Age, medication use affect initial response to SARS-CoV-2 vaccines among IBD patients

Most patients with inflammatory bowel disease (IBD) build an initial immune response to SARS-CoV-2 vaccination, but older patients, those treated with antitumour necrosis factor (anti-TNF) and an immunomodulator, and those on corticosteroids may require an additional vaccine dose to achieve better immunity against COVID-19, according to a study.

“Although mRNA-1273 demonstrated higher humoral immune responses compared with BNT162b2, it is important to recognize that both vaccines have demonstrated strong protection against severe COVID-19,” the researchers said.

“A continued emphasis on educating patients about the efficacy of SARS-CoV-2 vaccines is warranted to improve primary vaccination rates while simultaneously prioritizing patients for additional doses,” they added.

This prospective cohort study included 1,909 patients with IBD who had been immunized with SARS-CoV-2 vaccine. The researchers examined the associations between participant age, sex, vaccine type, medication use, and the presence of a detectable antireceptor binding domain antibody and quantitative antibody level.

Of the participants, 1,123 received the BNT162b2 vaccine, 692 had the mRNA-1273 vaccine, and 94 got the Ad26.COV2.S vaccine; majority of them (96 percent) achieved a positive antibody response. [Am J Gastroenterol 2022;117:462-469]

Multivariable analysis revealed the following factors to be associated with lack of antibody response: older age (p=0.043), BNT162b2 vs mRNA-1273 (odds ratio [OR], 2.1, 95 percent confidence interval [CI], 1.0–3.9), and combination therapy with anti-TNF and 6MP, azathioprine, or methotrexate (OR, 4.2, 95 percent CI, 2.4–7.3).

However, use of 5-aminosalicylate or sulfasalazine (OR, 0.3, 95 percent CI, 0.1‒0.8) and ustekinumab (OR, 0.2, 95 percent CI< 0.05‒0.8) correlated with a reduced likelihood of lacking an antibody response.

“Overall, these data provide reassurance that patients with IBD respond well to SARS-CoV-2 vaccination,” the researchers said. “Nevertheless, our findings that some patients fail to mount detectable antibodies after completion of their initial vaccination series support the recent Emergency Use Authorization in the US of additional vaccine doses in some immunosuppressed populations.”

Vaccines are effective

The findings on medication-related and other factors associated with humoral immune response may be used to guide and prioritize the use of additional vaccine doses in immunosuppressed patients, including those with IBD and other immune-mediated conditions, the researchers noted.

“Older patients, patients on combination therapy with anti-TNF and immunomodulator, and those taking systemic corticosteroids may benefit the most from additional doses of COVID-19 vaccination,” they added.

Real-word studies have demonstrated the effectiveness of both the BNT162b2 and mRNA-1273 vaccines against COVID-19‒related hospitalization in the general US population. [MMWR Morb Mortal Wkly Rep 2021;70:674-679]

However, vaccine effectiveness was partially attenuated, particularly for BNT162B2 (mRNA-1273: 76 percent, 95 percent CI, 58–87; BNT162b2: 42 percent, 95 percent CI, 13–62) due to waning immunity over time and new surges of cases associated with new COVID-19 variants. [medRxiv 2021:2021.07.29.21261317; medRxiv 2021:2021.08.03.21261496]

“Our findings of lower humoral initial immune response after BNT162b2 vs mRNA-1273 among patients with IBD are consistent with and extend these earlier studies in the general population,” the researchers said.