Published: September 04, 2023
DOI:https://doi.org/10.1016/S1473-3099(23)00492-9
Aniruddha Hazra, MD, Jason Zucker, MD, Elizabeth Bell, MD, John Flores, MD, Leanna Gordon, DO, Oriol Mitjà, PhD, et al.
Summary
Background
Since May, 2022, a large global outbreak of human mpox (formerly known as monkeypox) has predominantly a ected men who have sex with men. The strain responsible, Clade IIb, has mutated substantially from precursors originating from the 2017–18 outbreak in Nigeria. Immunity to smallpox, another orthopoxvirus, via previous infection or vaccination provides lifelong immunity. However, since the 2022 mpox outbreak, recent clusters were described in individuals with presumed immunity through recent infection or vaccination. We aim to describe the epidemiological and clinical characteristics of mpox in individuals with past infection or vaccination to improve the understanding of this disease in the setting of previous immunity.
Methods
In this global case series, international collaborators from nine countries provided data on individuals with PCR-con rmed mpox after documented previous infection or vaccination between May 11, 2022, and June 30, 2023. We excluded cases that could not con rm vaccination status or cases with partial immunisation or any doses received before the current multi-national mpox outbreak (cuto date May 1, 2022). Data were collected via a case report spreadsheet that reported on dates of infection and vaccination, route of immunisation, demographic characteristics, clinical ndings, HIV status, concomitant sexually transmitted infections, and markers of disease severity (mpox severity score system). We describe case epidemiology, clinical course, and mpox severity scores; all analyses were descriptive.
Findings
We report mpox infections in 37 gay and bisexual men who have sex with men: seven individuals had mpox reinfections, 29 individuals had mpox infections that occurred after two appropriately spaced Modi ed Vaccinia Ankara-Bavarian Nordic vaccine courses, and one individual had an infection that met the criteria for both reinfection and infection after vaccination. The median age of individuals was 36 years (IQR 30–45; range 21–58). Those with natural immunity after initial infection had a shorter disease course with less mucosal disease upon reinfection than with their initial infection. Infections post-vaccination were characterised by few lesions, little mucosal disease, and minimal analgesia requirements; two people received oral tecovirimat. Overall, there were no deaths, no bacterial superinfections, and all individuals were managed in the ambulatory clinic with one hospital admission for a necrotising neck lesion.
Interpretation
The epidemiology of people with mpox reinfection or infection post-vaccination was similar to other published cohorts during the 2022 outbreak—predominantly young, sexually active gay and bisexual men who have sex with men. Clinical features and outcomes of repeat infection and infection after vaccination appear to be less clinically severe than those described in 2022 case literature. Speci cally, compared with the 2022 case series, these individuals in the present study had fewer con uent lesions, less mucosal involvement, reduced analgesia requirement, and fewer admissions. Natural immunity and vaccine-induced immunity are not fully protective against mpox infection. However, in this small series both disease duration and severity appear to be reduced.
DOI:https://doi.org/10.1016/S1473-3099(23)00492-9
Aniruddha Hazra, MD, Jason Zucker, MD, Elizabeth Bell, MD, John Flores, MD, Leanna Gordon, DO, Oriol Mitjà, PhD, et al.
Summary
Background
Since May, 2022, a large global outbreak of human mpox (formerly known as monkeypox) has predominantly a ected men who have sex with men. The strain responsible, Clade IIb, has mutated substantially from precursors originating from the 2017–18 outbreak in Nigeria. Immunity to smallpox, another orthopoxvirus, via previous infection or vaccination provides lifelong immunity. However, since the 2022 mpox outbreak, recent clusters were described in individuals with presumed immunity through recent infection or vaccination. We aim to describe the epidemiological and clinical characteristics of mpox in individuals with past infection or vaccination to improve the understanding of this disease in the setting of previous immunity.
Methods
In this global case series, international collaborators from nine countries provided data on individuals with PCR-con rmed mpox after documented previous infection or vaccination between May 11, 2022, and June 30, 2023. We excluded cases that could not con rm vaccination status or cases with partial immunisation or any doses received before the current multi-national mpox outbreak (cuto date May 1, 2022). Data were collected via a case report spreadsheet that reported on dates of infection and vaccination, route of immunisation, demographic characteristics, clinical ndings, HIV status, concomitant sexually transmitted infections, and markers of disease severity (mpox severity score system). We describe case epidemiology, clinical course, and mpox severity scores; all analyses were descriptive.
Findings
We report mpox infections in 37 gay and bisexual men who have sex with men: seven individuals had mpox reinfections, 29 individuals had mpox infections that occurred after two appropriately spaced Modi ed Vaccinia Ankara-Bavarian Nordic vaccine courses, and one individual had an infection that met the criteria for both reinfection and infection after vaccination. The median age of individuals was 36 years (IQR 30–45; range 21–58). Those with natural immunity after initial infection had a shorter disease course with less mucosal disease upon reinfection than with their initial infection. Infections post-vaccination were characterised by few lesions, little mucosal disease, and minimal analgesia requirements; two people received oral tecovirimat. Overall, there were no deaths, no bacterial superinfections, and all individuals were managed in the ambulatory clinic with one hospital admission for a necrotising neck lesion.
Interpretation
The epidemiology of people with mpox reinfection or infection post-vaccination was similar to other published cohorts during the 2022 outbreak—predominantly young, sexually active gay and bisexual men who have sex with men. Clinical features and outcomes of repeat infection and infection after vaccination appear to be less clinically severe than those described in 2022 case literature. Speci cally, compared with the 2022 case series, these individuals in the present study had fewer con uent lesions, less mucosal involvement, reduced analgesia requirement, and fewer admissions. Natural immunity and vaccine-induced immunity are not fully protective against mpox infection. However, in this small series both disease duration and severity appear to be reduced.