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Vaccine made of live malaria parasites shows early success

nature.com

11–20 of 33 posts

Re: Vaccine made of live malaria parasites shows early success

#11

“Participants were then intentionally infected with malaria three months later to test the vaccine’s efficacy.” I did not know that purposely infecting people with a deadly parasite for research was a thing!

I wonder how disclosure works for the "field study testing the vaccine in adults is under way in Mali."

Do they screen enrollees based on scientific literacy? Seems like there could be significant moral hazards here.

Re: Vaccine made of live malaria parasites shows early success

#12
post #10

Nice idea, but there's no way something like this would pass FDA. Even for the live VSV Ebola vaccine that contains no Ebola at all in it, except for the encoded spike, it's recommended for a doctor to do administration, and it's not commercially available, so you have to justify your need for it to the federal government. You are also supposed to avoid close contact with anyone else for quite a while after, to preve…

Does the FDA have to approve it for American NGOs to distribute it internationally? Definitely would make more of a difference to African and India

Re: Vaccine made of live malaria parasites shows early success

#13
post #7

How do vaccines with live parasites work? Does attenuation somehow guarantee that the live parasites won't replicate to the point of becoming a full-on infection? Can these vaccines only be used on patients with healthy immune systems, and those with weakened immune systems have the potential for cascading replication and full infections?

The article mentions that the parasites are treated if they infect the blood or liver…

So I guess they are monitoring the vaccinated closely. Honestly sounds a bit touchy.

Re: Vaccine made of live malaria parasites shows early success

#15
post #7

How do vaccines with live parasites work? Does attenuation somehow guarantee that the live parasites won't replicate to the point of becoming a full-on infection? Can these vaccines only be used on patients with healthy immune systems, and those with weakened immune systems have the potential for cascading replication and full infections?

There are other vaccines such as the polio (the one which was swallowed) which had a similar mechanism. You could even infect others with it (which has benefits for herd immunity). But the chances of vaccine-associated paralytic poliomyelitis was extremely low 1:2.700.000 (it was not given to people with immunity defects).

Re: Vaccine made of live malaria parasites shows early success

#16
post #11

“Participants were then intentionally infected with malaria three months later to test the vaccine’s efficacy.” I did not know that purposely infecting people with a deadly parasite for research was a thing!

I wonder how disclosure works for the "field study testing the vaccine in adults is under way in Mali." Do they screen enrollees based on scientific literacy? Seems like there could be significant moral hazards here.

I’ve been the “lab rat” in many US studies, and generally all we get is a disclosure stating the purpose, risks and methods of the experiment. There’s no test for “scientific literacy” at all. I’m not even sure the point of this. What people care about is the risks and methods.

Re: Vaccine made of live malaria parasites shows early success

#17

“Participants were then intentionally infected with malaria three months later to test the vaccine’s efficacy.” I did not know that purposely infecting people with a deadly parasite for research was a thing!

Parasite, not a virus. For some parts of the world, it's like getting the flu. You expect to get it every year.

Thanks, updated. My ignorance of this practice extends to all deadly pathogens, really.

Re: Vaccine made of live malaria parasites shows early success

#18
post #7

How do vaccines with live parasites work? Does attenuation somehow guarantee that the live parasites won't replicate to the point of becoming a full-on infection? Can these vaccines only be used on patients with healthy immune systems, and those with weakened immune systems have the potential for cascading replication and full infections?

There are other vaccines such as the polio (the one which was swallowed) which had a similar mechanism. You could even infect others with it (which has benefits for herd immunity). But the chances of vaccine-associated paralytic poliomyelitis was extremely low 1:2.700.000 (it was not given to people with immunity defects).

Why “but”?

Re: Vaccine made of live malaria parasites shows early success

#19
post #10

Nice idea, but there's no way something like this would pass FDA. Even for the live VSV Ebola vaccine that contains no Ebola at all in it, except for the encoded spike, it's recommended for a doctor to do administration, and it's not commercially available, so you have to justify your need for it to the federal government. You are also supposed to avoid close contact with anyone else for quite a while after, to preve…

An RNA vaccine is starting human trials next year, and likely won't have these problems.

https://academictimes.com/first-vaccine-to-fully-immunize-ag...

Re: Vaccine made of live malaria parasites shows early success

#20
I'll be interested to see how this compares to Malaria vaccine, R21, which was recently announced to be highly effective[0]. It seems like R21 is similarly effective and may not have the perception or scalability issues that a "live parasite" vaccine might have. That said, I'm just happy to hear that there's progress being made. Hopefully we can see the vaccine rolled out to the millions at risk ASAP.

[0] https://blogs.sciencemag.org/pipeline/archives/2021/04/23/gr... Previous HN Discussion: https://news.ycombinator.com/item?id=26916237

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