4 1GT Tuesday July 21 2020 | the times
times2health
Dr Mark Porter
The vaccine news is promising,
but don’t get your hopes up
little useful protection to the over-65s,
leading to the development of
“stronger” versions for use in older
people. The same may apply to any
Covid vaccine.
And how is it going to be
administered? Vaccinating the whole
nation — probably with at least two
doses — is going to be a challenge
when personal protective equipment
and social distancing are still the norm
in the NHS. We managed to immunise
600 people against the flu on just one
Saturday morning last year. However,
I think we would struggle to inject a
tenth of that number with the
restrictions. At least we will
have this autumn’s flu
campaign to practise.
Last, but not least, there is
the question of safety. While
no serious side-effects
have been reported,
worrying vaccine-
related problems
tend to be rare and
only evident after
large numbers of
people have been
immunised. Based on
the technology used
to make these new
vaccines, researchers
expect them to be
safe, but public
confidence is
important and this is
an issue that will need
to be addressed
to get the sort
of uptake
required
to protect
the nation.
There’s
many a slip ’twixt
the cup and the lip.deaths between vaccinated and
non-vaccinated groups, you need
plenty of volunteers and lots of
circulating virus. Volunteers have
not been a problem, but the low
prevalence of Covid-19 has.
The less virus is circulating, the
fewer cases you get in your trial and
the longer your study needs to run
to prove significant benefit. Indeed,
researchers are so worried about
this, they are even considering
exposing healthy volunteers to
the virus to speed things up. Rather
them than me.
Another issue is that many of the
people most vulnerable to Covid-
are older, and the response to most
vaccines diminishes with age (a
process that starts in our fifties). This
has been a big problem with flu jabs,
which until recently have often offeredD
ifferent countries may have
differing strategies for
tackling Covid-19, but one
thing that unifies experts
around the world is the
belief that a vaccine is our best chance
of getting out of this mess. And the
light at the end of that particular
tunnel is growing brighter. The UK
government has secured 90 million
doses of the more promising vaccines
in development, and early research,
including from the leading group in
Oxford, looks exciting.
However, history is littered with
vaccines that looked good in the lab,
but subsequently failed to show useful
protection in the real world. As with
all new pharmaceuticals, the vast
majority of vaccines in development
never make it to market. And there are
still plenty of hurdles to clear.
First, time is not on our side. We
need a vaccine now, not in a decade.
With the notable exception of the flu
jab, which is tweaked every year to
reflect the latest strains, most vaccines
depend on sequential developmental
phases that take five to ten years.
Covid-19 has changed that. A novel
simultaneous approach has resulted in
pharmaceutical companies preparing
for production of a vaccine before it
has even been shown to work. Instead
of waiting for the new vaccine to pass
each phase of development — from
initial lab-based studies to large
human trials — researchers,
manufacturers and governments
across the world have taken a punt
and are hoping for the best.
The next hurdle is proving that it
works. Early lab-based studies have
shown that volunteers produce
antibodies and other markers for
immunity. However, the only way to
prove that these translate into useful
protection in the real world is to
compare outcomes between two
groups — one vaccinated, the other
not. These trials are continuing, but
are, paradoxically, being hampered by
low infection rates in Europe and
China, where much of the most
promising research is being done.
To detect significant differences in
infection rates, complications andQA
You hear a lot about
high blood pressure,
but very little about
what happens when
it is too low. Mine is
around 95/60, which
means I am prone
to feel light-headed
on standing,
particularly when
the weather is warm.
My doctor has been
very thorough ruling
out any underlying
problem. She says
it is normal for me
and I will have to
live with it. Are
there any medicines
that may help?Assuming you are
otherwise well, low
blood pressure is
generally a good
thing because it
reduces your risk
of problems such
as stroke and heart
disease. However, if
your readings are
below 110/60 then
it is likely that you
will feel light-headed
if you get up too
quickly or stand still
for any length of
time (blood tends
to pool into your
lower limbs and the
flow to your brain
is reduced if your
pressures are low).
Try to increase
your salt and fluid
intake. Drink more
first thing in the
morning and
consider adding salt
during cooking and
at the table (for you,
not the rest of the
household) and
nibble on healthy
salty snacks
such as nuts.
