With 1,453 confirmed cases of monkeypox identified as of July 19, including 678 cases in Ile-de-France, 111 in Occitanie and 103 in Auvergne-Rhône-Alpes, the High Authority for Health (HAS) recommends preventive vaccination of those most at risk. What vaccine is used? What are the side effects ?
After a first opinion issued last May, which recommended the implementation of a so-called “reactive” vaccine strategy, that is to say not in prevention, but only when the person has been in contact with an infected person and when this contact is considered “at risk”, HAS has updated the vaccination strategy against Monkeypox in view of the increasing number of infections (1,453 cases of monkey pox confirmed as of July 19, including 678 cases in Ile-de-France, 111 in Occitanie and 103 in Auvergne-Rhône-Alpes). Since July 8, the High Authority for Health therefore recommends preventive vaccination of people at risk of exposure to the virus. It is primarily:
- Men who have sex with men (MSM) and trans people reporting multiple sex partners
- People in prostitution
- Professionals in places of sexual consumption, whatever the status of these places.
#Communicated | HAS updates the vaccine strategy against #Monkeypox and recommends, in addition to post-exposure vaccination around a confirmed case, preventive vaccination of the most exposed people https://t.co/EMy9WtubPA
– High Authority for Health (@HAS_sante) July 8, 2022
However, at this stage HAS does not recommend the pre-exposure vaccination of health professionals who take care of sick people, “the usual hygiene measures and the wearing of personal protective equipment making the risk of contamination very low in practice” she explains. But this exposure may be considered on a case-by-case basis, depending on the exposure, the existence of individual risk factors or at their request.
Monkey pox: which vaccine and how many doses?
There is no specific vaccine against monkeypox, but the vaccine against human smallpox is 85% effective against this orthopoxvirus infection, as pointed out by the Institut Pasteur. The HAS also recommends administering a 3rd generation smallpox vaccine marketed in France under the name Imvanex®, which is better tolerated than the 1st and 2nd generation vaccines.
The vaccine is administered in two doses (or three doses in immunocompromised people), 28 days apart. People who were vaccinated against smallpox before 1984 may request a single booster dose. The first antibodies appear after one week and we can a priori consider that there is protection against the virus after two weeks, in a significant proportion of vaccinated people.
This proportion is even greater after the second dose, thus reaching 80 to 85% protection.
>> What are the side effects? Like all vaccines, some symptoms may appear within hours of vaccination. According to the Government of Quebec website, the most common effects, which affect 10% of vaccinated people, are:
- Pain, redness, swelling, hardness, itching at the injection site
- Headache, tiredness
- Muscle aches.
13 vaccination centers in Ile-de-France
At the beginning of July, the multiplication of cases of monkeypox (or Monkeypox) in the Ile-de-France region had prompted the Regional Health Agency to transform the 7 Parisian screening centers into real vaccination centers, then to open three centers additional vaccinations in Hauts-de-Seine, Val-de-Marne and Seine-Saint-Denis.
This Monday, September 18, 3 new vaccination centers opened in hospitals in the Ile-de-France region. These are the following hospitals: AP-HP Henri Mondor (Val-de-Marne), GHSF Melun (Seine-et-Marne), CHSF Corbeil (Essonne). Centers already open:
- St. Anthony
- Saint Louis
- Raymond-Poincaré (Hauts-de-Seine)
- Avicenna (Seine-Saint-Denis)
- Kremlin-Bicetre (Val-de-Marne).
Only certain days and time slots are reserved for vaccination against monkeypox. Those concerned must therefore make an appointment before going to the hospital. But since the opening of preventive vaccination, these centers are saturated and fail to meet all the demands of people who are at risk of exposure to the virus. A dozen other vaccination centers should therefore open slots in the coming days. The list will be regularly updated on the website of the Regional Health Agency.
Monkey pox: how to know if you are a contact at risk?
Monkeypox is suspected when you have had possible exposure to the virus in the previous 3 weeks through:
- High-risk contact with a confirmed or probable case in France, or a confirmed case in another country
- Return from a trip to an African country where the virus usually circulates (Nigeria, Congo Basin-DRC) and contact with rodents or monkeys (dead or alive), bushmeat consumption
- Multiple or anonymous sexual partners, regardless of sexual orientation
- Man having sex with men
>> Vaccination after risky contact: the vaccine should be administered ideally within 4 days of risky contact and a maximum of 14 days later.
What if you have already been vaccinated against smallpox?
Smallpox vaccines were compulsory in France until 1979 (1983 for boosters). The World Health Organization (WHO) having declared the eradication of smallpox in 1980, the compulsory vaccination was then stopped. And, as the Institut Pasteur explains, it is precisely because vaccination stopped that immunity continued to decline, leaving the current population vulnerable to a monkeypox pandemic.
Several studies referenced in the HAS opinion have demonstrated the persistence of the immune response in individuals vaccinated against human smallpox in their childhood and 3 clinical trials have also shown that the administration of a dose of Imvanex® in a person who has previously received a primary vaccination with another type of smallpox vaccine confers a booster effect, even very far from this primary vaccination. The HAS therefore recommends the administration of a single dose of the Imvanex vaccine® for at-risk contact persons who received smallpox vaccination with a 1st generation vaccine before 1980.
>> In the particular case where contact persons at risk are immunocompromised patients“previous vaccination with another smallpox vaccine does not modify the vaccination schedule initially recommended in this population, i.e. 3 doses of Imvanex®” emphasizes the HAS.
Should children be vaccinated?
So far, only one case in a child less than 10 years old was registered in France. However, theDuring the epidemic which affected the United States in 2003, among the 35 laboratory-confirmed cases, 11 were children aged 6 to 18, of whom 2 developed a severe form of the disease. The HAS has also looked into the possibility of vaccinating children.
She suggests that the reactive vaccination of children under 18 exposed and possibly more likely to develop severe forms of the disease, especially the most fragile and immunocompromised. either “considered on a case-by-case basis, by specialists alone and after a strict assessment of the benefits and risks for the minor concerned, within the framework of a shared medical decision, and with the consent of the parents (or the legal guardian of the child), and of the adolescent where applicable”.
It also recommends speeding up the conduct of clinical trials in the pediatric population in order to assess the efficacy and safety of third-generation smallpox vaccines.
Are there vaccine stocks? Even though vaccination against smallpox ceased in the early 1980s, France kept stocks of the vaccine to respond to the possible reappearance of new cases, or even a new epidemic.
HAS will adapt this preliminary recommendation according to the new epidemiological and clinical data available. It also indicates that the proposed vaccination strategy is part of a more comprehensive management strategy including in particular the provision of antiviral treatments not evaluated by HAS but having a Marketing Authorization in the indication of Monkeypoxin particular for eligible children, for whom the 3rd generation vaccine does not currently benefit from MA.
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