NEW YORK (Reuters Health) - Patients with rheumatoid arthritis did not experience flares after receiving a two-dose COVID-19 vaccination, a new study from Hong Kong shows.
An analysis of data from nearly 5,500 RA patients revealed that full vaccination with an mRNA vaccine or an inactivated-virus vaccine was not associated with arthritis flares, researchers report in Annals of the Rheumatic Diseases.
"Findings from this study provide real-world evidence of COVID-19 vaccine safety and could potentially overcome vaccine hesitancy among patients with RA," Dr. Ian Chi Kei Wong of The University of Hong Kong and colleagues write.
To explore whether vaccination against COVID-19 might lead to arthritis flares in RA patients, the researchers turned to electronic medical records (EMRs) from the Hospital Authority with linked vaccination records from the Department of Health of the Hong Kong Government.
The researchers obtained records from nearly 4 million patients with confirmed vaccination status. Their analysis focused on 5,493 patients with RA, 1,324 of whom had been vaccinated with either the Pfizer-BioNTech vaccine or the CoronaVac vaccine Compared with non-vaccinated patients, vaccine recipients were younger and less likely to have pre-existing chronic diseases.
During a median follow-up of 32 days, 35 of those who received the Pfizer-BioNTech vaccine had RA or reactive arthritis-related hospitalization. During a median follow up of 30 days, 41 of those who received the CoronaVac vaccine had RA or reactive arthritis-related hospitalization.
Based on propensity-score-weighted Poisson regression, there was no significant association between arthritis flare and vaccination (Pfizer-BioNTech: adjusted incidence rate ratio, 0.86, 95% confidence interval, 0.73 to 1.01; CoronaVac: aIRR, 0.87; 95% CI, 0.74 to 1.02).
The per-patient prescription and distribution of the four rheumatoid drug categories also showed no significant differences between patients who received one of the vaccines and those who were unvaccinated.
The study has a couple of limitations, said Dr. Medha Barbhaiya, an assistant professor of medicine and healthcare policy and research at Weill Cornell Medical College and an assistant attending physician at the Hospital for Special Surgery.
First, a common limitation for electronic health records that is particularly relevant is the defined outcomes, Dr. Barbhaiya said. The researchers are not able to use standard disease measures or patient-reported outcomes, she added.
"Using hospitalization or consultation with a specialist to define the outcome of a flare," Dr. Barbhaiya told Reuters Health by phone, "essentially means they are assessing more severe flares, ones that led to hospitalization or medical consultation."
"Second, very few patients at the time of the study cohort entry were on corticosteroids," Dr. Barbhaiya said. "That probably means most patients likely had stable disease and very few had active rheumatoid arthritis. Since the ones with active rheumatoid arthritis may be more likely to flare, the generalizability of these findings to patients with RA overall, or at least those with more active disease, is unclear."
"Taking these study limitations into consideration, this study provides complementary information to other studies that have looked at this issue and can offer some reassurance to patients with rheumatoid arthritis," Dr. Barbhaiya said.
"While further studies are needed, the lack of association of Pfizer or CoronaVac vaccination with severe flares in this study population, can help in vaccine decision making for both rheumatologists and patients with rheumatoid arthritis," she said.
The study did not have commercial funding. Several authors report financial ties to Pfizer.
Dr. Wong did not respond to a request for comment.
SOURCE: https://bit.ly/2ZJKLEw Annals of the Rheumatic Diseases, online October 22, 2021
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