Tonix Pharmaceuticals develops monkeypox vaccine for future by looking at past

Aug. 19—Tonix Pharmaceuticals, a company that has a research lab in Frederick, is developing a vaccine to prepare for a future where the monkeypox virus is endemic outside of Africa.

To do that, the company is looking more than 200 years in the past.

The base infrastructure that Tonix researchers use to design vaccines for infectious diseases is based on a virus called horsepox. That's the same virus Dr. Edward Jenner used when he started developing the first smallpox vaccine in 1796.

And the vaccine is still the most successful today, Tonix co-founder and CEO Dr. Seth Lederman said.

"It eradicated smallpox," he said in an interview on Thursday. "And, we also learned, it kept monkeypox out of the human population."

The reason people think monkeypox started spreading in Africa and eventually became endemic in some countries on the continent — 10, according to the World Health Organization — is because countries stopped vaccinating people against smallpox when the disease was eradicated, Lederman said.

Monkeypox and smallpox are closely related viruses. The two vaccines that have been approved for use against monkeypox — ACAM2000 and Jynneos — were initially developed for smallpox.

Tonix researchers have long been familiar with pox viruses. Similar to scientists at the U.S. Army Medical Research Institute of Infectious Diseases at Fort Detrick, they've been working on a smallpox vaccine for years in case the disease is used for biowarfare purposes.

But now that monkeypox is spreading in the U.S. — with 13,517 cases identified nationwide as of Thursday — developing more ways to keep people safe from the disease has become even more urgent, Lederman said.

So far, the horsepox-based vaccine from Tonix has only been tested on animals. But last month, the company announced it would be working with the Kenya Medical Research Institute to seek approval to start the first clinical trials of the vaccine on humans.

Tonix plans to start testing the vaccine in the first half of next year, Lederman said. And after the decision from the U.S. Department of Health and Human Services earlier this month to declare the monkeypox outbreak a public health emergency, the company plans to talk with the U.S. Food and Drug Administration about conducting a trial in America.

The company purchased a 48,000-square-foot facility last October, near Frederick Municipal Airport, to turn it into a research and development center for infectious diseases.

Although most of the work on the monkeypox vaccine has been done at the company's facility in Dartmouth, Massachusetts, Lederman said, scientists in Frederick have been helping study the horsepox virus and conducting other research to help develop and produce the vaccine.

Since COVID-19 was a new virus, it made sense that scientists used new technology when developing a vaccine to prevent it, Lederman said.

But he and other Tonix scientists don't think researchers should use the same approach with monkeypox.

"Monkeypox is not a new problem. It's a problem we actually understand," he said. "And it's a problem for which we actually have tools that are known to be able to protect populations."

The mRNA-based vaccines that millions of Americans have gotten against COVID-19 have two big weaknesses, Lederman said. They only protect people for a short period of time — that's why there are booster shots — and they don't stop people from spreading the virus if they become infected.

But live virus vaccines, like Dryvax — the vaccine that was used to eradicate smallpox — block "forward transmission," meaning they prevent people from infecting others, as well as getting sick.

The United States is currently only using the Jynneos vaccine in its response to the monkeypox outbreak. Approved in 2019 by the FDA to be used to protect people from smallpox and monkeypox, Jynneos doesn't contain live virus, meaning it's safe to be used by people with suppressed immune systems.

It makes sense why the U.S. is using the Jynneos vaccine, Lederman said. Since supply is so limited, the country is currently focused on vaccinating men who have sex with men — the population who has been most affected by the outbreak — and people who have come in contact with the disease.

According to a paper published in The New England Journal of Medicine that studied people infected with monkeypox across 16 countries between April and June, 41% were HIV positive. Getting a live virus vaccine may not be safe for them.

But, Lederman said, scientists don't know for certain whether the Jynneos vaccine will be able to protect against forward transmission.

"Its experience is really relatively limited," Lederman said. "I mean, there's been a fair number of studies. But it's obviously nothing like 120 years' experience of keeping societies and continents safe."

That's why Tonix is using live horsepox virus for its monkeypox vaccine. Although pregnant people, infants and people with suppressed immune systems would not be able to get the vaccine, they would be protected if enough of the rest of the population gets it, Lederman said.

At the rate monkeypox is spreading, it seems like it will one day become endemic outside of Africa, he said. The vaccine Tonix is creating is for that possibility.

"We are really taking the lessons of COVID and monkeypox to heart and preparing for the future," Lederman said.

Follow Angela Roberts on Twitter: @24_angier