Project 177 – Honours Scholarship – Bachelor of Biotechnology and Medical Research

21 Mar 2018

In 2018 Alice Harper was awarded a scholarship for: a research project –  Effect of diphtheria-tetanus-acellular pertussis vaccination on seasonal influenza vaccine antibody responses in young and old adults. This project is part of the VITAL trial and overseen by Dr Katie Flanagan  (Project 145).

Many studies show that vaccines can have broader effects on the immune system as well as providing protection against the vaccine-targeted diseases. These so called heterologous effects of vaccines can be positive leading to better immunity and improved responses to a range of non-targeted infections, but sometimes they can be negative and weaken the immune system. For example, measles vaccination is thought to enhance the immune system, while several studies suggest that diphtheria-tetanus-whole cell pertussis (DTwP) vaccination has a negative effect on the immune system.

Generally females are more likely to experience these heterologous effects than males. Heterologous effects of vaccines have been widely researched in infants and children but are yet to be investigated in the aging population. The immune system declines and becomes more inflamed with increasing age, thus elderly adults are known to have significantly reduced immune function causing weaker vaccine responses and leaving them at risk of contracting infections.

This trial is studying the heterologous effects of vaccination in the elderly focused on two routine vaccines: the diphtheria-tetanus-acellular pertussis vaccine (DTaP) and seasonal influenza vaccine. It will investigate a series of immune parameters including whether DTaP vaccination alters antibody responses to the influenza vaccine. The trial is enrolling up to 300 elderly adults (>65 years of age) and 300 younger adults aged between 20-50 years old. Participants are randomised into one of three vaccine groups: DTaP 4 weeks before influenza vaccine, influenza vaccine and DTaP at the same time, or influenza vaccine alone. The participants have blood samples drawn at multiple time points in order to understand what the different vaccination schedules do to the immune system. The results may have important implications regarding the vaccine schedule recommended for the elderly.