Curious Kids: how do vaccines kill viruses?



Palak Mehta, Author provided

Kylie Quinn, RMIT University and Palak Mehta, RMIT University

How are vaccines made to kill a virus? Layla, aged 7

Thanks Layla. This is a very important question, especially now, as scientists all around the world are working hard to develop a vaccine to protect us against the coronavirus. Actually, scientists are trying to find vaccines for many different diseases.

To understand how vaccines are made, we first need to understand how viruses make us sick, and how special cells in our bodies defend us against infections.




Read more:
Curious Kids: what are cells made out of?


Viruses are pretty sneaky

Viruses make us sick when they invade our cells. The way this works is kind of complicated — us scientists have to study for many years to fully understand it. But you can think of it like this.

Viruses can get inside our cells by using a special key that fits into a lock on the outside of our cells. Once inside, the virus hijacks the cell, forcing it to make more virus by turning cells into tiny virus factories.

Viruses use a special key to get inside our cells and start to make us sick.
Palak Mehta, Author provided

This is stressful for our cells, which can make us start to feel sick. The virus made in the virus factories can spread the infection through our body, to make us even sicker.

It can also spread from our body to infect other people, and make them sick too.

Your immune system is your defence force

Your immune system is made up of immune cells — very special cells that live all throughout your body. Their job is to look out for any signs of an infection and defend all the other cells in your body when there is a threat.

There are many types of immune cells that work as a team to stop and even kill the virus. Two very important immune cells are B cells and T cells.

Our immune cells — T cells and B cells — can defend us against viruses.
Palak Mehta, Author provided

B cells make a secret weapon called antibodies. Antibodies are tiny Y-shaped particles that are incredibly sticky — they stick all over the key on the virus so it no longer fits into the lock on our cells. This stops the virus from getting in and causing an infection.

If a virus does sneak past the B cells and get into our cells, T cells can deal with it — they are the ninjas of our immune system! They kill any cells that get infected to stop the virus from spreading within our body.

Our body comes across viruses — like the common cold, for example — every day, and they don’t always make us sick because our immune cells can protect us. But our immune cells are much better at their job if the virus is one they’ve seen before.

If we come across a new virus — like the coronavirus, for example — our immune cells can’t recognise it straight away. This gives the virus a chance to infect our cells and it can start to make us sick.




Read more:
Curious Kids: how does our blood fight viruses like chicken pox and colds?


Vaccines teach our immune cells about the virus

All vaccines contain a little piece of the virus, which our immune cells pick up and start to show to each other. Our B cells and T cells can then recognise that little piece of virus and remember it, sometimes for years.

Vaccines protect against viruses by teaching our immune cells what the virus looks like.
Palak Mehta, Author provided

The next time we see that virus, our immune cells recognise it straight away and kick into action.

If our immune cells can act quickly enough, we won’t get sick, and our bodies won’t make more virus that could make other people sick.

So, we hope that answers your question Layla. Your immune system is a powerful defence force — it protects you every day from infections. But sometimes it needs a little help from a vaccine, especially with a new virus it hasn’t seen before.


Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.auThe Conversation


Kylie Quinn, Vice-Chancellor’s Research Fellow, School of Health and Biomedical Sciences, RMIT University and Palak Mehta, PhD student, RMIT University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

‘Deeply worrying’: 92% of Australians don’t know the difference between viral and bacterial infections


Paul De Barro, CSIRO

We are four months into a global virus outbreak, and public health awareness could well be at an all-time high. Which is why it is astonishing to discover that 92% of Australians don’t know the difference between a viral infection and a bacterial one.

The statistic comes from a survey carried out by CSIRO in March to inform our work on the OUTBREAK project – a multi-agency mission aimed at preventing outbreaks of antibiotic-resistant bacterial infections.

Our survey of 2,217 people highlights a disturbing lack of knowledge about germs and antibiotics. It reveals 13% of Australians wrongly believe COVID-19, a viral disease, can be treated with antibiotics, which target bacteria.




Read more:
Why are there so many drugs to kill bacteria, but so few to tackle viruses?


More than a third of respondents thought antibiotics would fix the ‘flu or a sore throat, while 15% assumed antibiotics were effective against chicken pox or diarrhoea.

