Smallpox vaccine: recommended by the HAS, for whom?

Smallpox vaccine recommended by the HAS for whom

Faced with the confirmation of 3 cases of monkeypox in France, the Haute Autorité de Santé recommends the vaccination of contact cases. The vaccine against smallpox would be 85% effective against this form of smallpox according to the Pasteur Institute. Who invented it? When ? Is it still available in France? Mandatory ? Point.

[Mise à jour le 24 mai 2022 à 18h25] The control then theeradication of smallpox in 1980 were obtained by the widespread vaccination of the population. L’compulsory vaccination was completely abolished in France in 1984. On May 24, 2022, faced with the emergence of cases of monkeypox (more benign) in France, the Haute Autorité de Santé (HAS) recommends vaccinating contact cases with a 3rd generation smallpox vaccine (1st and 2nd generation vaccines have not been used in the general population since 1984, due to the eradication of smallpox and serious adverse effects). Several countries including France had kept stocks of smallpox vaccines and a production capacity of the traditional vaccine even after the eradication of the disease for exposed persons (caregivers for example), recalled the National Institute for Health Surveillance (INVS) in 2001. In 2006, the Ministry of Health confirmed that “France has sufficient smallpox vaccine stocks to cover the entire population if necessary”. Who invented the smallpox vaccine? To what date ? What are the contraindications of the vaccine? What is the situation in France ? Is it effective against monkeypox ?

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.

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.”

What vaccine is used against monkeypox?

The appearance of Monkeypox cases in several countries, particularly in Europe, and the confirmation of three cases 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 85% effective according to’Pastor Institute. On May 24, 2022, the HAS recommends 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 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 …).

When was the smallpox vaccine invented?

the English physician surgeon Edward Jenner (1749-1823) developed the 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 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 manufactured by Aventis-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©)

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). In 2006, the Ministry of Health reminded that “France has sufficient smallpox vaccine stocks to cover the entire population if necessary”.

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 in particular in pregnant women, immunocompromised subjects and children under one year old. 3rd generation vaccines 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 Imvanexthe 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.

What are the contraindications for the smallpox vaccine?

According to CPR of 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).

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

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