By the ninth time – measles is bad. Here's why …


Measles is a contagious virus that initially causes runny nose, sneezing and fever and later leads to a rash that starts on the face and spreads to the rest of the body. Most of those infected will recover, but measles can cause diarrhea and vomiting, which can Irrigation, Middle ear infection (Otitis media), Which can lead to hearing loss, or pneumonia or potentially fatal encephalitis (edema in the brain).

When a person gets an infection, their immune system produces antibodies to fight the infection. Once the body avoids infection, special immune cells remember it to be a specific pathogen and help the body defend itself faster if the same pathogen invades the body. But not with measles. The virus stops children's immune system, and "amnesia" makes them vulnerable to other pathogens that may protect them from a previous infection.

Inc One study [Puzzled[MJMinaetal[მჯმინადასხვ[MJMinaetalScience, 366: 599–606, 2019]In the Netherlands, measles infection in unvaccinated children was associated with a 70% decrease in antibody after further infection with other pathogens. After acute measles cases, uninfected children lost 40% of the existing pathogenic antibody (range 11-62%), and after moderate measles, children lost a median 33% (range 12-73%) of these pre-existing antibodies.

On the other hand, vaccinated children maintained more than 90% of antibody repertoires during the same period. Researchers looked at 77 non-communicable children infected with measles in the Netherlands during the 2013 infection and compared these samples to 115 unprotected children and adult blood. VirScan system, A tool that detects antiviral and antibacterial antibodies in the blood. Samples were obtained before and after measles infection.

The team found that rather than complete loss of total IgG, the most common type of antibody present in the bloodstream, there is restructuring of the measles antibody repertoire. This is the first study to measure the virus-induced immune damage and is further evidence for the "immune amnesia" hypothesis (that by destroying antibody repertoires, measles partially destroys immune memory against previously introduced pathogens).

The same investigators also infected mice with measles and observed their antibodies against other pathogens for five months. The monkeys infected with measles have lost 40-60% of their antibodies they have previously encountered, against pathogens, which indicate that measles infection removes long plasma cells in the bone marrow that can produce pathogen-specific antibodies.

A separate, independent team has released A related study [Vnpetrovadaskhv[VNPetrovaetal[ვნპეტროვადასხვ[VNPetrovaetalSci Immunol, 4: 2019]Influenza infection results in incomplete reconstitution of na (ve cells (without antigen), causing immunological deterioration and compromising immune memory in early cases of pathogens due to impaired B memory lymphocytes that persist after measles infection. The study provides a clear biological explanation for the observed Increase in child mortality And Secondary infections A few years after the measles episode.

These two new studies underscore the importance of vaccination against measles and suggest that, in light of these findings, enhancing shots against other diseases, such as hepatitis or polio, may be needed in children infected with measles.

In 2017, the World Health Organization (WHO) announced 110,000 measles have died worldwideMainly in children under the age of five. The actual number of people infected with measles is probably higher because the WHO only collects data on cases confirmed by laboratory testing or clinical visits, excluding thousands of citizens who do not seek medical attention.

With the global trend of vaccine hesitation, skeptical parents refuse to vaccinate their children because of false concerns about their safety. These 2 new studies add to the evidence and undoubtedly prove what scientists and public health experts all knew: measles bad, vaccines good. This time we have to remember … we should not have amnesia because measles can cause immune amnesia.