The smallpox bottles found in Merck’s laboratory were mislabeled and did not actually contain the deadly virus

Federal health officials reveal that the vials, labeled as “smallpox,” found in a freezer in a Philadelphia laboratory do not contain any traces of the deadly virus.

The Centers for Disease Control and Prevention (CDC) said Thursday that tests showed the bottles contained “vaccinia, the virus used in the smallpox vaccine” and not the variolavirus that causes smallpox.

The vials were “accidentally found by a lab worker” who wore gloves and a face mask to clean the freezer on Monday night.

There were a total of 15 vials, five of which were marked “smallpox” and the other 10 were marked “vaccinia”.

Smallpox was eradicated in a successful mass vaccination campaign in 1980, killing an estimated 300 million people in the 20th century alone.

Samples of the deadly virus are to be stored in only two laboratories: the CDC headquarters in Atlanta and the Vector Institute in Koltsovo, Russia.

The CDC says the bottles found at Merck’s lab in Philadelphia were incorrectly labeled “smallpox.” Pictured: Bottle of smallpox vaccine in 2003

According to the federal authorities, the vials contain “vaccinia, the virus used in the smallpox vaccine” and not the variolavirus that causes the smallpox. Pictured: CDC headquarters

The discovery was reportedly made at Merck's Upper Gwenydd plant outside Philadelphia

The discovery was reportedly made at Merck's Upper Gwenydd plant outside Philadelphia

The discovery was reportedly made at Merck’s Upper Gwenydd plant outside Philadelphia

Mark O’Neill, a spokesman for the Pennsylvania Department of Health, told the New York Times that the bottles were found at the Merck facility in Montgomery County.

It was not clear why the bottles were in the freezer.

The CDC said it was “in close contact with state and local health authorities, law enforcement agencies and the World Health Organization.”

The finding was first reported by Yahoo News, which received a copy of the “For Official Use Only” alert sent to Homeland Security.

What is smallpox and how does it spread?

Smallpox is a serious, life-threatening disease caused by the variolavirus.

A person may not show or feel ill for 7 to 14 days after exposure, but it must first symptoms include high fever, headache, back pain and vomiting.

About a third of those who die of the disease die.

After the first symptoms, a body-wide rash appears. The person is most contagious at this point.

The rash develops on the tongue, mouth and throat. They then spread to the face and arms, body and feet.

Wet-filled bumps, also called pustules, form and begin to start and fall within about 10 days.

It spread mostly over a long period of time due to airborne particles in the face. The virus also spread by distributing sheets, towels and clothes.

Source: Cleveland Clinic

Once found, the bottles were immediately secured and the facility placed in a lock that was removed on Wednesday night.

“Merck is currently investigating why it was there,” the source told NBC10 on Wednesday.

Merck did not respond immediately to DailyMail.com’s request for comment.

“There are no indications that anyone has been exposed to a small number of frozen vials,” a CDC spokesman told Yahoo.

“Frozen bottles marked ‘Smallpox’ were accidentally found by a laboratory worker while cleaning the freezer at a facility that conducts vaccine research in Pennsylvania.

The discovery was made at the Merck Upper Gwynedd plant in North Wales, about 50 miles northwest of Philadelphia, according to the WCAU.

“The CDC, its administrative partners and law enforcement are investigating the matter, and the contents of the bottles appear intact. The lab worker who found the bottles wore gloves and a face mask. We’ll provide more information when available,” the spokesman said.

The case is likely to raise new questions about what should be done about the world’s smallpox samples, which are only stored in two laboratories in the world.

Smallpox is an infection caused by the variolavirus. According to the CDC, patients develop a fever and a distinctive, progressive rash.

Most Americans have not been vaccinated against the disease, and those who are likely to have declining immunity, meaning the outbreak could have devastating consequences.

The vaccine leaves a penny-sized lesion that gradually forms a scab and leaves a scar, the CDC says. The lesion is contagious before the scab forms, and those who receive it must protect the vaccination site from other parts of the body and other people.