While 25% of those surveyed had never heard of antibiotic resistance, 40% admitted having taken antibiotics that didn’t clear up an infection. And 14% had taken antibiotics as a precaution before travelling overseas, despite this being unnecessary and ineffective for warding off holiday ailments.

Fuelling the rise of superbugs

The results are deeply worrying, because people who do not understand how antibiotics work are more likely to misuse or overuse them. This in turn fuels the rise of drug-resistant bacteria (also known as “superbugs”) and life-threatening infections.

While COVID-19 has brought the economy to its knees, superbugs pose economic challenges too. Australian hospitals already spend more than A$11 million a year treating just two of the most threatening drug-resistant infections, ceftriaxone-resistant E. coli and methicillin-resistant MRSA.

Without effective antibiotics, thousands more people will die from sepsis and people will be sicker for longer, slashing the size of the workforce and productivity. By 2050, drug-resistant bacteria are forecast to cost the nation at least A$283 billion and kill more people than cancer.




Read more:
Explainer: what are superbugs and how can we control them?


One crucial way to stop this is to improve public understanding of the value of antibiotics. Antibiotics that lose their effectiveness are very difficult to replace, so they need to be treated with respect.

Almost all today’s antibiotics were developed decades ago and, of the 42 antibiotics under development worldwide, only five are considered truly new, and only one targets bacteria of greatest drug-resistance concern.

No time to waste

We don’t know the full impact of drug-resistant bacteria in Australia. With about 75% of emerging infectious diseases coming from animals, there is no time to waste in getting a better understanding of how superbugs are spreading between humans, the environment and animals. That’s where the OUTBREAK project comes in.

This network, led by the University of Technology Sydney, uses artificial intelligence to analyse an immense amount of human, animal and environmental data, creating a nationwide system that can predict antibiotic-resistant infections in real time. It maps and models responses and provides important information to doctors, councils, farmers, vets, water authorities, and other stakeholders.

OUTBREAK offers Australia a unique opportunity to get on the front foot against superbugs. It would save millions of lives and billions of dollars, and could even be scaled globally.

Alongside this high-tech response, we need Australians to get to know their germs, and stop taking antibiotics unnecessarily. Without antibiotics, we may find ourselves facing a host of new incurable diseases, even as the world grapples with COVID-19.The Conversation

Paul De Barro, Senior Principal Research Scientist, Ecosystem Sciences, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How do viruses mutate and jump species? And why are ‘spillovers’ becoming more common?



Shutterstock

Steve Wylie, Murdoch University

Viruses are little more than parasitic fragments of RNA or DNA. Despite this, they are astonishingly abundant in number and genetic diversity. We don’t know how many virus species there are, but there could be trillions.

Past viral epidemics have influenced the evolution of all life. In fact, about 8% of the human genome consists of retrovirus fragments. These genetic “fossils” are leftover from viral epidemics our ancestors survived.

COVID-19 reminds us of the devastating impact viruses can have, not only on humans, but also animals and crops. Now for the first time, the disease has been confirmed in a tiger at New York’s Bronx Zoo, believed to have been infected by an employee. Six other tigers and lions were also reported as “showing symptoms”.

According to the BBC, conservation experts think COVID-19 could also threaten animals such as wild gorillas, chimps and orangutans.

While virologists are intensely interested in how viruses mutate and transmit between species – and understand this process to an extent – many gaps in knowledge remain.

Skilled in their craft

Most viruses are specialists. They establish long associations with preferred host species. In these relationships, the virus may not induce disease symptoms. In fact, the virus and host may benefit each other in symbiosis.

Occasionally, viruses will “emerge” or “spillover” from their original host to a new host. When this happens, the risk of disease increases. Most infectious diseases that affect humans and our food supply are the result of spillovers from wild organisms.

The new coronavirus (SARS-CoV-2) that emerged from Wuhan in November isn’t actually “new”. The virus evolved over a long period, probably millions of years, in other species where it still exists. We know the virus has close relatives in Chinese rufous horseshoe bats, intermediate horseshoe bats, and pangolins – which are considered a delicacy in China.

