" >What scientists are doing to develop a vaccine for the new coronavirus - The Conversation Africa | Canada News Media
Connect with us

Health

What scientists are doing to develop a vaccine for the new coronavirus – The Conversation Africa

Published

on


With an increasing number of confirmed cases in China and 24 other countries, the COVID-19 epidemic caused by the novel coronavirus (now known as SARS-CoV-2) looks concerning to many. As of Feb. 19, the latest numbers listed 74,280 confirmed cases including 2,006 deaths. Four of these deaths have occurred outside of mainland China: one each in the Philippines, Japan, Hong Kong and France. The case in France is the first COVID-19 death outside of Asia.

The World Health Organization (WHO) declared on Jan. 30 that the outbreak constituted a Public Health Emergency of International Concern.

In light of these events, health experts around the world are now divided as to whether this event will become a pandemic, or whether it will be possible to contain transmission of this virus.

Towards a pandemic?

In a recent New York Times article Dr. Thomas R. Frieden, former director of the Centers for Disease Control and Prevention, said it was “increasingly unlikely that the virus can be contained.” In the same article, Dr. Anthony S. Fauci, director of the U.S. National Institute of Allergy and Infectious Disease (NIAID), said, “It’s very, very transmissible, and it almost certainly is going to be a pandemic.”

On the other hand, the WHO remains optimistic. Its head of emergency responses, Dr. Michael Ryan, told STAT News, “there’s enough evidence to suggest that this virus can still be contained” and that “until [containment] is impossible, we should keep trying.”

This brings us to the scientists and experts who are doing just that, throwing everything they have at this public health issue. Some are focused on treating patients with existing or novel therapeutics, others are focused on stopping transmission between individuals by developing a vaccine. Luckily for scientists, lessons learned during the 2013-16 West African Ebola epidemic are now enabling the fast-track development of vaccines, without compromising their safety and efficacy.

Of course, it is critical to learn more about this specific novel virus, including its source and why transmission appears to be more efficient than with other coronaviruses.

Vaccine development

CEPI, the Coalition for Epidemic Preparedness Innovations, is an international, not-for-profit organization with the mandate of accelerating the development of vaccines against emerging infectious diseases. On Jan. 23, it announced financial support to three institutions for the development of a vaccine against the newly identified coronavirus: Inovio Pharmaceuticals Inc. and its “DNA platform,” the University of Queensland and its “protein clamp platform” and a Moderna Inc. partnership with NIAID using its “mRNA platform.”

On Jan. 31, CEPI also announced an extended partnership with CureVac, a biotechnology company, to adapt its RNA vaccine platform to SARS-CoV-2. Four days later, CEPI launched a call for proposals to develop new vaccines against the novel coronavirus, open to all organizations meeting its criteria and in possession of a readily available platform.

People wearing surgical masks sitting in the Shanghai metro in January 2020. The novel coronavirus that originated in Wuhan has spread to many cities in China.
(Robert Wei/Shutterstock)

Johnson & Johnson has also announced its participation in vaccine development, using its “adenovirus platform,” which consists of a virus that is modified to look like SARS-CoV-2, but is unable to cause disease in humans. GlaxoSmithKline, another large pharmaceutical company, recently announced a partnership with CEPI to offer access to anyone who would like to use its adjuvant platform (adjuvants are components that can be added to vaccines to increase the generation of an immune response).

Finally, adding its name to the list, the University of Hong Kong also announced it already had a vaccine, designed from a modified influenza virus vaccine.

Issues and solutions

But what do these platforms mean? Why are so many different organizations working towards the same goal of developing a vaccine against one pathogen? Wouldn’t it be easier if everyone worked together, instead of trying such a wide variety of approaches? The answers to these questions are not so simple.

Vaccine platforms are tools that scientists can use to develop a new vaccine, using a similar system to previously successful approaches. For example, one well-known and straightforward approach is the “inactivated platform,” where the pathogen is safely replicated in laboratories, inactivated and then administered as a vaccine.

Although these platforms use different approaches, they all have the same overall goal of training the immune system of the vaccinated individual to quickly recognize a pathogen inside the body.




Read more:
Coronavirus grown in lab outside China for first time, aiding the search for vaccine


So why are there so many different platforms? Well, each platform has its own advantages and disadvantages. Some are easier to mass produce, some are known to induce fewer side effects, and some are just better at training particular aspects of the immune system.

The human immune system is divided into two major arms: innate and adaptive. Our innate immune system is non-specific and provides an immediate, but limited level of protection against a foreign intruder inside the body. The adaptive immune system can target a specific pathogen, but needs time to develop its full effect, about 21 to 28 days following infection, or vaccination. The adaptive side can be further sub-divided into humoral and cellular immunity.

