Developing a vaccine

[b2bailey]

I was listening to something on the radio and it seems to go like this:
1. Possible/probable vaccine is invented and tested in lab.
2. Volunteers get injected to see if any side effects.
3. And then what? Do these people volunteer to be exposed to the virus to see if it works?
4. What if the person is an Asymptomatic carrier?

===
I'm wondering if the historical development of vaccines has always required people be intentionally exposed -- measles, mumps, polio? Can honestly say I have never wondered on this topic previously.

 

[TravelTime]

Here’s a good link about vaccines:

Basics of Vaccines | CDC

The Basics about Vaccines & Vaccine Preventable Diseases

www.cdc.gov

 

[TravelTime]

Here’s another link about how vaccines are tested:

How Vaccines are Developed and Approved for Use | CDC

Learn how new vaccines are developed, tested in clinical trials, approved and recommended for use in the United States.

www.cdc.gov

 

[TravelTime]

This link directly answers your question about the steps in testing whether a vaccine is effective.

Vaccine Development, Testing, and Regulation

Systems for developing and testing vaccines emerged after the 19th century, when many vaccines began to be used. The current system for developing, testing, and regulating vaccines developed during the 20th century as the groups involved standardized their procedures and regulations.

www.historyofvaccines.org

 

[dioxide45]

They don't usually purposely expose trial participants to the virus. Challenge trials would be where they purposely expose people to the virus. There was a thread on this earlier today;

https://tugbbs.com/forums/threads/covid19-and-challenge-trials.304046

 

[easyrider]

They did develop a vaccine for sars 1 back in 2002 or 2003 in response to H1N1. Yesterday on a news program the scientist who developed this vacine said it could be modified for any sars virus the same as the the flu virus is modified yearly but there is no incentive for drug makers to manufacture this.

Bill

 

[TravelTime]

They don't usually purposely expose trial participants to the virus. Challenge trials would be where they purposely expose people to the virus. There was a thread on this earlier today; https://tugbbs.com/forums/threads/covid19-and-challenge-trials.304046

The link I posted says they try to do challenge trials.

 

[dioxide45]

The link I posted says they try to do challenge trials.

Actually, the third link specifies this under Phase I Trials;

In a small minority of Phase 1 vaccine trials, researchers may use the challenge model, attempting to infect participants with the pathogen after the experimental group has been vaccinated.

 

[TravelTime]

Actually, the third link specifies this under Phase I Trials;

In a small minority of Phase 1 vaccine trials, researchers may use the challenge model, attempting to infect participants with the pathogen after the experimental group has been vaccinated.

Thanks for noticing that. Personally I was wondering about the ethics of doing challenge trials.

 

[dioxide45]

Thanks for noticing that. Personally I was wondering about the ethics of doing challenge trials.

The post I linked to did discuss some of the ethics involved in challenge trials, especially when there is no known cure or effective treatment.

 

[dioxide45]

They did develop a vaccine for sars 1 back in 2002 or 2003 in response to H1N1. Yesterday on a news program the scientist who developed this vaccine said it could be modified for any sars virus the same as the the flu virus is modified yearly but there is no incentive for drug makers to manufacture this.

Bill

I think the SARS vaccine was created in response to the SARS outbreak. H1N1 was in 2009 and a vaccine was developed and rolled out pretty quickly. Though we have much more knowledge of the flu and vaccines to prevent it. I suspect that is why they were able to get a vaccine out much faster for H1N1.

However, as you say, a vaccine was created for SARS but because there were only 700 deaths and it faded rather quickly there was no incentive to produce a vaccine. Who would take it? Why? There was no immediate threat. it doesn't make sense to produce the vaccine if there is no market to buy it.

A vaccine may be challenging for COVID-19. Since we don't have one yet, we have no way of knowing if it works or how effective it might be. It could be like MMR or tetanus where we have to get the vaccine for life on a set schedule. Some of those are every 5 or 10 years. Perhaps our immunity to COVID will only last a few months or a couple years and we will need to constantly vaccinate people. Who knows. Only time will tell.

 

[easyrider]

I think the SARS vaccine was created in response to the SARS outbreak. H1N1 was in 2009 and a vaccine was developed and rolled out pretty quickly. Though we have much more knowledge of the flu and vaccines to prevent it. I suspect that is why they were able to get a vaccine out much faster for H1N1.

However, as you say, a vaccine was created for SARS but because there were only 700 deaths and it faded rather quickly there was no incentive to produce a vaccine. Who would take it? Why? There was no immediate threat. it doesn't make sense to produce the vaccine if there is no market to buy it.

