Showing posts with label vaccine. Show all posts
Showing posts with label vaccine. Show all posts

12 Dec 2020

How Do Vaccines Work?

 by Yolanda Ridge

After a year of bad news stories, there’s finally some good news on the horizon when it comes to COVID-19: a vaccine!


So how do vaccines work? Here’s a step-by-step guide on how vaccines—also known as immunizations—prevent people from getting disease like the measles, the flu and (hopefully soon) COVID-19. For the simplicity, I’ll refer to the disease as “YUCK” and the germ that causes it as “Y”.


    Scientists modify Y so it is weak or even dead but still recognizable (a bit like a zombie).





    This zombified version of Y is given to a person, usually by injection or nasal spray.

    Once a person has been exposed to Y-modified they start to develop an immune response.

    This immune response can cause some people to develop a fever or maybe a bit of a runny nose but it will not cause someone to get YUCK because of the way Y has been modified (or zombified).

    The body essentially learns from this exposure to Y-modified through something called adaptive immunity.

    When an immunized person is next exposed to Y (this time through contact with someone who has YUCK) their immune system will immediately recognize the intruder and launch a full-scale assault… usually enough of an attack to stop Y from causing YUCK.





There’s more detail on vaccines and immunity in this excellent TED-Ed video. Because it was made in 2015, there’s no mention of COVID-19. But did you know that there are more than 150 coronavirus vaccines currently in development across the world? As I write this, people in the United Kingdom and Russia are receiving the first immunizations against COVID-19.


For more details on the different types of coronavirus vaccines and the process of getting them approved, check out this comprehensive article: Here’s the latest on COVID-19 vaccines, from National Geographic magazine.


According to a poll done by National Geographic magazine, 61% of Americans are likely to get an FDA-approved coronavirus vaccine once it’s available. What about you?


Yolanda Ridge is a middle grade author and science writer from Rossland, BC. Visit her website at www.yolandaridge.com to find out more.


Photo credits: Male Zombie by Gordon Dylan Johnson from opengameart.org; Soldier by André Santana from pixabay.com

27 Mar 2020

Epidemics, Smallpox, and William Osler

By Gillian O'Reilly

These days, our minds are on epidemics (the rapid spread of disease to a large number of people in a given population within a short period of time) and pandemics (disease epidemics that have spread across large regions or worldwide).
 

One of my current projects is a book about the brilliant Canadian diagnostician and medical
educator Dr. William (Willie) Osler. Born in 1849 when people still thought diseases were
caused by bad air, Osler lived through the huge changes brought about by the discovery of
germs. There are several stories of his encounters with smallpox during his career.




Photo of William Osler from 1881 used with permission
of the Osler Library for the History of Medicine

In the nineteenth century, smallpox was a terrifying disease, often fatal. Survivors were left with bad scarring or blindness. Symptoms were fever, a rash, and characteristic pustules all over the body. Once diagnosed, smallpox patients had to be quickly isolated from other patients in a separate ward or hospital.
 

Vaccinations, successfully tested in 1796, had replaced variolation (an earlier form of inoculation used in Asia and Africa for centuries). Over the nineteenth century, widespread vaccination, sometimes mandated by law, had reduced the number of infections and deaths, but there were still regular outbreaks where vaccination rates were low.

In the spring of 1872 after his final year of medical school, Willie worked briefly at a hospital in Hamilton, Ontario. There he encountered a rare case of smallpox and drove the dying patient to mayor’s home to force the authorities to provide proper isolated accommodation for the man.
 
Quarantine poster image used with permission 
of the Osler Library for the History of Medicine
 
Montreal was one part of Canada where vaccination rates were low. Willie was teaching at McGill University during the smallpox epidemic of 1875-1876 and he took time to work in Montreal’s smallpox hospital, earning $600. Although he had been vaccinated (like all his siblings), he caught a mild case of the disease.
 

In those days, medical students learned mostly from lectures, rarely seeing patients or working in a lab. One of Willie’s innovations as a teacher was to make sure that his students had microscopes, so they could see and understand the diseases they were studying. The $600 he earned went to pay for microscopes.
 