With new pathogens like SARS-CoV-2, scientists don’t know which sub-division of the immune system will provide protection, so they aren’t certain which platform will produce the most successful vaccine.

What are scientists doing then?

Vaccine design looks simple on paper, but making it work all the way to human use is a whole other story.

Currently, scientists are working on identifying which parts of SARS-CoV-2 they can use in their vaccines. These parts have to be carefully selected, because they need to mimic what a real infection would look like to our bodies. This has to be done in conjunction with selection of an appropriate vaccine delivery method: the platform that will be used.

Coronaviruses, like MERS CoV seen here, are named for their appearance under a microscope: projections give the edges of these viruses a characteristic corona, or crown-like shape.
(NIAID)

For ethical reasons, once a vaccine candidate is available, it needs to undergo safety and efficacy testing in animals (although exceptions are possible). Not all laboratory animals are susceptible to infection in the same way as humans. This is why scientists are also working to identify an animal model suitable for evaluating candidate vaccines. At this point, many months and tens of thousands of dollars have been invested in vaccine development.

Once animal trials are satisfactory, the vaccine can be administered to humans in a clinical trial to evaluate the vaccine’s safety and efficacy. This means additional months to years (if not decades), and millions of dollars in investment.

The last steps are often out of the scientists’ hands. The vaccine must be registered and receive regulatory approval, produced at large-scale and distributed. Although these steps take only a few lines to list here, they can take years to actually achieve.

On the other hand, health experts tell us over and over again that if we’re lucky and everything goes well, we could have a safe and effective vaccine in about a year. It remains to be seen at what stage of the process we will be in early 2021. If China has managed to build a 1,000-bed hospital in 10 days to counter the spread of the epidemic, who knows what can be achieved in a year on the vaccine side.

Let’s block ads! (Why?)



Source link

Continue Reading

Health

How prepared is Canada for a possible Coronavirus outbreak? – OttawaMatters.com

Published

on


OTTAWA — Canadian medical experts say the country’s already overstretched emergency rooms would find it difficult to cope if a true outbreak of the novel coronavirus, or COVID-19, were to take hold in Canada.

So far, the virus has been relatively contained to mainland China, thanks in part to one of the largest quarantines in modern history.

“We must not look back and regret that we failed to take advantage of the window of opportunity that we have now,” Dr. Tedros Adhanom Ghebreyesus, director general of the World Health Organization, said in a message to all the world’s countries Friday.

The risk of contracting the virus in Canada right now is extremely low, and public health officials have been lauded for their efforts to detect and isolate the nine cases confirmed in the country so far.

The hundreds of patients across the country who have tested negative for the virus are also a sign that containment efforts are working as they should.

But Canada’s most recent case in British Columbia has raised fears about where and how the disease is being transmitted abroad. Unlike others who’ve imported the virus from China or from people who have recently been to China, the woman in her 30s contracted the illness while in Iran.

“Any imported cases linked to Iran could be an indicator that there is more widespread transmission than we know about,” said Canada’s chief medical officer Dr. Theresa Tam Friday.

Canada has taken major steps to prevent the kind of shock that befell Ontario during the outbreak of the coronavirus known as SARS in 2003 that led to 44 deaths. Creating the Public Health Agency of Canada, which Tam heads, is one of them.

The country is now better co-ordinated, has increased its lab-testing capabilities and is prepared to trace people’s contacts to find people who might have caught a contagious illness without knowing it.

But once the number of incoming cases reaches a critical mass, the approach must change, according to infectious-diseases physician Dr. Isaac Bogoch of Toronto’s University Health Network.

He likens the response to trying to catch fly balls in the outfield: as the number of balls in the air increases, they become harder and harder to snag.

“Every health care system has limits,” Bogoch says. “The question is, if we start getting inundated with cases, how stretched can we get?”

Many emergency-room doctors argue Canada’s ERs are already as stretched as they can get and are worried about what would happen if they suddenly had to start treating COVID-19 cases en masse.

From the public-health perspective, the greatest challenge may be as simple communicating across all parts of the health system across the country, said Dr. Jasmine Pawa, president of the Public Health Physicians of Canada.

“We cover a very wide geographic area,” she said, though she added that Canada has made great strides over the course of the SARS experience and the H1N1 flu outbreak in 2009.

Dr. Alan Drummond of the Canadian Association of Emergency Physicians, who works at the hospital in Perth, Ont., says he doesn’t want to fearmonger, especially considering all the lessons Canada has learned from past outbreaks, but the reality of life in the ER gives him pause.

