Vaccines alone will not stop Covid spreading – here’s why

4 月 14, 2021World News

Many of us are hoping vaccines against coronavirus will be our route out of lockdown, enabling us to reclaim our old lives. But scientists say jabs alone will not currently be enough and other measures are still needed.

Scroll down to find out why.

Cleaning hands and surfaces

Illustration of a family and their options for reducing risk from coronavirus

The problem is that no single measure to prevent the spread of coronavirus is 100% effective, and that includes vaccines.

Take a look at this block of Swiss cheese with its characteristic holes, sliced into nine pieces. Each layer represents one of our defences against the virus.

None of the slices is perfect. Each of them has holes – representing the measure’s flaws – which allow the virus to find a way through.

Yet if there are several layers, the chance the virus will be stopped by one of them is increased.

Let’s take a look at each cheese slice in turn.

Vaccines are widely regarded as the most powerful weapon in our Covid-19 armoury. Some are more than 90% effective and prevent people getting sick and dying with the disease.

But no vaccine is ever 100% and there is a chance we might catch the virus or pass it on even after our jab.

Widespread testing can find people carrying the virus who are unaware they have it.

But rapid turnaround, or lateral flow tests are imperfect and can miss some cases.

Contact tracing systems track down people who have been in close contact with a positive case, to advise them to isolate.

But such schemes need to be fast and reach between 80%-100% of contacts to work effectively.

Most countries advise people who suspect or know they have Covid to stay at home and avoid others. Some also require travellers to quarantine.

But some people do not follow this advice or are unable to do so.

Masks and face coverings can block virus droplets from coughs, sneezes and speaking. But even the highest-grade masks still let some virus through.

Masks also need to be worn correctly and used by enough people to make a difference.

Keeping 2m (6ft) away from someone reduces the chance of the virus passing on. But we can still catch it even from further away.

Fresh air cuts the risk of infection and the ultraviolet radiation from sunlight can destroy virus left on surfaces. But the risk outside is not reduced to zero.

The chance of catching the virus increases in areas that are poorly ventilated. The greater the airflow, the lower the risk, but the danger is still there.

Good hygiene can help stop the spread of the virus, but the risk from particles in the air remains.

As we can see


How many Covid cases does China have and what are its rules?

By Wanyuan Song BBC News China has seen its first deaths from Covid-19 in six months, and thousands more people are catching the disease, despite the government's strict lockdown policy. The World Health Organization (WHO) has said China should rethink its strategy....

Covid in Scotland: The latest cases

The number of Covid-19 infections in Scotland has fallen, according to the Office for National Statistics (ONS). The ONS Covid infection survey estimates an average of 97,500 people were infected on any given day in the week up to 8 November - that's about one in 55...

About Us

Taiwan Cloud Environmental Technology Co., Ltd


HeadOffice:2F, No. 128, 1st sec. Freedom Road, Taichung403, Taiwan.

TEL:+886 4 22257222