Willie was one of the founders of the Johns Hopkins School of Medicine in Baltimore. When it opened in the fall of 1893, he at last had the medical school he wanted – a place where learning, hospital work and research were intertwined and where students could learn by doing. Willie led a weekly general clinic at the hospital, where he and students would see patients. 

By then, some diseases had become rare enough that many doctors and students had trouble diagnosing them. One resident proudly displayed what he thought was an interesting case of chicken pox to Osler and 30 or 40 students and doctors. When he threw back the sheet, a horrified Willie exclaimed, “My God, Futcher, don’t you know smallpox when you see it?” The patient was quickly isolated, the ward quarantined for six weeks and the students and staff hurriedly vaccinated.

In 1980, smallpox became the only human disease to be declared eradicated, thanks to a worldwide vaccination program in the 20th century.


More on William Osler and the history of medicine can be found at The Osler Library of the History of Medicine at McGill  https://www.mcgill.ca/library/branches/osler

The Osler Library Instagram page at https://www.instagram.com/oslerlibrary/  has a good drawing of emergency smallpox vaccinations being performed on American-bound trains from Montreal.


6 Mar 2020

Virus VS Bacteria — Know your enemy

Viruses and bacteria are the typical things that make us sick. But what are they? The first thing to know is that you can’t see them without a microscope. The second thing to know is that they find a great home in our bodies, where they can grow, reproduce, and spread to new hosts. But in the process, most of them make us very, very sick. Bacteria rots our food, too.

What do viruses and bacteria look like?

Viruses are different from bacteria in many ways, and not all viruses look alike. Bacteria don’t all look the same either. Here are some things that make them different.


 
the coat on some viruses looks spiky, like a ball of velcro
Virus

some bacteria have flagellum, a tail that helps them move
Bacteria

Size Smaller: 20–400 nm
Need an electron microscope to see them
Larger: 200–1000 nm
See them with a school microscope
Structure Protein coat only, no cell Single cell with a wall
Living/Non-Living Between living and non- Living organism
Reproduction Forces host cell to reproduce its DNA Reproduces on its own by splitting (fission)
Prevention Fight with vaccines and hand washing Fight with hand washing
Recovery from infection Heal with antiviral medications Heal with antibiotics

Images by Arek Socha from Pixabay.

How do you fight an infection of virus vs bacteria?

Viruses and bacteria that make a home in your body can make you sick. The solution for each is found right in the name: Anti-biotics fight the biotic, living bacteria. Anti-virals fight the viral infection caused by viruses. But not every virus and bacteria has a medicine to fight it.

An antibiotic cannot fight a virus, and vice versa.

Not all bacteria are killed by the same antibiotic medications.

Not all viruses are killed by the same antiviral medicines. Medicine has to be matched to the specific problem.
Amazing fact: Bacteria can catch a virus!
Some viruses can be prevented by taking a vaccine before you are exposed to the virus! Each vaccine fights a specific virus. Flu vaccines change every year to match the particular type of flu that is spreading that year, since flu (influenza) is a whole family of viruses. In Canada, most people take a group of vaccines when they are children, to prevent once-common deadly illnesses like chickenpox, measles, and mumps. When we travel to foreign places, we can take vaccines to prevent picking up viruses that are widespread there; hepatitis and malaria are common viruses that travellers get vaccinated against.

Animals get vaccinated against viruses such as rabies. Viruses and bacteria make animals sick too, but not always the same ones that make humans sick.

Your doctor will determine whether it is a virus or bacteria that is making you sick. Or it may be a different illness! They will prescribe the right medicine for the job, if that is an option.
Amazing fact: Some kinds of bacteria are good for you! Probiotics are an example of bacteria that are helpful in your stomach.

5 Jan 2018

Crayola’s New Blue and Other Hidden Opportunities

By Larry Verstraete

Months ago, Crayola, the crayon giant announced the removal of Dandelion from its palette of yellows and oranges. In March, the company issued a news release saying that Dandelion’s replacement would be in the blue family. Not long after, it added another tidbit of information. The replacement would be a newly invented, never seen before, hue of blue with a backstory as unique as its name, “YInMn Blue”.

