Vaccine made of live malaria parasites shows early success | Hacker News Reader

Vaccine made of live malaria parasites shows early success

nature.com

138 pointsgmays29 comments

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

That vaccine is mentioned in the article:

> The vaccination protected 87.5% of participants who were infected after three months with the same strain of parasite that was used in the inoculation, and 77.8% of those who were infected with a different strain. This is a significant improvement on earlier efforts to use live parasites in a malaria vaccine, which did not perform as well against different strains.

> Another vaccine, called R21, was recently shown to be up to 77% effective in a trial of 450 young children, and a larger study is under way.

I assume we can't rally make direct comparisons between the two based on these very different studies, but both appear to be working really well.

There's also the "Yale lab develops revolutionary RNA vaccine for malaria" vaccine using "self-amplifying RNA, or saRNA" which looks interesting although it's in earlier stages testing wise. https://yaledailynews.com/blog/2021/03/12/yale-lab-develops-...

Fantastic news. It’s such a debilitating disease even for people who don’t die from it. A whole life of frequent crises.

It has killed atleast 50 times more people than covid, but its shocking how little coverage it has received over time, mostly because its not a concern for many ‘first world’ countries.

Curious where the 50X number comes from? From what I see, around 600K people die a year from Malaria but that is not 50X of world wide covid deaths?

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 prevent transmission of the vaccine virus.

https://www.cdc.gov/vaccines/hcp/acip-recs/vacc-specific/ebo...

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

I don't think so, especially if it's nominally part of a trial. US Ebola drugs and vaccines were used in Africa before approval.

No it only requires the approval of the destination country. But in the case of Ebola, some of those countries didn't have an established infrastructure to run trials so the WHO initially hesitated. But in the end they got Merck to run the trials and FDA and EMA to evaluate the results.

https://www.statnews.com/2020/01/07/inside-story-scientists-...

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...

It'd be a great silver lining for this pandemic to turn out to be the kickstart for a new generation of vaccines to curb malaria and such

Pfizer is working on a Lyme vaccine which is increasingly sorely needed.

Would be nice to see a better Dengue Fever vaccine too.

There's an article in Wired arguing it's helped fix the economics of that https://www.wired.co.uk/article/mrna-vaccines-economics

That's ok, though; the US hardly sees any malaria, and the cases that do present here are typically contracted in other countries. It can spread here, and we shouldn't be complacent, but the US isn't where a vaccine is needed.

> The sporozoites must be harvested from mosquito salivary glands and then stored at extremely low temperatures, complicating their distribution in resource-poor areas. No vaccine has ever been mass-produced using mosquitoes before. Alonso remembers someone asking him about the possibility years ago: “It is a crazy idea,” he replied at the time.

Crazy indeed, it’s amazing the things people think up.

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.

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).

As per their publication, they simultaneously give you anti-malaria medication in addition to the sporozoites. Its called chemoprophylaxis vaccination. (Just learned of it today)

Someday, perhaps the vaccine will be the major disease vector, as it is now for Polio.

This is not an anti-vax position. This is desirable, but I'm really curious how to manage the message of "The only way you'll catch this disease nowadays is from this vaccine, but you still have to get it".

This is great news, would probably rephrase the whole "injecting you with live parasites" thing though

“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!

It's called a challenge trial. It's done to compress later stages of clinical trials and only uses low risk volunteers. It's also generally only done when theres effective treatment for expected negative outcomes.

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.

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.

All patient consent must be worded for patient comprehension. This is done by the IRB.

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