A vaccine may be challenging for COVID-19. Since we don't have one yet, we have no way of knowing if it works or how effective it might be. It could be like MMR or tetanus where we have to get the vaccine for life on a set schedule. Some of those are every 5 or 10 years. Perhaps our immunity to COVID will only last a few months or a couple years and we will need to constantly vaccinate people. Who knows. Only time will tell.

I will look for that report so I can link it. I really can't explain it any better than the scientist who developed the vaccine for H1N1 , which can turn into a sars , like the MERS did , said that the vacine they developed could be ( my words) tweaked to be a vacine for any sars type condition, including this new one.

Bill

 

[dioxide45]

I will look for that report so I can link it. I really can't explain it any better than the scientist who developed the vaccine for H1N1 , which can turn into a sars , like the MERS did , said that the vacine they developed could be ( my words) tweaked to be a vacine for any sars type condition, including this new one.

Bill

It would be interesting to see. From what I understand, SARS, MERS and COVID are all coronaviruses where H1N1 is influenza. I don't think they could build off of the H1N1 virus to make one for COVID.

 

[amycurl]

A Phase I clinical trail for a COVID-19 vaccine is already underway, and has been for over a month:

NIH clinical trial of investigational vaccine for COVID-19 begins

Study enrolling Seattle-based healthy adult volunteers.

www.nih.gov

The six week trial will be coming to an end soon.
The reason this was able to be rolled out so quickly is because it took scientists only a month to genetically map the virus, which was basically in a record amount of time.

 

[GetawaysRus]

This is long and somewhat complex (especially for those without a scientific or medical background), but it will provide an overview of the different vaccine candidates (strategies) and the difficulties involved in vaccine development. It was posted on April 15.

Science | AAAS

blogs.sciencemag.org

I'll translate a little bit to help you read this. The author discusses 5 different vaccine strategies:
1. live attenuated - the vaccine contains live virus, but the virus has been weakened so that it is unlikely to produce human disease. An example: you infect eggs with a virus, then harvest the new viruses that grow in that egg. Then repeat that process over and over again, reinfecting new eggs perhaps 80-100 times. At the end of this, you've hopefully got a virus that now prefers to infect eggs rather than humans.
2. inactivated virus - this is the real virus, but it is killed so that it won't sicken you
3. protein fragment - you use a portion of the virus as your vaccine. Since it is only a portion, it can't cause disease. In the case of Covid-19, you'd probably use what is called the "spike protein." That's the spiky thing on the exterior surface of the virus that it uses to attach to human cells so that it can infect the cell.
4. DNA vaccine - the injected DNA is hopefully going to code for and (then your body will) manufacture a portion of the virus. Your immune system will hopefully then recognize it as foreign.
5. mRNA vaccine - the Moderna vaccine, already in clinical trials, is an mRNA vaccine. As I understand it, you inject viral mRNA. This is not the full virus, so it shouldn't sicken you. The hope is that the human body will then incorporate that mRNA and start to manufacture the portion of the virus (not the entire infectious virus) that is encoded from that RNA. Next, your immune system recognizes that these viral pieces you have manufactured are foreign, leading to an immune response. My understanding is that there are currently no other mRNA vaccines in use for any other human diseases.

Finally, the author discusses "adjuvants." An adjuvant is something you add to your vaccine to boost its effectiveness (boost its immunogenicity) so that you get a stronger immune response.

 

[MULTIZ321]

An old vaccine could be a new godsend for
coronavirus.

An old vaccine could be a new godsend for coronavirus

Using the oral polio vaccine could prevent or reduce the spread of COVID-19 to immunized individuals.

amp.usatoday.com

.


Richard

 

[MULTIZ321]

Coronavirus: clinical trial begins on third vaccine
candidate in China.

Coronavirus: clinical trial begins on third vaccine candidate in China

It targets the initial strain of the virus and other mutations that have emerged as it has spread around the globe.

www.scmp.com

.


Richard

 

[MULTIZ321]

COVID-19 vaccine protects monkeys from new coronavirus, Chinese biotech reports.

COVID-19 vaccine protects monkeys from new coronavirus, Chinese biotech reports

China’s Sinovac makes headway with old-fashioned technology that “kills” whole virus

www.sciencemag.org

.


Richard

 

[MULTIZ321]

Scientists have turned the structure of the coronavirus into music.

Scientists have turned the structure of the coronavirus into music

“Sonification” could help researchers identify binding sites for new drugs

www.sciencemag.org

.


Richard

 

[nkldavy]

From the UK:

Oxford University scientists reveal coronavirus vaccine timeline as human trial begins

A coronavirus vaccine being developed by Oxford University will begin human trials as early as this Thursday, according to U.K. health secretary Matt Hancock.

www.marketwatch.com