In 2009, Mas Subramanian, an Oregon State University (OSU) chemist, discovered the colour with his grad student, Andrew Smith. The two were heating batches of manganese to 1200 °C (~2000 °F), hoping to produce a high-efficiency electronic material. After one attempt, Smith pulled a striking, brilliant-blue compound out of the furnace. Subramanian knew right off it was a research breakthrough. Unwittingly, they had created a shade of blue unlike any other from a combination of yttrium, indium, manganese, and oxygen.

Recognizing opportunity, Subramanian and his team shifted gears. They expanded their research. To date, they have created a range of new pigments, everything from bright oranges to vibrant hues of purple, turquoise, and green.

Discoveries of this sort are not uncommon in science. X-rays, penicillin, and Kevlar are a few items that owe their existence to usual circumstances where scientists were looking for one thing and happily found something else. The nicotine patch is another.

In 1986, as Frank Etscorn, a behavioural psychologist, walked across the floor of his basement laboratory in the New Mexico Institute of Mining and Technology carrying an open vial, he stumbled. He had been studying sugar dependency in rats and the vial contained a nausea-inducing substance found in tobacco that he thought might reduce the rats’ cravings for sweets. When he stumbled, the brown liquid sloshed on to his arm. “I wiped it off and didn’t pay attention,” he told a reporter for People Magazine later. “But after about 15 minutes I felt nauseated.”

The experience sidetracked Etscorn, steering him into a new area of research. “Almost immediately, I realized this could be a way for people to stop smoking.”

It took years to produce a workable nicotine patch, but the accident was the start of the process. Just as in Subramanian’s case, Etscorn saw something others might have missed.

What does it take to recognize hidden opportunities when they arise? Brain research provides some clues. The corpus callosum, a thick band of more than 200 million nerve fibres, connects the left and right hemisphere. Think of it as a busy freeway where impulses fire back and forth, facilitating communication between the two sides of the brain.

In brain studies, neuroscientists discovered that the corpus callosum of creative individuals was thicker than normal. In such brains, there appears to be more communication between the two hemispheres and greater potential of connecting seeming disconnected ideas.

Not every brain hardwired with a thick callosum connects the dots and capitalizes on unexpected circumstances, however. And it doesn’t mean that a brain with a thin callosum cannot be a member of the discovery club either. There’s more at play in taking advantage of serendipitous events than simple brain mechanics.

Over a century ago, Louis Pasteur made a major discovery after his lab assistants neglected a batch of petri dishes. Wondering how this would affect his results, Pasteur opted to carry on the experiment.  His decision led to a breakthrough in the development of vaccines.

Luck played a role in the discovery. The lab assistants messed up, providing Pasteur with opportunity. But Pasteur recognized that more than luck was involved, too. Knowledge and experience combined with curiosity seem to be another part of the formula. Or, to quote Pasteur’s famous line, ‘Chance favours the prepared mind’.

There you go, crayon lovers. Colour on with Crayola’s new blue knowing that you are holding a bit of chance between your fingers.

Images from Pixabay

31 Mar 2017

I Blame Dr. Suzuki, or, Why I Write about Science

By Gillian O'Reilly

How did a history and art history graduate end up writing about science? I blame it on Dr. David Suzuki. Specifically, I blame it on a 30-year-old episode of the radio program Quirks and Quarks, which Suzuki hosted, and on a talk he gave to a group of booksellers some 25 years ago. In both cases, the stories he told lodged themselves in a corner of my mind and slowly, slowly pushed science to the forefront of my interests.

The Quirks and Quarks episode was a presentation of ordinary citizens grappling with a new aspect of science in an extraordinarily thoughtful way. It showed a community somewhere in New England faced with a proposal for a laboratory examining recombinant DNA. Back then, for the ordinary layperson, recombinant DNA was the stuff of science fiction or nightmares or both. As I recall, Quirks and Quarks broadcast parts of the public hearings over at least two episodes, devoting hours to the topic with very little editorial comment. We simply heard ordinary people informing themselves, working through questions and coming up with their conclusions. The lab was allowed.

When David Suzuki spoke to the booksellers a few years later, he began by discussing the all-too-common idea that science doesn’t have anything to do with one’s day-to-day life. Intellectually, I agreed with Suzuki that this idea was wrong, but, frankly, science didn’t seem to have much to do with my day-to-day life either.

