Vaccines For Dummies. Sharon Perkins

given at birth reduced this risk. Now, treatment for the mother before, during, and after pregnancy greatly reduces the risk of transmission and lets HIV-positive mothers breastfeed.

      These same antiretrovirals can help prevent transmission to us. Those who are at high risk for HIV, through sex or injection drug use, can take a daily pill to reduce their risk. This is called PrEP, or pre-exposure prophylaxis. This reduces but does not entirely eliminate the risk of infection.

      Another preventive measure is PEP — or post-exposure prophylaxis — which can be taken after a specific exposure, such as through sex, an injection, a needlestick, or other health-worker exposure. This reduces but does not entirely eliminate the risk of infection. These antiretrovirals are best taken within the first 24 hours after exposure but must be taken at least in the first 72 hours. The medications need to be taken daily for four weeks and then stopped.

      These same medications that are used to prevent HIV transmission also treat HIV. Treatments developed in the last few decades mean that with treatment, you can live as long with HIV as without it. These medications do not cure HIV. They keep HIV in check, but if these medications are stopped, HIV can bounce back. Medications need to be taken as prescribed, usually daily; otherwise, resistance can develop and the medications may not work anymore for that person. Nearly 20 million people with HIV currently take antiretroviral drugs to manage this disease. Treatment is prevention. Those who take these medications and have the virus fully suppressed won’t transmit the virus to others.

Trying to Say Goodbye to Measles

      Measles, once a common, extremely contagious, but sometimes deadly illness in children, is a viral disease we’re trying to say goodbye to. It’s a virus that causes a high fever, runny nose, cough, and pink eye. It may just seem like a bad cold at first, but then three to five days later, the rash it’s known for pops up.

We don’t have a drug that cures measles, but most people get better in one to two weeks. About one in five need to be hospitalized. Some people develop lung or brain infections. Between one and three in every 1,000 infected will die. Measles also weakens the immune system for a bit, so you may get sick from another infection even after getting better. In rare cases, years after getting better, a fatal brain disease develops out of the blue in those who have recovered from measles.

      

The problem is that measles spreads silently in the air, and it spreads far. It can drift and infect people far away in a sports stadium, who never even saw the person who was ill. It can also spread before the telltale rash appears. One person can cause 12, maybe 18, new infections if no one is vaccinated. It also doesn’t make people sick for another 10 to 12 days, so it can be hard to track where they got it.

      Before there was a vaccine, 2 to 3 million people, mostly children, died each year from measles. With vaccination, we have been able to eliminate chains of transmission in many countries. Measles was declared eliminated in the United States in 2000, but cases pop up each year, often a souvenir from travel possibly followed by local spread. Worldwide, too many people still die from it, around 200,000 a year.

      

Because measles is so easily transmitted, you need almost everyone to be in this together to say goodbye to measles. The virus is really good at spreading to a lot of people, invisibly, all at once. Because it can spread so easily, at least 19 out of every 20 people need to be vaccinated to eliminate measles altogether. Where there has been a reluctance to vaccinate, the measles takes advantage and hides out, causing outbreaks to pop up, mostly among the unvaccinated.

      Measles is different from German measles (also called rubella), which has now been eliminated from the Western Hemisphere and is on the decline elsewhere.

Checking Out the Cause of Chicken Pox: Varicella

      The varicella virus causes chicken pox. Chicken pox used to be a common infection in children, until vaccination for chicken pox made it uncommon in the United States. In the United Kingdom and other countries, vaccination isn’t routine, so cases are more common.

This virus is most common in children, but more worrisome in adults and especially pregnant women. About 1 in 5,000 infected adults die from chicken pox, but many more adults need to be hospitalized. It is worse in those with weakened immune systems. If most people are vaccinated but a few are not, the average age of infected people grows older. Those few may not come in contact with the virus early on when they are kids, but instead it may take years for them to be infected and they get sick as adults, when the disease is more serious. This can be a problem, and it’s important to be vaccinated.

      Varicella looks a lot like measles. Its rash starts first on the abdomen and then spreads. The measles rash starts first on the forehead and face and then spreads. The measles rash is mostly flat, but chicken pox has raised bumps with liquid inside, which become itchy. Both can spread in the air. Both can infect many people quickly if others aren’t immune.

      

This virus remains in our bodies after we get better. It can stay dormant, or asleep, in our nerves. It can then return many years later as a painful rash in just a small patch on just one side of the body. This is shingles (or herpes zoster), and it only develops in people who have had chicken pox when the virus awakens in one dermatome (or area of skin with nerves coming from one spinal nerve root). Shingles can recur multiple times. If you’ve had chicken pox in the past, the shingles vaccine can prevent this painful disease from affecting you.

Fighting Ebola

      Ebola wasn’t known about until 1976. In that year it suddenly caused separate outbreaks in the now Democratic Republic of the Congo and South Sudan. It’s a virus that remains most of the time in bats, largely in Central and Western Africa, but every once in a while, it spreads to humans. It can spread from contact with a bat or from hunting or picking up another animal that’s sick or dead from Ebola.

      

Ebola is something we consider important to control because it can kill about half of those infected and can close down many hospitals and clinics, resulting in others not being able to get care.

      The virus spreads by direct contact with blood or other body fluids (such as vomit, diarrhea, urine, breast milk, sweat, and semen) as well as bedsheets or clothing contaminated by the body fluids of an infected person. The virus often spreads in hospitals when people who are sick seek care, especially women in labor as it can cause more bleeding in labor.

Ebola develops 2 to 21 days after exposure (usually 8 to 10 days). Ebola doesn’t spread before symptoms. There are usually two stages of Ebola:

       Dry stage: The first stage is the dry stage, characterized by fever, aches and pains, sore throat, and fatigue. This stage can be mistaken for influenza or the flu. Some people also have hiccups, which can help identify the illness as Ebola because hiccups and fever are not that common.

       Wet stage: The disease then progresses to the wet stage (with more fevers and now diarrhea and vomiting and sometimes bleeding and miscarriage in pregnant women). It is in the wet stage that people are very sick and often become confused. They need the help of others to take care of them, and they are also the most infectious then. Ebola can spread from the diarrhea, sweat, and other body fluids, making others sick. The virus often infects family members who care for those who are sick, nurses and doctors, and those involved in preparing for funerals as bodies after death remain infectious.

      Some people have very mild cases, and others have very serious cases. The initial amount of virus someone has in their blood when tested can predict their chance of getting better. People who get better from Ebola can go back to their regular lives and aren’t infectious once they clear the virus. However, the