Re: 'Clinical characteristics of ambulatory and hospitalised patients with monkeypox virus infection' by Mailhe et al.

To the Editor,

We read with great interest the article of Mailhe et al. on the characteristics of patients with monkeypox virus infection in Paris (France) [1]. As underlined by the authors, there are currently no data on the profile of subjects receiving vaccination as a PrEP against Monkeypox.

We performed a cross sectional study in Hôtel-Dieu hospital, a university hospital located in Paris (France) with one of the largest vaccination capacities. The aim of the study was to assess the socio-demographic characteristics, motivations, and level of literacy of people receiving a first dose of Modified Vaccinia Ankara–Bavarian Nordic vaccine (MVA-BN, Imvanex®) vaccine.

We included consecutive patients for 7 days between July 28 and August 5, 2022, receiving a first dose of MVA-BN as a PrEP against Monkeypox following French recommendations. They were given an anonymous written questionnaire. The Research Ethics Committee of the French Infectious Diseases Society approved the study (IRB00011642).

We analyzed 263 subjects: 260 (98.9%) were men; median age was 38 years-old (interquartile range, (IQR) [30-50]) and 115/263 (43.7%) were born before 1980 (Table 1 ). Two-hundred fifty-five participants (255/260, 98.1%) identified as MSM, and median number of sexual partners within the 30 days prior to vaccination was of 3 ([2, 3, 4, 5, 6]). Two-hundred and sixteen (216/263, 82.1%) subjects had at least a Bachelor’s degree. Of note, there were 16 healthcare workers (16/263, 6.1%) in participants included, all of them were MSM having changing sexual contacts.

Table 1

Baseline characteristics and demographics of 263 patients receiving a pre-exposition (PrEP) vaccination for Monkeypox in Hotel-Dieu Hospital, Paris, France. Continuous variables are presented as medians with interquartile ranges unless otherwise stated. Categorical variables are presented in absolute numbers (percentage, %).

Characteristics	Value
Age, years	38 [30-50]
Born before 1980	115 (43.7)
Gender
Male	260 (98.9)
Female	1 (0.4)
Transgender	2 (0.8)
Occupation
Self-employed (craftsperson, shopkeeper, entrepreneur)	35 (13.3)
Manager and ‘higher intellectual profession’	132 (50.2)
Healthcare worker	16 (6.1)
Worker	10 (3.8)
Intermediate professions	26 (9.9)
Student	13 (4.9)
Unemployed	8 (3.0)
Retired	13 (4.9)
Sex worker	2 (0.8)
Don’t want to answer/Missing data	7 (2.7)
Education
Below High School Diploma	10 (3.8)
High School Diploma	33 (12.5)
Bachelor’s Degree	60 (22.8)
Master’s Degree	106 (40.3)
Above Master’s Degree	50 (19.0)
Don’t want to answer/Missing data	4 (1.5)
Men having sex with men (N=260)
Yes	255 (98.1)
No	1 (0.3)
Don’t want to answer/Missing data	4 (1.5)
Number of sex partners within the previous 30 days before vaccination	3 [2-6]
Comorbidities
Active smoking (N=250)a	61 (24.4)
Obesity (N=243)	9 (3.7)
Atopic dermatitis (N=229)	3 (1.3)
HIV	30 (11.5)
Immunosuppressive disease	4 (1.5)
Other comorbidity (N=263)	12 (13.1)
Infectious risk prevention
HIV pre-exposure prophylaxis (PrEP) user (N=261)	102 (39.1)
COVID-19 vaccine status
Fully vaccinated (valid Green Pass)	244 (92.8)
Not vaccinated/not fully vaccinated	12 (4.6)
Don’t want to answer/Missing data	7 (2.7)
Hepatitis A vaccine status
Fully vaccinated or previous infection	158 (60.1)
Not vaccinated	18 (6.8)
Unknow status/Don’t want to answer/Missing data	87 (33.1)
Hepatitis B vaccine status
Fully vaccinated or previous infection or current infection	187 (71.1)
Not vaccinated	20 (7.6)
Unknow status/Don’t want to answer/Missing data	56 (21.3)
Human Papillomavirus vaccine status (N=73 eligible)b
Fully vaccinated	32 (43.8)
Not vaccinated	41 (56.2)
Motivations to get vaccinated
“To protect myself” (I completely agree)c (N=256)	253 (98.8)
“To avoid transmission to others” (I completely agree) (N=253)	238 (94.1)
“To follow public health guidelines” (I completely agree) (N=249)	166 (66.7)
Main source of information about Monkeypox vaccination (N=236)
Mass media (television, radio, press etc.)	130 (55.1)
Relatives/friends/sex partners	53 (22.5)
Social media/websites/dating applications	34 (14.4)
General practitioners or other healthcare workers	14 (5.9)
Others	5 (2.1)
Knowledge on Monkeypox vaccine (Imvanex ®) (N=216)
Brand Name	56 (25.9)
Vaccine technology	42 (19.4)
Level of protection	80 (37.0)

(N=): number of subjects with available data.

