Recent vaccination was not associated with an increased risk for the development of systemic lupus erythematosus (SLE), a case-control study found.
A total of 21% of individuals who developed lupus had received any vaccine within the previous 2 years, as did 25.4% of controls, for an adjusted odds ratio (OR) of 0.9 (95% CI 0.5-1.5), according to Lamiae Grimaldi-Bensouda, PharmD, PhD, of LA-SER and Conservatoire National des Arts et Metiers in Paris, and colleagues.
Similarly, 16.2% of cases and 20.8% of controls had been vaccinated within the previous 12 months, for an adjusted odds ratio of 0.9 (95% CI 0.5-1.6), the researchers reported in the June Arthritis & Rheumatology.
“Because vaccinations are designed to stimulate an antigen-specific immune response, they have been proposed as potential triggers for autoimmunity and the onset or exacerbation of SLE,” they wrote.
To examine this possibility, Grimaldi-Bensouda and colleagues analyzed data from the Pharmacoepidemiologic General Research eXtension (PGRx) system in France and Quebec, which conducts surveillance for vaccine-associated adverse events. The system also maintains a registry of SLE cases.
Between April 2008 and June 2012, there were 105 incident cases of SLE reported from the 36 centers participating in PGRx. A group of 712 controls also were recruited, matched for age, sex, smoking, alcohol use, and family history of autoimmunity.
Participants were interviewed by telephone and provided information about 85 health conditions and medications, as well as 27 vaccines.
The minimum detectable odds ratio for vaccination during the 2 years before SLE onset was set at 1.96.
The most common vaccinations among the cases in the 2 years before disease onset were for influenza and for diphtheria/tetanus/pertussis/poliomyelitis (DTPP).
The influenza vaccine had been given to 7.6% of cases and 9.1% of controls, for an odds ratio of 1.1 (95% CI 0.5-2.6), while the DTPP immunization had been given to 9.5% and 11%, respectively (OR 0.9, 95% CI 0.4-1.9).
The researchers also analyzed the risks according to age, and found an odds ratio of 1.1 (95% CI 0.5-2.3) for patients under 30 versus those older at the time of disease onset.
In an additional analysis, they excluded patients who had been exposed to medications that have been linked with SLE, such as chlorpromazine and isoniazid, and once again found no association (OR 0.8, 95% CI 0.5-1.3).
“Our study shows that exposure to vaccines is not associated with an increased risk of developing SLE. Although our study has some limitations, we are reassured by the finding that the ORs for the relationship between vaccination and SLE onset are less than 1,” Grimaldi-Bensouda and colleagues concluded.
These limitations included the small numbers, potential unmeasured confounders, and the lack of information about ethnicity in the database.
In addition, the study only addressed SLE onset, not disease flares, although other studies have found no association of vaccination with disease exacerbations.
The study was supported by LA-SER. Grimaldi-Bensouda is a director of LA-SER and has received research support from INSERM.
One co-author disclosed relevant relationships with LA-SER, which is a research organization that owns the PGRx database. LA-SER receives funding from various sources, including AstraZeneca, Bioron, Genevrier, GlaxoSmithKline, Pfizer, Novartis, and Sanofi.