Subcutaneous hepatitis A vaccination is as effective and may be safer for patients with bleeding disorders, according to a study by Mayumi Nakasone, MD, and colleagues.

A close-up of medical syringe with a vaccine. MarianVejcik/Getty Images

The large number of donor exposures in bleeding disorder patients who require routine use of clotting factor concentrates remains a concern with regard to the risk of virus infection. Therefore, vaccinations for viruses such as hepatitis A are recommended. Although the intramuscular (IM) route is recommended for hepatitis A vaccination, patients with bleeding disorders have been advised to avoid IM injections because of the risk of bleeding and bruising of muscles, requiring infusion of clotting factor concentrates or other blood products for its treatment, according to Dr. Nakasone of the University of São Paulo and colleagues. They assessed 78 adult and pediatric patients with blood disorders randomized to vaccination for hepatitis A either subcutaneously (SC) or IM, according their study published on Vaccine.

The study was conducted at a single hemophilia center between May 2006 and February 2017.

Among the 78 patients, 58 (74.4%) presented hemophilia A (34 of the SC group and 24 of the IM group), 13 (16.7%) hemophilia B (4 of the SC group and 9 of the IM group) and 7 (8.9%) other bleeding disorders. There were no statistically significant differences between the SC and the IM groups in patients diagnosis or sex.

A total of 38 patients had serology performed after the first vaccine dose, determining seroconversion rates of 83.3% and 90.0% for the SC and the IM group, respectively, a nonsignificant difference. After the second vaccine dose, the seroconversion rate for the SC group was 97.5% and for the IM group was 97.4%, also a nonsignificant difference.

At a median of 9 years after a second vaccine dose, antibody titers for the SC group were slightly greater than the IM group (7.6 vs. 7.4), but this was also not a significant difference. There were no serious adverse events in both groups, according to Dr. Nakasone and colleagues. And although twice as many patients of the IM group required clotting factor concentrates for adverse events, compared with the SC group (15.8% vs. 7.5%), the difference was not significant.

“Hepatitis A vaccine administered subcutaneously is as immunogenic, long-term protective, and even safer as the intramuscular route for both children and adults not only with hemophilia, but also with other bleeding disorders,” the researchers concluded.

The authors declared that they had no disclosures.

SOURCE: Nakasone M et al. Vaccine 2020;38:4162-6.