Measles virus infection diminishes preexisting antibodies that offer protection from other pathogens, 2019, Mina et al

Andy

Andy

Retired committee member
The toll of measles on the immune system
Many of the deaths attributable to measles virus are caused by secondary infections because the virus infects and functionally impairs immune cells. Whether measles infection causes long-term damage to immune memory has been unclear. This question has become increasingly important given the resurgence in measles epidemics worldwide. Using a blood test called VirScan, Mina et al. comprehensively analyzed the antibody repertoire in children before and after natural infection with measles virus as well as in children before and after measles vaccination. They found that measles infection can greatly diminish previously acquired immune memory, potentially leaving individuals at risk for infection by other pathogens. These adverse effects on the immune system were not seen in vaccinated children.

Science, this issue p. 599

Abstract
Measles virus is directly responsible for more than 100,000 deaths yearly. Epidemiological studies have associated measles with increased morbidity and mortality for years after infection, but the reasons why are poorly understood. Measles virus infects immune cells, causing acute immune suppression. To identify and quantify long-term effects of measles on the immune system, we used VirScan, an assay that tracks antibodies to thousands of pathogen epitopes in blood. We studied 77 unvaccinated children before and 2 months after natural measles virus infection. Measles caused elimination of 11 to 73% of the antibody repertoire across individuals. Recovery of antibodies was detected after natural reexposure to pathogens. Notably, these immune system effects were not observed in infants vaccinated against MMR (measles, mumps, and rubella), but were confirmed in measles-infected macaques. The reduction in humoral immune memory after measles infection generates potential vulnerability to future infections, underscoring the need for widespread vaccination.
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Open access, https://science.sciencemag.org/content/366/6465/599
 
Article in Stat:
How measles infections can wipe away immunity to other diseases
Measles wipes out some of the immunity to other diseases that children acquire through vaccinations and infections, leaving them more vulnerable to illness for months and even years afterward, two new studies published Thursday report.

The findings help explain why countries that start to vaccinate children against measles see pediatric death rates drop substantially, beyond just the decrease that would be expected with the prevention of measles deaths.
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Interesting findings. These are the natural conditions the immune system has developed in over millennia. Now we have a vaccine and a handful of studies and think we know everything. Do we...?

I’m wondering what impact recalibration of the immune system by childhood measles infection might have on incidence of, say, autoimmune or other immune-related disorders. Is it all bad?
 
Sorry, I don't get that stuff about psoriasis like stuff. I just don't understand. I'm age 71 now and have psoriasis which started for me around 2-3 years ago.

I had measles at around age 7 to the best of my recollection. It was horrible as my Mother made me stay in bed with the curtains drawn and I wasn't allowed to read. This was long before TVs were common - I think we might have got our first TV when I was about 9.

It was just so horribly boring! Just lie in bed with absolutely nothing to do, just lie there. Maybe good training for my current life? ;) At least I can look out my window now, and watch dross TV!

What I do remember about the measles was I could smell a sort of gingery smell. And also that's when I started not being able to stand having sugar in my tea. Drove my Mother wild, for years she forgot and kept putting sugar in my tea, and I couldn't drink it - just tasted disgusting to me even though before measles I'd loved sugar in my tea.

I remember when I first got on the internet at home, back in the late 90s, I found an article about how some diseases have their own smell. Never found it since - but looking at recent things about how dogs can tell if someone is about to have epileptic fit and similar stories in the press maybe it was right.
 
I would like to see a long term followup (and studies of other infections), this doesn't actually demonstrate there is long term "memory loss" of prior immunity. It simply suggests that 2 months after infection, most antibodies in circulation were focused on the measles infection, suggesting selective activation of B-cells that targeted the infection (to mature into plasma cells), versus memory B-cells. Which sounds like a more efficient process. The half life of serum IgG is around 3 weeks and the typical halflife of plasma cells is 3-10 days, but some speculate a few can live a lot longer. It would be very curious if the memory B-cells specific to other infections have been permanently eliminated (suggests very disruptive processes going on in the bone marrow/spleen), but this study merely suggests this, rather than demonstrates this. The study begs for further confirmation.
 
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I am sceptical about this study. They looked at the diversity of antibody binding to small chopped up epitopes from viruses. Antibodies do not in real life blind to chopped up epitopes but to whole antigen. I think it is very likely that what they have shown is that the random noise of irrelevant antibody making by evanescent plasma cells that goes on while we are well - sort of punchbag practice for the possible fight ahead - is replaced by focused antibody response from longer lived plasma cells.
 
Jonathan Edwards said:
I am sceptical about this study. They looked at the diversity of antibody binding to small chopped up epitopes from viruses. Antibodies do not in real life blind to chopped up epitopes but to whole antigen. I think it is very likely that what they have shown is that the random noise of irrelevant antibody making by evanescent plasma cells that goes on while we are well - sort of punchbag practice for the possible fight ahead - is replaced by focused antibody response from longer lived plasma cells.
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Did you read the other study, which conducted B cell receptor sequencing of human peripheral blood lymphocytes before and after MeV infection?
https://immunology.sciencemag.org/content/4/41/eaay6125
 
Snow Leopard said:
Did you read the other study, which conducted B cell receptor sequencing of human peripheral blood lymphocytes before and after MeV infection?
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I'm not sure what that means either to be honest. B cell clones in the peripheral blood are by and large cells with nothing much to do. The ones with something to do are doing things in the lymphoid organs. I suspect people do studies of this sort because the molecular biology has made them possible. But good old-fashioned antibody tests against specific microbes are probably closer to measuring functional capacity.

It may well be that there is a well documented clinical immunodeficiency after measles but I would be more persuaded by a traditional measure of immunity to one or two important viruses rather than this sort of approach.
 
Anecdote: I contracted measles while on holiday in North Wales when I was 7. In the following year, me and my sisters seemed to be much more susceptible to seasonal bugs, and some quite unusual things - EBV (usually asymptomatic in under-teens) for me and scarlet fever for my sis. I lost half my hearing as a result.

I've seen lots of comments about whether it could be used to prevent autoimmune disease, but I suspect it is far to non-specific to be of any use whatsoever.

I hope Vincent Racianello will be doing a podcast on it shortly though.
 
I thought this was old news? David Gorski has covered measles erasing immune system memory in has excellent blog. Wasn't it discovered long ago?
 
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