Having covered the
subject in our article about ‘vaccine
nationalism' a sensation took place when on Monday the German company
BioNTech and the US pharmaceutical giant Pfizer announced via a press release
that their jointly developed vaccine candidate had outperformed expectations in
the crucial phase 3 trials, proving
90% effective in stopping people from falling ill.
In an article
published today the scientist behind the coronavirus vaccine believes that people
could start to be inoculated by mid-December.
And in an exclusive
interview with The Guardian yesterday BioNTech’s CEO Uğur Şahin says he is
confident his product can “bash the virus over the head” and put
an end to the pandemic that has held the world hostage in 2020.
Deliverance, when it
arrives, will come in a small glass vial. First, there will be a cool sensation
on the upper arm as an alcohol wipe is rubbed across the skin. Then there will
be a sharp prick from a needle. Twenty-one days later, the same again. As the
nurse drops the used syringe into the bin with a clatter, it will be hard not
to wonder how something so small can solve a problem so large.
Some of the questions
we have of course is we have to see more data about the 90% effectiveness
whereby there is a problem with distribution as it must be stored at -70 to -90
c. This whereby good news also came from Oxford three days ago when they claimed
vaccine data will likely be available in ‘weeks’.
On 9
November Pfizer and BioNTech, two firms working as partners on a vaccine
against covid-19, announced something extraordinary about the first 94 people
on their trial to develop symptoms of the disease. At least 86 of them—more
than nine out of ten—had been given the placebo, not the vaccine. A bare
handful of those vaccinated fell ill. The vaccine appeared to be more than 90%
effective.
Within a few weeks,
the firms could have the data needed to apply for emergency authorization to
put the vaccine to use. The British and American governments have said that
vaccinations could start in December. The countries of the eu
have also been told it will be distributed quickly.
The news lifted
spirits around the world, not to mention stockmarkets.
The end of the pandemic seemed insight; scientific insight and industrial
know-how had, in a bravura display of their power, provided an exit strategy.
Pfizer and BioNTech have not just developed a vaccine against a previously
unknown disease in a scant ten months. They have done so on the basis of an
approach to vaccination never before used in people. And their novel vaccine
has shown an unanticipated efficacy. Most in the field thought 70% efficacy was
good as could be hoped for the first time out; just 50% could have been good
enough for regulatory approval. Exceeding 90% hits the virus for six.
Russia and China have
been vaccinating some citizens against covid-19 for some time outside the scope
of clinical trials. On November 11th the Russian Direct Investment Fund
announced that data showed Russia’s vaccine, known as Sputnik V, to be 92%
effective. Before the Pfizer announcement, this would have seemed highly
implausible. Now it may seem less so, though the evidence is weak compared with
Pfizer’s. And neither Sputnik V nor the Chinese vaccines have yet had their
safety and efficacy addressed by the stringent regulators at the Food and Drug
Administration (fda) in America and the European
Medicines Agency EMA).
Pfizer’s vaccine is
now headed into that regulatory gamut with a small posse of followers hot on
its heels (see table). Two other vaccines which are in phase-three trials, the
sort of large, randomized trials designed to show the efficacy of treatment, could
submit data to the regulators fairly soon. Moderna, an American biotech firm,
is expected to deliver interim findings of the efficacy of its vaccine in the
next few weeks. AstraZeneca, a pharmaceuticals company working in partnership
with the University of Oxford, should deliver results from its trial before the
end of the year.
As suggested above,
challenges remain. Though the regulators will want to move quickly, they will
still have to do their job. Missteps could erode confidence in the vaccine, as
well as vaccination more generally. Plans for scaling up manufacture and for distribution
on an unprecedented scale have been being made around the world for months, but
it is hard to imagine that they will not require revision on the hoof. Even if
the news continues to be good, the numbers vaccinated will remain small for
months to come. But a fateful corner has been turned.
Speeding up regulatory processes should be without
sacrificing standards
Great speed has come
from great efforts. Cath Green, the boss of the clinical biomanufacturing
facility at the University of Oxford, remembers the pressure to get the
first candidate-vaccine vials filled in April. Everyone was doing double shifts
and working on weekends. “We knew it had to be this fast if we were to get a
vaccine to people this year,” she says.
But it was not just
hard work. New technology, a lack of financial constraint and a commitment to
speeding up regulatory processes without sacrificing standards mattered, too.
Technology first.
Vaccines against viruses used to be based on the virus particles they were
meant to stymie. Some were strains of the virus “attenuated” so as not to cause
disease; some were normal virus particles inactivated so that they could not
reproduce at all. The design was somewhat hit and miss. Today vaccine
development is based on viral genomes. Researchers look for a gene that
describes a protein the immune system seems likely to recognize. Then they put
that gene into a new context.
In the case of
sars-cov-2, the virus that causes covid-19, the genome was published on January
10th. Understanding its structure on the basis of their experience with other
coronaviruses, would-be vaccine-makers immediately homed in on the gene for the
distinctive spike protein with which the virus’s membrane is studded: just the
sort of thing, they reckoned, to provoke a response from the immune system.