“Our day-to-day experience in crowded hospitals, unable to get the right patient in the right bed on a day-to-day basis … makes us really question what the integrity of our health-care system would be like in a major severe pandemic,” Drummond says.

He envisions that a disease like COVID-19, if it spread widely, would have a major impact, including the possibility of cancelled surgeries and moving stable patients out of hospitals who would otherwise stay.

“I think there would have to be hard decisions made about who lives and who dies, given our limited availability by both speciality and (intensive-care) beds and we would probably see some degree of health-care rationing,” he says.

The problem may be even more pronounced because of Canada’s aging population, he said. The virus tends to hit older people harder, according to observations made in China and abroad, and is also particularly dangerous for people with other health problems.

Older people also tend to stay admitted in hospital beds even when they are in relatively stable condition because of a lack of long-term-care beds across the country.

That keeps emergency rooms from being able to move acute patients out of the ER and into those beds, limiting hospitals’ capacity to handle new cases.

Tam agreed Friday that hospital capacity is a “critical aspect” of Canada’s preparedness for a potential coronavirus outbreak, but said even very bad flu seasons can have a similar effect on emergency rooms.

“If we can delay the impact of the coronavirus until a certain period, when there’s less influenza for example, that would also be very helpful,” she said.

She also suggested people who are concerned about the possibility that they’re developing COVID-19 symptoms should call ahead to a hospital so they can make proper arrangements for containment and isolation.

Canada is doing its best, along with every other country in the world, to seize this time of relative containment and plan ahead, Tam said.

This report by The Canadian Press was first published Feb. 22, 2020.

Laura Osman, The Canadian Press

Let’s block ads! (Why?)



Source link

Continue Reading

Health

Coronavirus: How does Covid-19 spread? These new studies offer clues. – Vox.com

Published

on


How does the new coronavirus disease, Covid-19, spread? That’s just one of many basic, unanswered questions about this latest pandemic threat.

The virus that causes Covid-19 — known as SARS-CoV-2 — has already infected more than 75,000 people in two months. (Of them, 2,130 have died.) And the best explanation for this rapid spread is that it’s being passed through droplets from coughing or sneezing. When these virus-laden droplets from an infected person reach the nose, eyes, or mouth of another, they can transmit the disease.

But are there other ways SARS-CoV-2 moves between people? And what do they tell us about why this disease seems to be even more contagious than SARS and MERS? The latest science on the virus offers possible answers to these questions — and why Covid-19 might be particularly difficult to stop. Here’s what we know so far.

Respiratory illnesses generally fall into two categories: upper respiratory — infections in the nose, pharynx, or larynx, like the common cold and seasonal influenza; and lower respiratory illnesses, like pneumonia, which infect the lungs.

The original SARS virus that spread around the world in 2003 was thought to be a lower respiratory infection: It replicated in the cells deep within the lungs and caused the pneumonia. People also seemed to only spread the virus days into their illness, when it was already clear they were sick. This made SARS more difficult to pass on to others and the job of containing it relatively easy.

The new virus that causes Covid-19 disease appears to be a different beast: While it also can eventually lead to pneumonia, the virus does a great job of replicating in the upper respiratory tract, even when people don’t have any symptoms or just begin to feel sick.

Check out this new New England Journal of Medicine paper. Chinese researchers monitored how much virus could be found in the upper respiratory tracts — noses and throats — of 18 patients in Guangdong, China. One of the 18 never had any symptoms.

The big finding? The way people shed this virus, potentially exposing others, looked a lot more like the flu than the first SARS, which might help explain why Covid-19 appears to be more infectious. You can see why in this chart from the study, focused on the patients who experienced symptoms: Just as they were starting to feel ill, they had the highest concentrations of virus in their noses:

New England Journal of Medicine

What’s more, the one person who was asymptomatic carried a similar amount of virus as the symptomatic patients, “which suggests the transmission potential of asymptomatic or minimally symptomatic patients,” the researchers wrote.

In a separate, newly published New England Journal of Medicine paper, researchers in Germany were also able to isolate the virus from patients’ upper respiratory tract even before they showed any symptoms or were very mildly symptomatic — more evidence of the potential for spread of the virus from the nose and throat when people barely know they’re sick.

So what does this imply about the contagiousness of Covid-19 and stopping the outbreak? “For a virus pretty closely related to SARS, it shows very effective person-to-person transmission, something nobody really expected,” Stephen Morse, a professor of epidemiology at Columbia University Mailman School of Public Health, told Vox. Researchers currently believe one infected person generally infects two to more than three others, which would make the new coronavirus more contagious than seasonal flu, SARS and MERS.

