalent
rhesus-based rotavirus vaccine, the Vaccine Adverse Events
Monitoring System received reports regarding 15 infants
who had experienced intussusception after receipt of the
vaccine, 12 within 1 week of receipt. Active field investigation revealed that receipt of the vaccine was significantly
associated with increased risk of intussusception, with a frequency of approximately 1 case/10,000 doses administered.
The vaccine was removed from the market. EISOs also participated in epidemiologic assessments and vaccine policy
efforts that resulted in introduction of newer rotavirus vaccines in 2006 that have already led to substantial reductions
in rotavirus illness throughout the United States (20).
Smallpox eradication, polio eradication, and
accelerated measles mortality reduction
Beginning in 1966, CDC assigned EISOs (typically paired
with public health advisors—nonphysicians trained in
practical-field public health (21)) to work in programs to
eradicate smallpox and to control measles in West Africa,
as well as to participate in smallpox eradication activities
throughout the world. Some worked on short-term assignments
(typically 3 months), whereas others were assigned overseas
for periods of 2 or more years. In total, 46 EISOs participated in the smallpox eradication program. A former EISO
(D. A. Henderson) was assigned by CDC to be director of
the Smallpox Eradication Program at the World Health
Organization in Geneva, Switzerland (22). EISOs documented
the effectiveness of the surveillance-containment approach,
which was the strategy that ultimately resulted in global
eradication of smallpox (23).
During the ongoing campaign launched in 1988 to eradicate poliomyelitis, EISOs have played leading roles at
CDC, the World Health Organization (both at headquarters
and at regional offices), and in countries around the world,
again working on both short- and long-term assignments.
A recent initiative to accelerate measles mortality reduction
in sub-Saharan Africa has had remarkable success (24). Approximately 84 EISOs have participated in the global Polio
Eradication Initiative and the Accelerated Measles Mortality
Reduction Initiative. As of December 2010, only 4 countries
are considered endemic for polio transmission (Afghanistan,
India, Nigeria, and Pakistan) (25). Measles mortality in subSaharan Africa was reduced by 75% during 2000–2005 (24).
Additionally, EISOs have played key roles in global efforts
to develop and introduce vaccines against rotavirus, pneumococcal disease, and meningitis in developing countries.
DISCUSSION
Introduction and widespread use of vaccines has led to
dramatic declines in the incidence of vaccine-preventable diseases, typically by more than 95% for vaccines recommended for universal use before 1980. Less dramatic declines
have been observed for certain vaccines introduced more
recently.
As described in the introductory paper to this Journal
supplement (3), the numbers of investigations summarized
here substantially underestimate the total number of vaccineAm J Epidemiol. 2011;174(Suppl):S16–S22
S21
preventable disease investigations involving EISOs, because
Epi-Aids were typically issued only when Atlanta, Georgia–
based EISOs were dispatched or when state-based EISOs
were involved in investigations that crossed state lines. Investigations by state-based EISOs within the state of their
assignment usually did not result in issuance of an Epi-Aid.
During 1966–1969, immunization grants paid the salaries of
40 EISOs assigned to work in state health departments, half
of the time on immunization (specifically, measles eradication) and half of the time on general epidemiology (26).
Consequently, many investigations of vaccine-preventable
diseases are not reflected in the Epi-Aid summaries.
Another limitation of this paper is that final reports on
some of these Epi-Aids were not readily accessible. As a result, further characterizing the 4 general immunization assistance investigations during 1961–1965 was impracticable.
Notwithstanding these limitations, we believe that the information summarized here provides a flavor of the depth
and breadth of EISO involvement in vaccine-preventable
diseases and immunizations during 1946 –2005. The majority
of that involvement has related to vaccines and vaccinepreventable diseases affecting children, but increasing
attention is being paid to adolescents and adults.
Post-EIS contributions made by former EISOs are worth
mentioning. In addition to having trained 4 of the 5 directors
of immunization activities at CDC, many former EISOs
have gone on to become important staff for state and local
health departments as well as CDC. Former EISOs have
been important members (and chairs) of the Advisory Committee on Immunization Practices and the National Vaccine
Advisory Committee as well as members and chairs of
World Health Organization and professional society advisory committees. Additionally, they have made important
contributions to the development and assessment of vaccines, both in academia and within industry.
SUMMARY AND CONCLUSIONS
Investigations into diseases now preventable by vaccines
have been a hallmark of CDC since the early 1950s. Both in
the United States and abroad, EISOs have played a critical
role in describing the epidemiology of vaccine-preventable
diseases, contributing to development of immunization policies, participating in the implementation of immunization
programs, and establishing effective means for assessing adverse events after vaccination. As newer vaccines are developed and introduced, EISOs will continue to play similar
roles and most likely will be involved increasingly in investigations of the factors that affect people’s willingness to
accept vaccination for themselves or their children.
ACKNOWLEDGMENTS
Author affiliations: The Task Force for Global Health,
Decatur, Georgia (Alan R. Hinman); Bill and Melinda Gates
Foundation, Seattle, Washington (Walter A. Orenstein); and
National Center for Immunization and Respiratory Diseases, Atlanta, Georgia (Anne Schuchat).
S22 Hinman et al.
The authors did not receive any funding for this project.
The findings and conclusions in this report are those of
the authors and do not necessarily represent the official
position of the Centers for Disease Control and Prevention.
Conflict of interest: none declared.
REFERENCES
1. Centers for Disease Control and Prevention. Immunization
schedules. Atlanta, GA: US Department of Health and Human
Services, CDC; 2009. (http://www.cdc.gov/vaccines/recs/
schedules/default.htm). (Accessed July 8, 2009).
