Orenstein's epiphany occurred in 1974. It happened in India,
where he was sent to help eradicate smallpox after joining the CDC
as an Epidemic Intelligence Service officer.
changed my life," says Orenstein. "I saw this
terrible, disfiguring disease with a high mortality disappear before
my eyes because of a vaccine. It lured me to the power and potential
of vaccines. It also taught me that just having the vaccine in the
bottle isn't enough. There's a science that goes beyond
merely having an effective vaccine to get the desired impact on
as director of the CDC's National Immunization Program and
now as director of vaccine policy and development for the Emory
Vaccine Center—revolves around that premise. Such was the
case with smallpox. The vaccine worked because the strategy to halt
disease transmission—surveillance and containment—succeeded.
"It illustrated the power of the vaccine and using the right
strategy to deliver it," he says.
Orenstein understands such lessons
well, having led the CDC's $1.6 billion effort to reduce vaccine-preventable
diseases worldwide and helping create the blueprint for the nation's
childhood immunization program. Today, he is applying lessons learned
to help advance scientific discovery at the Emory Vaccine Center
and to address the challenges related to vaccine development, manufacture,
delivery, financing, and policy.
More than ever, his utmost concern
is influenza and the very real possibility of a flu pandemic. The
key to prevention, says Orenstein, is "to determine whether
a policy emphasizing vaccination of children, who are major transmitters
of influenza viruses, would have greater benefit than the current
strategy, which focuses on people like the elderly, who are at risk
of complications and who frequently don't have good immune
Orenstein is tackling the flu vaccine
question with medicine, nursing, and public health researchers at
Emory. In one study, experts are gathering opinions from physicians,
parents, insurers, manufacturers, and others to determine the feasibility
of a policy requiring annual vaccination of the U.S. population
against influenza. In another study, experts are seeking to determine
the best method for flu immunization delivery.
"We've been working with
the state of Georgia and public and private providers to look at
whether they offer flu vaccine through special clinics, walk-in
clinics, or by appointment," Orenstein says. "We want
to determine what kinds of practices are associated with better
coverage so we can set standards for what works best."
He is also seeking to improve flu
vaccination rates among health care workers at Emory and Atlanta
hospitals. "Health care workers often have the same misconceptions
and fears about vaccines as the public," he says. "We
are working with hospitals to determine their vaccination policies,
how successful they've been, and which policies are associated
with higher coverage levels. We'd like to achieve better coverage
than the 40% average for health care workers in the country."
The Emory Vaccine Center has afforded
Orenstein opportunities to address diseases beyond the scope of
his CDC work. HIV tops the list. In a five-year study funded by
NIH, investigators from Emory, the University of Pennsylvania, Georgia
Tech, and Duke are working to genetically engineer a specific vector,
modified vaccinia ankara or MVA, which carries HIV genes, to induce
a better immune response than other MVA vectors now in clinical
trial. The goal of the study is to take this new MVA HIV vaccine
from the laboratory into development and eventual clinical trial
to demonstrate that it safely induces an immune response that can
At the Hope Clinic, the clinical trial
arm of the Emory Vaccine Center, investigators are looking at ways
to prevent viscerotropic disease, a rare but severe reaction to
the vaccine for yellow fever. They are giving yellow fever vaccine
in combination with immunoglobulin, which contains protein antibodies
that attach to the virus. They hope the combination will reduce
the amount of virus in the blood to levels easier for the body to
control and thereby reduce risk of developing viscerotropic disease.
Hope Clinic study could set the stage for delivering vaccines
through the skin. Orenstein's collaborators are using a
technique to clean the skin that also removes the stratum corneum,
the layer that inhibits access to dendritic cells. These cells
help generate an immune response in the body. If successful, this
technique could deliver vaccines more effectively, eliminate syringes,
and provide more doses from the same amount of vaccine.
In the policy arena, Orenstein serves
on a working group with the National Vaccine Advisory Committee
to look at the financing of vaccines, especially those for children.
Given the large number of vaccines recently incorporated into
the child and adolescent immunization schedule, the cost to buy
vaccines for children has risen substantially. In 1987, the price
to purchase vaccine doses for eight diseases was $116 per child.
Today, vaccines for 16 diseases cost $1,700 per child.
"This tremendous change accounts
for the cost increase," says Orenstein. "But having
new vaccines available and recommendations to use them are not
sufficient to reduce disease burdens if doctors can't afford
to give them, or parents can't afford to buy them, or insurance
policies don't cover them, or the government is not purchasing
vaccines for people the same as before. These issues need to be
solved to obtain the same level of control with new vaccines and
recommendations as we did with the old."
In the eyes of others, the former
CDC administrator carries a lot of clout when it comes to vaccine
policy. "Walt has the ability to collect information, analyze
it, and then make recommendations that will be listened to and
followed in this country and around the world," says School
of Medicine Dean Thomas Lawley.
A case in point was the "Universal
Vaccination Against Influenza: Are We Ready?" meeting in
2005. Emory's Exploratory Center for Interdisciplinary Research
in Vaccinology co-sponsored the meeting with the CDC and the National
Vaccine Program Office.
"One result that came out
of that meeting was a consensus to move toward a universal vaccination
approach for the country," says Orenstein. "The logical
first group was children 24 to 59 months of age, and that became
Participants came to that conclusion
based on evidence that showed young children have a significant
health burden in terms of doctor's visits and ER visits
for flu. These children also transmit the flu to others.
When it comes to developing vaccine
policy, "showing community benefits as a result of decreased
disease transmission is not enough," says Orenstein. "There
must be individual benefits as well. You can't just say,
‘Let's get Johnny vaccinated to protect grandma.'
That may make sense to us as health professionals. But parents
aren't willing to do that unless they feel the vaccine is
very safe and Johnny is getting some benefit."
This spring, Orenstein took on another
role in the Center for Influenza Research and Surveillance, one
of six new national centers funded by NIH. Researchers from the
School of Medicine and the University of Georgia's veterinary
school will investigate how flu viruses adapt to new hosts and
how they are transmitted between hosts. Their primary goal: to
determine how flu viruses mutate to infect other species—especially
humans infected with the avian flu virus—in order to prevent
a possible flu pandemic.