When a new disease emerges, one of the first things that people want to know
is who's at most risk ... whether your newborn baby or asthmatic child
or your elderly grandmother might be particularly vulnerable
to this disease that we're hearing so much about every day.
As the number of cases increases and scientists have started to get
more reliable data about who's being affected, we're starting to get some answers.
In China, one of the first trends to emerge
was that men seemed to be making up more of the cases
and also more likely to die than women.
The fatality rate there for men was 2.8% compared to 1.7% for women.
At first this was largely put down to smoking rates being so much higher
in men than in women in China; around half of men in China smoke
compared to just one or two percent of women.
We've seen this trend mirrored in lots of different countries now,
South Korea, Italy, Spain, countries where there aren't these huge differences
between male and female smoking rates, so now scientists are starting to look
at whether there's something different in the immune system’s response
between men and women.
Older people are at greater risk from Covid-19,
so if you look in the over 80s, the mortality for that group,
based on the cases we know about, is about 14%, and that drops down
to around 3.5% for people who are in their 60s, and then progressively
less and less, so it's less than 1% once you get to the under 50s
and a vanishingly small chance for people in their 20s.
Although the fatality rate is much, much lower in younger people,
that's not to say that there's nothing to worry about …
there can still be very serious symptoms, you can still end up in hospital
and, of course, your actions will affect other people as well
so it's still really important to self isolate and stay indoors
and protect the community at large.
A lot of diseases follow what scientists call a U-shaped risk curve;
the very youngest people and the very oldest people are the ones at most risk,
and then it dips down in the middle,
and I suppose one of the positive things at Covid-19 is that we haven't seen this
and that the youngest children don't seem to be at any increased risk
of getting serious symptoms or dying.
One thing that isn't really clear at the moment is
why children are at risk and whether they're still getting the infection and
passing it on to the people but not getting symptoms themselves.
Covid-19 is a disease that attacks the upper respiratory system
and can also make breathing more difficult,
so any condition that affects your lung health, things like asthma, COPD.
There's also evidence that illnesses that affect your immune system
so things like cardiovascular disease, diabetes, any autoimmune disorders
that those also make you at greater risk and more vulnerable.
It's definitely the case that health care workers are at greater risk
of catching Covid-19, they're going to be exposed on wards day in, day out,
and obviously that risk is even greater if people don't have
the right protective equipment.
It's possible that because they're exposed to a greater viral load that they end up
getting a worse version of the illness.
Doctors and nurses have represented quite a lot of the deaths in some
countries ... in Italy, for example, there's been dozens of doctors
who have died, even though they might not necessarily fit into
those high-risk groups that we've seen in the general population.
Pregnancy is also something that can affect how your immune system responds
but reassuringly, in this case, it doesn't seem that pregnant women are having
worse outcomes or suffering worse symptoms, but because this is
such a new disease and there's so much we don't understand about it yet,
pregnant women are still being considered an at-risk group
and being asked to take extra precautions.
If you belong to one of those more vulnerable groups then it's
so important to make sure you self isolate in the strictest way possible,
and if you're not in one of the groups that have been labelled
as high risk, it's still really important, both for yourself and other people, to follow
the social distancing measures and isolation measures that have been laid out,
but you could also help the more vulnerable groups by joining NHS volunteers
or perhaps helping out a neighbour or people who live near you who are unable
to go out to the shops and do their normal day-to-day jobs.