University of Colorado Anschutz Medical Campus

Association between tick-bite history and safety of gelatin-containing vaccines: Analysis of a large database of the United States.

Alpha-gal syndrome (AGS) is an allergic reaction caused by sensitization to alpha-gal, a sugar molecule in gelatin-containing vaccines. Tick bites can induce alpha-gal IgE sensitization, as ticks inject alpha-gal through their saliva. However, there is no real-world data on the anaphylaxis rates associated with gelatin-containing vaccines in patients with tick bite history. We utilized TriNetX, a research network database, to analyze data in November 2024. The history of tick bites (i.e., the presence of a tick-bite history) was categorized into three groups: ehrlichiosis, tularemia, and bites from nonvenomous arthropods. Vaccines were classified into two categories: (1) gelatin-containing vaccines (live intranasal influenza [FluMist], varicella, measles/mumps/rubella [MMR], oral typhoid, rabies [RabAvert], and yellow fever vaccines [YF-VAX]) and (2) gelatin-free vaccines. Anaphylactic episodes were identified in patients with a history of tick bites who developed anaphylaxis within one day following vaccination. The anaphylaxis rates after receiving gelatin-containing vaccines were 0.06 %, 0.7 %, and 0.2 % in patients with ehrlichiosis, tularemia, and nonvenomous arthropod bites, respectively. In contrast, the anaphylaxis rates after receiving gelatin-free vaccines were 0.04 %, 0.0 %, and 0.1 % in patients with ehrlichiosis, tularemia, and nonvenomous arthropod bites, respectively. Among the gelatin-containing vaccines, live intranasal influenza and varicella vaccines posed a higher rate of anaphylaxis compared to other gelatin-containing vaccines. While tick bites are associated with AGS, a history of tick bites is not a contraindication for most gelatin-containing vaccines, including MMR, oral typhoid, rabies, and yellow fever vaccines. Further investigations are warranted to evaluate the safety of intranasal influenza and varicella vaccines in this population.

Incidence of anaphylaxis in patients with alpha-gal syndrome receiving gelatin-containing vaccines: A large database analysis.

Associations Between the Maternal Diet Index and Childhood Asthma: The NorthPop and Healthy Start Cohorts.

A novel maternal diet index (MDI), characterizing offspring asthma- and allergy-associated maternal intake during pregnancy was constructed and validated in Healthy Start, USA. This study aims to (1) externally validate the asthma findings from Healthy Start in the NorthPop Birth Cohort Study (NorthPop) in Sweden; and (2) characterize the diet and demographics of the two cohorts. The MDI was computed as a weighted combination of seven components associated with offspring allergies and asthma, including vegetables and yogurt (associated with decreased odds) and cold cereals, fried potatoes, juice, red meat, and rice (associated with increased odds). Doctor diagnoses provided childhood asthma incidence and timing. Parametric Weibull time-to-event analysis evaluated associations between the MDI, dichotomized at the median (72.2) for Healthy Start, and offspring asthma. The NorthPop and Healthy Start mean MDI values differed significantly (p < 0.001) and in NorthPop, only 6.1% had MDI < 72.2. Data from 6446 mother-child dyads in NorthPop yielded a crude hazard ratio (HR) for asthma of 0.70 (95% confidence interval [CI] 0.50-0.98, p = 0.037) and a fully adjusted HR of 0.84 (0.55-1.29; p = 0.428) for MDI > 72.2 versus < 72.2 (n = 4655). The fully adjusted HR for 945 Healthy Start dyads was significant at HR 0.41 (0.29-0.57; p < 0.0001). Results show that in a population with different maternal dietary patterns and demographics compared to the source population, MDI > 72.2 was not an independent predictor of offspring asthma. Further proof of the utility and generalizability of the MDI needs to be tested in other populations.