This article is written live from ID Week 2017 Annual Meeting in San Diego, CA. MPR will be reporting news on the latest findings from leading experts in infectious diseases. Check back for more news from IDWeek 2017.

SAN DIEGO—No significant associations were seen between 25(OH)D levels and post-vaccination antibody titers or respiratory infections, presented Rachel Lee, MD, FACP, FAAAAI from Naval Health Res. Ctr., San Diego, CA. 

Although vaccination is the main prevention for influenza, “its effectiveness may be limited even among young, healthy adults,” explained Dr. Lee. She and her team of researchers investigated whether vitamin D deficiency was linked to poor vaccine immunogenicity and a higher risk of respiratory infections. They conducted a retrospective cross-sectional study among young, healthy military workers (n=437). Associations between 25(OH)D levels and post-vaccination antibody titers and healthcare encounters for respiratory infections during the 2009/10 flu season were evaluated. 

Vitamin D levels were categorized as normal (>30ng/mL), insufficient (20–30ng/mL), and deficient (<20ng/mL). Of the total study patients, 34.8% were vitamin D deficient, 38.2% were vitamin D insufficient, and 27% had normal vitamin D levels; most of the participants (91%) were aged 18–39 years.  

Half (51%) of the patients exhibited a seroprotective anti-influenza post-vaccination titer (≥1:40), which did not vary by the different vitamin D levels (deficient vs. normal: odds ratio [OR] 1.10, 95% CI: 0.68–1.78) and insufficient vs. normal: OR 1.25, 95% CI: 0.78–2.01) or continuous vitamin D levels (OR 0.98, 95% CI: 0.84–1.15).

Dr. Lee added, “There were no associations with respiratory diagnoses between the vitamin D groups.” 

Even among a relatively young and healthy adult study population, vitamin D insufficiency and deficiency were commonly seen. Overall, no significant associations were seen between 25(OH)D levels and post-vaccination antibody titers or with respiratory infections. With only half of the vaccine recipients showing seroprotective anti-influenza titers, “strategies for improving influenza vaccine responses,” concluded Dr. Lee.

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Lee, R. Are Higher Vitamin D Levels Associated with Improved Influenza Vaccine Immunogenicity and Fewer Healthcare Encounters for Respiratory Infections among Young Adults? Poster presented at IDWeek 2017;October 4–8, 2017; San Diego, CA.