Monkeypox already has confirmed cases in Spain and many countries are taking measures to prevent its spread. In this context, vaccines against the “conventional” version of the infection have once again come to the fore. We know that this serum is capable of combating the disease we are now fighting with some efficacy. The problem is that, with smallpox eradicated in the 1970s, the vaccine was discontinued in the following decade. This has led some to recover an article published in 1988 that warned us of the risk of this situation occurring.
What did they say in the 80s?
The article was published in the magazine International Journal of Epidemiology by a team of three scientists from the London School of Hygiene and Tropical Medicine. The group of experts had been analyzing the cases of this disease in Zaire (now the Democratic Republic of the Congo) during the five-year period 1980-85.
The analysis concluded that the smallpox vaccine offered 85% protection against the monkey variant. At the time the article was published, the disease was considered eradicated and the serum was not administered to newborns. Therefore, the scientists warned that as the proportion of the population immunized decreased, “the average magnitude and duration of monkeypox epidemics” would increase.
Prophecy fulfilled.
The WHO announced in 1979 the eradication of smallpox after a period without observing cases. With the disease eradicated, vaccines were no longer necessary, so in 1980 they were no longer administered to the general population (but not to laboratory personnel susceptible to contracting it when studying it).
This implies that older people are the ones who are most protected against monkeypox, both in Spain and in the rest of the world. Moreover, the situation continues to change and will continue to do so over the years, with an immunized population progressively older and smaller in number. Despite the lower infectivity of the monkey variant in humans, the authors conclude from all this that the emphasis to prevent the spread of the disease is control and surveillance in endemic areas, not necessarily through vaccination.
Return to the future.
If the first warnings about the possible effects of this infection in the “post-vaccine era” date back to the late 1980s, you don’t have to look far back to find the latest ones. In an article published in February of this year, an international team reviewed how the epidemiology of this disease had changed.
Reviewing various studies, the team noted an increase in the mean age of monkeypox patients, which was expected given demographic changes and the cessation of vaccination. Perhaps more worrying is one of the studies they cite, which, through mathematical models, estimates that the R0 factor of the monkey can exceed the value of 1 with low levels of immunization.
Without ruling out epidemics.
This means that the virus has the capacity to create epidemics, but as the Covid pandemic has taught us, the ease of contagion of a disease depends on many factors and calculations must be constantly adjusted. For all this, it is not surprising that the authors of this new study agree in recommending the control and surveillance of a disease that will not cause the havoc that smallpox caused, but it is not without risks.
The purchase of vaccines begins.
The Spanish authorities have already proposed the purchase of a number of vaccines with which to immunize close contacts of infected people. Not the only country to stock up on doses to deal with this new threat, the UK recently offered these serums to its healthcare professionals. The United States has already bought millions of units after detecting the first case in Massachusetts. One advantage of these vaccines is that they can be useful even for people who have already been exposed to the disease.
