There is at least one family who is mourning today. Eleven years ago they lost their daughter Brie She was just 52 days old. Sadly she succumbed to a disease called pertussis, also known as whooping cough, which they knew little about at the time.
Since Brie’s death we’ve learned that changes made to improve the safety of the pertussis vaccine may have resulted in a vaccine that is not as effective. In the 1990′s the U.S.switched from whole-cell pertussis vaccine (DTP) to combined acelluar pertussis (DTaP) vaccine. A study in the June 2013 issue of Pediatrics looked at individuals born between 1994 and 1999 who received four pertussis-containing vaccines. The authors compared two groups during a 2009 and 2010 pertussis outbreak, some who received the older vaccine and some who received the newer DTaP. They discovered that those who received the newer vaccine had a six times higher risk of contracting pertussis due to waning immunity compared to those who received the older vaccine.
While vaccines are a very effective way at preventing disease, they’re not perfect. Pertussis vaccines typically offer high levels of protection within the first 2 years of getting vaccinated, but then protection decreases over time. In the case of pertussis, this also occurs with natural infection, meaning that even if you contract pertussis you do not retain any lifelong immunity and it’s possible to be infected again.
In general, DTaP vaccines are 80-90% effective in children with the highest protection following the fifth dose when 9 out of 10 kids are still fully protected. In each year following the last dose there appears to be a modest decrease in effectiveness. Still, five years after the last dose 7 out of 10 kids are still fully protected and the other 3 are partially protected. So how long has it been since some adults have been vaccinated? How much immunity do you suppose they have? Read more…
While the majority of people support immunizations and recognize their value in reducing the incidence of disease around the world, there are a handful of people who cling to the preposterous idea that some big vaccine conspiracy exists that will lead the ”sheeple” to their doom. They claim conspirators include doctors, scientists, pharmaceutical companies and government agencies. However, by familiarizing ourselves with the reporting structure of immunization related agencies, and the way in which vaccine recommendations and policies are developed and disseminated (as outlined in the image below) it’s easy to see the value of our current policies and procedures and dismiss these conspiracy claims.
One important part of the puzzle is the work of The Advisory Committee on Immunization Practices (ACIP). Having recently returned from the latest ACIP meeting, I can honestly say that the committee is an impressive group of medical and public health experts who are committed to making decisions that are in the best interest of the American public. Not only do they develop recommendations on how to use vaccines to control diseases in the United States, their role is to also ensure that the recommended vaccines remain safe and effective.
The ACIP consists of 15 voting members, fourteen of which have expertise in vaccinology, immunology, pediatrics, internal medicine, nursing, family medicine, virology, public health, infectious diseases, and/or preventive medicine, and one additional member who provides perspectives on the social and community aspects of vaccination as the community representative. In addition to these 15 members, ACIP also includes 8 ex officio members who represent various federal agencies each responsible for immunization programs in the United States, and 30 non-voting representatives of liaison organizations that bring related immunization expertise. Remarkably, this committee was first established 50 years ago and is still an integral part of immunization policy today.
It’s important to note that all those who serve on the committee do so voluntarily and their applications are heavily screened to ensure there is no conflict of interest in regards to vaccine-related activities. In addition to the three yearly meetings that are held, ACIP members also participate in “working groups” which study a specific topic and specialize in providing data and safety information in regards to that topic. The work these subcommittees do is critical to sharing the latest scientific information that then helps members make appropriate immunization recommendations.
For instance, this week’s meeting included the following agenda items and outcomes: