It appeared like a flash: in just a few days, it has reached 16 countries. But it is caused by an ancient virus, MPXV, which has been circulating for decades and has never caused international outbreaks. Why is he attacking now? There is a hypothesis – and it is disturbing.
Last week, no fewer than 16 countries reported cases of monkeypox: Spain, Portugal, UK, Canada, Belgium, Italy, Germany, Australia, Netherlands, USA, Denmark, Switzerland, France, Sweden, Israel and Austria confirmed a total of 112 infected, and there are another 92 suspected cases – also including Argentina and Greece. All this in just a few days, with the outbreak spreading across the world like lightning. The WHO convened an emergency meeting, and said the transmission of the disease in Europe may increase in the next few weeks.
Ape smallpox is a terrible disease. It is caused by MPXV, a virus that was discovered in monkeys in the 1950s – and first infected humans in 1970 in Africa. MPXV is transmitted through physical contact with the patient’s skin, their body fluids, or objects they have touched (including sheets and towels).
Until now, the WHO works with the thesis of transmission via sexual intercourse. But would this means of transmission alone be enough to explain the emergence of the disease, almost simultaneously, in 18 countries on four continents?
A 2013 US study found that the virus stays in the air for up to 90 hours. This has led some scientists to speculate that ape smallpox could be airborne — just as common smallpox, which was eradicated in the 1980s, was.
The disease has an incubation period of 5 to 21 days, during which the victim has no symptoms. From there, she begins to experience fever, tiredness, headaches and body aches, as well as swelling in the lymph nodes (the most visible in the neck region). A few days later, sores begin to appear on the body, mainly on the hands, face, mouth and genital region. They can disfigure a person – and, if the virus gets into the eyes, cause blindness.
He can also kill. There are two variants of MPXV: the one from Congo, which kills 10% of those infected, and the one from West Africa, with a lethality of 1%. The current outbreak of apepox is caused by the second, least lethal strain.
The disease can be prevented with the common smallpox vaccine. But this vaccine can cause serious side effects, and it is not immediately available: it ceased to be part of immunization programs in the 1980s. There is also a specific vaccine for smallpox. It’s called Jynneos, and it was approved in the US and Europe in 2019.
It is a recent product, and therefore scarce – not least because, last week, the US government ordered 13 million doses from the Danish laboratory Bavarian Nordic, its manufacturer. The disease is treatable with two antivirals, tecovirimat and brincidofovir. But they are also recent (they were approved in the US in 2018 and 2021), and little available.
Will ape smallpox cause a new pandemic? If it really spreads through the air, and is as contagious as it looks, there is a real risk – not least because, as with Covid-19, it will take humanity a while to manufacture and distribute the necessary vaccines and medicines. on a global scale.
At the same time, there are three things that don’t make sense in the rise of the disease. They may point to a different scenario, in which MPXV does not become ubiquitous – but similar, or even worse, threats may appear later. Come on.
1. Why did ape smallpox reach so many countries at the same time?
The disease is endemic in parts of Africa, and has never caused a global outbreak. In July 2003, it appeared in the US – 35 people from various states contracted the disease after coming into contact with prairie dogs, a wild rodent typical of North America. These animals are believed to which are also marketed as pets, have caught the virus from animals imported from Ghana.
At the time, infected people were given the common smallpox vaccine (it is also effective after contamination, if given no more than 4 days after exposure to the virus), were kept in quarantine, and the outbreak disappeared. Most importantly, there was no transmission between humans.
Now, in 2022, it seems to be different. Ape smallpox could hardly have reached so many countries, so quickly, without direct transmission between people. It is very likely that this is happening, which is bad news. But the spread of the disease, even considering human-to-human transmission, was atypical. Some of the cases, in some of the countries, are related to each other: the first infected in the UK, for example, had been in Nigeria.
But there are also several cases, in several of the affected countries, without any geographical or causal link with the other places of infection. Another unusual thing: all 16 countries reported the cases at almost the same time, just a day or two apart.
This is not normal. In the Covid-19 pandemic, there has been a clear progression, with the virus taking weeks to reach every continent. Sars-CoV-2 has not manifested itself in the four corners of the world in a few days. But the simian smallpox virus did it.
two. MPXV is apparently identical to a strain sequenced in 2018. How to explain?
Scientists from Portugal and Belgium performed the first two sequencing (readings of the genetic code) of the virus. The sample collected in Portugal has gaps, and it was not possible to read all the DNA of the virus. In the case of the Belgian, yes – and it is identical that of a strain sequenced in the UK in 2018.
(A third sample, sequenced in the US, has some genetic differences – but that seems to be related to read errors.)
As viruses spread in nature, between animals and humans, they undergo and accumulate mutations. So it is strange that the simian smallpox virus has none. When a virus reappears in humans and brings with it an “old” genetic code, without mutations, this could be a sign that it was being kept in the laboratory and escaped. it has happened a few times.
But there is also a natural explanation for the stability of MPXV. Unlike Sars-CoV-2, which is an RNA virus (and therefore more prone to copying errors, which generate mutations), it is made of DNA. Therefore, its replication is more accurate, and it – theoretically – undergoes fewer mutations.
Could it be that, from 2018 to 2022, MPXV spread endemically across Africa – and even then did not incorporate any mutations? He can. But this thesis raises another question: why didn’t the virus spread around the world in 2018, or since then, and only started now?
3. If the virus hasn’t changed, something else may have.
Throughout the Sars-CoV-2 pandemic, several studies have been showing that it can attack the immune system. It is common for Covid patients to have reduction in the number of lymphocytes. This drop tends to follow the severity of the disease (the worse the Covid, the greater the loss), but also occurs in cases that are not severe.
In addition, tests in vitro revealed that the coronavirus is capable of directly infect CD4 subtype T cellsa lymphocyte that has two crucial functions: it coordinates the immune response and kills cells that are infected by viruses.
When the person recovers from Covid, the lymphocyte levels return to normal. But this direct action of Sars-CoV-2 on the immune system has raised the fear, in a still small part of the scientific community, that the coronavirus may cause some kind of long-term immune compromise (CD4 cells are also the main target of the HIV virus, which causes AIDS).
By compromising CD4 cells, even temporarily, Covid could make the body more susceptible to other infections, or to the reactivation of latent viruses in the body. in the pandemic, there were cases of reactivation of the chickenpox virus, mononucleosis and herpes. Patients carried these viruses but had no symptoms – which only appeared after they had Covid.
These two possibilities may explain why the simian smallpox virus, even without mutations, would have been transmitted more easily. The supposed immunosuppressive effects of Covid could make contagion easier. Or, perhaps, people who are presenting the disease already had MPXV in their body, and he didn’t do anything – but a post-Covid immune reduction has given space for the virus to multiply in the body and cause symptoms.
This would explain why ape smallpox appeared at almost the same time in so many different parts of the planet, with no visible epidemic progression. It’s a hypothesis.
The possible immunological effects of Covid, including in the long term, are not yet proven. But, if they do exist, they could have important impacts in the future. In a scenario where vaccines continue to protect against severe Covid, but are no longer able to prevent the transmission of Sars-CoV-2, almost the entire world population will sooner or later end up being exposed to the virus.
If this yields some degree of immune dysfunction, the world of the future could be very different, with the outbreak or reappearance of various infectious diseases – including those caused by viruses such as MPXV, which already existed but were not global problems.