Experts have warned that the deadly smallpox virus, which claimed an estimated 500 million lives in the 20th century, could be a potential trigger for a future pandemic.
Experts have pointed out that the world has become more vulnerable to outbreaks of viruses from the Orthopoxviruses family, to which smallpox belongs, after the eradication of smallpox itself, which killed an estimated half a billion people in the twentieth century.
The cessation of mass vaccination against smallpox, also known as variola, which the World Health Organization declared eradicated in 1980, has led to a decline in herd immunity against similar viruses.
Scientists explained that this immune gap allows viruses such as monkeypox and camelpox to occupy the space left by smallpox, potentially becoming the source of a new global pandemic.
Dr. Raina MacIntyre, a global biosecurity expert at the University of New South Wales in Sydney, told The Telegraph: “Before smallpox was eradicated, people were frequently exposed to the virus and there were mass vaccination campaigns that led to more broad basic protection against orthobox viruses. But the world’s population is, at the moment, vulnerable to any emergence of an orthobox virus, because we have no immunity. Monkeypox has the potential to cause a pandemic, and we have seen other orthobox viruses emerge in the last 10 to 15 years, such as smallpox.”
Monkeypox is a major concern, especially after the outbreak of a new, more deadly strain called Clade 1b, which was first detected in late 2023 in the Democratic Republic of Congo and several neighboring African countries, such as Burundi, Rwanda, Uganda, and Kenya. Travel-related cases have also been reported in the UK, the US, and India. This strain has resulted in at least 1,000 deaths, mostly children under the age of 15.
At that time, the World Health Organization (WHO) declared a public health emergency of international concern, the same classification that the WHO gave to COVID-19 in late January 2020, just a few weeks before the virus spread around the world.
Although monkeypox is not as easily airborne as the coronavirus, which may limit its global spread, orthobox viruses are considered among the highest health threats, and their potential to cause the next pandemic is considered "moderate." Current preventative measures, while in place, face challenges: stockpiled smallpox vaccines may offer some protection, but they have not been extensively tested against the new, more virulent strain, and scaling up their production to large quantities will take time.
Professor Mallocker de Mots, a virologist at the University of Surrey, told The Telegraph: "The Orthobox outbreak is not an immediate emergency like Ebola or Covid-19, against which we had nothing when they first emerged, but the countermeasures we have are far from foolproof."
Thus, this warning highlights a historical paradox: the great medical triumph of eradicating smallpox has unintentionally exposed humanity to an increased risk from other viruses of the same family, in a world that has lost its collective immunity against them, calling for global vigilance and proactive medical preparation.
