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 In interviews with Reuters, more than a dozen influential infectious
disease and vaccine development experts said there is growing
evidence that a first round of global vaccinations may offer
enduring protection against the coronavirus and its most worrisome
variants discovered to date.
Some of these scientists expressed concern that public expectations
around COVID-19 boosters are being set by pharmaceutical executives
rather than health specialists, although many agreed that preparing
for such a need as a precaution was prudent.
They fear a push by wealthy nations for repeat vaccination as early
as this year will deepen the divide with poorer countries that are
struggling to buy vaccines and may take years to inoculate their
citizens even once.
"We don't see the data yet that would inform a decision about
whether or not booster doses are needed," said Kate O'Brien,
director of the Department of Immunization, Vaccines and Biologicals
at the World Health Organization (WHO).
O'Brien said the WHO is forming a panel of experts to assess all
variant and vaccine efficacy data and recommend changes to
vaccination programs as needed.
Pfizer Inc Chief Executive Albert Bourla has said people will
"likely" need a booster dose of the company's vaccine every 12
months - similar to an annual flu shot – to maintain high levels of
immunity against the original SARS-CoV-2 virus and its variants.
"There is zero, and I mean zero, evidence to suggest that that is
the case," countered Dr. Tom Frieden, former director of the U.S.
Centers for Disease Control and Prevention.
"It's completely inappropriate to say that we're likely to need an
annual booster, because we have no idea what the likelihood of that
is," Frieden, who now leads the global public health initiative
Resolve to Save Lives, said of Pfizer's assertions on boosters.
Pfizer, responding to the criticism, said it expects a need for
boosters while the virus is still circulating widely. That could
change once the pandemic is more firmly under control, a company
spokeswoman said.
Moderna Inc CEO Stephane Bancel aims to produce a vaccine by the
fall that targets a variant first identified in South Africa and
expects regular boosters will be needed.
The United States is preparing to have such doses on hand for
Americans, while the European Union, Britain and Israel have ordered
new supplies of COVID-19 vaccines to deploy as protective boosters.
Some health experts, including Richard Hatchett, chief executive of
the Coalition for Epidemic Preparedness Innovations (CEPI) that has
funded many vaccine projects, say vaccine makers are right to plan
ahead for boosters given the uncertainty over what will be needed in
the long run.
Governments can then decide for themselves whether to buy the
products, he said.
"A LITTLE EVIDENCE"
Pfizer and German partner BioNTech SE have so far found that their
shot remains more than 91% effective for six months after people
received their second dose, compared with nearly 95% demonstrated in
their clinical trial. The companies will track how robust the
protection remains over time.
Dr. William Gruber, Pfizer's senior vice president of vaccine
clinical research and development, told Reuters earlier this month
the prediction for yearly boosters was based on "a little evidence"
of a decline in immunity over those six months.
Pfizer expects the COVID-19 vaccine to be a major revenue
contributor for years, and has forecast sales of $26 billion from
the shot in 2021. Global spending on COVID-19 vaccines and booster
shots could total $157 billion through 2025, according to U.S.
health data firm IQVIA Holdings.
[to top of second column] |
 Moderna President Stephen Hoge
expects boosters will be needed to keep immunity
levels high, due in part to vaccine hesitancy,
as an estimated 30% of the U.S. population may
not agree to be vaccinated. As long as the virus
is circulating widely, people at high risk of
severe illness may need to boost their immune
protection, Hoge said.
"All governments are in conversations with (Moderna)
and other companies about boosters," he said.
BROADER IMMUNITY?
Late last year, scientists were optimistic that
highly effective vaccines could quickly curb the
global pandemic that has battered economies and
killed more than 3.4 million people.
Those hopes dimmed by February with evidence
that mutant versions of the virus might evade
protection offered by vaccines. Laboratory
studies showed that the South African variant
could produce six to eight-fold reductions in
antibody levels among people vaccinated with the
Pfizer or Moderna vaccines.
Clinical trial data also showed that vaccines
from AstraZeneca Plc, Johnson & Johnson and
Novavax Inc were less effective at preventing
infections in South Africa, where the variant is
widespread.
These studies spurred drug companies to start
testing booster doses of their vaccines and to
develop shots that target specific variants of
the virus.
However, more recent research suggests that the
Moderna and Pfizer/BioNTech vaccines produce
high levels of protective antibodies to create a
"cushion effect" against the known variants,
said Dr. Anthony Fauci, head of the National
Institutes of Allergy and Infectious Diseases (NIAID)
and a top White House adviser.
And antibodies - which block the coronavirus
from attaching to human cells - do not tell the
whole story. Several studies suggest that T
cells - a type of white blood cell that can
target and destroy already infected cells - may
help prevent severe COVID-19 and
hospitalization.
NIAID researchers found that T cells in the
blood of people who recovered from the original
virus could still fight off infections caused by
the concerning variants found in the UK, South
Africa and Brazil.
"It's quite possible" that boosters would not be
needed, Fauci told Reuters. "It is conceivable
that the variants will not be as much a problem
with a really good vaccine as we might have
anticipated."
 Nevertheless, health authorities in the United
States, Britain and Europe are assuring their
populations that a new round of shots will be
available if needed, with many nations still
desperate for vaccine supplies.
"It's a huge concern that ... wealthy countries
would begin administering booster doses and
further constraining supply of people's first
dose of vaccine," said Rajeev Venkayya, head of
global vaccines for Takeda Pharmaceutical Co.
Dr. Monica Gandhi, an infectious disease doctor
at the University of California, San Francisco,
said ultimately, decisions on whether boosters
will be needed "will best be made by public
health experts, rather than CEOs of a company
who may benefit financially."
(Reporting by Julie Steenhuysen in Chicago and
Kate Kelland in London; Additional reporting by
Michael Erman in Maplewood, N.J.; Editing by
Michele Gershberg and Bill Berkrot)
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