Smallpox vaccine: monkey, for whom, mandatory?

[Mise à jour le 30 mai 2022 à 14h19] The smallpox vaccination is back in France in the face of the emergence of cases of the virus Monkeypox responsible for the so-called “monkey pox”. L’compulsory vaccination against smallpox was completely abolished in France in 1984. The vaccine remained recommended for people who may be exposed to the virus, such as caregivers or professionals working in the laboratory. Today the contact persons at risk of a person with monkeypox in France or health care professionals exposed to the virus Monkeypox can be vaccinated with the IMVANEX vaccine and the JYNNEOS vaccine according to the decree published in Official newspaper May 26. These vaccines are used in prevention. Who invented the smallpox vaccine? To what date ? What are the vaccine contraindications ? What side effects? What is the situation in France ? What efficiency against the monkey pox ?

What vaccines are used against monkeypox?

The appearance of Monkeypox cases in several countries, particularly in Europe, and the case confirmation in France, led the General Directorate of Health to urgently contact the HAS in order to specify the vaccination strategy to be implemented to reduce human-to-human transmission of the virus. There is no vaccine against Monkeypox but the one against smallpox would be 85% efficient according to’Pastor Institute. On May 24, 2022, the HAS recommended the vaccination of contact cases to people infected with monkeypox in France, “with a 3rd generation vaccine only, ideally administered in the 4 days after at-risk contact and a maximum of 14 days later with a regimen at two doses (or three doses in immunocompromised subjects), spaced 28 days apart”. This vaccine is allowed only from 18 years old. Nowadays, it has not been evaluated in the pediatric population and the data being limited in pregnant or breastfeeding women, as a precautionary measure, it is preferable to avoid its use during pregnancy and lactation. According to the decree published in Official newspaper on May 26, two vaccines can be administered in France (same principle of action, similar efficacy): the vaccine IMVANEX (authorized in Europe) and the vaccine JYNNEOS (authorized in the United States). These two vaccines are manufactured by the firm Bavarian Nordique located in Denmark.

→ According to Santé Publique France, is considered a contact case at risk of monkeypox:

• Anyone who has had direct unprotected physical contact with damaged skin or biological fluids of a probable or confirmed symptomatic case, whatever the circumstances, including acts of medical or paramedical care, or sharing of toilet utensils, or contact with textiles (clothing, bath linen, bedding) or dirty dishes used by the probable or confirmed symptomatic case.
• Anyone who has had unprotected contact within 2 meters for 3 hours with a probable or confirmed symptomatic case (e.g. close or intimate friend, transport neighbour, office neighbour, people sharing the same place of living without intimate ties, care or hygiene act, school and university environment, sports club …).

Definition: what is the smallpox vaccine?

The smallpox virus belongs to the group of orthopoxvirus. This group includes, in addition to the smallpox virus, 3 viruses transmissible to humans, the vaccinia virus (virus that affects cows) which is used in the vaccine (similar to smallpox but less harmful). The smallpox vaccine is thus a live attenuated virus vaccine. There have been three generations of smallpox vaccines:

• 1st generation vaccine: old live attenuated replicative vaccine
• 2nd generation vaccine: old replicative live attenuated vaccine
• 3rd generation vaccine: non-replicating live attenuated vaccine (which cannot multiply in the human organism)

1st generation and 2nd generation vaccines against smallpox are not no longer used since 1984 due to the eradication of smallpox. “These vaccines required a particular injection technique (injection by bifurcated needle), showed reactogenicity and serious side effects (encephalitis, encephalopathy, eczema vaccinatum, progressive or general vaccinia, heart damage, etc.)” recalls the HAS in its press release of May 24, 2022. The Imvanex© vaccine from Bavarian Nordic said to be “3rd generation”, has a European Marketing Authorization (MA) since July 2013 and is indicated for active immunization against smallpox in adults. “It presents a mode of administration and a much more favorable safety profile than those of 1st and 2nd generation vaccines, while ensuring comparable immunogenicity.” It is marketed in the United States under the trade name Jynneos© and can also be administered in Europe against monkeypox.

When was the smallpox vaccine invented?

the English physician surgeon Edward Jenner (1749-1823) developed the first smallpox vaccine in 1796. Smallpox was the first vaccination in human history, long before Pasteur. The first smallpox vaccinations in France took place in 1799 (150,000 in 1806 to 750,000 in 1812).

Who discovered the smallpox vaccine?

the english surgeon doctor Edward Jenner discovered the smallpox vaccine.