At BioNTech, a German
biotechnology company that specializes in the use of mRNAs, sequences of
genetic material that provide cells with recipes for making proteins, the
spike-protein gene was more or less all it took. The company’s researchers made
an mRNA version of it that could be injected into the body in tiny capsules
made of lipids. There it would lead cells to produce the spike protein, and the
immune system would then take note. Or so they hoped: no mRNA vaccine had been
used in humans before. Moderna, too, has as its name suggests taken the mRNA
route.
In Oxford a version
of the spike gene was instead put into the genome of a harmless adenovirus
originally found in monkeys; when the resultant virus infects cells it, too,
makes them produce spike proteins that attract the immune system’s attention.
The vaccine developed by J&J also uses the adenovirus approach, as does the
apparently hopeful
Sputnik V.
It is no accident
that the vaccines that have come along fastest are based on these novel
strategies. Before the coronavirus struck these technologies were already being
developed as platforms on which a rapid response to a new viral disease could
be built, work supported in part by the Coalition for Epidemic Preparedness
Innovations (CEPI). Vaccines that are built on
such platforms are quick to engineer and comparatively easy to make.
Governments willing to shovel cash at vaccine
developers should also calculate the specific return.
That said, the work
still requires money, which in the vaccine world is usually in short supply.
With covid-19, though, governments have been willing to shovel cash at vaccine
developers even though there was a risk they would get nothing in return. “We persuaded
the uk government to fund us before they had any idea
whether it would work,” says Dr. Green. It was this ready cash, sometimes
provided in the form of a commitment to buy the end product, which sped the
process up, rather than any loosening of normal rules and procedures. “We
haven’t cut any corners,” Dr. Green continues. “And we haven’t taken any risks
with our product.”
Rather than standing back,
regulators in many countries have worked closely with companies to make sure
their trials provide all the data needed for approval when the time is right.
When it was safe to do so, the different phases of trials were allowed to
overlap, with larger, later trials starting before smaller preliminary ones had
produced all their data. At Oxford, they were able to start human trials the
day after animal safety data had been published.
Richard Hatchett, the
head of CEPI, says Pfizer’s positive results increase the probability that
other covid vaccines will be successful, too. They show that an mRNA vaccine
can work, which is good news for Moderna; they also show that targeting the
spike protein pays off. And the success goes beyond the current pandemic. Work
CEPI expected to take five or ten years has been managed in less than one; if
the various platforms in play all pay off, Dr. Hatchett says, it will
“transform vaccinology”.
The fact that there
are more vaccines on the way matters for a number of reasons. One is that,
despite this week’s good news, the Pfizer vaccine is not yet guaranteed
approval. For one thing, its safety needs to be more fully ascertained. The
firm says that no serious safety concerns have arisen during the trial. But the
vaccine will come with side-effects, at least for some, and the company will
only be in a position to request approval for the vaccine on an “emergency use”
basis after it has two months of safety data showing such effects to be
manageable. That requirement looks likely to be met in time for an application
in the third week of November.
Then comes the
question of what exactly the vaccine does: is it stopping infections
completely, providing “sterilizing immunity”, or simply amping up the body’s
response so that infections do not cause disease? The latter attribute is
undoubtedly a useful one for the individual concerned; all the better if, as
well as lowering the chance of infection leading to disease, it also makes the
disease less severe in those who succumb (there is as yet no available data on
this). But it is a lot less desirable in public-health terms. If the vaccine
stops disease but not an infection, vaccinated people may be able to infect
others while staying safe themselves.
If the Pfizer vaccine
does not provide sterilizing immunity there will be a need for one that does.
And there are other ways that subsequent vaccines might prove preferable.
Different vaccines can work better or worse with different populations, and for
covid-19 it is important to find a vaccine that works well in old people. Their
immune systems can often be unresponsive to vaccination, and they may do better
with vaccines which, in the general population, do not look as effective. There
is no guarantee that the best vaccine overall will be the best for the elderly.
And the Pfizer
vaccine has some inconvenient characteristics. It needs to be kept at -70°C or
even colder as it is moved from where it is made to where it is used, which
requires a lot of equipment that other vaccines do not need. Seth Berkley, head
of the vaccine
finance group Gavi, warns that many countries do not currently have the
wherewithal to meet that challenge. But he also notes that the lack is not
insuperable. The Democratic Republic of Congo successfully deployed an Ebola
vaccine that required similarly special care. “It’s a pain in the ass, it’s
expensive, but it’s doable.”
Still, a vaccine
which, if not liking it hot, at least liked it less cold would be a boon. So
would one that only needed to be given once. The Pfizer, AstraZeneca, and
Moderna vaccines all require two jabs weeks apart. A one-and-done vaccine,
which is what J&J hopes for, makes setting up a vaccination program far
simpler. It also means a given number of doses will go a lot further.