2. Roush SW, Murphy TV. Historical comparisons of morbidity
and mortality for vaccine-preventable diseases in the United
States. Vaccine-Preventable Disease Table Working Group.
JAMA. 2007;298(18):2155–2163.
3. Thacker SB, Stroup DF, Sencer DJ. Epidemic assistance by the
Centers for Disease Control and Prevention: role of the Epidemic Intelligence Service, 1946–2005. Am J Epidemiol. 2011;
174(suppl):S4–S15.
4. Sencer DJ, Dull HB, Langmuir AD. Epidemiologic basis for
eradication of measles in 1967. Public Health Rep. 1967;82(3):
253–256.
5. Oren J, McAteer RF, Serfling RE. Rhode Island poliomyelitis,
1960. Preliminary report. R I Med J. 1961;44:337–342.
6. Joseph PR, Millar JD, Henderson DA. An outbreak of hepatitis
traced to food contamination. N Engl J Med. 1965;273:188–194.
7. Byrne EB, Rosenstein BJ, Jaworski AA, et al. A statewide mass
measles immunization program. JAMA. 1967;199(9):619–623.
8. Schaffner W, Schluederberg AE, Byrne EB. Clinical epidemiology of sporadic measles in a highly immunized population. N Engl J Med. 1968;279(15):783–789.
9. Landrigan PJ. Epidemic measles in a divided city. JAMA.
1972;221(6):567–570.
10. Epidemiologic notes and reports: paralytic poliomyelitis—
Pennsylvania. MMWR Morb Mortal Wkly Rep. 1979;28:
207–208.
11. Epidemiologic notes and reports: poliomyelitis—United
States, Canada. [Reprinted from MMWR May 25 and July 27,
1979, with current editorial notes]. MMWR Morb Mortal Wkly
Rep. 1997;46(50):1194–1195.
12. Farizo KM, Stehr-Green PA, Simpson DM, et al. Pediatric
emergency room visits: a risk factor for acquiring measles.
Pediatrics. 1991;87(1):74–79.
13. Sprauer MA, Cochi SL, Zell ER, et al. Prevention of secondary
transmission of pertussis in households with early use of
erythromycin. Am J Dis Child. 1992;146(2):177–181.
14. Rodgers DV, Gindler JS, Atkinson WL, et al. High attack rates
and case fatality during a measles outbreak in groups with
religious exemption to vaccination. Pediatr Infect Dis J. 1993;
12(4):288–292.
15. Sutter RW, Hardy IR, Kozlova IA, et al. Immunogenicity of
tetanus-diphtheria toxoids (Td) among Ukrainian adults: im-
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
plications for diphtheria control in the Newly Independent
States of the former Soviet Union. J Infect Dis. 2000;
181(suppl 1):S197–S202.
Nathanson N, Langmuir AD. The Cutter incident. Poliomyelitis following formaldehyde-inactivated poliovirus vaccination in the United States during the spring of 1955. II.
Relationship of poliomyelitis to Cutter vaccine. Am J Hyg.
1963;78:29–60.
Hinman AR, Thacker SB. The Cutter incident. Poliomyelitis
following formaldehyde-inactivated poliovirus vaccination in
the United States during the spring of 1955. II. Relationship of
poliomyelitis to Cutter vaccine [invited commentary]. Am J
Epidemiol. 1995;142(2):107–108.
Etheridge EW. Sentinel for Health: A History of the Centers
for Disease Control. Berkeley, CA: University of California
Press; 1992:79–80.
Intussusception among recipients of rotavirus vaccine—
United States, 1998–1999. MMWR Morb Mortal Wkly Rep.
1999;48(27):577–581.
Prevention of rotavirus gastroenteritis among infants and
children: recommendations of the Advisory Committee on
Immunization Practices (ACIP). MMWR Recomm Rep. 2009;
58(RR-2):1–25.
Meyerson BE, Martich FA, Naehr GP. Ready to Go: The
History and Contributions of U.S. Public Health Advisors.
Research Triangle Park, NC: American Social Health Association; 2008.
Henderson DA. Smallpox—the Death of a Disease: The Inside
Story of Eradicating a Killer. Amherst, NY: Prometheus Press;
2009.
Ogden HG. CDC and the Smallpox Crusade. Atlanta, GA: US
Department of Health and Human Services, Public Health
Service, Centers for Disease Control; 1987. (HHS publication
(CDC) 87-8400).
Wolfson LJ, Strebel PM, Gacic-Dobo M, et al. Has the 2005
measles mortality reduction goal been achieved? A natural
history modelling study. Measles Initiative. Lancet. 2007;
369(9557):191–200.
World Health Organization. Wild poliovirus weekly update.
Geneva, Switzerland: World Health Organization; 2009. (http://
www.polioeradication.org/Dataandmonitoring/Poliothisweek/
Poliocasesworldwide.aspx). (Accessed January 19, 2011).
Hinman AR. The history of immunization at CDC. Proceedings of the 30th National Immunization Conference. Atlanta,
GA: Centers for Disease Control and Prevention; 1996:7–13.
Final 2010 reports of nationally notifiable infectious diseases.
MMWR Morb Mortal Wkly Rep. 2011;60(32):1088–1101.
Orenstein WA, Pickering LK, Mawle A, et al. Immunization.
In: Mandell GL, Bennett JE, Dolin R, eds. Principles and
Practice of Infectious Diseases. 7th ed. Philadelphia, PA:
Churchill Livingston; 2009.
Centers for Disease Control and Prevention. Active Bacterial
Core Surveillance Report: Streptococcus pneumoniae, 2009.
(http://www.cdc.gov/abcs/reports-findings/survreports/spneu09.
html). (Accessed August 31, 2011).
Am J Epidemiol. 2011;174(Suppl):S16–S22