Smuggled pangolins are killed for their scales to be used in traditional Chinese medicine. They are suspected to be the world’s most-trafficked mammal, apart from humans.
Shutterstock

Past coronaviruses, including the severe acute respiratory syndrome coronavirus (SARS-CoV), have jumped from bats to humans via an intermediary mammal. Some experts propose Malayan pangolins provided SARS-CoV-2 this link.




Read more:
Coronavirus origins: genome analysis suggests two viruses may have combined


Although the original host of the SARS-CoV-2 virus hasn’t been identified, we needn’t be surprised if the creature appears perfectly healthy. Many other coronaviruses exist naturally in wild mammal and bird populations around the world.

Where do they keep coming from?

Human activity drives the emergence of new pathogenic (disease-causing) viruses. As we push back the boundaries of the last wild places on Earth – felling the bush for farms and plantations – viruses from wildlife interact with crops, farm animals and people.

Species that evolved separately are now mixing. Global markets allow the free trade of live animals (including their eggs, semen and meat), vegetables, flowers, bulbs and seeds – and viruses come along for the ride.




Read more:
The new coronavirus emerged from the global wildlife trade – and may be devastating enough to end it


Humans are also warming the climate. This allows certain species to expand their geographical range into zones that were previously too cold to inhabit. As a result, many viruses are meeting new hosts for the first time.

How do they make the jump?

Virus spillover is a complex process and not fully understood. In nature, most viruses are confined to particular hosts because of specific protein “lock and key” interactions. These are needed for successful replication, movement within the host, and transmission between hosts.

For a virus to infect a new host, some or all protein “keys” may need to be modified. These modifications, called “mutations”, can occur within the old host, the new one, or both.

For instance, a virus can jump from host A to host B, but it won’t replicate well or transmit between individuals unless multiple protein keys mutate either simultaneously, or consecutively. The low probability of this happening makes spillovers uncommon.

To better understand how spillovers occur, imagine a virus is a short story printed on a piece of paper. The story describes:

  1. how to live in a specific cell type, inside a specific host
  2. how to move to the cell next door
  3. how to transmit to a new individual of the same species.

The short story also has instructions on how to make a virus photocopying machine. This machine, an enzyme called a polymerase, is supposed to churn out endless identical copies of the story. However, the polymerase occasionally makes mistakes.

It may miss a word, or add a new word or phrase to the story, subtly changing it. These changed virus stories are called “mutants”. Very occasionally, a mutant story will describe how the virus can live inside a totally new host species. If the mutant and this new host meet, a spillover can happen.

We can’t predict virus spillovers to humans, so developing vaccines preemptively isn’t an option. There has been ongoing discussions of a “universal flu vaccine” which would provide immunity against all influenza virus mutants. But so far this hasn’t been possible.

Let wildlife be wildlife

Despite how many viruses exist, relatively few threaten us, and the plants and animals we rely on.

Nonetheless, some creatures are especially dangerous on this front. For instance, coronaviruses, Ebola and Marburg viruses, Hendra and Nipah viruses, rabies-like lyssaviruses, and mumps/measles-like paramyxoviruses all originate from bats.

Given the enormous number of viruses that exist, and our willingness to provide them global transport, future spillovers are inevitable. We can reduce the chances of this by practising better virus surveillance in hospitals and on farms.

We should also recognise wildlife, not only for its intrinsic value, but as a potential source of disease-causing viruses. So let’s maintain a “social distance” and leave wildlife in the wild.The Conversation

Steve Wylie, Adjunct Associate Professor, Murdoch University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

What is a virus? How do they spread? How do they make us sick?



NIAID Rocky Mountain Laboratories (RML), U.S. NIH, CC BY-SA

Lotti Tajouri, Bond University

Viruses are the most common biological entities on Earth. Experts estimate there are around 10,000,000,000,000,000,000,000,000,000,000 of them, and if they were all lined up they would stretch from one side of the galaxy to the other.

You can think of them as nature’s own nanotechnology: molecular machines with sizes on the nanometre scale, equipped to invade the cells of other organisms and hijack them to reproduce themselves. While the great majority are harmless to humans, some can make you sick and some can even be deadly.

Are viruses alive?

Viruses rely on the cells of other organisms to survive and reproduce, because they can’t capture or store energy themselves. In other words they cannot function outside a host organism, which is why they are often regarded as non-living.

