Pertussis, or whooping cough, is more than just an annoying cough. It is a serious and highly contagious disease. The coughing is so severe it causes those affected to gasp for air in between coughs, which make a “whooping” sound that can last for weeks or months. The cough may cause a person to stop breathing temporarily, turn blue, and even vomit. Many people are unable to eat or sleep due to the severe coughing spells. It can lead to complications, such as pneumonia, cracked ribs, and seizures. It can also be life-threatening.

Whooping cough is on the rise in the U.S. Here’s what you should know to protect yourself and those around you.

You can spread it before you even know you have it.

Whooping cough may feel like you have a cold at first. This stage lasts one to two weeks. It often includes a runny nose, sneezing, low-grade fever, and a mild cough. Unfortunately, many people don’t realize they have whooping cough during this stage and can spread it to others.

Infants under 6 months of age are the most likely to die from pertussis.

Babies are given whooping cough vaccine at two, four and six months of age. Until they have had all these vaccines, they are more likely to catch whooping cough. The Immunization Action Coalition says babies under six months of age are the most vulnerable because they don’t yet have strong immunity to protect against it.

Adults are the most likely to pass the infection to young infants.

The National Foundation for Infectious Diseases (NFID) says adults are the most common source of whooping cough infection in babies.

Even if you already had a whooping cough vaccine, you might need another one.

Vaccines aren’t just for babies and kids. Recommendations for whooping cough vaccination have changed in recent years.

The NFID says the following adults should be vaccinated:

•  All adults age 19 and older need a whooping cough booster. This is called a Tdap vaccine. It also protects against tetanus and diphtheria.

•  Pregnant women need a Tdap vaccine during the third trimester (between 27 and 36 weeks of every pregnancy).

•  Adults of any age who may be in close contact with babies younger than 1 year of age should get a Tdap vaccine. It should be given at least two weeks before being around the baby, if possible.

•  Health care employees in hospitals and health centers should get the Tdap.

•  After getting the Tdap vaccine, all other adults should get the Td (tetanus and diphtheria) booster every 10 years.