High Exposure to Perfluoroalkyl Substances and Antibody Responses to SARS-CoV-2 mRNA Vaccine-an Observational Study in Adults from Ronneby, Sweden

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are widely used, environmentally ubiquitous, and stable chemicals that have been associated with lower vaccine-induced antibody responses in children; however, data on adults are limited. The drinking water from one of the two waterworks in Ronneby, Sweden, was heavily contaminated for decades with PFAS from firefighting foams, primarily perfluorohexane sulfonic acid and perfluorooctanesulfonic acid (PFOS). Vaccination against SARS-CoV-2 offered a unique opportunity to investigate antibody responses to primary vaccination in adults who had been exposed to PFAS.

OBJECTIVES

Our objective was to evaluate associations between PFAS, across a wide range of exposure levels, and antibody responses in adults 5 wk and 6 months after a two-dose vaccination regime against SARS-CoV-2.

METHODS

Adults age 20-60 y from Ronneby (n = 309 , median PFOS serum level 47  ng / mL , fifth to 95th percentile 4 - 213  ng / mL ) and a group with background exposure (n = 47 , median PFOS serum level 4  ng / mL ) received two doses of the Spikevax (Moderna) mRNA vaccine. The levels of seven PFAS were measured in serum before vaccination. Serum immunoglobulin G antibodies against the SARS-CoV-2 spike antigen (S-Abs) were measured before vaccination and at 5 wk (n = 350 ) and 6 months (n = 329 ) after the second vaccine dose. Linear regression analyses were fitted against current, historical, and prenatal exposure to PFAS, adjusting for sex, age, and smoking, excluding individuals with previous SARS-CoV-2-infection.

RESULTS

PFAS exposure, regardless of how it was estimated, was not negatively associated with antibody levels 5 wk [current PFOS: - 0.5 % S-Abs/PFOS interquartile range (IQR); 95% confidence interval (CI): - 8 , 7] or 6 months (current PFOS: 3% S-Abs/PFOS IQR; 95% CI: - 6 , 12) after COVID-19 vaccination.

DISCUSSION

Following a strict study protocol, rigorous study design, and few dropouts, we found no indication that PFAS exposure negatively affected antibody responses to COVID-19 mRNA vaccination for up to 6 months after vaccination. https://doi.org/10.1289/EHP11847.

Increased Intimal Hyperplasia After Vascular Injury in Male Androgen Receptor-Deficient Mice

Intimal hyperplasia is a vascular pathological process involved in the pathogenesis of atherosclerosis. Data suggest that T, the most important sex steroid hormone in males, protects men from atherosclerotic cardiovascular disease. T mainly acts via the androgen receptor (AR), and in this study we evaluated formation of intimal hyperplasia in male AR knockout (ARKO) mice using a vascular injury model. Two weeks after ligation of the carotid artery, male ARKO mice showed increased intimal area and intimal thickness compared with controls. After endothelial denudation by an in vivo scraping injury, there was no difference in the reendothelialization in ARKO compared with control mice. Ex vivo, we observed increased outgrowth of vascular smooth muscle cells from ARKO compared with control aortic tissue explants; the number of outgrown cells was almost doubled in ARKO. In vitro, stimulation of human aortic vascular smooth muscle cells with a physiological T concentration inhibited both migration and proliferation of the cells. Analyzing the expression of central regulators of cell proliferation and migration, we found that mRNA and protein levels of p27 were lower in uninjured arteries from ARKO mice and that T replacement to castrated male mice increased p27 mRNA in an AR-dependent manner. In conclusion, AR deficiency in male mice increases intimal hyperplasia in response to vascular injury, potentially related to the effects of androgens/AR to inhibit proliferation and migration of smooth muscle cells.

Changes in Mini Mental State Examination score after stroke: lacunar infarction predicts cognitive decline

Stroke and cognitive impairment are inter-related. The purpose of this study was to show the natural evolution of cognitive performance during the first year after a stroke, and to show which factors that predict cognitive decline. Subjects were patients with a first-ever stroke who were treated in a stroke unit. A total of 160 patients were included. At baseline patients were evaluated with regard to stroke type, stroke severity, pre-stroke dementia and other risk factors. Mini Mental State Examinations (MMSE) were performed after 1 week and after 1 year. Patients had a median increase of 1 point (range -8 to +9) on the MMSE. Thirty-two pre cent of the patients deteriorated, 13% were unchanged, and 55% improved. Lacunar infarction (LI) and left-sided stroke were associated with a failure to exhibit improvement. Patients with LI had an average decline of 1.7 points, whilst patients with other stroke types had an average increase of 1.8 points. Most stroke survivors improve cognitively during the first year after the event. The outcome for LI patients is worse, which suggests that LI may serve as a marker for concomitant processes that cause cognitive decline.