Patients eligible for HPV vaccination in France i.e., since 2017, patients aged under 26 years-old.

Four-answer questionnaire ranking answers from “I completely agree” to “I completely disagree” (see questionnaire in Supplementary Material).

Thirty patients (11.5%) were living with HIV (PLVIH). All of them were men, had a plasma HIV RNA level below 20 copies per mL and a CD4 count above 200 per mm3. A hundred and two participants (102/261, 39.1 %) were on HIV pre-exposure prophylaxis (HIV PrEP).

Vaccination coverage was 92.8% for COVID-19, 60.1% for hepatitis A and 71.1% for hepatitis B, the last two vaccines being recommended in France for subjects at sexual risk. Compared to others participants, PLVIH and those taking HIV PrEP were significantly more frequently vaccinated against hepatitis A (69.7 % vs 66/131, 50.4% p = 0.014), hepatitis B (105/132, 79.6 % vs 82/131, 62.6%, p = 0.015) but HPV vaccination coverage was equally low (32/73, 43.8%).

The main reason for vaccination was individual protection (“I get vaccinated to protect myself”, 253/256, 98.8%), 238 (238/253, 94.1%) completely agreed with “I get vaccinated to avoid transmissions to others” and 166 (166/249, 66.7%) with “I get vaccinated to follow public health guidelines”.

The main source of information about Monkeypox vaccination was mass media for 55.1% (130/236) of participants. Fourteen (14/236, 5.9%) participants, all being PLVIH, were mostly informed by health care professionals. Most of subjects did not know the brand name of the vaccine, nor the vaccine technology, nor the level of protection. All participants who reportedly knew the level of protection declared a 85% level of protection, corresponding to previous data of smallpox vaccines efficacy against endemic Monkeypox in Africa, according to CDC [2].

Overall, participants were mostly MSM, of high social status, motivated to get vaccinated to protect themselves, though their theoretical knowledge about vaccination was limited.

We also confirm the population receiving Monkeypox vaccination as PrEP matches the one targeted by the guidelines, as well as the cohort published in the literature. Indeed, Mailhe and colleagues reported a cohort study of 264 patients with proven Monkeypox infections in France in which 262 patients (262/264, 99%) were men, 245 (245/259, 95%) were MSM and seventy-three (73/256, 29%) were PLVIH [1]. Our population, with 39.1% HIV PrEP user, and 82.1% with higher education, corresponds to a population with high intention to get vaccinated [3]. We identify a “high confidence, low literacy” vaccinee profile, confirming the importance of confidence in vaccine uptake [4].

Our work has several limitations. First, our study was led in a unique vaccination center, but to which patients from all neighborhoods in Paris were addressed. Secondly, these data were collected at the beginning of the Monkeypox PrEP vaccination campaign, and temporal changes may occur about the perception of the vaccination and/or the disease and may affect the intention to get vaccinated, particularly as vaccine scarcity is becoming an increasing problem worldwide [5].

In conclusion, this study confirm that PrEP Monkeypox vaccination campaign has been successful in France to reach the targeted population. Participants got information about vaccination mostly from mass media and were motivated by individual protection. Public health authorities should be aware of this “high-confidence, low-literacy” profile which may potentially be influenced by the contradicting data in the literature, with optimistic preliminary data from the USA and Israel, but contradictory immunogenicity data from the Netherlands [6, 7, 8]. This also may be associated with risk compensation, e.g. participants feel protected and thus stop being precautious. This emphasizes the critical role of a transparent communication on vaccine efficacy and safety, and further studies on the impact of PrEP vaccination in the outbreak dynamics.

Transparency declaration

Conflict of interest

None.

Funding

No external funding was received.

Data availability

On simple request to the corresponding author.

Authors’ contributions

Conceptualization: YK, OL; Methodology: YK, LBLN, OL; Formal analysis and investigation: YK, LBLN, OL; Writing - original draft preparation: YK, LBLN, OL; Writing - review and editing: YK, LBLN, FB, OL; Supervision: FB, OL.