The FBI and CDC are investigating Tuesday's findings.  Smallpox is to be stored in only two laboratories in the world: the CDC in Atlanta and a state-owned laboratory in Russia.

The FBI and CDC are investigating Tuesday's findings.  Smallpox is to be stored in only two laboratories in the world: the CDC in Atlanta and a state-owned laboratory in Russia.

The FBI and CDC are investigating Tuesday’s findings. Smallpox is to be stored in only two laboratories in the world: the CDC in Atlanta and a state-owned laboratory in Russia.

In 2014, a government scientist cleaning an old storage room at the National Institutes of Health in Bethesda, Maryland – just outside of Washington DC – found six decades-old glass bottles containing freeze-dried smallpox, according to the Washington Post.

The samples were packed and forgotten in a cardboard box. At the time, it was the first such discovery in the country.

In 2019, an explosion in a state-owned Russian laboratory with some samples sent one worker to the hospital, although according to the World Health Organization, the explosion did not occur near warehouses, according to the NPR.

Earlier this month, Microsoft founder and philanthropist Bill Gates said the U.S. and the UK should invest “tens of billions” in virus research, including how to prevent the spread of smallpox attacks in places like airports, according to Yahoo News.

“So alongside the climate message and the ongoing battle with poor diseases, I talk a lot about pandemic preparedness,” he said in an interview with British health policy officer Jeremy Hunt.

How was the deadly virus that killed about 300 million people in the 20th century finally destroyed?

The disease causes pus-filled bumps or pustules that cover the body.  An unknown man with smallpox in an undated photo above

The disease causes pus-filled bumps or pustules that cover the body.  An unknown man with smallpox in an undated photo above

The disease causes pus-filled bumps or pustules that cover the body. An unknown man with smallpox in an undated photo above

The origin of smallpox is unknown, but the earliest written description of a similar virus appeared in China in the 4th century.

It has typically been involved in outbreaks, and European settlers brought it to North America in the 17th century.

About a third of those infected died. Survivors were sometimes left with various scars or even blind.

The “Basics of Vaccination” began in 1796 when English physician Edward Jenner discovered that dairy girls who contracted cowpox were also protected from smallpox, according to the CDC.

In the 19th century, the virus used to make the smallpox vaccine was transformed from a vaccine into a vaccinia virus. (Five of the fifteen vials found in Philadelphia on Tuesday were labeled “vaccinia.”)

Prior to vaccination, variolation was a common way to protect against the virus. People who had never had smallpox took material from the pustules of infected people and scratched it in their arms or inhaled it through their nose to develop immunity.

Smallpox killed about 300 million people in the 20th century before it was eradicated by a mass vaccination campaign.  The boy above was vaccinated in New York in 1938

Smallpox killed about 300 million people in the 20th century before it was eradicated by a mass vaccination campaign.  The boy above was vaccinated in New York in 1938

Smallpox killed about 300 million people in the 20th century before it was eradicated by a mass vaccination campaign. The boy above was vaccinated in New York in 1938

In 1948, the virus infected about 50 million people a year worldwide, according to the WHO.

Experts estimate that the virus killed about 300 million people in the 20th century.

Soviet scientist Viktor Zhdanov proposed a four-year global vaccination campaign starting in 1959, and the campaign gained worldwide momentum from U.S. funds in 1966 and 1967 through the Intensified Eradication Program.

“Laboratories in many countries with smallpox on a regular basis were able to produce more, higher-quality freeze-dried vaccines,” the CDC notes.

“Other factors that played an important role in the success of the intensified efforts were the development of a double-pronged needle, the establishment of a case monitoring system, and mass vaccination campaigns.”

The last known natural occurrence occurred in 1977 in Somalia. The last natural outbreak in the United States was in 1949.

By 1980, the WHO had declared the disease eradicated.

Currently, most Americans are not vaccinated against the disease, and those who are likely to have a weakened immune system, according to Yahoo News.

Sources: World Health Organization, US Centers for Disease Control

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