Outside a cell, a virus it wraps itself up into an independent particle called a virion. The virion can “survive” in the environment for a certain period of time, which means it remains structurally intact and is capable of infecting a suitable organism if one comes into contact.

When a virion attaches to a suitable host cell – this depends on the protein molecules on the surfaces of the virion and the cell – it is able to penetrate the cell. Once inside, the virus “hacks” the cell to produce more virions. The virions make their way out of the cell, usually destroying it in the process, and then head off to infect more cells.

Does this “life cycle” make viruses alive? It’s a philosophical question, but we can agree that either way they can have a huge impact on living things.

This illustration shows the shape of a coronavirus particle.
CDC / Alissa Eckert, MS; Dan Higgins, MAM, CC BY

What are viruses made of?

At the core of a virus particle is the genome, the long molecule made of DNA or RNA that contains the genetic instructions for reproducing the virus. This is wrapped up in a coat made of protein molecules called a capsid, which protects the genetic material.

Some viruses also have an outer envelope made of lipids, which are fatty organic molecules. The coronavirus that causes COVID-19 is one of these these “enveloped” viruses. Soap can dissolve this fatty envelope, leading to the destruction of the whole virus particle. That’s one reason washing your hands with soap is so effective!

What do viruses attack?

Viruses are like predators with a specific prey they can recognise and attack. Viruses that do not recognise our cells will be harmless, and some others will infect us but will have no consequences for our health.

Many animal and plant species have their own viruses. Cats have the feline immunodeficiency virus or FIV, a cat version of HIV, which causes AIDS in humans. Bats host many different kinds of coronavirus, one of which is believed to be the source of the novel coronavirus that causes COVID-19.

Bacteria also have unique viruses called bacteriophages, which in some cases can be used to fight bacterial infections.

Viruses can mutate and combine with one another. Sometimes, as in the case of COVID-19, that means they can switch species.

Why are some viruses so deadly?

The most important ones to humans are the ones that infect us. Some families of viruses, such as herpes viruses, can stay dormant in the body for long periods of time without causing negative effects.

How much harm a virus or other pathogen can do is often described as its virulence. This depends not only on how much harm it does to an infected person, but also on how well the virus can avoid the body’s defences, replicate itself and spread to other carriers.

In evolutionary terms, there is often a trade-off for a virus between replicating and doing harm to the host. A virus that replicates like crazy and kills its host very quickly may not have an opportunity to spread to a new host. On the other hand, a virus that replicates slowly and causes little harm may have plenty of time to spread.

What’s the difference between COVID-19 and the flu?

How do viruses spread?

Once a person is infected with a virus, their body becomes a reservoir of virus particles which can be released in bodily fluids – such as by coughing and sneezing – or by shedding skin or in some cases even touching surfaces.

The virus particles may then either end up on a new potential host or an inanimate object. These contaminated objects are known as fomites, and can play an important role in the spread of disease.

The novel coronavirus that causes COVID-19 (yellow) emerging from the surface of cells (blue/pink) cultured in the lab.
NIAID Rocky Mountain Laboratories (RML), U.S. NIH, CC BY

What is a coronavirus?

The coronavirus COVID-19 is a member of the virus family coronaviridae, or coronaviruses. The name comes from the appearance of the virus particles under a microscope: tiny protein protrusions on their surfaces mean they appear surrounded by a halo-like corona.

Other coronaviruses were responsible for deadly outbreaks of Serious Acute Respiratory Syndrome (SARS) in China in 2003 and Middle East Respiratory Syndrome (MERS) from 2012. These viruses mutate relatively often in ways that allow them to be transmitted to humans.The Conversation

Lotti Tajouri, Associate Professor, Biomedical Sciences, Bond University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Christians in Pakistan Fear Further Firestorms


Cooperation among police, Muslim and Christian leaders stave off religious brushfires.

LAHORE, Pakistan, September 8 (CDN) — In the wake of Islamists setting fires that killed at least seven people in Punjab Province last month, the latest of several attempts to provoke further attacks on Christians took place in a village on Friday (Sept. 4) when unidentified men tore pages of the Quran and left them at a church.

