Doctors and nurses need to explain to parents who are hesitant to have their children vaccinated that not only may they be putting their children at risk, they may be endangering their whole community.

So advises a special article in the New England Journal of Medicine.

Lead author Saad B. Omer, an assistant professor of global health and epidemiology at Emory University's Rollins School of Public Health, says doctors and other health care professionals need to listen respectfully to parents' concerns about vaccines, and discuss with them the risks of non-vaccination.

The authors note concerns about vaccine safety have led to a rise in vaccine refusal in the United States over the last decade.

Several states now allow "personal belief" exemptions from school vaccination requirements in addition to exemption for religious or medical reasons. In those states that allow exemptions for personal beliefs, exemption rates rose from less than 1 per cent to more than 2.5 per cent between 1991 and 2004.

Omer and his colleagues review evidence from several states that finds that in communities where the incidence of vaccine refusal has increased, the children are at substantially higher risk for infectious diseases, such as measles and whooping cough.

Even children whose parents did not refuse vaccination -- those who are too young to be vaccinated, can't be vaccinated for medical reasons, or whose immune systems do not respond sufficiently to vaccination -- are put at risk because "herd immunity" normally protects those children.

"The implication of recent research findings is that everyone who is living in a community with a high proportion of unvaccinated individuals has an elevated risk," Omer says.

The authors advise family doctors, pediatricians and other health care workers not to break off relationships with parents that refuse vaccines, as some have done.

A recent survey of pediatricians found that almost 40 per cent said they would not provide care to a family that refused all vaccines. But the authors says "firing" a patient is not the best approach.

Research has found that parents who were uncertain about vaccinating their children were still open to discussions with doctors, the authors write. So doctors and nurses have a critical role to play "in explaining the benefits of immunization and addressing parental perceptions and concerns about its risks."

"Continued refusal after adequate discussion should be respected unless the child is put at significant risk of serious harm (e.g., as might be the case during an epidemic). Only then should state agencies be involved to override parental discretion on the basis of medical neglect," they write.