One reason
we encourage
people to restrict
their salt intake
is that it tends
to push blood
pressure up,
but you have the
opposite problem.
There are drugs
(eg midodrine) but
these are only used
as a last resort.
If you have a health
problem, email
drmarkporter
@thetimes.co.ukTime is not on
our side. We need
a vaccine now,
not in a decade
Facts about the vaccine
I
f you are gearing up for a return
to the gym, it might be worth
trying something completely
different, particularly if your
previous fitness efforts have
floundered. What makes
workouts work for some people
and not for others was the
subject of a groundbreaking new
study, published in The Journal of
Physiology, in which a team of
researchers from the University of
Western Australia (UWA) and the
University of Melbourne found that
we can all get fitter and leaner, and
that there is an ideal exercise for
everyone, but — and here’s the big
surprise — our genes play less of
a role than was previously thought.
For a decade or more, many exercise
scientists believed that our aptitude
for running or cycling, yoga or weight
training, was written within our DNA.
According to these theories, some of
us were genetic non-responders to
aerobic exercise, while others were
programmed to respond poorly to
strength training.
It provided the perfect excuse to
ditch running or weight training when
improvements seemed tediously slow.
And it produced a booming market for
DNA home-testing kits that promise
to predict genetically matched
personalised fitness plans. However,
this latest study on twins, selected
because they offer direct genetic
comparison, found that we can’t blame
our genes when our chosen workouts
fail to produce the results we are after.
Daniel Green, a professor in
cardiovascular exercise physiology at
UWA, and the doctoral researchers
Hannah Thomas and Channa Marsh
recruited 42 sets of twins — a mix
of male and female, with 30 pairs
identical and 12 non-identical — all of
whom were young and healthy, but
non-exercisers at the start of the trial.
For two three-month periods the
twins were asked to exercise in their
pairs, completing 60 minutes of
running or cycling three times a week
for one of the 12-week programmes,then thrice-weekly weight training for
an hour during the other 12-week slot.
After each three months of exercise
prescription, Green and his colleagues
tested for improvements in aerobic
capacity, power and strength,
comparing results with each person’s
starting point as well as with the
results obtained from their twin.
If genes underpinned fitness gains,
their results would be similar, yet the
data showed a mixed bag of reactions.
Almost everyone got fitter, but even
within twin pairs the responses varied
considerably. Green says, “We found
little evidence that changes with
training were primarily genetically
determined. Our data suggests that,
while genes contribute somewhat to
the ‘size of your engine’, your ability to
‘tune it up’ — that is to enhance your
fitness or strength — is mostly down
to environmental factors.”
In other words, Green says, it’s not
who or what you are that matters if
you want to get fitter, leaner and more
toned, but which workout you select
and how else you live your life.
Other researchers are taking the
findings seriously and asking, if it’s
not genes, what is it that makes us
respond differently to the same dose
of exercise? “For many years it was
thought that our genes play a central
role in how we respond and adapt to
exercise, but this latest study suggests
that our DNA probably doesn’t limit
us as much as we previously thought,”
says Dr Richard Blagrove, a lecturer
in physiology at Loughborough
University. “It is likely to be lifestyle
and other personal factors, such as
diet, psychological state, body weight
and previous exercise history, that
have a larger bearing on the outcomes
of our workouts.”
Of course, the million-dollar
question is how do we know which
workout will transform us from fatty
to fitty? In his study Green found that
roughly 30 to 50 per cent of people
responded positively to both the
weights and cardio exercises. There
were a few wayward low respondersf
6 If we do get a vaccine it is likely to
be offered to health and social care
workers first, followed by the most
vulnerable groups (such as older
people and those with underlying
health conditions that make them
more susceptible to Covid-19).
6 There are two UK vaccine
studies approved by the National
Institute for Health Research —
one led by the University of Oxford
and the other by Imperial College
London — and the government
is hoping to recruit half a million
volunteers (I am one of them) by the
autumn to help development of the
most promising versions. You
can find out more and register
at http://www.nhs.uk.