Vaccines

What are vaccines?

Vaccines are injections (shots), liquids, pills, or nasal sprays that you take to teach your body's immune system to recognize and defend against harmful germs. For example, there are vaccines to protect against diseases caused by:

• Viruses, like the ones that cause the flu and COVID-19
• Bacteria, including tetanus, diphtheria, and pertussis

What are the types of vaccines?

There are several types of vaccines:

• Live-attenuated vaccines use a weakened form of the germ.
• Inactivated vaccines use a killed version of the germ.
• Subunit, recombinant, polysaccharide, and conjugate vaccines use only specific pieces of the germ, such as its protein, sugar, or casing.
• Toxoid vaccines that use a toxin (harmful product) made by the germ.
• mRNA vaccines use messenger RNA, which gives your cells instructions for how to make a protein (or piece of a protein) of the germ.
• Viral vector vaccines use genetic material, which gives your cells instructions for making a protein of the germ. These vaccines also contain a different, harmless virus that helps get the genetic material into your cells.

These vaccines may work in different ways, but they all spark an immune response. The immune response is the way your body defends itself against substances it sees as foreign or harmful. These substances include germs that can cause disease.

What happens in an immune response?

There are different steps in the immune response:

• When a germ invades, your body sees it as foreign.
• Your immune system helps your body fight off the germ.
• Your immune system also remembers the germ. It will attack the germ if it ever invades again. This "memory" protects you against the disease that the germ causes. This type of protection is called immunity.

What are immunization and vaccination?

Immunization is the process of becoming protected against a disease. But it can also mean the same thing as vaccination, which is getting a vaccine to become protected against a disease.

Why are vaccines important?

Vaccines are important because they protect you against many diseases. These diseases can be very serious. So getting immunity from a vaccine is safer than getting immunity by being sick with the disease.

For a few vaccines, getting vaccinated can actually give you a better immune response than getting the disease would.

But vaccines don't just protect you. They also protect the people around you through community immunity.

What is community immunity?

Community immunity, or herd immunity, is the idea that vaccines can help keep communities healthy.

Normally, germs can travel quickly through a community and make a lot of people sick. If enough people get sick, it can lead to an outbreak. But when enough people are vaccinated against a certain disease, it's harder for that disease to spread to others. This type of protection means that the entire community is less likely to get the disease.

Community immunity is especially important for people who can't get certain vaccines. For example, they may not be able to get a vaccine because they have weakened immune systems. Others may be allergic to certain vaccine ingredients. And newborn babies are too young to get some vaccines. Community immunity can help to protect them all.

Are vaccines safe?

Vaccines are safe. They must go through extensive safety testing and evaluation before they are approved in the United States.

What is a vaccine schedule?

A vaccine, or immunization, schedule lists which vaccines are recommended for different groups of people. It includes who should get the vaccines, how many doses they need, and when they should get them. In the United States, the Centers for Disease Control and Prevention (CDC) publishes the vaccine schedule.

It's important for both children and adults to get their vaccines according to the schedule. Following the schedule allows them to get protection from the diseases at exactly the right time.

Acute Bronchitis

Bronchitis is an inflammation of the bronchial tubes, the airways that carry air to your lungs. It causes a cough that often brings up mucus. It can also cause shortness of breath, wheezing, a low fever, and chest tightness. There are two main types of bronchitis: acute and chronic.

Most cases of acute bronchitis get better within several days. But your cough can last for several weeks after the infection is gone.

The same viruses that cause colds and the flu often cause acute bronchitis. These viruses spread through the air when people cough, or though physical contact (for example, on unwashed hands). Being exposed to tobacco smoke, air pollution, dusts, vapors, and fumes can also cause acute bronchitis. Less often, bacteria can also cause acute bronchitis.

To diagnose acute bronchitis, your health care provider will ask about your symptoms and listen to your breathing. You may also have other tests.

Treatments include rest, fluids, and aspirin (for adults) or acetaminophen to treat fever. A humidifier or steam can also help. You may need inhaled medicine to open your airways if you are wheezing. Antibiotics won't help if the cause is viral. You may get antibiotics if the cause is bacterial.

NIH: National Heart, Lung, and Blood Institute

Allergy

An allergy is a reaction by your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that often cause reactions are:

• Pollen
• Dust mites
• Mold spores
• Pet dander
• Food
• Insect stings
• Medicines

Normally, your immune system fights germs. It is your body's defense system. In most allergic reactions, however, it is responding to a false alarm. Genes and the environment probably both play a role.

Allergies can cause a variety of symptoms such as a runny nose, sneezing, itching, rashes, swelling, or asthma. Allergies can range from minor to severe. Anaphylaxis is a severe reaction that can be life-threatening. Doctors use skin and blood tests to diagnose allergies. Treatments include medicines, allergy shots, and avoiding the substances that cause the reactions.

Alpha-1 Antitrypsin Deficiency

What is alpha-1 antitrypsin deficiency (AAT deficiency)?

Alpha-1 antitrypsin deficiency (AAT deficiency, or AATD) is an inherited condition that raises your risk for lung and liver disease. If you have this condition, your body doesn't make enough alpha-1 antitrypsin (AAT).

