Stress 'affects pneumonia vaccine'

Pneumonia can be life threatening

Stress may reduce the impact of a vaccination for the respiratory infection pneumonia, scientists have found.

Researchers found elderly people who were suffering from high stress levels at the time they were vaccinated received less protection against the potentially fatal disease.

The study, by an Ohio State University team, provides the first hard evidence that a bacterial vaccine can be affected by a patient's stress levels.

Most earlier work in the area has focused on viral vaccines.

Lead researcher Professor Ron Glaser said patients who were feeling highly stressed should consider delaying vaccination.

He said: "The bottom line is that they should probably wait until they feel less stressed.

"If they do, they may stand a better chance of developing a stronger immune response from the vaccine and therefore better protection against the disease."

The pneumonia vaccine study follows similar studies suggesting stress also reduces the impact of vaccines for flu and the liver disease hepatitis B.

The researchers looked at 52 older adults who had never received a pneumonia vaccine before.

Dementia carers

They compared people who had experience of caring for a spouse suffering from dementia with those who had not undergone such a stressful experience.

Dealing with the daily needs of dementia patients is known to cause chronic stress and changes in caregivers' immune systems.

All participants completed psychological tests to determine their current stress level and blood samples were taken to gauge their immune status.

They received a vaccine against pneumococcal bacteria, which causes most cases of pneumonia following a bout of flu.

The researchers tested for levels of immunoglobin-G (IgG), an antibody formed by the body to fend off pneumococcal bacteria.

Strong IgG levels indicate a healthy immune response ready to protect against the disease while weaker levels mean that a person could be at risk for pneumonia.

The immune system of all the volunteers was initially boosted by the vaccine.

However, after six months those people who were caring for sick relatives recorded a big drop in IgG levels.

Professor Glaser believes stress may cause a reduction in the number of B-lymphocytes produced by the body.

These cells manufacture antibodies which target bacterial invaders for termination.