COVID Vaccines: Production, Approval, Distribution, Vaccination Take-Up
Challenge of distribution for COVID-19 (AFP) |
"We need to be absolutely transparent about what is known and what is not known about each vaccine in order to allow people to weigh the risks and benefits of these novel vaccines.""We must be utterly clear about who the vaccines were tested on, what kinds of safety issues we might expect -- even when they are typically very rare in vaccines -- how long the immunity from the vaccine can be expected to last, and whether or not the vaccine stops you from being able to transmit the virus.""Messaging around these vaccines should be fairly neutral and stick to the facts as we know them at the time.""There simply isn't enough vaccine supply to achieve this [herd immunity] -- and we don't even know yet if these vaccines will halt transmission of COVID-19. So the choice to get the vaccine or not will be a personal health decision in the early days of immunization programs and people need to have the facts in order to make informed choices about whether and when to get vaccinated."Allison Thompson, researcher, University of Toronto
"We can plan, but at this point it's unknown which of the vaccines will be approved first and what quantities will come to Canada.""The military has significant expertise in logistics, especially in medical and health service support. They will be skilled in quickly setting up places where vaccines could be administered to patients, set up processes for administration, plan logistics, routes for shipping and transport if needed."Mahesh Nagarajan, professor of supply chain management and health care operations, Sauder School of Business, University of British Columbia"This is a completely new platform [messenger RNA in both the Pfizer and Moderna vaccines] for a vaccine.""The public has to understand how they work. We already have people who are worried about standard vaccines. These are even newer.""Many of the larger hospitals have that [sub-zero-plus] capability. But then you have to figure out how to get it out [safely to the end-user].""Fridges will break down. If we work hard and we're diligent, that wastage can be kept to a minimum."Dr.Gerald Evans, chair, division of infectious diseases, Queen's University"What we are doing is unprecedented in scale."Dr.Kate O'Brien, director, department of immunization, vaccines and biologicals, World Health Organization
Getty Images Natalia Kokhanova |
The
WHO's Dr. O'Brien spoke at the Canadian Immunization Conference that
took place last week, addressing the complex logistics health
professionals will be facing in the effort to roll out approved
vaccines, taking into account measures to safeguard their efficacy, and
inoculating billions of people across the globe. Public health officials
have a need to identify those in the public to be given priority
status, she stressed, those most in need of immediate protection from
the virus simply because they represent the demographic most at risk of
serious complications, often death.
The
three vaccine front-runners still awaiting final approval destined to
be distributed in Canada; Pfizer/BioNTech, Moderna and Astra-Zeneca, are
two-dose vaccines. Transport and storage of the Pfizer vaccine is in
and of itself a challenge since it must be stored under ultra-chilled
conditions requiring freezers able to keep products at -70C. To further
complicate matters it's highly likely that multiple types of vaccines
will be delivered simultaneously across the country, including those to
be delivered to remote and isolated parts of the Canadian geography.
To
develop a vaccine and market it typically takes between ten and fifteen
years, under normal circumstances. The advent of the novel coronavirus
is anything but typical, and this is an abnormal circumstance the world
is now living in -- on tenterhooks to obtain a reliable, effective and
safe vaccine. And because the scientific community took heed of the
desperate need and worked feverishly in many countries of the world to
develop a suitable vaccine, these COVID-19 vaccines took under a year for development, now contemplating distribution.
Having
to be transported over long geographic distances, vaccines undergo many
transfers and types of transportation, requiring constant cold
temperatures to ensure their viability. Should a vulnerability occur in
the transportation link and the integrity of their ultra-cold stability
be interrupted, potency can be affected and the vaccine rendered
unusable. Additionally, when vials are lost, damaged or have expired and
when doses are left over in multi-dose vials, a certain percentage of
vaccine is wasted.The average of spoilage and waste sits at around
fifteen to 20 percent.
