In an article for VICE UK, I answer questions from Darcey Edkins about staying safe this Christmas in the midst of a wave of Covid-19 infections driven by the Omicron SARS-CoV-2 variant. We cover topics such as the Three C Approach to personal safety, why you should wear a well-fitting FFP2 mask, and testing for Covid-19.
1. Given the scientific data out there, is it safe to
travel home for Christmas right now?
There is currently a high level of Covid-19 in the UK so you
need to take appropriate precautions when travelling such as adopting the “Three
C Approach” to reduce the risk of infection to you. This means: Avoid
closed spaces; Avoid crowded spaces; Avoid getting too close to other people
when outside your household. When you travel home, you should use
a good quality FFP2 face mask to protect yourself better if you are on
public transport or enter places such as bus, train and service stations. You
can test yourself before you travel with a lateral flow test. If you have
symptoms, you should not travel until you hear that your PCR test is negative.
2. I have seen people saying that lateral flows are not reliable – how much can I rely on them to make a call on whether I am COVID-negative?
Lateral flow tests will detect the majority of people with
Covid-19 but they are not as accurate as PCR tests (which are processed in a
laboratory). The accuracy of a lateral flow test can improved if it is carried
out correctly. Lateral flow tests will detect
infections from the Omicron variant.
Before you start, read the instructions that came with the
test. If your test needs a throat swab, open your mouth wide and rub the swab
over your tonsils (or where they would have been if you have had a
tonsillectomy). Put the same swab inside your nose (about 2.5 cm up or until
you feel resistance). If your test requires only a nose swab, put the swab
inside your nose (about 2.5 cm).
After you have done this, put the end of the swab into the
tube so it's in the liquid, then squeeze the liquid from the tube onto the test
strip and read the test result once the waiting time advised in the instruction
leaflet has passed. Once you have the result, report this via the website. This is important
as it allows the government and the NHS to monitor Covid-19 infections in the
UK.
Full instructions on how to carry out the test are available
on the NHS
Website. There are also several NHS videos available
online that show people how to use the tests properly.
3. People online have had negative lateral flows but positive PCRs – why is this? Should I get a PCR ahead of travelling home?
Lateral flow tests and PCR tests work in different ways. Lateral
flow tests detect some of the proteins in the virus, can be carried out at home
and give a result quickly. PCR tests detect the genetic material (RNA) in the
virus and require a laboratory to do this. The result of a PCR test takes
longer to come back but it will pick up more infections than a lateral flow
test because the test has a higher sensitivity than a lateral flow test.
Because lateral flow tests are not as accurate as PCR tests,
they can sometimes be negative in people with symptoms when the subsequent PCR
test is positive. If you have symptoms of a possible Covid-19 infection, you
should always get a PCR test and not rely on a lateral flow test. If you don’t
have symptoms, a lateral flow test is sufficient. PCR tests should be reserved
for people with symptoms of a possible Covid-19 infection to avoid overloading
government laboratories with unnecessary test requests.
When Covid-19 first arrived in the UK in early 2020, the
main symptoms people were asked to look out for were a high temperature, a new
continuous cough, or a loss or change to their sense of smell or taste. Now
that so many people in the UK have some immunity because of vaccination or a
previous Covid-19 infection, they may get other symptoms when infected – such
as a headache, runny nose, sore throat, or sneezing. So even if you think you
might just have a cold, you should still get a PCR test.
4. Is there any other precautionary stuff I can do to ensure I don't give COVID to my loved ones this Christmas?
People who are unvaccinated are more likely to become
infected with Covid-19 and transmit infection to others. To protect yourself
and others, ensure you are vaccinated – including with a booster. Your friends
and family members should also ensure they are fully vaccinated. Another step
you can take to reduce the risk of infection is to test for Covid-19 before you
all meet up and then once or twice each week.
Good ventilation will also reduce the risk of infection as
will limiting the size of the gathering. For ventilation to work best, you need
a good flow of air in and out of the room you are in. This would mean opening
at least one window and the door to the room. The more air that flows through
the room, the quicker any virus that is in the air will disperse, thereby reducing
the risk of infection. If you want to measure the quality of air in a room, you
can use a carbon dioxide monitor. Higher levels of carbon dioxide indicate
poorer air quality and are a sign that you need to open more windows to improve
ventilation.
Regarding the number of people you have in a room, there is
no “right” number. The more people who are in a room, the more likely it is
that one will have a Covid-19 infection. But other factors also important –
such as the size of the room and its ventilation, whether all the people are
fully vaccinated, and whether they have all carried out a recent lateral flow
test to check their infection status.
When you are outside in places such as public transport and
shops, you should wear a good-fitting mask. Higher specification FFP2
masks provide better protection from infection than the cloth masks and
surgical masks you see many people wearing. Good hygiene is also important.
5. Should I be testing every day I'm home for Christmas, just to be sure? Should I be testing multiple times a day?
Testing every day is not a good use of lateral flow tests. Some
people do carry out more than one test per day but this will lead to tests
running out very quickly as the supply of tests in the UK is limited and there are not enough tests
available for everyone to do this. You should test before you meet up and then
once or twice weekly. There is no need to carry out multiple tests on the same
day. There is currently a shortage of lateral flow tests in many parts of
England and they should be used sensibly. We also need to ensure that key
workers such as NHS staff have sufficient tests for their own use. If you have
symptoms, you should get a PCR test and wait for the result rather than
carrying out multiple lateral flow tests.
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