Where can I find definitions of "sterilising vaccine" and "neutralising vaccine"?
2/
Nobody has replied, and I can't remember what I was reading that prompted the question. So I'll say what I think the answer is!
At least for "sterilising vaccine" (or, if you use US spelling, "sterilizing vaccine".
Nobody has replied, and I can't remember what I was reading that prompted the question. So I'll say what I think the answer is!
At least for "sterilising vaccine" (or, if you use US spelling, "sterilizing vaccine".
3/
A sterilising vaccine is one which provides sterilising immunity.
"Sterilizing immunity means that the immune system is able to stop a pathogen, including viruses, from replicating within your body." thehill.com/changing-ameri…
A sterilising vaccine is one which provides sterilising immunity.
"Sterilizing immunity means that the immune system is able to stop a pathogen, including viruses, from replicating within your body." thehill.com/changing-ameri…
4/
See also sciencedirect.com/topics/agricul…
(As the context is the Covid-19 pandemic, I shall in this thread, for brevity, refer to "virus" - but the concept applies equally to other pathogens; this is just shorthand. Dont @ me. )
See also sciencedirect.com/topics/agricul…
(As the context is the Covid-19 pandemic, I shall in this thread, for brevity, refer to "virus" - but the concept applies equally to other pathogens; this is just shorthand. Dont @ me. )
5/
Sterilising immunity means that if you are exposed to the virus, it cannot infect you. It cannot replicate in your body. So you can't be infectious, and infect others.
Sterilising immunity means that if you are exposed to the virus, it cannot infect you. It cannot replicate in your body. So you can't be infectious, and infect others.
6/
Ideally, and Covid-19 vaccine would provide sterilising immunity, so people who have responded to the vaccine can't infect others.
This means it will provide herd immunity.
Ideally, and Covid-19 vaccine would provide sterilising immunity, so people who have responded to the vaccine can't infect others.
This means it will provide herd immunity.
7/
A vaccine might protect the person who has been vaccinated, so that they don't get ill (or not seriously) if infected.
A vaccine might protect the person who has been vaccinated, so that they don't get ill (or not seriously) if infected.
8/
The (no longer used) un-conjugated meningococcal polysaccharide vaccines did this, for example: they prevented invasive disease, but didn't stop the bacteria growing in the nasopharynx, so people who had been vaccinated could still be colonised and infectious.
The (no longer used) un-conjugated meningococcal polysaccharide vaccines did this, for example: they prevented invasive disease, but didn't stop the bacteria growing in the nasopharynx, so people who had been vaccinated could still be colonised and infectious.
9/
It was also suggested, when we switched from oral (live virus) polio vaccine to inactivated injected vaccine that the virus might be able to replicate in the gut - the vaccinated individual protected, but not providing herd immunity.
It was also suggested, when we switched from oral (live virus) polio vaccine to inactivated injected vaccine that the virus might be able to replicate in the gut - the vaccinated individual protected, but not providing herd immunity.
10/
Most vaccines, however, do provide sterilising immunity.
Most vaccines, however, do provide sterilising immunity.
11/
Note that a vaccine that provides sterilising immunity is not (necessarily) the same as a therapeutic vaccine.
Note that a vaccine that provides sterilising immunity is not (necessarily) the same as a therapeutic vaccine.
12/
A therapeutic vaccine would not only prevent people from becoming infectious, but would also stimulate the immune system in such a way that it clears "dormant" or "latent" infection.
A therapeutic vaccine would not only prevent people from becoming infectious, but would also stimulate the immune system in such a way that it clears "dormant" or "latent" infection.
13/
There were hopes, for example, that HPV vaccine would not only prevent future infection; but would also clear current infection. (HPV infection can cause cancer - but only after the infection has not been cleared, but has been present for many years.)
There were hopes, for example, that HPV vaccine would not only prevent future infection; but would also clear current infection. (HPV infection can cause cancer - but only after the infection has not been cleared, but has been present for many years.)
14/
TB is another example. Many people who are infected with TB clear the infection; in some, the bacteria remain, hidden away, able to reactivate if the immune system becomes weakened. Work has been underway for years to find a vaccine that would clear the infection.
TB is another example. Many people who are infected with TB clear the infection; in some, the bacteria remain, hidden away, able to reactivate if the immune system becomes weakened. Work has been underway for years to find a vaccine that would clear the infection.
15/
It's particularly important for TB, because the bacteria is able to become resistant to many, even all known antibiotics (or "antimicrobial chemotherapy", to be pedantic).
A therapeutic vaccine could mean antibiotics are not required.
It's particularly important for TB, because the bacteria is able to become resistant to many, even all known antibiotics (or "antimicrobial chemotherapy", to be pedantic).
A therapeutic vaccine could mean antibiotics are not required.
16/
Of course, there are many other properties of an ideal vaccine: works at all ages; no significant side effects; effective in all recipients; long, ideally permanent duration of protection; cheap and quick to produce in bulk; easy to distribute (no cold chain)…
Of course, there are many other properties of an ideal vaccine: works at all ages; no significant side effects; effective in all recipients; long, ideally permanent duration of protection; cheap and quick to produce in bulk; easy to distribute (no cold chain)…
17/
…Easy to [self-]administer - eg via vaccine microneedle patches; does not interfere with other vaccines; a single dose will suffice; antibodies created react with stable parts of the virus, so mutations in the virus don't render the vaccine inefficient…
…Easy to [self-]administer - eg via vaccine microneedle patches; does not interfere with other vaccines; a single dose will suffice; antibodies created react with stable parts of the virus, so mutations in the virus don't render the vaccine inefficient…
18/
I will be very interested to see what happens if we start using more vector vaccines, for example. If you become immune to the vector, will you subsequently respond to future vaccinations using the same vector?
I will be very interested to see what happens if we start using more vector vaccines, for example. If you become immune to the vector, will you subsequently respond to future vaccinations using the same vector?
19/
I also asked about neutralising vaccines.
I think this refers to vaccines which stimulates the production of neutralising antibodies.
I also asked about neutralising vaccines.
I think this refers to vaccines which stimulates the production of neutralising antibodies.
20/
This article on neutralising antibodies says they "…are responsible for blocking the entry of a pathogen into a cell so that it is firstly unable to infect healthy cells, and secondly, it is unable to replicate and cause severe infection."
news-medical.net/health/What-ar…
This article on neutralising antibodies says they "…are responsible for blocking the entry of a pathogen into a cell so that it is firstly unable to infect healthy cells, and secondly, it is unable to replicate and cause severe infection."
news-medical.net/health/What-ar…
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