How Long Does Protection from DTaP Vaccination Last?

MedicalResearch.com Interview with:

Dr. Matthieu Domenech de Cellès PhDBiostatistics, Biomathematics, Pharmacoepidemiology, and Infectious Diseases Unit, Institut Pasteur, Inserm U1181, University of Versailles St-Quentin-en-Yvelines,Versailles, France

Dr. Domenech de Cellès

Dr. Matthieu Domenech de Cellès PhD
Biostatistics, Biomathematics, Pharmacoepidemiology, and
Infectious Diseases Unit, Institut Pasteur, Inserm U1181,
University of Versailles St-Quentin-en-Yvelines,
Versailles, France

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Most high-income countries now use acellular pertussis vaccines (called DTaP, which are sub-unit vaccines based on purified antigens of the bacterium Bordetella pertussis) to protect children against pertussis. Although clinical trials demonstrated the short-term effectiveness of DTaP vaccines, there was a growing concern that the duration of protection they conferred was not very long. Those concerns were mostly based on the results of a number of epidemiological studies, which showed that the relative risk of contracting pertussis increased substantially over time, typically by 20–40% every year since last vaccination.

Although such increases seem high, it was not immediately obvious how to interpret them—the more so because pertussis epidemiology is complex.

In our study, we developed mathematical models of pertussis epidemiology to try to understand what the results of recent epidemiological studies really meant about the effectiveness and the duration of protection of DTaP vaccines. The most interesting—and perhaps counterintuitive—finding of our study was that those results are fully consistent with highly effective DTaP vaccines, which confer long-term protection. This is a consequence of the fact that pertussis is highly contagious and that the immunity conferred by DTaP, though very high, is not perfect.    Continue reading

Vaccines Prevent Disease and Death – Why Are Some US Children Not Vaccinated?

MedicalResearch.com Interview with:
"Vacuna influenza / Flu vaccine" by El Alvi is licensed under CC BY 2.0Kathryn M. Edwards, M.D.
Sarah H. Sell and Cornelius Vanderbilt Chair in Pediatrics
Professor of Pediatrics
Vanderbilt University School of Medicine

Dr. Edwards discusses the statement from the Infectious Diseases Society of America (IDSA) regarding the Centers for Disease Control and Prevention’s new data on child vaccine rates across the United States.

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: To monitor the uptake of vaccines the CDC conducts a National Immunization Survey each year.  This survey is conducted by random-digit dialing (cell phones or landlines) of parents and guardians of children 19-35 months of age.  The interviewers ask the families who provides the vaccines for their children and if these providers can be contacted to inquire about the immunizations received.  The overall response rate to the telephone survey was 26% and immunization records were provided on 54% of the children where permission was granted.  Overall 15, 333 children had their immunization records reviewed.

When comparing immunization rates for 2017 and 2016, the last two years of the study, several new findings were discovered.

First the overall coverage rate for 3 doses of polio vaccine, one dose of MMR, 3 doses of Hepatitis b, and 1 dose of chickenpox vaccine was 90%, a high rate of coverage.  Children were less likely to be up to date on the hepatitis A vaccine (70%) and rotavirus vaccine (73%). Coverage was lower for children living in rural areas when compared with urban areas and children living in rural areas had higher percentages of no vaccine receipt at all (1.9%) compared with those living in urban areas (1%).

There were more uninsured children in 2017 at 2.8% and these children had lower immunization rates.  In fact 7.1% of the children with no insurance were totally unimmunized when compared with 0.8% unimmunized in those with private insurance. Vaccine coverage varies by state and by vaccine. Continue reading