What is the name of the smallpox vaccine?

Three smallpox vaccines have been available in France:

→ the vaccine manufactured until the 1980s by the Vaccine Institute of Doctor Pourquier: Freeze-dried smallpox vaccine from the vaccine institute of Doctor Pourquier dit “Pourquier Vaccine”

→ the vaccine produced by Sanofi Pasteur : purified and stabilized liquid smallpox vaccine called ” Aventis vaccine “.

→ The vaccine says 3rd generation authorized in Europe, Imvanex® from Bavarian Nordic. This vaccine also has marketing authorization for United States (under the name of Jynneos©). These two vaccines can be administered in France.

Do we still vaccinate against smallpox in France?

In France, compulsory vaccination against smallpox was completely stopped in 1984. But she stayed recommended for people at high risk, such as laboratory and health care personnel who work with smallpox virus or related materials. Since May 24, 2022, the HAS recommend vaccination for all people in contact with a case of monkeypox (Monkeypox). This vaccination can be carried out with the IMVANEX® and JYNNEOS® vaccines, both based on the modified live Ankara vaccinia virus and manufactured by the laboratory Bavarian Nordic.

Vaccination should be postponed in case of high fever.

Is the smallpox vaccine compulsory?

In France, vaccination against smallpox was compulsory from 1901 to 1979 remind him Ministry of Health. On this date, it was decided to no longer impose primary vaccination against smallpox (Law 79-520 of July 2, 1979) before, finally completely abolish the obligation of vaccination in 1984 (Law 84-404 of May 30, 1984) long after the occurrence of the last case of smallpox in the world (1977 in Somalia) and when all the countries adhering to the WHO also decided to stop systematically vaccinating against this disease . However, the possibility of having recourse to it has been retained thanks to a regulatory text which indicates that:in the event of war, public calamity, epidemic or threat of an epidemic, vaccination or re-vaccination against smallpox may be made compulsory by decree or by prefectural orders for anyone, regardless of age“.

What are the side effects of the smallpox vaccine?

The 1st and 2nd generation vaccines against smallpox – which are no longer authorized today – showed reactogenicity and serious side effects : encephalitis, encephalopathy, eczema vaccinatum, progressive or general vaccinia, heart attacks… They are contraindicated in many cases and especially in pregnant women, immunocompromised subjects and children under one year old. 3rd generation vaccines (such as Imvanex and Jynneos) present “a much more favorable safety profile than those of 1st and 2nd generation vaccines, while ensuring comparable immunogenicity” reassures the HAS. According to CPR vaccine Imvanexthem most commonly observed adverse reactions in clinical trials were injection site reactions and systemic reactions commonly observed after vaccination: headache, myalgia, injection site pain, injection site erythema, injection site swelling, injection site induration, injection site pruritus, fatigue. These reactions were mild to moderate in intensity and resolved without treatment within seven days of vaccination. “To note that people with atopic dermatitis developed more local and systemic symptoms after vaccination” specifies theMedicines Agency in an information note published on May 26. In a non-placebo-controlled clinical trial comparing the safety of Imvanex in people with atopic dermatitis and in healthy subjects, people with atopic dermatitis experienced erythema (61.2%) and swelling (52.2%)) at the injection site at a higher frequency than in healthy subjects (49.3% and 40.8%, respectively). 7% of people with atopic dermatitis experienced a flare-up or worsening of their condition.

What are the contraindications for the smallpox vaccine?

According to CPR from Imvanex® vaccine authorized in Europeit is contraindicated in case of hypersensitivity to the active ingredient or to any of the excipients (Trometamol / Sodium chloride / Water for injections) or to residues present in trace amounts (chicken proteinbenzonase, gentamicin and ciprofloxacin). Finally, vaccination should be postponed in the event of severe acute febrile illness (high fever).

Sources:

– Opinion No. 2022.0034/SESPEV of 20 May 2022 from the College of the High Authority for Health relating to vaccination against Monkeypox. HAS. May 20, 2022.

– Case of Monkeypox in Europe, definitions and course of action May 20, 2022. Santé Publique France.

– Use of the smallpox virus as a biological weapon. INVS, October 25, 2001.

— Smallpox Vaccine, Jun 2021, The Merck Manuals

– Smallpox Prevention and Treatment, CDC

– Opinion on the revision of the smallpox plan, High Council for Public Health, 21 December 2012

– Pastor Institute