Measles Virus Makes You Forget All About Prior Infections

Measles virus erases memory of previous infections you already beat. I was stunned when I learned about it. Researchers call it « immune amnesia ». It’s a scary term that nobody wants to be associated with. A piece of advice, if it’s not already done, you should definitely update your Measles-Mumps-Rubella vaccines. And here is why.

For a long time, healthcare professionals noticed troubling results in several of their patients that underwent testing for tuberculosis. The test results were coming back negative after initially showing positivity. A common explanation for such an occurrence would be an immunodeficiency state usually caused by HIV virus. But not here. The patients had never been in contact with HIV virus. Something else was causing this immunological switch.

After years of crossing info from medical records, researchers finally found a potential link between these patients. It was the Measles virus. The patients had been infected with Measles virus after the first tuberculin test but also before the second test. This infection impaired the immune system such that it couldn’t recognize the tuberculin toxin anymore. Usually, when one gets infected with a virus or other infectious agents, the body does a great job to remember this for the next encounter. The body stores this information in memory B cells — guardians of infections’ memory. However, this information is no longer available when one is exposed to Measles viruses.

Measles Virus Symptoms and Treatment

Measles is a highly contagious virus — also known as Rubeola virus. Before the first vaccination campaign started, in 1963, every single child experienced high fever and red rashes — common symptoms of Measles virus infection. Most of us certainly remembered seeing our siblings or classmates with typical itchy red dots on the face. We also all remember waking up a couple days later with similar cutaneous eruption. Unfortunately, there is no cure for it. Just medication to lower the drudgery of the symptoms. Time will do the rest with hopefully no complications.

Despite the common symptoms described above, Measles virus infection has also been associated with the loss of memory cells causing an immune amnesia to prior infections.

How Measles infection erase immunity

To understand how Measles virus impairs immune system responses, scientists decided to track the virus down. Localizing Measles virus at any step of the disease would help to determine what happens with the immune system. You may already know but researchers are creative people. They are using fluorescent molecules to track the virus like James Bond would use a GPS tracker to track down the bad guys. Similar to sticking the tracker under the car and following the signal on a screen, scientists are modifying the Measles virus with fluorescent probes and using specific cameras to track it down. No, you are not dreaming, this is not science fiction, it’s real — and to be honest, it’s one of the amazing techniques used routinely in laboratories.

And by the way, if you are wondering what it looks like to observe fluorescence under a microscope, try this. Imagine laying down on your back on a soft grass field, facing the sky during a warm summer starry night. You are in the middle of nowhere — no light pollution — you are able to discern the Milky Way. There you go, that’s pretty much what fluorescent microscopy images look like — a dark abyss speckled with bright spots.

Using this fluorescent technique, scientists were able to observe the spread of Measles virus in live organisms. They made the critical observation that the infection spreads to memory B cells — a cell type destined to disappear from the radar screen shortly thereafter. The reason for this disappearance was simple but indeed, not obvious at first. Infected memory B cells were being recognized and destroyed by the immune system as any infected cells would be. However, the death of memory B cells is not without consequence, as the information about previous infections anchored in these memory cells is annihilated in the process as well. With this clean slate, it is like the immune system never encountered any infections prior to Measles virus infection.

Public Health and Key Numbers

According to the latest studies that brought these findings to light, Measles virus infection could destroy 11–73% of memory B cells. Circulating antibodies are also affected. The detrimental effects can last over a long period to time.

Here are some key numbers from the World Health Organization (WHO) and the Center of Diseases Control and Prevention (CDC).

• Over the past 20 years, an estimated 23.2 million lives have been saved by Measles vaccination.
• Still, Measles was responsible for 142,000 deaths worldwide in 2018.
• Between 2018 and 2019, the number of Measles cases in the United States almost quadrupled — 3.4 fold to be accurate.

Today, even with intensive vaccine campaigns, Measles cases keep happening — not to mention the states of emergency recently declared in several other countries such as Samoa island and Republic of Congo. The rise of anti-vaccination campaigns, non-vaccinating religious communities and limited access to the vaccines in some areas are at the core of such outbreaks. With all the convincing scientific data generated over the years, one might wonder how negativity towards the good of vaccination has been sustained to this day. I don’t have a perfect answer to it. However, I think one of the reasons may very well have to do with credibility of messages from the scientific community.

Scientific Community Credibility Issue

The credibility of the scientific community has been adversely affected by the disproportionately magnified lens that society places on imposturous or fraudulent practices — many of which are motivated by monetary or personal gain instead of the noble goal of aiding humanity. With so many conspiracy theories out there, delivering an impactful message — that of “pro-vaccination” for our purposes — based on scientific proofs has become very difficult. Today’s society tends to respond positively to messages filled with emotions, but has meanwhile gotten bored with rationality. Naturally, marketers acknowledge this phenomenon. In light of this culture, one can imagine the hustle the scientific community is confronting to be heard through the noise.

But scientists are not without resources, and they have a unique sense of innovation when it comes to communicating with a crowd that extends well beyond their own community.

From Scientist to Famous Scientist

A good illustration of this can be found in this well written Science magazine article. Pr. Burioni, a respected virologist at a university in Milan, Italy, was invited on TV to debate about vaccination. The other two debaters happened to be celebrities from show business. The scene took place in 2016.

Interestingly, but not surprisingly, the host was focusing on the celebrities and not so much on the virologist. Not much time was left on air and it was finally his turn to speak. He clearly did not have enough time to go through his traditional, rigorous, pro vaccine argumentation. He had to be convincing and impactful. Such an opportunity for a scientist to directly address the national lay audience is not given every day. All the sudden, Pr. Burioni said:

“Earth is round, gasoline is flammable and vaccines are safe and effective. All the rest are dangerous lies”

Pr. Burioni bundled vaccines with historically undeniable scientific truths. It was just brilliant. His popularity rose, and with it, so did the credibility of the scientific community. Additionally, shocked by the fact he was invited to debate against non-experts on the subject, Burioni leveraged his moment in the spotlight to also re-affirm and promote the crucial importance of expertise. The following quote is one of my favorites:

“I know something about vaccines, viruses, and bacteria because I have been studying them for a lifetime, but I have no idea how to bake a cake or wire a lamp, so I go to a bakery or call an electrician.”

His simple and truthful words are now reaching more and more people around the globe.

Measles virus has always been around us. The tremendous and silent efficacy of vaccination campaigns has transformed how we interact with invisible or microscopic threats. One tends to forget how deadly viral infections such as Measles, flu and many others once used to be — eradicating entire populations. Out of respect for our ancestry — without whom we would not be as lucky today — let’s fulfill our duty of remembering the importance of vaccinations before viruses like Measles erase their impact from our memory, but this time… forever.