Time September 21/September 28, 2020Another challenge: just one vaccine
likely won’t be enough. From a manu-
facturing and distribution perspective,
immunizing the world’s population will
take several different vaccines and prob-
ably contributions from all of the compa-
nies currently pushing to produce a prod-
uct. “This is a global problem, and no one
company is going to have the solution,”
says John Shiver, senior vice president
for global vaccine research and develop-
ment at Sanofi, a French pharmaceutical
company. “Because we don’t know what
will work, what will work best or what
will best serve the need in really, really
stopping the pandemic, more shots on
goal are important.”
Even with multiple vaccines, it won’t
be easy to ensure they get to the right peo-
ple at the right time. Nearly all of the can-
didates require two shots, spaced up to a
month or so apart. Some vaccines need
to be maintained at below- freezing tem-
peratures from the manufacturing plant
until close to when they’re injected into
a person’s arm. And once the vaccines are
shipped to hospitals and medical clinics,
who should get immunized first? The most
aggressive manufacturing schedules still
won’t produce enough vaccines to inoc-
ulate everyone, especially in the first few
months. Health experts will have to make
tough decisions about how to distribute
those first precious doses, and are turning
to ethical principles such as risk and social
utility. These put health care workers, peo-
ple with existing health conditions and the
elderly in group living facilities toward the
top of the list, as well as first responders
and others working in essential occupa-
tions such as teachers, law- enforcement
officers and those in waste management.
But, notes Dr. Ezekiel Emanuel, vice
provost for global initiatives at the Uni-
versity of Pennsylvania, such discussions
haven’t addressed the practicalities. Up
to 40% of the U.S. population have exist-
ing health conditions that would qual-
ify them for priority vaccination—far
more than the number of doses that will
likely be available in the first manufac-
turing runs. “We haven’t really thought it
through because it’s a hard problem and
therefore we’ve avoided it,” he says. As
several of the most promising vaccines
barrel toward the final stages of testing,
however, avoidance won’t be possible,
and decisions will have to be made aboutthe 1790s, discovered that exposing peo-
ple to small amounts of the smallpox virus
could give them immunity to the disease.
Today, pharmaceutical and biotech com-
panies are developing or testing more than
100 COVID-19 vaccine candidates and
governments are pumping billions of dol-
lars into a massive global effort the likes
of which we haven’t seen since the polio
epidemic of the 1950s. Everything about
this vaccine endeavor could be history-
making, from the speed with which shots
are developed, to the way they are tested
and authorized, to how they are doled out
to people around the world. Months after
scientists first identified the new corona-
virus, Chinese teams are already testing
nearly 10 potential vaccines. Fueled by
President Donald Trump’s Operation
Warp Speed, which will provide at least
$10 billion in federal funding for research
and testing of promising COVID-19 vac-
cine candidates, the U.S. is conducting
three late-stage trials in healthy volun-
teers. Other countries— including Italy,
Russia, Japan, Singapore, South Korea,
Australia and India—have all launched
human tests of their own vaccines.
Operation Warp Speed promises to
deliver an ambitious 300 million doses
by January 2021; to do so, manufactur-
ers including Moderna, AstraZeneca,
Pfizer, Sanofi and Johnson & Johnson
have already begun to produce their vac-
cine candidates, before ongoing studies
show they are effective. And the U.S. Cen-
ters for Disease Control and Prevention
(CDC) alerted governors in early Sep-
tember of the government’s plan for how
initial doses can be ordered and shipped
when they are available.
These are all calculated risks, made
more fraught by growing tensions be-
tween the political need to restart econ-
omies and educational institutions, and
the requirements of the rigorous scien-
tific and regulatory process that man-
dates a threshold of data proving that a
new vaccine is safe and effective before
it can be released to the public. Russia’s
announcement in August that its Ministry
of Health had approved a vaccine devel-
oped by scientists in Moscow that was still
being tested was widely criticized by the
scientific community as premature and
potentially dangerous to the high-risk
groups that would receive it first. In Sep-
tember, soon after major vaccine makers
Science
pledged in an unusual show of solidarity
to conduct full safety studies on their vac-
cines before submitting them for regula-
tory review, AstraZeneca put its trial on
hold so researchers could investigate an
unexplained illness in one of the study
participants.
These actions serve as reminders that
the development and testing period for
these vaccines is already strained to the
stretching point. Massachusetts- based
Moderna Therapeutics, along with sci-
entists from the government’s National
Institute of Allergy and Infectious Dis-
eases (NIAID), already set records by de-
veloping and readying one candidate for
human testing in 42 days—a process that
in the past has taken years.
And that’s why the accelerated sched-
ule must come with a dose of humility.
The quest to develop a vaccine for a new
infectious disease is a gamble at best;
nearly four decades after HIV was dis-
covered, there is still no effective vac-
cine against that virus. SARS-CoV-2 is so
new to the scientific community that it’s
not even clear yet what the human body
needs to prevent infection—or if such a
thing is even possible. The urgency of
the pandemic means doctors will have
only about a month’s worth of informa-
tion from studies on how long the immu-
nity from the shots might last. Given that,
some experts, including those developing
the vaccine candidates, say we should at
best expect a vaccine that can minimize
the effects of the disease, rather than
provide the “sterilizing immunity” that
would protect people from infection en-
tirely. “For many respiratory pathogens,
it’s a challenge to achieve a sterilizing im-
mune response,” says Dr. Evan Anderson,
associate professor of medicine at Emory
University School of Medicine and the
lead researcher on one of the Moderna
trials. “We don’t know whether that will
be the case with SARS-CoV-2.”