Police said they were able to cool tensions in Chak 8-11-L Mission Village, near Chichawatni, after the torn pages of the Muslim scriptures were left at the Associated Reformed Presbyterian Church and on a nearby road. Sources said they have witnessed similar attempts to ignite attacks on Christians in several areas of Punjab Province since an Islamic mob on Aug. 1 burned seven Christians alive in Gojra over a false accusation of blaspheming the Quran.

Superintendent of Police Ahmed Nawaz Cheema said the pages of the Quran were left at the dividing line between Chak 8’s Christian-inhabited Mission village and the Muslim-populated Maliks village, indicating “it was planted to create tensions between the two villages.”

Associated Reformed Presbyterian Church Pastor Salmoon Ejaz told Compass that Muslim women on their way to glean cotton early in the morning had found the torn pages of the Quran. They took the pages to local Muslim clerics, who in turn took them to the police. Pastor Ejaz said the clerics came to Christian leaders and told them they had no suspicion that Christians had torn the pages, and that both Muslims and Christians should be vigilant and try to find the culprit.

Since then, the pastor said, the situation has been tense but under control, with police fully cooperating.

“The situation is calm, and we have no fear from the local Muslims, but the real threat is from the madrassas of Chak 11-11-L, 81-9-L and Multan Road,” said the pastor of the church, which was founded in 1906. “Even in Gojra the local Muslims had not attacked, but outsiders were the assailants, and that is the reason we are still frightened.”

In Gojra, members of the banned Sipah-e-Sahaba Pakistan, a pro-Taliban, Sunni Muslim group, and its al Qaeda-linked offshoot, Lashkar-e-Jhangvi, were suspected of planning the attack that killed the Christians and injured at least 19 others. Urged on by clerics from mosque loudspeakers, the rampaging Islamists set fire to 50 homes and looted more than 100 houses.

Christian advocacy group Community Development Initiative (CDI) Field Officer Napoleon Qayyum said al Qaeda remnants have lost support following a Pakistani military operation in tribal areas along the Afghanistan border, and that to regain backing they were trying to exploit anti-U.S. and anti-Christian sentiment. He said well-coordinated efforts were underway to instigate Muslims against Christians by inciting hatred against the United States and the Pakistani government, a U.S. ally in anti-terrorism efforts. In this way, he said, the al Qaeda militants justify terrorist activities against the Pakistani government.

“Terrorism is like the AIDS virus, which keeps changing its tactics,” Qayyum said.

CDI helped to encourage police to increase security in the Mission Village area, he added.

Superintendent of Police Cheema said 50 policemen had been stationed in the area to prevent potential conflicts and would remain there until rumors died down. Christian leaders outside the district had contacted area police warning that Islamists could try to spark violence.

“These Christians have a good liaison with the Christians of other districts and cities,” he said.

Muslims in Maliks were cooperating fully with police to keep conflict from erupting, he said, adding that area Muslims were concerned that Christians in the 400-home Mission Village were not sending their children to school, which is located in the Maliks village of 2,000 Muslim homes. Cheema said area Muslims had indicated that if Christians were afraid, they would be willing to go to the Christian colony and bring their children to school.

Tensions after Gojra

The rumor of desecration of the Quran that led to the attack in Gojra, 50 kilometers (31 miles) from Faisalabad, on July 30 had prompted an Islamist arson assault on Korian village, seven miles from Gojra, that gutted 60 houses.

On June 30, a cleric in Kasur district’s Bahmaniwala village used a mosque loudspeaker to announce a call to attack Christians that resulted in more than 500 Muslims ransacking and looting at least 110 houses. Chief Minister of the Punjab Shahbaz Sharif has ordered the arrest of six Muslim extremists, including suspected mastermind Qari Latif.

On Aug. 1, as houses in Gojra were burned and plundered, Muslim clerics called for demonstrations to protest the arrest of Islamists suspected in the Kasur violence. Pakistan People’s Party’s Provincial Assembly Member Ahmed Riaz Tohlu and Pakistan Muslim League-Nawaz’s National Assembly Member Sheikh Wasim resolved the issue by assuring Christians that Kasur would remain secure and by promising the Islamists that the arrested Muslims would be released. The officials told the provincial deputy general inspector, however, that the names of the released Muslims “should be the first to be mentioned in the FIR [First Information Report] if any untoward incident takes place.”

