How contagious is monkeypox? Is it necessary to take a vaccine?

Previous outbreaks in Africa have infected women, children and men of all ages. “There is no impediment. This virus will not necessarily be restricted to one gender or one population,” warns Anne Rimoin, an infectious disease epidemiologist and professor at the School of Public Health at the University of California, Los Angeles, United States. This dissemination is already underway. The WHO has started reporting cases in children, says Lewis.

Rosamund sees this as an evolving situation that should be closely monitored. “I believe this issue needs a lot of attention and a prompt reaction.”

Public awareness is critical. “The goal is not to cause panic, but awareness is needed to take precautions,” adds Lewis. “It is necessary for each person to know their own risks… and to prevent them.”

Are tests and vaccines readily available?

There are monkeypox tests available, which simply consist of taking a sample of a lesion. In the United States, the tests are then sent to a laboratory to confirm orthopoxvirus and then sent to the CDC to confirm monkeypox. After a positive result, preventive treatment of patients is started.

Despite existing testing for the infectious disease conducted in the US by the Laboratory Response Network, a collaborative effort between the US government and laboratories, activists complain of backlogs and delays in testing and results; currently, demand is concentrated in urban areas.

So far, California, New York, Illinois and Florida are the most affected states, according to the CDC. To provide more testing, the US Department of Health and Human Services (HHS) will send orthopoxvirus tests to five commercial labs.

Obtaining vaccines has been difficult, but that scenario is changing. On May 18, after the first case in the United States was reported, numbers surged and monkeypox vaccines quickly sold out. On June 28, the Biden administration announced that it would distribute 56,000 additional doses, prioritizing regions with higher transmission. Another 240,000 doses will be distributed in the coming weeks, reaching a total of 1.6 million by the end of the year.

Brincidofovir, an antiviral drug developed for smallpox, has been licensed for the treatment of monkeypox.

Should I get the monkeypox vaccine? Who is the priority target audience for vaccination?

“There is no justification for vaccinating the general population,” says Niaid’s Moss. Currently, the virus is only multiplying within a small demographic.

But amid this growing outbreak, contact tracing is no longer possible. Some countries, including the United States, have had to change planning and expand vaccination from people with known contacts to anyone at high risk.

“The inoculation is more effective if it is done before the contagion”, points out Moss. After exposure, the vaccination interval is four days, but people can be immunized up to two weeks later.

What is the difference between the two monkeypox vaccines, and when were they developed?

Edward Jenner, considered the founder of vaccinology in the West, successfully inoculated a 13-year-old boy against smallpox in 1796 using the virus. vaccinia – cowpox. Two years later, researchers developed the first smallpox vaccine. Because orthopoxviruses share 90% or more of their genetic makeup, “a vaccine made against any one of them protects against all of them,” says Moss.

Unlike the situation at the start of the Covid-19 pandemic in 2020, the good news is that there are effective vaccines against monkeypox, notes Lewis. Two are available in the United States. In 2007, the US Food and Drug Administration approved ACAM2000 to prevent smallpox.

It is similar to early vaccines of the past, using the virus vaccinia live and attenuated, and has been applied to military personnel, laboratory workers, and other groups for decades. Those who were immunized against smallpox before the end of the US vaccination campaign in 1972 must have some remaining immunity.

Current vaccines have never been tested in phase 3 clinical trials against smallpox or monkeypox. While health professionals believe that smallpox vaccines are effective against monkeypox, “this has not yet been demonstrated in rigorous studies,” notes Lewis, “or even ‘in practice’ to date.

Some groups need to avoid this live virus vaccine, including pregnant women, as immunizations can put the unborn child at risk. Immunosuppressed people or people with skin problems should also stay away from vaccines: the virus can spread uncontrollably. This vaccine can also be dangerous for people with heart problems, as it can cause coronary inflammation.

The second vaccine, Jynneos, causes far fewer side effects and is the only one approved specifically for monkeypox.

However, along with awareness and proper precautions, “vaccination is key to controlling the disease and keeping it under control,” McCollum points out.

Was this international outbreak unexpected?

Experts did not predict that monkeypox would “spread through intimate social contacts and across borders at its current magnitudes,” McCollum responds.

But there were warning signs.

In Africa, monkeypox cases began to rise after smallpox was eradicated globally in 1980 and vaccination campaigns ended: these vaccines offered cross-protection against all orthopoxviruses. As the remaining immunity waned, smallpox infections from monkeys skyrocketed, increasing 20-fold between 1986 and 2007 in the DRC.

The first outbreak in the Western Hemisphere occurred in 2003, when a shipment of exotic pets – rodents of the family Gliridae and the species Cricetomys gambianusand squirrels – from West Africa caused 47 human infections in the United States.

Subsequently, in 2018, authorities recorded an increasing number of travel-related cases. “This caught our attention,” says McCollum. “We were quite concerned that it was just the beginning.”

There were favorable environmental conditions for the start of the spread, says Lewis. She lists some factors that increase the risk of zoonotic diseases moving from wildlife to people: climate change and deforestation, which open access to the forest, the need for protein and the sale of wild animal meat in markets.

“We all share a planet,” she reiterates, and research is needed to help protect humanity and nature. “As long as we don’t have these two goals in mind, we will continue to face problems.”