In July 2022, the ongoing monkeypox (MPX) outbreak was declared a public health emergency of international concern. Modified vaccinia Ankara—Bavarian Nordic (MVA-BN, also known as Imvamune, JYNNEOS or Imvanex) is a third-generation smallpox vaccine that is authorized and in use as a vaccine against MPX. To date, there are no data showing MPX virus (MPXV)-neutralizing antibodies in vaccinated individuals nor vaccine efficacy against MPX. Here we show that MPXV-neutralizing antibodies can be detected after MPXV infection and after historic smallpox vaccination. However, a two-shot MVA-BN immunization series in non-primed individuals yields relatively low levels of MPXV-neutralizing antibodies. Dose-sparing of an MVA-based influenza vaccine leads to lower MPXV-neutralizing antibody levels, whereas a third vaccination with the same MVA-based vaccine significantly boosts the antibody response. As the role of MPXV-neutralizing antibodies as a correlate of protection against disease and transmissibility is currently unclear, we conclude that cohort studies following vaccinated individuals are necessary to assess vaccine efficacy in at-risk populations.
In July 2022, the ongoing monkeypox (MPX) outbreak was declared a public health emergency of international concern by the World Health Organization. Modified vaccinia virus Ankara (MVA-BN, also known as Imvamune, Jynneos, or Imvanex) is a 3rd generation smallpox vaccine that was generated by serial passaging of the more pathogenic parental vaccinia virus (VACV), and is authorized as a vaccine against MPX in humans in a two-shot regimen. Up to now, there is a lack of data that demonstrate MPX virus (MPXV)-neutralizing antibodies in vaccinated individuals and vaccine efficacy data against MPXV infection. Here, we measure MVA-, VACV-, and MPXV-reactive binding and neutralizing antibodies with validated in-house assays in cohorts of historically smallpox-vaccinated, MPXV PCR-positive, and recently MVA-BN-vaccinated individuals. We show that MPXV neutralizing antibodies were detected across all cohorts in individuals with MPXV exposure as well as those who received historic (VACV) vaccination. However, a primary MVA-BN immunization series in non-primed individuals yields relatively low levels of MPXV neutralizing antibodies. As the role of MPXV neutralizing antibodies for protection against disease and transmissibility is currently unclear and no correlate of protection against MPXV infection has been identified yet, this raises the question how well vaccinated individuals are protected. Dose-sparing leads to lower antibody levels, whereas a third MVA vaccination further boosts the antibody response. Cohort studies following vaccinated individuals are necessary to further assess vaccine efficacy in risk populations and determine correlates of protection for this emerging pathogen.
Purpose
Patients with inborn errors of immunity (IEI) are at increased risk of severe coronavirus disease-2019 (COVID-19). Effective long-term protection against COVID-19 is therefore of great importance in these patients, but little is known about the decay of the immune response after primary vaccination. We studied the immune responses 6 months after two mRNA-1273 COVID-19 vaccines in 473 IEI patients and subsequently the response to a third mRNA COVID-19 vaccine in 50 patients with common variable immunodeficiency (CVID).
Methods
In a prospective multicenter study, 473 IEI patients (including X-linked agammaglobulinemia (XLA) (N = 18), combined immunodeficiency (CID) (N = 22), CVID (N = 203), isolated or undefined antibody deficiencies (N = 204), and phagocyte defects (N = 16)), and 179 controls were included and followed up to 6 months after two doses of the mRNA-1273 COVID-19 vaccine. Additionally, samples were collected from 50 CVID patients who received a third vaccine 6 months after primary vaccination through the national vaccination program. SARS-CoV-2-specific IgG titers, neutralizing antibodies, and T cell responses were assessed.
Results
At 6 months after vaccination, the geometric mean antibody titers (GMT) declined in both IEI patients and healthy controls, when compared to GMT 28 days after vaccination. The trajectory of this decline did not differ between controls and most IEI cohorts; however, antibody titers in CID, CVID, and isolated antibody deficiency patients more often dropped to below the responder cut-off compared to controls. Specific T cell responses were still detectable in 77% of controls and 68% of IEI patients at 6 months post vaccination. A third mRNA vaccine resulted in an antibody response in only two out of 30 CVID patients that did not seroconvert after two mRNA vaccines.
Conclusion
A similar decline in IgG titers and T cell responses was observed in patients with IEI when compared to healthy controls 6 months after mRNA-1273 COVID-19 vaccination. The limited beneficial benefit of a third mRNA COVID-19 vaccine in previous non-responder CVID patients implicates that other protective strategies are needed for these vulnerable patients.
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