LONG BEACH - Nassau County health officials are investigating a possible outbreak of mumps in Long Beach and surrounding communities.

Officials say that  there are 18 suspected cases in the area so far, most of whom are in their 20s.  As of Tuesday afternoon, six of those patients have become confirmed cases.

Health officials say the majority of the people affected by the highly contagious infection had previously been vaccinated against the disease.

Nassau's health commissioner says it's not unusual because vaccines don't always work against all strains of a virus.

Doctors say that if someone was given the initial mumps shot and then the booster, there is no reason to get vaccinated again.

Anyone who thinks they may be sick  or isn't sure about their vaccination should contact their doctor for advice.