A development that challenges the health authorities. Cases of monkeypox infection are likely to accelerate on the Old Continent, warned the director of the World Health Organization (WHO) in Europe on Friday May 20. “To date, at least eight countries – Portugal, Spain, Germany, Belgium, France, Italy, UK and Sweden – have reported cases”noted Hans Kluge in a press release *, while specifying that most infections were light.
Faced with the acceleration of contamination, should a vaccination campaign be planned to prevent an evolution towards an epidemic? “If smallpox vaccines are available in the country, vaccination of high-risk close contacts should be considered after a benefit/risk assessment”said the European Center for Disease Prevention and Control (ECDC) in a statement.
Franceinfo answers five questions about a possible vaccination against monkeypox.
How is the disease transmitted?
Monkeypox, or monkeypox, is a viral zoonosis, which is transmitted from animal to human, and vice versa. People can be infected by infected rodents or primates, through a direct contact with blood, body fluids, broken skin or mucous membranes of these animals. Consumption of undercooked meat from infected animals may also pose a risk of infection.
As specified by European Center for Disease Prevention and Control, “Human-to-human transmission is primarily through large respiratory droplets. Prolonged face-to-face contact is required.” The virus can also be transmitted through skin lesions or “objects recently contaminated with body fluids or material from lesions”, continues the WHO. What makes the British Health Security Agency say that the virus is not transmitted “not easily”.
Hans Kluge, the director of the World Health Organization in Europe, notes that a majority of those infected are men who have sex with other men. The UN health agency therefore wishes to shed light on the sexual transmission of the virus among gay and bisexual men.
Are there effective vaccines?
Monkeypox cannot be cured by treatment. Symptoms of this viral infection usually disappear two to three weeks after they appear, according to the World Health Organization.
In terms of vaccines, “It has been shown through several studies that vaccination against smallpox [humaine] is 85% effective in preventing monkeypox”, underlines the WHO*. It’s about a “very good efficiency”recalls the virologist Yannick Simonin, specialist in emerging viruses, with franceinfo.
Nevertheless, the WHO recalls that the first generation of vaccines against smallpox “no longer accessible to the general public” today. Indeed, smallpox was eradicated globally in 1980, following the 1967 launch by WHO of the “Intensified Smallpox Eradication Programme”. A vast vaccination campaign spread over a decade, which enabled “all the peoples of the world” to be “freed from smallpox”.
What is the status of vaccine stocks?
Faced with the increase in these cases of monkeypox, the authorities of several countries are beginning to talk about the first vaccinations against the virus. In Spain, the Ministry of Health has thus prepared the order for thousands of doses, according to El País (in Spanish), and Canada does not rule out using its stock of vaccines in the face of these contaminations.
According to The cross, the High Authority for Health (HAS) should decide on Monday, May 23 on the advisability of the first vaccinations against monkeypox. But what is the stock status? According to the High Council of Public Health, in 2012, there were just over 82 million doses of first-generation vaccines left.
On the other hand, after the eradication of the disease, “States have been asked to destroy their stocks of viruses [nécessaires à la fabrication des vaccins] and the remaining virus stocks were entrusted to two security laboratories”the United States and Russia, according to a document from the Ministry of Health dating from 2006.
What about herd immunity?
In France, in 1979, a first law put on hold the obligation of primary vaccination against smallpox for young children, recalls Vie-publique.fr. This suspension led to the end of the vaccination obligation five years later. According to the High Council for Public Health, “the general population’s immune status against smallpox has been drastically altered with the gradual discontinuation of smallpox vaccinations”.
“It is thought that stopping smallpox vaccination allowed the virus [de la variole du singe] to emerge, especially in relatively young people who have never received the vaccine”, believes India Leclercq, researcher at the Institut Pasteur, interviewed on France Inter. “In France, the people who have benefited from these vaccines are rather those who are now over 50 years old. On a total population scale, we only have very relative protection”, adds Yves Buisson, member of the Academy of Medicine, on BFMTV.
Can we compare the situation to Covid-19?
In its press release, the European Center for Disease Prevention and Control specifies that the viral strain detected in Europe, originating from West Africa, has an average lethality rate of 3.6%. And the ECDC to specify: “The mortality rate is higher for children and young adults and immunocompromised people are particularly at risk of developing a severe form.”
Asked by franceinfo, virologist Antoine Gessain, head of the epidemiology unit at the Institut Pasteur, believes that “Vaccination does not seem to me to be, to date, justified”.
“The purpose of vaccination is to prevent contamination or serious forms of a disease. This is not the case at the moment.”
Antoine Gessain, virologist at the Institut Pasteurat franceinfo
“One of the few problems that this epidemic could possibly cause would be that this virus comes to affect immunocompromised people in large numbers”, emphasizes the zoonosis specialist.
Antoine Gessain rejects any similarity with the beginnings of the Covid-19 pandemic. “The mode of transmission is completely different, as is the severity of the disease. In addition, this virus, which is a DNA virus, is very stable.”insists the virologist, who calls for “prevention”, “with the isolation of infected people and the reduction of potentially infectious contacts”.
If the situation becomes epidemic in Europe, “we will not enter the massive vaccination scheme” like the one against Covid-19“but we can imagine a vaccination of contact cases”, continues Yannick Simonin.
* All links followed by an asterisk refer to articles in English.