Suzuki pointed out that, when he was a child, he wasn’t allowed to go to the movies or the swimming pool because of polio scares. As someone who had measles before there was a vaccine and who had seen the results of childhood polio in 1980s Africa, his statement hit home for me. He detailed other ways that science had changed his and everyone’s lives, but what I remember was the vaccines – the very ordinary way that children’s lives have been changed in ways today’s kids can scarcely imagine.

Over the years, I have recalled and reflected on the stories Suzuki told, as I gradually became more interested in writing about STEM topics. These two episodes showed both the ways in which ordinary people’s lives can be affected by science and the way ordinary laypeople can grasp and make intelligent decisions about science.

So I write about STEM subjects, not just for the budding scientist, but for the kids who will grow up to be historians or artists or school principals or lawmakers – all of whom will need to understand and make intelligent decisions about the wonderful science around us.

Gillian O’Reilly is the co-author with Cora Lee of The Great Number Rumble, Revised and Updated: A Story of Math in Surprising Places (Annick Press, 2016), illustrated by Lil Crump.

11 Jul 2014

Quarantine Tent looks to the past in the discussion about vaccines

By Pippa Wysong

When it comes to communicating science, talking to people in-person is still a valid approach. Often getting an idea or information across is about the experience, and interacting with real people.

The Quarantine Tent is an experience. Here, visitors meet people transported from the past who have vaccine-preventable diseases from an era before vaccines were available.

At the Quarantine Tent, volunteers play the roles of diseases vaccination can now prevent. Pippa Wysong photo.
With vaccination rates dropping, diseases such as whooping cough and measles that were once tamed in populations are starting to make a come-back. And for some people, these diseases have debilitating long-term effects. Many of today’s parents don’t have the context, in terms of history, as to what the risks of these diseases mean in terms of a non-vaccinated population.

The Tent was first presented at Canada’s biggest, nation-wide science festival, Science Rendezvous in 2013 at the University of Toronto location where the actors (mostly medical students) and I interacted with over 500 visitors to the tent. As of July 2014, the Tent has now been to two Science Rendezvous festivals, was invited to set-up at a 100th anniversary fair put on by Sanofi-Pasteur on the historic Connaught Laboratories property, and hosted by the Hamilton Public Health Services for the city’s Open Streets festival.

At the Tent you can meet smallpox. He’s 20, from 1921, and the blisters on his face and hands look terrible. He contracted the disease in Ottawa when he was visiting family during an outbreak. He lost several family members there to smallpox, including his father and younger brother. That year, Ottawa saw 1,352 cases, and 30%-50% of non-vaccinated people who got smallpox died.

The last case in Canada occurred in 1967 from someone returning from Brazil. A success story of vaccination, globally smallpox was eliminated in 1979.

Or meet diphtheria. She is 19 and from 1913 when there was an outbreak in Toronto. She‘ll tell you how she lost her kid sister from the disease just a few days ago, how a younger brother is struggling, and will describe the symptoms of “The Strangling Disease”.

In the 1920s, diphtheria killed 15% of children between 2 and 14 every year. Until 1920, about 12,000 cases and 1,000 deaths occurred each year in Canada (those numbers would be bigger with today’s population). After the vaccine was introduced, diphtheria deaths and incidence fell sharply and major cities, for the first time, reported zero cases by the mid 1930s.

The Quarantine Tent also features polio, HPV, measles, 1918 flu and whooping cough. My grandfather, Dr. Gordon Bates was a physician and national public health activist from WW-I through to the 1970s who treated these diseases and saw the havoc they wreaked. The inspiration for the Tent came from the stories of old that I grew up with, and the education bug is probably inherited.

Vaccines have been an incredible success story in terms of reducing the incidence of these diseases. Unfortunately, growing numbers of people not vaccinating their children – largely because they don’t know how devastating these diseases, unchecked, really can be. People from the past will tell you about seeing loved one or friends getting sick, dying or developing disabilities from these diseases. Ever hear of the permanent hearing loss caused by ‘measles ear’? Serious complications occur in upwards of 10% of measles cases.

