Next to the common cold, ear infections are the most commonly diagnosed childhood illness. More than three out of four children in the US have at least one ear infection by the time they reach three years of age.
The infection known as acute otitis media could be very painful and - very rarely - cause long term damage.
Roman Prymula, from the University of Defence at Hradec Kralove, Czech Republic, administered almost 5,000 infants with either the ear vaccine or a hepatitis A vaccine at various ages between three and 15 months.
When the researchers followed them up at the age of two, 333 of the children given the new vaccine had a middle ear infection, compared with 499 in the control group, reported the online edition of BBC News. The vaccine was shown to be effective against disease-causing bacteria.
'We found a reduction in ear, nose and throat specialist-confirmed episodes of acute otitis media by about a third in infants in the vaccine group compared with the control group,' Prymula said.
The researchers say the findings are important because both bacterium are significant causes of lower respiratory tract infections. The study was published in the latest issue of British Medical journal.