Inflammatory bowel disease (IBD) patients who were fully vaccinated with the Pfizer/BioNTech or Moderna vaccines developed higher antibody titers compared to those who had taken the Johnson & Johnson vaccine, according to a new study reported in the journal Gastroenterology.

Pfizer/BioNTech or Moderna vaccines are mRNA vaccines, while Johnson & Johnson vaccine is an adenovirus vector vaccine.

The study included 353 patients with IBD and no history of COVID-19 and evaluated the differences in the antibody response among those who received J&J vaccine vis a vis those who received the mRNA vaccine. Of these, 148 had been fully vaccinated with the Moderna vaccine, 193 with the Pfizer vaccine, while 12 patients had taken the Johnson & Johnson vaccine. More than 80% patients were being treated with biologics, Janus kinase inhibitors and/or systemic corticosteroids at the time of the first vaccine. The levels of antibodies were measured at 2 weeks and 8 weeks after the second dose of the vaccine.

At 2 weeks after completion of the vaccination, all patients were found to have developed antibodies - 121 (100%), 142 (99%), and 9 (90%) patients receiving the Moderna, Pfizer and Johnson & Johnson groups, respectively, but antibody (anti-spike Ig G) levels were higher in those who had taken the mRNA vaccines (4.20 in the Moderna group vs 3.92 in the Pfizer group vs 1.96 in J&J group). Similarly, the antibody titers were also significantly higher in the mRNA vaccine recipients at 8 weeks compared with the adenovirus vector vaccine (3.72 vs 3.41 vs 2.65, in the Moderna group, Pfizer group and Johnson & Johnson group respectively).

This study demonstrated antibody levels in nearly all patients with IBD included in the trial regardless of the type of the vaccine. Although they demonstrated reduced immunogenicity with the adenovirus vector vaccine in comparison to the mRNA vaccines, the authors have cautioned that T-cell mediated immunity must also be taken into account, which was not a part of this study. Cellular immunity is an important component of the immune response to vaccines along with the humoral immunity. These findings also suggest that similar to other immunocompromised patients, the need for a booster vaccine dose in this patient group cannot be discounted.

The findings of this study are encouraging and should reassure IBD patients who may be hesitant to take the vaccine on account of their disease and different immunomodulatory treatments they could be taking for it.