AAT is made by your liver. It helps protect your lungs from inflammation and irritating substances you might breathe in, such as smoke. If your liver doesn't make enough AAT, your lungs may be more easily damaged from smoking, pollution, or dust from the environment. This can lead to a serious lung condition called chronic obstructive pulmonary disease (COPD). AAT deficiency may also cause a liver disease called cirrhosis. This is more common in children who have AAT deficiency.

What causes alpha-1 antitrypsin deficiency (AAT deficiency)?

AAT deficiency is a genetic disorder. That means it's caused by changes in your genes, which may also be called gene variants or mutations.

Your genes carry information that controls what you look like and how your body works. AAT deficiency is caused by changes in the SERPINA1 gene, which carries instructions for making the AAT protein. These gene changes are inherited from your parents, so AAT deficiency tends to run in families:

• If you have two mutated copies of the gene, it means you have a condition called AAT deficiency. People with this disorder have a higher risk of getting lung disease or liver damage before the age of 45.
• If you have one mutated copy of the gene, you are a carrier of AAT deficiency. In these cases, this means you are at slightly higher risk of developing lung disease, especially if you have other risk factors, such as being a smoker. You could still pass the mutated gene on to your children.

There are a few gene changes that cause AAT deficiency. These gene changes can:

• Decrease the amount of AAT protein your liver makes.
• Prevent your liver from making any AAT.
• Affect the shape of the AAT protein so that it can't move out of your liver to protect your lungs. Over time, AAT builds up in your liver and causes damage.

What are the symptoms of alpha-1 antitrypsin deficiency (AAT deficiency)?

Some people who have AAT deficiency do not have any symptoms. For those who do, symptoms usually appear in people between 20 and 50 years old. These symptoms may include:

• Wheezing
• Shortness of breath, especially after exercise
• Chronic cough with phlegm (mucus)
• Repeated respiratory infections such as colds and the flu
• Chest pain
• Fatigue
• Faster-than-normal heartbeat when you stand up
• Vision problems
• Losing weight without trying

Some people who have AAT deficiency may have liver damage. Signs of liver damage include jaundice (a condition that causes your skin and eyes to turn yellow) and swelling in your legs.

Rarely, AAT deficiency can cause skin problems, such as painful lumps or patches.

How is alpha-1 antitrypsin deficiency (AAT deficiency) diagnosed?

Your health care provider may test you for AAT deficiency if you have:

• Symptoms of AAT deficiency
• A condition that could be related to AAT deficiency
• Relatives who have AAT deficiency
• Relatives who have a lung or liver disease that could be related to AAT deficiency

AAT deficiency in babies often affects the liver. Your baby may need AAT testing if he or she has signs of liver disease such as jaundice or abnormal liver enzyme tests.

A blood test can check the level of AAT protein in your blood. If the level is lower than normal, it is likely that you have AAT deficiency.

A genetic test is the most certain way to check for AAT deficiency and should be done to confirm the results of the blood test. There are two types of genetic tests:

• A genotype test looks for the more common types of gene changes that can cause AAT deficiency.
• A phenotype test checks for changes in the AAT protein that change how it would normally work.

If your lungs are affected, you may also have lung function tests to see how well your lungs are working.

What are the treatments for alpha-1 antitrypsin deficiency (AAT deficiency)?

There is no cure for AAT deficiency, but there are treatments to help with the symptoms and slow the lung damage it causes. Treatment options may include:

• Inhaled medicines to help you breathe better.
• Pulmonary rehabilitation.
• Oxygen therapy.
• Augmentation therapy, which is a lifelong treatment. It raises the levels of the AAT protein in your lungs, using ATT protein taken from the blood of donors. It helps slow down lung damage. It cannot prevent liver damage.
• Lung surgery or a lung transplant, if your lungs are severely damaged.
• Liver transplant, if your liver is severely damaged.

To help prevent or delay lung damage, it is important to quit smoking (if you smoke) and avoid secondhand smoke, dust, and air pollution. Ask your provider If you need to stop drinking alcohol.

Animal Diseases and Your Health

Animal diseases that people can catch are called zoonoses. Many diseases affecting humans can be traced to animals or animal products. You can get a disease directly from an animal, or indirectly, through the environment.

Farm animals can carry diseases. If you touch them or things they have touched, like fencing or buckets, wash your hands thoroughly. Adults should make sure children who visit farms or petting zoos wash up as well.

Though they may be cute and cuddly, wild animals may carry germs, viruses, and parasites. Deer and deer mice carry ticks that cause Lyme disease. Some wild animals may carry rabies. Enjoy wildlife from a distance.

Pets can also make you sick. Reptiles pose a particular risk. Turtles, snakes and iguanas can transmit Salmonella bacteria to their owners. You can get rabies from an infected dog or toxoplasmosis from handling kitty litter of an infected cat. The chance that your dog or cat will make you sick is small. You can reduce the risk by practicing good hygiene, keeping pet areas clean and keeping your pets' shots up-to-date.