Numerous federal agencies have begun to investigate 15 vials, five of which were alarmingly labeled’smallpox’. They were found at a Philadelphia-based pharmaceutical laboratory Tuesday night.

According to the Centers for Disease Control, the vials were found by a worker in a laboratory while he was clearing out a freezer.

After it had killed 300 million people worldwide in 20th-century, smallpox was eliminated in 1980 by a mass vaccination campaign.

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

Now, the FBI and CDC investigate Tuesday’s finding.

Fifteen vials, five labeled 'smallpox,' were discovered at a Pennsylvania lab Tuesday night. Above, a bottle of the smallpox vaccine in 2003

A Pennsylvania laboratory discovered fifteen vials of smallpox vaccine Tuesday night. Five were labeled as’smallpox’. Above is a smallpox vaccine bottle from 2003

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

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

The FBI and the CDC are investigating Tuesday's findings. Smallpox is only supposed to be stockpiled in two labs in the world: the CDC in Atlanta and a state-owned lab in Russia

On Tuesday, the FBI and CDC were notified of these findings. Two labs around the world are supposed to have smallpox: The CDC in Atlanta, and a Russian state-owned laboratory. requested comment but the two agencies didn’t immediately reply. 

The finding was first reported by Yahoo News, which obtained a copy of an alert sent to the Department of Homeland Security labeled ‘For Official Use Only.’ 

We don’t know how these vials got to the Merck facility, Montgomery County, Pennsylvania.

How does smallpox spread and what is it? 

Smallpox is a serious, life-threatening illness causes by variola virus.

For 7-14 days, a person might not feel or look sick after being exposed. However, initial symptoms may last for up to seven days. High fever, high blood pressure, headaches, backaches and vomiting are some of the symptoms.

About a third dies from the disease. 

The body develops a rash that covers the entire body after initial signs. This stage is when the person becomes most infectious.

The tongue, throat and mouth can develop rashes. These rashes then spread to face, arms and legs.

The pustules (pus-filled bumps) form over time and scab over over time. They usually fall off in about 10 days.

It was mostly spread by prolonged face-to-face due to respiratory particles. It was also transmitted by the sharing of sheets, towels, and clothes.     

Source: Cleveland Clinic 

They were immediately taken into custody and locked the place down. The lockdown was lifted on Wednesday night.

NBC10’s source said that Merck was still trying to figure out the reason it was there. asked Merck to comment but did not receive a response immediately.

Yahoo! reported that there is no evidence anyone was exposed to small quantities of frozen vials. 

“The Smallpox vials, which were frozen in small quantities in Pennsylvania, were discovered accidentally by a lab worker as he was cleaning out a freezer at the Pennsylvania facility for vaccine research.

According to WCAU, the discovery was made at Merck Upper Gwynedd in North Wales about 30 miles north of Philadelphia. 

The vials are still intact and the matter is being investigated by the CDC and its Administration partners. Laboratory worker who found the vials was covered in gloves and wearing a mask. “We will give you more information as soon as we have them,” the spokesperson added. 

This incident will likely raise questions regarding what to do with world Smallpox specimens, which are currently kept at two laboratories around the globe. 

Smallpox is an infection caused by the variola virus. According to the CDC patients will experience a mild fever with a progressive, distinctive skin rash.  

People aren’t vaccinated for the disease in large numbers. Those who do have some immunity may have diminished protection. A potential outbreak can have severe consequences.  

The CDC states that the vaccine creates a tiny lesion about the size of a dime. This gradually develops into a scab, and eventually leaves a scar. It is possible to spread the disease from the vaccine site before it forms.

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

These samples were stored in a cardboard container and then forgotten about. This was the country’s first ever such discovery. 

One worker was injured in an explosion that occurred at a state-owned Russian laboratory holding samples. NPR reports that the World Health Organization stated the blast did not occur close to stockpiles.  

According to Yahoo News, Bill Gates, Microsoft’s founder and philanthropist, stated earlier this month that the US and UK should spend ‘tens to billions’ on virus research. This includes how to prevent smallpox attacks in areas like airports. 

In an interview, he stated that pandemic preparedness was something he would be discussing a lot with British health policy officer Jeremy Hunt.

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

The disease causes pus-filled bumps, or pustules, the cover the body. Above, an unidentified man with smallpox in an undated photo

This disease can cause pustules (pustules) that cover your body. Unidentified male with smallpox, in an undated picture

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

This plant has proven to be effective in preventing outbreaks. It was first introduced to North America in the 17th Century by European settlers.

Around a third died from the disease infected. Sometimes, those who survived had multiple scars and even went blind.

The ‘basis for vaccination’ began in 1796 when English doctor Edward Jenner noticed that milkmaids who had gotten cowpox were also protected from smallpox, according to the CDC.

Smallpox was first made from vaccinia viruses in 1800s. On Tuesday, five of 15 vials that were found in Philadelphia had been identified as vaccinia.

Variolation was an effective method to protect against the disease before vaccines were developed. To develop immunity, people who have never been infected with smallpox ingested material from infected persons and scratched their arms or inhaled the pustules. 

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

Before mass vaccination campaigns eradicated smallpox, it killed approximately 300 million people. Above: A boy in New York is being vaccinated against smallpox in 1938

The WHO estimates that the virus infected approximately 50 million people per year worldwide by 1948. 

Experts believe that around 300 million people died from the virus in the 20th Century.

Soviet scientist Viktor Zhdanov proposed a four-year global vaccination campaign starting in 1959, and the campaign got a global boost aided by US funds in 1966 and 1967, with the Intensified Eradication Program.

According to the CDC, “Laboratories located in many countries that have smallpox are able more efficiently to make freeze-dried vaccine of higher quality,” 

“Other important factors in the success rate of the intensified effort included the development and use of the bifurcated, case-monitoring system, mass vaccination campaigns, as well as the introduction of the bifurcated needle.

Last known natural case was in 1977 in Somalia. It was 1949 that the US experienced its last natural epidemic. 

In 1980, WHO declared the illness eradicated.

According to Yahoo News, the majority of Americans have not been vaccinated for the disease, and even those who are are likely to be weakened immunity. 

Sources: World Health Organization, US Centers for Disease Control