High Pathogen Exposure May Reduce Vaccine Efficacy

For example, if you have been vaccinated against the measles, but someone sneezes very close to your face, or you're caring for a sick kid who is sneezing, coughing, etc., are you more likely to get sick? In addition, if you're run down (maybe from chasing that kid the week earlier), are you more likely to get infected even if you've been vaccinated? Langwig and her lab found in their simulations that vaccines are predicted to be less effective at higher pathogen doses and when individuals in the population have similar susceptibility. These findings were recently published in Scientific Reports. “Susceptibility, meaning how likely an individual is to get infected, is also important. Individuals that are younger or have poor nutrition can be more likely to get infected, even if they have been vaccinated. We found that populations that have more variable susceptibility have higher vaccine efficacy,” said Langwig, an affiliated faculty member of the Global Change Center, an arm of the Fralin Life Science Institute. What we found was a bit of a shock - there are a very small number of studies that test whether vaccines are effective across multiple pathogen doses. We reviewed almost 6,000 articles and identified only about a dozen studies that had tested vaccines across multiple pathogen doses. Within those few studies, the pattern was generally consistent with our simulation - vaccine efficacy tended to be lower at high pathogen doses,” said Langwig. They did find that some vaccines did offer complete protection regardless of pathogen dose in several model organisms, suggesting that not all vaccines are less effective when individuals are exposed to high doses. https://www.technologynetworks.com/diagnostics/news/simulation-study-suggests-when-pathogen-exposure-is-higher-vaccine-efficacy-is-lower-316481?utm_campaign=NEWSLETTER_TN_Breaking%20Science%20News&utm_source=hs_email&utm_medium=email&utm_content=70597978&_hsenc=p2ANqtz--psWTREy59LJtsywQM7DTaZLEnlIGxswwUNc9lDvJsx8GokLoa9qlmYCOUiFEkBK3VlH1pTrH4O1Lt4A9K_Jh8LZyq4w&_hsmi=70597978