Potential tensions were also warded off in Shantinagar, a village near Khanewal that suffered a massive onslaught from Islamic extremists in 1997, after another incident involving the Quran on Aug. 8. District Councilor Chaudhry Salamat Allah Rakha told Compass that when one of the village Christians went out in the fields, he saw a bearded person holding something.

“That man yelled at him, at which point the other man ran away,” Rakha said. “This man tried to catch him but failed, and then he saw that there were three Qurans wrapped in a white cloth.”

The Christian suspected the bearded man who fled intended to tear pages of the Quran in order to frame Christians for blasphemy. District Councilor Wazir Jacob arrived at the site and called police, and Sadar police station House Officer Chaudhry Zaka came soon after and seized the three Qurans.

Rakha said that police were asked to file a First Information Report on the incident, but the district police officer refused on grounds that it would create tensions in the area.

Tensions were simmering in St. Henry Colony in Lahore after an altercation over an inconveniently parked car led to a gang fight. Local Pastor Azam Anthony told Compass that on Aug. 6 a Muslim family parked a car close to the front of a house owned by Christians, and a Christian woman came out of the house and asked them to move as it hampered their ability to enter.

“At this the Muslim woman dragged her by her hair, and the Christian woman in her effort to release herself got hold of her shalwar [a garment like trousers],” Pastor Anthony said. A man with the Muslim woman grew furious and began beating the Christian woman, he said.

“The sight further incited Christian boys there who were watching this all going on,” he said. “They asked that man why did he beat a woman, and they beat the man.”

The Muslim man gathered other Muslims, along with a Muslim councilor of the area, and began fighting the Christian boys. Pastor Anthony said that before leaving, the Muslims said they would deal with the Christians after Friday prayers.

“That afternoon was quite tense, and Christians of the area had prepared themselves for another Gojra incident,” Pastor Anthony said. The timely intervention of Christian leaders and police has averted any further incidents – so far.

In the wake of the Gojra attack, Christians have deliberated whether to arm themselves so they can defend themselves against further attacks. One Christian, Naveed Masih, who fired into the air as the Islamist throng attacked, has been credited with reducing the number of casualties and damages. Dubbed Naveed the Soldier, he was the only man with a rifle when the mobs charged Gojra. Several Christian women had taken refuge in his house.

A Muslim association based in Gojra, the Muslim Mahaz Tanzeem for Peace, has since tried to blame Maish for setting off the violence and charged three priests and another Christian with providing him weapons. According to Asia News, the association has threatened another Islamist wave of violence unless the four Christians are arrested.

District Councilor Rakha said that since the attack, about 15 boys have been armed and trained to keep watch at night. Christians in other areas, such as Youhanabad and Bahar Colony in Lahore, told Compass that they would rather die defending themselves than be killed doing nothing.

Petition for Prosecution

In view of the increase in attacks against Christians in Pakistan, the American Center for Law and Justice (ACLJ) has filed a petition with the United Nations through its European body, the European Center for Law and Justice.

“We have expressed in the strongest terms possible that the Pakistani government must prosecute acts of violence based upon religion,” said Jay Sekulow, Chief Counsel of the ECLJ and the U.S.-based ACLJ. “Christians are being singled out and murdered because of their faith. Only when the Pakistani government effectively prosecutes those responsible for the acts of violence will attacks against Christians end.”

The “blasphemy laws” that encourage Muslim violence against Christians violate the principle of the universality of religious freedom to which Pakistan officially adheres, Sekulow said.

The ECLJ petition calls on Pakistan to prosecute deadly attacks on Christians, which have claimed the lives of at least 60 Christians in the past decade in at least 27 separate incidents of Muslim-on-Christian violence. The ECLJ filing states: “More than two decades of blasphemy laws have taught Pakistani Muslims that the punishment for allegedly insulting Islam is death. The Pakistani government must repeal or procedurally change blasphemy laws.”

Because Pakistan has proclaimed the Universal Declaration of Human Rights and the International Covenant on Civil and Political Rights in a resolution to the U.N. that it presented on behalf of the Organization of the Islamic Conference, it should abide by those terms for its own religious minorities, the ECLJ petition states.

Report from Compass Direct News