A booster dose of a SARS-CoV-2 vaccine cut infection risk nearly in half, study finds.
People with systemic lupus erythematosus (SLE) who get a booster dose of a SARS-CoV-2 vaccine have a significantly lower risk of breakthrough COVID-19 infections, according to a new report published online today in The Lancet Rheumatology.
This report found the rate of breakthrough infections among people with SLE who did not receive a booster shot was nearly double that seen among people with SLE who were boosted.
“Our study results offer people living with SLE clinical confirmation that vaccines are highly effective at guarding against severe COVID-19, despite their increased risk of catching the disease,” said co–lead investigator and rheumatologist Amit Saxena, MD, MS, of the New York University (NYU) Grossman School of Medicine, in a statement.
People with SLE are at a higher risk from COVID-19, the authors explained, likely due to immunologic perturbations associated with the disease and the common use of immunosuppressant medications by patients. Previous research has shown people with SLE are more likely to have severe COVID-19, be hospitalized, require mechanical ventilation, experience thrombosis, and die. Those statistics have made COVID-19 vaccination a key issue for people with SLE, both because an effective vaccine could have meaningful health benefits and because of concerns that the vaccines might not work as well in this population.
In the new study, the investigators recruited 163 fully vaccinated patients receiving treatment for SLE at NYU-affiliated hospitals. Half of the patients were taking at least 1 immunosuppressant at the time of the study; 16% were on multiple immunosuppressants.
The investigators wanted to know whether a booster shot would have a long-term impact on the risk of infection in this patient population. They evaluated patients 6 months following their initial dose, with follow-up beginning on or after February 4 of this year. Most of the patients (125 patients; 76.7%) had received a booster shot in addition to their initial course.
By the end of the monitoring period in late April, 44 patients had experienced breakthrough infections: 28 of the 125 patients (22%) who had received a booster shot and 16 of the 38 patients (42%) who did not get boosted. Only 2 of the 44 patients in the study were hospitalized because of their infection; both recovered. The authors noted that all but 2 of the breakthrough cases in the study occurred after December 2, 2021, when the first Omicron-variant case of COVID-19 was reported in New York.
The investigators also completed serologic testing of 57 patients. Those tests revealed that patients with the booster shot had significantly higher levels of SARS-CoV-2 antibodies (median of 1036 U/mL after the booster shot vs 397 U/mL after the initial vaccine series). However, the authors did not find any association between antibody level and COVID-19 breakthrough infections.
Still, Saxena said the study findings show that vaccination, including a booster shot, provides a meaningful benefit for people with SLE.
“COVID-19 vaccine boosters, or third shots, offered an added, doubled layer of protection from breakthrough infection,” Saxena said. “Even in cases of SARS-CoV-2 infection, cases were overwhelmingly mild among SLE patients who were fully vaccinated.”
Saxena A, Engel AJ, Banbury B, et al. COVID-19 breakthrough infections, morbidity, and seroreactivity in SLE patients following initial SARS-CoV-2 vaccination series and additional dose through the Omicron BA.1 wave in New York City. Lancet Rheumatol. Pubished online July 12, 2022. doi:10.1016/S2665-9913(22)00190-4