I was watching a travel show on PBS and the guide said he was lucky he only gets Malaria about every other year. He says most people get it about once a month or so. This was in the Solomon Islands
So how often can you get Malaria? If you get it repeatedly is it less dangerous each time?
Some forms of malaria are chronic - you relapse periodically and the disease may never be fully eradicated from your body.
A friend who spent time in Ghana many years ago had malaria while there but has never relapsed, and counts himself very lucky.
This is why those who have had malaria or even lived in an area where it can be contracted, are not allowed to give blood. The disease can lie dormant.
Chronic, OK that makes a lot more sense that getting it repeatedly. I never looked at it like that.
What kind of malaria? Falciparum? Vivax? There are 4 (maybe 5) species of Plasmodium that cause malaria in humans.
There is no real immunity - you can be re-infected. The parasite is very good at evading the host immune system - that’s why it has been so difficult to develop a vaccine.
For falciparum malaria (the major killer), there is a sort of acquired attenuation. In endemic african countries, pretty much everyone gets malaria. If it doesn’t kill you as a child, you generally live with it fine. The more you are exposed to it, the less the symptoms get until most people are asymptomatic or have very mild symptoms. They are still infected, of course.
But its not permanent. If you leave the area for a few years, then come back, you will get sick again.
Vivax malaria parasites go dormant in the liver, and can relapse periodically. The dormant liver stage is hard to treat - there is only one drug (I believe) effective against it. Again, you can get infected after being cleared.
My father got malaria in the Philippines or New Guinea in World War II and it was my understanding that he always had it but the symptoms were dormant. If he were to have gone back to that area he would have to take medication (quinine?) to prevent the symptoms from recurring.
Probably vixax. Those damn liver stages 
My father got it in Indonesia in the late just prior to 49, but he never had a recurrence.
I can give now, because it’s been a certain amount of time (5 years?) since I have been back to the country. But indeed, I have had it twice in my life.
For too many people, just once.
Interesting. I was told by our doctor back when we left Africa that we would not be able to give, and I assumed that was as in “ever”. It’s been eleven years now.
I visited for a couple of days a potential malarial region (only in a corner where there was no malaria, but everyone agreed to play it safe and go by the letter of the policy). The Red Cross made me wait a year from my visit, IIRC, to donate blood.
I think he’d need to take the meds not so much to prevent his symptoms from recurring, but to prevent him from acquiring a new infection (which applies pretty much the same whether you had malaria in the past or not).
For people who have lived in Africa, I believe the concern with donating blood revolves around rare strains of HIV that cannot easily be tested for.
My grandmother got it as a child in the Caribbean, and had recurrences all through her life - though they became less and less frequent as she aged.
My dad got malaria in Vietnam in 1970. He’s never had a recurrence (well he hasn’t left Cleveland since) but he was able to donate blood 2 years ago.