Due
to its need of ultra-cold storage, the Pfizer vaccine -- which must be
maintained at -70C and administered within five days after transfer to a
refrigerator -- it is likely to be used in large cities. Having reached
its destination, a dilutant is added to each vial containing vaccine to
produce five doses which gives the solution six hours of effectiveness.
In large cities, hospitals and research institutions equipped with
suitable freezer units are to be found, whereas towns and small cities
are unlikely to have these ultra-cold freezers in use which come with a
price tag of $15,000 and $20,000 apiece.
Wastage
occurs for the most part when the vaccine is sent to providers such as
physicians' offices and clinics, unlikely to possess the refrigeration
type whose quality is a requirement for vaccine efficacy preservation.
According to Dr.Halperin, central and regional storage depots are
monitored and alarmed, the type of equipment not generally to be found
in the offices and clinics of the end-users. The Canadian military has
been tasked to work with private companies with their own competent
logistical systems and delivery trucks.
As
an example, McKesson, a medical logistics provider, is able to ship,
store, transport, plan and control inventory and resources for freezing
and refrigeration.Vials of Pfizer's vaccine are to be shipped in large
thermal boxes containing dry ice -- with companies like UPS and FedEx --
from its manufacturing site in Kalamazoo, Michigan. Moderna
manufactures its vaccine in New Hampshire, Pennsylvania and Indiana,
shipping through McKesson's Irving, Texas distribution centre where the
hub of the U.S. government's Operation Warp Speed is located as a
public-private vaccination initiative with the aim of producing and
delivering 300 million doses beginning in December.
The
shipping temperature for Moderna's vaccine is -20C, a temperature that
will keep the vaccine stable for six months. Thawed, the vaccine can be
refrigerated for up to 30 days and as such may be a more suitable
candidate for dispatch to remote areas. Typically, people are required
to wait for fifteen minutes post-injection, just in case an allergic
reaction to the vaccine occurs. For the COVID vaccines, that wait time
may be a little longer, during which time physical distancing must be
maintained.
To
the present, only short-term efficacy results are known. Unknown as yet
is whether COVID vaccines will require boosters, and when, if required.
There can be no expectation that immunity from vaccines will last
longer than does natural immunity, and even that is an unknown at the
present time. And then the issue of take-up presents; how many in the
public will immediately agree to vaccinate. According to an
Ipsos/Radio-Canada Internet poll of 3,001 people last week, 64 percent
indicated they would likely or certainly get vaccinated; 16 percent that
they definitely would not, and 21 percent were uncertain.
High
rates of coverage always present a challenge. To achieve herd immunity
for COVID, between 65 to 75 percent of the population would have to be
immunized, lower as it happens than is required for infections like
measles which requires substantially over 90 percent coverage. Data on
long-term safety and effectiveness has been elusive outside the
controlled atmosphere of clinical trials. Once it is clear a protective
effect can be achieved for the community with higher uptake rates,
messaging may need to change, observed Dr.Thompson. "People need to be reassured, not have their concerns dismissed as baseless."
"For the two vaccines that require very low temperature storage, this likely means there will be less wastage because the vaccine will be more centrally controlled.""Natural immunity lasts at least three to six months. We need to follow how people who recover from the disease do over time and we just haven't had long enough follow-up to know how long protection does last.""If protection lasts only a year, then we will need annual vaccination like with flu vaccines.""We need high levels of confidence and low levels of refusal.""Some say they will [get vaccinated] but don't, others say they won't but after a few months when they see that the vaccine is well tolerated, they will."Dr.Scott Halperin, director, Canadian Center for Vaccinology, Halifax
A person in Mainz, Germany gets a dose of the Pfizer/BioNTech vaccine as part of the product's clinical trial. Public health officials said as many as three million Canadians will be vaccinated in the first three months of 2021 (Reuters) |
Labels: Canada, COVID-19, Distribution Challenge, Inoculation Take-up, Refrigeration, Shipping, Storage
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