How does a pandemic end? How Spanish flu, Bubonic Plague and HIV were managed - and if coronavirus will ever end
The Black Death is considered the deadliest pandemic in human history, causing up to 200 million deaths
The UK has been in the grip of the coronavirus pandemic for more than six months now, with Prime Minister Boris Johnson first imposing a nationwide lockdown back in March.
Tough restrictions on social gatherings and more stringent hygiene measures have helped to bring the virus under greater control, but with winter approaching, it is feared infection rates could worsen.
Combined with the risk of catching flu in the winter, the threat of co-infection with coronavirus could prove deadly and has prompted plans for a possible harsher lockdown, which would see the likes of pubs forced to close and a ban on all social contact outside of household groups.
With restrictions expected to become even tighter, the return to a sense of normality seems excruciatingly far away and begs the question, will the pandemic ever come to an end?
How were other global pandemics handled?
Several devastating diseases have swept the globe over the years, causing millions of deaths in their wake - and many are still in existence today.
The bubonic plague is just one example of a disease which was never fully eradicated and has killed millions of people over a 2,000-year period, with the earliest recorded case back in 541 AD.
The disease is caused by bacteria transmitted by fleas on rats and respiratory droplets from people who are infected, causing flu-like symptoms including fever, headaches and vomiting.
Swollen and painful lymph nodes appear closest to where the bacteria entered the skin, and occasionally break open.
Vaccines have not been found to be particularly effective for preventing the plague, with several antibiotics used instead. With treatment, the risk of death is around 10 per cent.
Preventative public health measures, including avoiding handling dead animals in areas where the plague is common, has helped to reduce infection, but cases are still recorded today.
The Bubonic Plague was the cause of the Black Death which is considered the deadliest pandemic in human history, resulting in the deaths of up to 200 million people.
The Black Death swept through Asia, Europe and Africa in the 14th century and was caused by the bacterium Yersinia pestis that circulates among wild rodents, causing swollen and infected lymph nodes.
It is believed that the disease was finally brought under control by strict quarantining and improved sanitation, but again, it was never fully eradicated. The peak of the pandemic in Europe took place between 1347 and 1351.
However, numbers of the disease are low today and it can be successfully treated with antibiotics.
Human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the HIV virus.
HIV is primarily spread by unprotected sex, and contaminated blood transfusions and hyperdermic needles.
The infection causes an initial brief influenza-like illness, followed by a prolonged period with no symptoms. If infection progresses, it interferes with the immune system, increasing the risk of infections like tuberculosis.
Late symptoms are referred to as AIDS, with unintended weight loss typically occurring during this stage.
The disease has claimed the lives of more than 32 million across the world so far, but advances in diagnostic techniques and global public health campaigns have helped to slow the number of infections.
There is currently no cure or vaccine for HIV, but antiretroviral treatment can slow the course of the disease and lead to a near-normal life expectancy. Without treatment, the average survival time after infection is around 11 years.
HIV is considered by some as a global pandemic, although the World Health Organisation (WHO) currently uses the term “global epidemic” to describe it.
Global incidence of HIV fell rapidly from 3.3 million per year between 1997 and 2005 to around 2.6 million cases per year. At the end of 2019, 38 million people in the world were living with HIV, according to the WHO.
There have been various flu pandemics from the 1800s to the present day, with the biggest recorded in 1918. Often referred to as the Spanish flu, the influenza pandemic was the most severe outbreak in recent history, accounting for between 50 and 100 million deaths worldwide.
Similar to today’s coronavirus pandemic, the spread of the virus was slowed by isolation and quarantine, with this particular flu strain eventually fading to a more benign version that still circulates every year. The global pandemic lasted for around two years and infected up to 500 million people.
It was the first of two pandemics caused by H1N1 influenza A virus - the second of which was the 2009 swine flu pandemic, which killed up to 284,000 people. Thousands of people are also killed by seasonal flu every year.
Coronavirus is a respiratory disease which is an evolved version of the 2003 Sars virus.
People who catch it can be asymptomatic or may have very severe symptoms and the virus can be fatal.
The disease has a high transmission rate as many people unknowingly spread it before any symptoms develop, making it difficult to control.
The virus has claimed the lives of more than one million people across the world so far, and the search for an effective vaccine is ongoing.
Will the pandemic ever end?
Greater knowledge about virus transmission and public hygiene, combined with global health campaigns and new vaccines and treatments have all played a big part in reducing the spread of diseases and bringing pandemics to an end in the past.
It is expected the end of the current pandemic will be brought about with a combination of similar measures.
While scientists are currently working on producing an effective vaccine for the virus, it is still uncertain whether this will be achieved.
As such, it will mean adjusting to life living with the virus, while developing a greater level of resistance to it to cope with any resurgences.