Javier Zarracina and Christina Animashaun/Vox

Second, it means stopping the outbreak might be more difficult, since people start to become infectious early on in their disease or may even spread the virus when they’re asymptomatic.

But to confirm these two findings, we’ll need more science, said Jennifer Nuzzo, an infectious disease expert and senior scholar at the Johns Hopkins Center for Health Security. “We still don’t know to what extent people without symptoms can infect,” she pointed out.

It’s also possible that transmission early in the illness or from asymptomatic people won’t end up being important contributors to the outbreak, said Marion Koopmans, who studies emerging infectious diseases and heads the department of virology at the Erasmus Medical Center in Rotterdam, Netherlands. In most parts of the world where travelers with Covid-19 turned up, she added, the spread of the disease has been contained by only testing people with symptoms. But, she added, “both of these statements can coexist: Asymptomatic shedders could spread the virus, but it probably is not the main driver of this epidemic.”

Another way viruses can spread is through poop. Think of the norovirus, the extremely contagious bug that can be passed along by ingesting the stool of an infected person, often through food or touching a contaminated surface. This is known as the “fecal-oral” route of disease transmission.

Now there’s some suggestion in the emerging literature that Covid-19 could be passed through exposure to virus-laden feces, too.

In this new paper from the Chinese Center for Disease Control and Prevention, researchers managed to isolate live virus from stool samples of Covid-19 patients. And they’re not the first to find the virus in stool.

As with norovirus, this means the disease could be passed around when there’s less than optimal hygiene. “If true, it would not be surprising,” Morse said. “A number of other coronavirus are excreted from the intestines, and infectious virus can be found in stool.”

That’s why the China CDC recommended taking measures to stop the spread of the virus this way, including:

maintaining environmental health and personal hygiene; drinking boiled water, avoiding raw food consumption, and implementing separate meal systems in epidemic areas; frequently washing hands and disinfecting of surfaces of objects in households, toilets, public places, and transportation vehicles; and disinfecting the excreta and environment of patients in medical facilities to prevent water and food contamination from patients’ stool samples.

But just because the virus is found in stool doesn’t mean that’s how it’s transmitting. And, again, more research is needed to figure out how important the fecal-oral route is in the spread of this disease.

Poop was also implicated in the first SARS outbreak, when a large housing estate in Hong Kong called Amoy Gardens became ground zero of a public health nightmare. More than 300 people were infected with the disease through yet another viral transmission route: airborne transmission of virus-ridden feces aerosols.

Airborne spread happens when the residue from evaporated, infected droplets gets suspended in the air and indirectly infects those who breathe it in. It’s different from droplet transmission, since droplets are too large to float through the air and need to get sprayed directly on someone’s eye, nose, or mouth in order to infect them.

In the case of Amoy Gardens, researchers learned SARS was capable of going airborne, spreading through the building’s faulty plumbing and ventilation systems to the people who lived on the estate. “The infections [were] officially attributed to faulty toilet traps which were thought to have aerosolized patients’ virus when the toilet was flushed, allowing dispersal of the virus to other residents,” Morse explained. “This has been demonstrated with SARS and MERS and others, and therefore is plausible, although we currently lack good evidence.”

So researchers and doctors are looking into whether the news SARS virus spreads this way — and taking precautions in case it can. Vito Iacoviello, chief of the division of infectious diseases at Mount Auburn Hospital in Cambridge, Massachusetts, and an editor at Dynamed, noted that the US Centers for Disease Control and Prevention is recommending people admitted to hospitals with Covid-19 be put in an airborne isolation room. “That’s the precaution we use for TB, measles, and chickenpox,” he said, and it suggests health officials are preparing for the possibility that this virus is capable of airborne spread.

But again, for now, there’s no good evidence of Covid-19’s airborne transmission. It’s just another thing to watch out for as our understanding of this virus, and how it moves through populations, evolves.

Let’s block ads! (Why?)



Source link

Continue Reading

Health

COVID-19: Canadian hospital space a concern despite lessons from SARS, experts say – Global News

Published

on


Canadian medical experts say the country’s already overstretched emergency rooms would find it difficult to cope if a true outbreak of the novel coronavirus, or COVID-19, were to take hold in Canada.

So far, the virus has been relatively contained to mainland China, thanks in part to one of the largest quarantines in modern history.

“We must not look back and regret that we failed to take advantage of the window of opportunity that we have now,” Dr. Tedros Adhanom Ghebreyesus, director general of the World Health Organization, said in a message to all the world’s countries Friday.


