The History of Vaccines: A Glance Behind and a Look Ahead
A pediatrician evaluates the past and future of kids' inoculations
The Battle Rages On
There are currently 13 different germs covered in our childhood vaccines, but despite these amazing gains against serious diseases, the battle is far from over. With increased global travel, the risk of exposure to both old and new germs increases. As medical advances allow sick and disabled children to live longer, our vulnerable population persists. Even for the healthy and vaccinated, the strong immune response generated in childhood can diminish over time, so that by adolescence or young adulthood, the protection is gone.
This is what happens in the case of pertussis, the only disease in our current vaccines that has been on the rise, mostly because older children and adults are getting and spreading the illness. Unfortunately, none of these germs has yet been wiped off the planet completely. When a society chooses to stop vaccinating, disease quickly returns. This was the case in Japan in the 1970s. In 1974, with over 80 percent of its population protected against pertussis, it was mistakenly believed that pertussis was no longer a threat, and the number of vaccinated children plummeted. By 1976, only 10 percent of the population was being immunized. Soon after, a pertussis epidemic swept though Japan that sickened 13,000 and left 41 dead.
Until these germs are truly extinct, our guard cannot be let down. To maintain the progress made, vaccinations need to continue. New vaccines, once proven safe and effective, should also be accepted by today’s parents so that our grandchildren can forget the illnesses that plague us today. Doctors are considering extending some vaccines later into childhood and adolescence to boost the immunity that has waned. Along these lines, here are the latest developments and recommendations coming to our communities:
Meningococcal vaccine: Meningococcal meningitis is a leading cause of bacterial meningitis in older children and adolescents. Although not common, (about 1 in 100,000 is affected), it is fatal 10 percent of the time and almost 20 percent of those that survive have permanent disabilities. What is particularly heart wrenching about this illness, though, is that it can attack a perfectly healthy, vibrant college freshman on a Friday, leaving him dead by Monday. A new, more targeted vaccine has come on the market this year to replace the older, less effective one. Called Menactra, this vaccine was approved in February 2005 for use at ages 11 or 12, upon entrance into high school, or in college freshmen living in dorms.
Pertussis: This has been the only illness included in childhood vaccines that has been increasing in our country, largely because the protection generated from the first shots wanes after five to 10 years. This means many adolescents and young adults become susceptible again, catch pertussis, and spread it to the community (even to their newborns, where it is particularly dangerous). In 2005, two preparations of a tetanus, diphtheria, and pertussis booster vaccine, called Adacel and Boostrix, came to the US market. Boostrix is approved as a single booster for children aged 10 to 18. Adacel has approval for those 11 to 64. The goal is to replace the usual tetanus booster, given between 11 and 12 years and then every ten years thereafter, with these newer preparations to boost immunity against pertussis.
Influenza: Every winter, Americans suffer through an influenza epidemic, and every 30 years or so (due now), a super epidemic called a pandemic comes along. Flu shots have been targeted to the elderly and other vulnerable populations for years, but became available as a routine immunization in 2004 for children aged six months to 23 months for the first time. Infants and toddlers are particularly hard hit by the flu, and it is hoped that immunizing them will reduce both illness and death in this age group.
Human papilloma virus: Whether they know it or not, astounding numbers of Americans are infected with this virus through sexual intercourse. About half of all sexually active adults will become infected at some point in their lives, and 80 percent of women are infected by age 50. There are more than 100 strains of HPV, but a few in particular are known to cause cancer. HPV causes almost all cervical cancers, with 70 percent of those cancers attributed to just two HPV subtypes. A newly released vaccine (also known as the “cervical cancer vaccine”) was shown to be almost 100 percent effective against these cancer-causing HPV subtypes. This is generating great excitement among the scientific community, as it is truly an anti-cancer vaccine. This vaccine is recommended for the pre-teen (11- to 12-year) population as a series of three injections.
The battlefront in the war on disease is ever changing. As new germs emerge, old ones mutate, and resistance to antibiotics becomes more common. New developments on the vaccine front are an important part of our ability to control and sometimes even eliminate serious diseases.
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