Measles, The Hero for Other Viruses?

At just 12 months, we receive a measles vaccine. After 2 or three years, we get the second dose. So what is this really protecting us from? As some of us might know, Measles is known to be a childhood infection that it's caused by a virus. Measles can be fatal for children, but now, it can almost always be prevented with a vaccine. Beyond the nasty symptoms caused by measles, it was found that the infection erases the immune system’s memory, making it harder for the body to remember and attack other invaders. 

When an infected person sneezes or coughs, the measles virus stays in the air for up to two hours until it makes it into the airways of the next victim. Once inside the victim’s body, the virus targets immune cells found the lungs, nose, and throat. The initials symptoms of the virus include high fevers, red watery eyes, cough and of course, the rash; red, livid splotches that make infection painfully visible. The splotches appear on the face at the hairline and spread downward to the neck, trunk, arms, legs, and feet of the child. This can be a very painful time for the child. The immune cells that are usually attacked by the virus, contain a protein called CD150. This protein allows the virus to invade, according to experiments done on animals. The virus quickly replicates inside the cells, then spreads to places packed with other immune cells such as bone marrow, thymus, spleen, tonsils and lymph nodes. The loss of these immune cells leaves people very vulnerable to infections that the immune system would be able to handle. This is why an acute measles infection, can sometimes bring other viruses infections such as pneumonia. The immune cells that usually would fight this, are being lost due to the virus that causes measles.

Measles not only weaken the host’s immune system in the short term, but the virus also seems to wipe your immune system's memory of previously experienced infections, causing the body to forget how to fight off things that your body may have already conquered. The cells responsible for the memory of these viruses are called B and T cells. They are cellular protectors that normally remember threats the body has already neutralized, allowing the immune system to spring into action quickly if those threats return. After a measles infection, the numbers of some types of these memory cells dropped, creating immune amnesia, the researchers reported in 2018 in Nature Communications. Immune amnesia can linger for months to years after an infection. Studies published in Science and Science Immunology compared blood samples from unvaccinated children before and after measles exposure. The results showed that for up to five years after their bout of measles, children who had previously had the virus experienced more diagnosed infections than children who hadn’t. Children who’d had measles were 15 to 24 percent more likely to receive a prescription for an infection than children who never had measles. 

Before the vaccine for the virus was introduced in 1963, it was nearly guaranteed that every child would catch measles, and an estimated 2.6 million died from the disease each year. The vaccine is incredibly effective, with two doses imparting nearly 97-percent protection, resulting in dramatic declines in measles deaths around the world. In recent years, though, measles has been once more on the rise. In 2018, 98 countries reported more cases than in the prior year, according to a UNICEF report. Infrastructure issues and civil strife have been interfering with vaccination campaigns in some parts of the world, experts say there’s another issue behind the recent slew of cases: complacency about vaccination. A lot of people don’t see vaccines as a relevant intervention, but the studies that have been done show the opposite. The measles cases plummet once the vaccine use became widespread, but cases of other virus diseases dropped as well. In resource-poor regions, the decline was as dramatic as 50 percent; in impoverished regions, it dropped by as much as 90 percent, according to National Geographic. 

Posted by "Pamela Jimenez"