Monkeypox | Why Can't We Just Mass Vaccinate With Smallpox Vaccines?

WHO says Monkeypox is a public health emergency. We already have a vaccine. But does it mean we should be using it?

Monkeypox vaccine: What do we know about it?

(Photo: iStock)

As the world continues to grapple with COVID, another virus that has made its presence felt this year is Monkeypox.

On 23 July, Saturday, the World Health Organisation announced that the ongoing monkeypox outbreak "represents a public health emergency of international concern."

India had reported its first case of monkeypox, just days prior, on 14 July, in a 35 year old man from Thiruvananthapuram in Kerala, who had recently returned from UAE.

Unexplained cases of monkeypox started popping up in part of Europe in May. And since then, 14,000 cases have been reported globally.

Moreover, we're no closer to figuring out how this virus — which is endemic in some parts of Africa — came to infect people in other parts of the world, who didn't have a travel history to these regions.

The WHO is likely to decide soon if the global outbreak is a global health emergency or not.

So what happens if monkeypox does turn out to be a global health crisis?

Do we start mass inoculate before it becomes a pandemic? We do have the vaccine already.

How much do we know about these vaccines?

FIT speaks to experts.

Monkeypox: A Known Enemy

COVID forced us to take a close, hard look at our healthcare system and gear up to fight a new, fast spreading virus.

The healthcare world managed to develop and distribute COVID vaccines in record time, despite the virus throwing us curveballs after curveballs.

Unlike COVID though, this time we know what we're dealing with. We know how it spreads, and we already have vaccines.

Still reeling from the inertia of the COVID pandemic, and a successful mass inoculation drive, the plan to go all guns blazing at the virus before it spreads out of control has been considered by some countries including the UK and the US.

Many countries started stocking and offering smallpox vaccines to high risk patients at the beginning.

But, the question remains, just because mass inoculation worked for COVID, is it suitable approach for monkeypox?

Mass Inoculation With Smallpox Vaccines May Not Be a Great Idea

"I have had the smallpox vaccine. Just because I'm 72 now. Younger people haven't had the chance to. It was given to everyone because smallpox is a deadly disease, but thank god it is gone!" Virologist Dr J P Muliyil said while speaking to FIT for a previous article.

Elaborating, Dr Muliyil explained the side effects of the vaccine are 'no joke', ranging from high fever to delirium.

These types of responses "were acceptable in those days," Dr Vineeta Bal, an immunologist and scientist at IISER-Pune, tells FIT now.

Basically, the side effects of the smallpox vaccine aren't what would be 'considered acceptable side effects now', added Dr Bal.

Take ACAM2000 - one of the two vaccines approved by the US FDA for monkeypox - for instance.

ACAM2000 is a smallpox vaccine made using vaccinia, which is a "pox"-type virus related to smallpox, but one that causes milder disease.

The vaccine isn't administered like your regular shots. Instead, a two pronged needle is dipped into the vaccine, and the skin is repeatedly pricked with quick shallow stabs.

According to the US Food and Drug Administration, the site of inoculation then forms a localised infection that looks like a red and itchy sore.

Because the vaccinia virus used here is live, it can spread to other parts of the body and multiply if the site of the inoculation is not properly cared for.

Which means overzealous inoculation could actually lead to a spread of disease where there wasn't one.

However, there are less brutal alternatives that can be safely used to vaccinate without the risk of the infection spreading.

"The other vaccine, JYNNEOS also uses the vaccinia virus, but has been modified in a way that the virus cannot replicate, and so that the local responses are even more diminished" adds Dr Bal.

With the newer vaccines being developed for monkeypox, researchers are aiming for greater safety and milder side effects.

"These vaccines are designed to be safe, but there are side effects, as with many other vaccines," says virologist, Dr Gagandeep Kang.

"Particular side effects related to these vaccines are myocarditis, encephalitis and eczema vaccinatum."

Dr Gagandeep Kang, Virologist

"Monkeypox isn't COVID. Can't Apply the Same Vaccination Approach"

We know how monkeypox behaves — at least the variants that are circulating right now.

"The diseases are different in the sense that there have already been known epidemics of monkeypox," says Dr Bal.

These small clusters of outbreaks that we are seeing seem to be spreading through intimate contact, she adds.

"The fluid in the irruption is what normally carries virus and that is what spreads it."

Vineeta Bal, immunologist and scientist at IISER-Pune

According to Dr Kang, "the risk groups such as laboratory workers who might need to work with the virus, or potentially those in contact with infected individuals might need to be vaccinated."

Would we need mass inoculation if cases keep going up?

In the near future, it doesn't seem so, says Dr Kang.

Adding to this, Dr Bal says, "it will depend on the health infrastructure of the place where you are."

If we have an efficient tracing and investigation system, then "it cannot spread like COVID" she adds.

India is also one of the last countries in the world to discontinue smallpox vaccines in the late 70s. This means, everyone roughly over the age of 45 is already vaccinated against smallpox, and by extension monkeypox.

So, until the virus starts behaving differently, world health authorities including the WHO are dissuading mass vaccinations at this point.

So, How Do You Protect Yourself?

According to the WHO, Monkeypox is usually a self limiting disease, adding, "during human monkeypox outbreaks, close contact with infected persons is the most significant risk factor for monkeypox virus infection."

They advice healthcare workers to be very careful while handling samples of infected patients.

For the rest of us who aren't at a high risk of exposure, the WHO says, 'maintain hygiene, and practice safe sex'.