READ MORE:
COVID-19: Coronavirus multiplies eight-fold in South Korea as cases jump to 433

The risk of contracting the virus in Canada right now is extremely low, and public health officials have been lauded for their efforts to detect and isolate the nine cases confirmed in the country so far.

Story continues below advertisement

The hundreds of patients across the country who have tested negative for the virus are also a sign that containment efforts are working as they should.

But Canada’s most recent case in British Columbia has raised fears about where and how the disease is being transmitted abroad. Unlike others who’ve imported the virus from China or from people who have recently been to China, the woman in her 30s contracted the illness while in Iran.






5:05
Coronavirus outbreak: China reports significant drop in daily cases, down to 397


Coronavirus outbreak: China reports significant drop in daily cases, down to 397

“Any imported cases linked to Iran could be an indicator that there is more widespread transmission than we know about,” said Canada’s chief medical officer Dr. Theresa Tam Friday.

Canada has taken major steps to prevent the kind of shock that befell Ontario during the outbreak of the coronavirus known as SARS in 2003 that led to 44 deaths. Creating the Public Health Agency of Canada, which Tam heads, is one of them.

The country is now better co-ordinated, has increased its lab-testing capabilities and is prepared to trace people’s contacts to find people who might have caught a contagious illness without knowing it.


READ MORE:
COVID-19 and the Tokyo Olympics: What you need to know

But once the number of incoming cases reaches a critical mass, the approach must change, according to infectious-diseases physician Dr. Isaac Bogoch of Toronto’s University Health Network.

Story continues below advertisement

He likens the response to trying to catch fly balls in the outfield: as the number of balls in the air increases, they become harder and harder to snag.

“Every health care system has limits,” Bogoch says. “The question is, if we start getting inundated with cases, how stretched can we get?”


READ MORE:
With COVID-19 emerging in new countries, health officials worry about untraceable clusters

Many emergency-room doctors argue Canada’s ERs are already as stretched as they can get and are worried about what would happen if they suddenly had to start treating COVID-19 cases en masse.

From the public-health perspective, the greatest challenge may be as simple communicating across all parts of the health system across the country, said Dr. Jasmine Pawa, president of the Public Health Physicians of Canada.

“We cover a very wide geographic area,” she said, though she added that Canada has made great strides over the course of the SARS experience and the H1N1 flu outbreak in 2009.






2:14
Coronavirus outbreak: British passengers disembark Diamond Princess cruise ship


Coronavirus outbreak: British passengers disembark Diamond Princess cruise ship

Dr. Alan Drummond of the Canadian Association of Emergency Physicians, who works at the hospital in Perth, Ont., says he doesn’t want to fearmonger, especially considering all the lessons Canada has learned from past outbreaks, but the reality of life in the ER gives him pause.

“Our day-to-day experience in crowded hospitals, unable to get the right patient in the right bed on a day-to-day basis ? makes us really question what the integrity of our health-care system would be like in a major severe pandemic,” Drummond says.

Story continues below advertisement

He envisions that a disease like COVID-19, if it spread widely, would have a major impact, including the possibility of cancelled surgeries and moving stable patients out of hospitals who would otherwise stay.


READ MORE:
Italy reports 1st death from COVID-19 as cases more than quadruple to 19

“I think there would have to be hard decisions made about who lives and who dies, given our limited availability by both speciality and (intensive-care) beds and we would probably see some degree of health-care rationing,” he says.

The problem may be even more pronounced because of Canada’s aging population, he said. The virus tends to hit older people harder, according to observations made in China and abroad, and is also particularly dangerous for people with other health problems.

Older people also tend to stay admitted in hospital beds even when they are in relatively stable condition because of a lack of long-term-care beds across the country.

That keeps emergency rooms from being able to move acute patients out of the ER and into those beds, limiting hospitals’ capacity to handle new cases.






0:36
Repatriated Canadians from Japan to be treated individually if diagnosed with COVID-19


Repatriated Canadians from Japan to be treated individually if diagnosed with COVID-19

Tam agreed Friday that hospital capacity is a “critical aspect” of Canada’s preparedness for a potential coronavirus outbreak, but said even very bad flu seasons can have a similar effect on emergency rooms.

“If we can delay the impact of the coronavirus until a certain period, when there’s less influenza for example, that would also be very helpful,” she said.

Story continues below advertisement

She also suggested people who are concerned about the possibility that they’re developing COVID-19 symptoms should call ahead to a hospital so they can make proper arrangements for containment and isolation.

Canada is doing its best, along with every other country in the world, to seize this time of relative containment and plan ahead, Tam said.

© 2020 The Canadian Press

Let’s block ads! (Why?)



Source link

Continue Reading

Trending