MONDAY, Sept. 3, 2001 (HealthDayNews) -- American researchers working on a vaccine to prevent tooth decay in children have found a new antigen that creates a stronger immune response than many previously tested ones.
The antigen, discovered by a research team at The Forsyth Institute in Boston, is a key component in a new vaccine formulation that can be squirted in the nose, rather than injected or swallowed like some other vaccines. The vaccine has proved effective in pre-clinical trials.
Antigens are proteins not normally present in the body that stimulate the body to produce antibodies.
"What we are trying to do is create in the oral cavity, especially the saliva, an immune response which will prevent those bacteria which cause tooth decay from gaining a foothold and colonizing the oral cavity," says Daniel Smith, one of the research team leaders and a senior staff member at Forsyth.
"So we're not strengthening the tooth enamel. What we are doing is preventing either the action or the colonization of the tooth decay-causing bacteria on the tooth surface," he explains.
The 2000 U.S. Surgeon General's Report on Oral Health calls tooth decay the most chronic childhood disease. It's five times more common than asthma and seven times more common than hay fever in children.
Tooth decay occurs when microorganisms accumulate on the teeth, particularly in the presence of sugar. These microorganisms, mutans streptococci bacteria, produce lactic acid, a product of sugar metabolism, which causes tooth enamel to erode.
The new vaccine works by stimulating immunity to the mutans streptococcal enzyme, which is responsible for the accumulation of mutans bacteria on teeth.
The antibody created by the vaccine binds to the enzyme, deactivates it and prevents it from making the sticky substance that cause bacteria to bind to each other and accumulate on the tooth surface, Smith says.
The new antigen is composed of a combination of peptide constructs taken from the mutans enzyme and is more effective at stimulating immunity than other individual peptide antigens, the researchers say. Peptides are molecules that are structurally like proteins, but smaller. They include many hormones, antibodies and other compounds involved in the metabolic function of living organisms.
The new antigen was reported in a recent issue of the Infection and Immunity journal.
Forsyth researchers have received government approval for clinical trials and are now seeking support or partners to produce the vaccine.
A vaccine for tooth decay is being pursued by a number of scientists worldwide, Smith says. Forsyth researchers are investigating many different aspects, including trying to determine the best time to administer such a vaccine to children.
"We found that within a few weeks of life, children are beginning to form antibodies to bacteria that they came in contact with in food items," Smith says.
"As we followed that, we were able to conclude that a vaccine for tooth decay could, in fact, have the potential to give a protective immune response if given at 1 year of age or 18 months of age," he adds.
And that's important, he notes, because the bacteria that cause tooth decay colonize the teeth in kids who are between 18 months and 36 months of age.
"The idea is, like any other vaccine therapy, to give the vaccine before the bacteria colonizes the person," he says.
But it likely wouldn't be a one-shot deal. The vaccine would be needed again when a child's permanent teeth begin to appear, Smith adds.
Until clinical trials are done, it's too soon to say whether this new antigen will produce an effective tooth-decay vaccine, says Dr. Kenneth Burrell, senior director of the American Dental Association's council on scientific affairs.
"People have been trying to develop vaccines for at least 20 years," he says.
There have been many notices about tooth-decay vaccines going to clinical trials, Burrell says.
"I'm skeptical because of the past experience with this -- hearing so many announcements and never getting follow-up on them," he adds.
What To Do
Both Smith and Burrell say that, contrary to what many people think, tooth decay is an important public health issue in the United States.
The Surgeon General's report also says that more than half the children between the ages of 5 and 9 have at least one cavity or filling, and that increases to 78 percent of all 17 year olds. Poor children suffer twice as much tooth decay as their more affluent peers, but are less likely to be treated.
Another finding in the report is that 25 percent of poor children haven't seen a dentist by the time they start kindergarten.
For more information about dental care, go to the American Dental Association, or the virtual office of the U.S. Surgeon General.