On top of all this,
the long-term efficacy of the vaccine will matter a lot. The Pfizer/BioNTech
collaboration says that protection should last at least a year. But that will
not be known for sure before they apply to regulators for full authorization on
the basis of final trial results, which they are expected to do in the first
quarter of next year (as are the makers of the other front-runners). A vaccine
that provides protection only briefly might well not be able to disrupt the
virus’s transmission, instead of feeding a constant stream of newly susceptible
people back into the population at large. Marcus Schabacker, the boss of the
Emergency Care Research Institute, an American organization focused on the
quality and safety of medical practices, thinks six months of follow-up data
ought to be scrutinized, not just two before final decisions are made on
deploying the vaccine.
Such questions will
be on the minds of regulators at the fda and ema when
they are asked to consider the Pfizer vaccine for emergency use later this
month and when Pfizer and the makers of other vaccines submit all the data from
their trials next year. Their opinions will have worldwide effects, as the
World Health Organisation (who) will use the
analytical capabilities of those authorities to accelerate the review of
vaccines for use in low- and middle-income countries.
If emergency
authorization is granted it is likely the agencies will restrict the use of
these vaccines, initially, to those at highest risk of death or serious
disease. If after seeing the full data the regulators still have worried they
may continue to limit the vaccines’ use. Whatever they decide they are very
likely to insist on years of follow-up.
Andrew Pollard,
director of the Oxford Vaccine Group, says it is important that all developers
carry on with trials as long as possible. But this may be hard unless early use
is restricted to specific groups. If a vaccine is approved for use in the general
population, few will volunteer to take part in a trial for another vaccine that
uses a placebo as a control (if Pfizer and BioNTech receive an emergency
authorization they plan to offer all the volunteers who were given a placebo
the active vaccine). A trial that compares an experimental vaccine with one
that is already approved needs to be very large to get results since both wings
can be expected to show comparatively few infections. Such trials are under
discussion, but they will take a long time.
If vaccines are
approved for widespread use, the world will face what some have called the
largest supply-chain challenge in history. There is normally little spare
vaccine-manufacturing capacity to repurpose. And production is not the only
limiting factor. Analysts at ubs, a bank, warn that
“fill and finish”, where the vaccine is put into vials and packaged, could be
one of the most significant bottlenecks.
Pfizer says it will
only be able to make enough vaccine to inoculate 25m people in 2020. Up to
1.3bn doses are possible, in theory, next year, enough for another 650m people.
If other vaccines are approved then the supply will increase. In even the most optimistic
scenarios, though, Dr. Hatchett expects demand to exceed supply throughout
2021.
Various countries
have already set up purchase agreements with vaccine developers (see chart).
The COVAX facility set up by the above mentioned CEPI, Gavi, and the who will buy vaccines for
150 countries, and aims to procure enough for them to get 20% of their
populations vaccinated over the course of 2021. unicef,
the un’s children’s agency, will take a leading role
in distribution. It normally procures 600m-800m syringes for routine childhood
immunizations every year. The demands of covid are likely to treble or
quadruple that number.
There is clearly a
risk that nations will hoard some vaccines for their own use rather than that of the neediest, but it is
not easy to say how large the problem will be. Pharma firms have cleverly
placed manufacturing sites around the world, including in small countries such
as Belgium and Switzerland which can quickly produce more vaccines than these
countries could ever want. And the COVAX
framework has wide international support.
That framework
follows advice from the who in identifying three priority groups for early
vaccination: front-line health- and social care workers; the over 65s; and
those under 65 who have underlying health conditions, such as diabetes, which
put them at particular risk. Countries setting their own priorities are by and
large prioritizing the same groups. This means that young and middle-aged
people not in any risk categories are unlikely to be vaccinated until well into
next year. Social distancing and mask-wearing will stay important for some time
to come even after vaccination becomes widespread. But a more normal form of
life looks unlikely to be too long delayed.
For vaccination to
work as well as it can require a widespread willingness to be
vaccinated—something that cannot be taken for granted in a world where
anti-vaccine disinformation has a strong foothold. The data on this front,
though, are broadly encouraging. A survey of 20,000 adults in 27 countries
undertaken for the World Economic
Forum this August found that 74% would get a vaccine if it were available. In
China, the figure was 97%, in India 87%, in America 67%. Countries with low
rates of acceptance were Russia (54%), Poland and Hungary (both 56%), and
France (59%).
The traditional flu season and the current second wave
Better testing, new
antibody treatments, and improvements in care will continue to drive down the
death rate for coronavirus both before widespread vaccination and after it.
Vaccination will instead change the fundamentals. Its advent marks the
beginning of the end of covid-19 as a pandemic.
But for all the hope
that diligence and science have kindled, there are hard winter months to face
before that spring. The official tally of daily deaths around the world is now
for the first time higher than it was in the pandemic’s first peak, and the spread
of the virus in America appears to be out of control. In the next three months,
hundreds of thousands of people look likely to die. Not only will their loved
ones have to come to terms with this loss, but they will also have to live with
the knowledge that a vaccine that could have saved them, even though developed
at breakneck speed, arrived just too late.
For updates click homepage here