Or, they have been misinformed about the safety and efficacy of vaccines, both challenging things to communicate to people who don’t understand statistics. A simple message from the Tent is ‘what does society look like without vaccines’?

Or, they’re worried about ingredients in vaccines (which were all tested for safety before being added, by the way). Formaldehyde sounds scary. But the amount in a vaccine is far less than what your own body produces, and 600 times less than what occurs in a pear (it’s a natural metabolite), and is easily cleared by the body. With many things, it’s the quantity that makes the poison and the amounts naturally made by your body and in vaccines are miniscule.

By the way, there are over 12,000 peer-reviewed studies in the medical literature on vaccines, population effects, long-term effects, safety and more. Knowledge is constantly increasing.

No medical treatment is 100% effective or 100% safe, and that’s another difficult concept to communicate. People would like zero risk, but that’s not possible. Surgery and headache remedies have risks too, but most of us benefit from them. A risk that is ‘rare’ is difficult to communicate because people think ‘what if I’m that one?’. So, turn that around to how ‘common’ the risks are if diseases are unchecked -- and suddenly a ‘rare’ risk looks better.

There is always someone out there for whom a treatment doesn’t quite do the job, or who experiences a bad side effect. But looking at it from a population point of view, the treatments are far safer and beneficial than having masses of people suffering the condition.

All these diseases (except smallpox) are still around, and if vaccination rates keep dropping, could make a serious come back. All of them.

So, vaccines, why bother? Take a trip to the past to find out.

17 Feb 2012

Thoughts on WiFi, Science and Science Reporting


Posted by Gillian O’Reilly

Recently, the Ontario English Catholic Teacher's Association called for an end to new WiFi setups in the province's 1,400-plus Catholic schools, saying computers in new schools should be hardwired instead. The union – which represents 45,000 teachers – cites research by the World Health Organization and said the “safety of this technology has not thoroughly been researched and therefore the precautionary principle and prudent avoidance of exposure should be practised.”

Here are two stories on it:




I must admit that I have a little trouble with the WiFi topic because I know someone whose family seems to have been affected by WiFi (grown child with seizures, a grandparent with other issues) and who is very concerned by it.

I am basically agnostic/skeptic on this issue. The only detailed media I have heard about it was a CBC Sunday Edition program that was not very scientifically presented – lots of personal anecdotes from thoughtful and sincere people who have had dramatic encounters with WiFi, one scientist who has talked a lot about this issue and, it seemed, a lack of probing into the scientific details (more the fault of the journalists than the fault of the people concerned about the issue).

On the opposite side, all I have heard are health bodies who say there is no problem. Any one with a memory knows that there have been lots of times that we've been told something was no problem when in fact it was -- but that's history, not science. Again, no real science reporting on how they arrived at that conclusion.

As someone who comes to science from an arts background, my general approach to science is that "there are more things in heaven and earth than are dreamed of in your philosophy." There are all sorts of new and interesting things being discovered all the time (like a sea sponge that makes a structure of glass! cool, eh?) and scientific thinking changes all the time. The point is to try to be intelligent about it, whether or not one has a science background oneself.

For instance, and to take a dramatic example, it wouldn’t have taken a scientist to ask a few questions to the now-disgraced anti-vaccine campaigner Andrew Wakefield; it would only take a logical, intelligent thinker. How big was your sample, Dr. Wakefield? (Twelve.) Is that a useful sample? (No.) Do you have any conflicts of interest in this matter? (Yes.) You wouldn’t even have to ask, Is it possible you falsified the data? (Yes.) It’s a pity the editors of The Lancet, a peer-reviewed medical journal, didn’t ask these questions before they published his report.

So I'm quite prepared to believe that WiFi is a problem and I'm quite prepared to believe that it isn't – as long as I'm told something about the science behind it. I don't want to be told (like my friend) that if I'm concerned, I should go out and get a tinfoil hat. I don't want to be mollified by an official "there is no problem." And I don’t want people feeding me quotes that they haven’t sourced properly.

I simply want science reporters and institutions like OECTA to do what they are supposed to do – ask the tough, logical, scientifically literate questions these issues demand and present the answers to those questions to me clearly. That way I, and the folks making policy decisions on these topics, can do some intelligent informed thinking, whether we are scientists or not.