Why Some Vaccines May Require a Booster
December 01, 2009
Preventing disease is the goal of every health care provider and fortunately every year, new vaccines are being added to assist in disease prevention. But do all vaccines boost immunity for the same period of time? And, if not, when are additional ‘booster shots’ needed to keep immunity strong?
In this month’s issue of Pediatrics, the Journal of the American Academy of Pediatrics, Michael Pichichero MD, Director of the Rochester General Research Institute, based at Rochester General Hospital in Rochester NY, studies the medical necessity for occasional booster shots to sustain immunity.
It is a well known medical fact that a booster shot for tetanus is needed every 10 years to maintain your immunity. But, what happens if you fail to get that booster? “Fortunately, a patient has a window of opportunity to get a booster shot even after getting a dirty wound,” said Dr. Pichichero. “In this case, the booster shot will take hold before the tetanus infection can establish itself. The problem is that this scenario is not true for all diseases.”
In his published study, Dr. Pichichero, an international authority on vaccines and vaccine-induced memory, discusses the effectiveness of booster vaccinations and disease progression. “We found that for slow moving infections like hepatitis, immune memory is activated within plenty of time to prevent the disease after a person has been vaccinated and booster vaccines are not needed” said Dr. Pichichero. “Other examples of vaccines that do not appear to require boosters because the pace of disease progression is slow include: polio, measles, mumps, and German measles.”
The study found, however, that there are several newer vaccines that may require booster shots to remain effective during a lifetime, including vaccines for diphtheria, all three types of spinal meningitis caused by bacteria, and the new vaccine to prevent cervical cancer. “Booster shots are needed in these cases because the disease progression is too fast for the memory response to occur in time,” said Dr. Pichichero.
The study offers several important findings. “Pediatricians and family doctors must begin to anticipate the need to provide booster vaccinations for several of the newer vaccines introduced in recent years,” said Dr. Pichichero. “And, public health agencies, such as the Centers for Disease Control, must begin to consider the cost of booster shots as they calculate the cost-benefit of vaccines. Up to now, cost calculations for the introduction and public payment of meningitis vaccines and the cervical cancer vaccine have not included the need (and cost) of periodic boosters, nor the consequences of missed boosters with disease development later in life.”
While the article has a strong and clear scientific basis, Dr. Pichichero acknowledges that only continued monitoring will determine whether he is correct in his assessment of the need for booster shots for certain diseases. “We do not want to face a diphtheria epidemic in the U.S. as occurred in Russia a decade ago due to lack of boostering of adults,” said Dr. Pichichero.
Dr. Pichichero was a member of the discovery team of the first bacterial spinal meningitis vaccine against Haemophilus influenzae type b, commonly called Hib; and participated in the foundational studies of the second spinal meningitis vaccine against pneumococci called Prevnar; and the third spinal meningitis vaccine against meningococcus called Menactra. He was an early champion for the introduction of safer whooping cough vaccines, called acellular vaccines. He has ongoing support from the National Institutes of Health to study the prospects of an ear, sinus and bronchitis vaccine. He has also received financial support for his research from vaccine companies including GlaxoSmithKline, MedImmune, Sanofipasteur and Wyeth (now Pfizer).
Marty Aarons, Public Relations