A small percentage of people living with glomerular disease may experience mild disease flares after COVID-19 vaccines, according to a new study. Fortunately, these flares are rare overall and don’t typically require intensive treatment – suggesting that these patients may just need a bit of extra monitoring by their doctors after vaccination. Importantly, the data suggest that the risks of COVID infection still outweigh the risks of vaccination.
Glomerulonephritis (GN) is an autoimmune disease that affects the kidneys. As with several other autoimmune diseases, it’s possible to experience a disease flare (increased disease activity) after certain vaccines, including the common flu vaccine. This is because vaccines work by stimulating the immune system, and people with autoimmune diseases tend to have hyperactive immune systems to begin with.
Whether COVID-19 vaccines were associated with an increase of GN disease activity was previously unknown.
“Anecdotally we had noticed some patients were showing glomerular disease flares within a few weeks of getting their COVID vaccines,” says Dr. Sean Barbour, an assistant professor at the University of British Columbia’s Division of Nephrology who specializes in GN research.
Barbour and his team wanted to better understand how frequently disease flares were happening at a population-based level. Thanks to the GN Registry, a database that captures all GN patients across BC, they were uniquely well-positioned to analyze data at a provincial scale to gain more insight. As well, the BC Ministry of Health was collecting comprehensive data on both vaccination cases and COVID-19 infections – offering a detailed picture of who with GN was getting vaccinated, who contracted COVID-19, and who experienced a disease flare.
The results show that 134 out of 1,105 GN patients in the study experienced a disease flare, or about 12 percent. Importantly, about half of these patients would have experienced a disease flare naturally, as GN typically comes and goes throughout a person’s life regardless of whether they receive a vaccine or not. This means someone’s risk of experiencing a flare from the vaccine is still very low, at an estimated 6 percent.
“The other thing we observed was that the type of flare that did occur tended to be quite mild – patients didn’t need a repeat kidney biopsy or huge changes in their immunosuppression therapy,” explains Barbour.
Together, these results suggest that it’s possible for GN patients to experience mild disease flares following COVID-19 vaccination, and should speak with their doctors about monitoring their disease closely following vaccination. In the handful of cases when flares did happen, it was following a second or subsequent dose of vaccine, but not after the first dose.
“It’s important to understand what these risks are, monitor them, and put a treatment plan in place to facilitate subsequent vaccines,” explains Barbour, noting that COVID-19 is not going away, and vaccines will still be needed into the future. “Now we know what the risks of the vaccine are for glomerular disease and can be confident that this risk of a flare is far, far lower than what would happen if you didn’t get vaccinated and got COVID.”
