The new vaccine is designed to protect against a strain of the virus that has been showing up in more and more children — especially young children — since the fall.

The current vaccine, made by Merck & Co., is quite effective at preventing the flu and its complications, such as pneumonia and bronchitis, but it doesn't protect against the most common type of RSV infection in adults and older children. The new vaccine will be available as early as 2020, according to Merck's website.

(CNN) -- As the country continues to grapple with a surge in respiratory syncytial virus (RSV) cases, health officials are hoping for a new vaccine.

The Centers for Disease Control and Prevention is currently developing a vaccine against RSV that will protect babies 2 months old or younger. The agency is also looking into whether it can modify the existing vaccine so that older children and adults can receive it as well.

The vaccine is designed to match the virus’s outer coating and is expected to work as well as the current shot.

A new vaccine against respiratory syncytial virus (RSV), which has been linked to severe illness in children and young adults, is expected to be available by 2020. The National Institutes of Health (NIH) announced Thursday that it was working with pharmaceutical company GlaxoSmithKline on developing a new version of the vaccine.

The current version of the vaccine protects against three types of RSV, which causes about 80,000 hospitalizations each year in the United States alone. But some experts worry that the number of cases could spike again if there are no improvements with this year's vaccine or if an outbreak occurs later this year. The main question is what is RSV and why it is rising?

What Is RSV and why It Is Rising?

RSV stands for respiratory syncytial virus, which is a type of respiratory flu. It is a common illness that affects children and infants. The virus causes symptoms that are similar to those of the common cold: a runny nose, cough, sneezing, and fever.

RSV can be passed from person to person through close contact — touching or breathing in droplets from someone who has the infection. RSV can also spread very easily within families and among friends who live together.

Some people are especially at risk for getting RSV if they have asthma or other lung diseases such as COPD (chronic obstructive pulmonary disease).

Children younger than 2 months old are at highest risk of dying from RSV pneumonia because they're too young to be vaccinated against it and their immune systems aren't fully developed yet. This can make them more likely to suffer severe complications if they contract RSV pneumonia.

There are many different types of viruses that can cause symptoms like RSV, including rhinoviruses, coronaviruses and influenza viruses. There are several different types of human coronavirus (HCoV) that cause disease in humans: HCoV-229Av and HCoV-229C — both of which cause HAV infection — HCoV-OC43 — which causes severe respiratory illness characterised by fever, cough, shortness of breath with pulmonary congestion; and HCoV-NL63 — which was isolated from a patient in Hong Kong with an acute respiratory illness characterised by fever.

RSV is also responsible for at least half of all wintertime deaths in young children. In fact, it's the leading killer of infants under six months old and second only to pneumonia among all causes of death in kids younger than five years old.  The good news is that most people who get RSV experience only mild symptoms like sneezing, runny nose and congestion — but it's still important to know what it is and how to prevent getting sick.