The Centers for Disease Control and Prevention has approved a Biosafety Level 4 laboratory to operate on Boston University's medical campus in the South End, according to the Boston Public Health Commission.
Scientists in the National Emerging Infectious Diseases lab would have clearance to study the world's deadliest pathogens, such as Ebola. The biolab still needs to win approval from the city's health commission before that research can begin.
"It's an important step; we're excited that they have recognized the quality of our people and facilities, but we still need to wait on the rest of the process," said Ronald B. Corley, the lab's director.
The spread of Ebola and, more recently, the Zika virus, has shown how quickly pathogens can travel around the world, Corley said — and there are some we have not even discovered.
"This isn't a closed circle. There are many pathogens out there that, as we encroach on the wilderness areas and forests, as we change the environment, we're going to run into more and more," Corley said. "Every little bit we learn helps us solve the problems for the next one."
The Boston Public Health Commission said in a statement that it has been reviewing safety plans and procedures at the lab since 2013.
The commission "will continue to carry out a rigorous review process of National Emerging Infectious Diseases Laboratories' application, including a review of safety and security protocols and an ongoing monitoring and inspection program to ensure that the Level 4 laboratory can operate safely prior to issuing any permits," the commission said.
The biolab, built with a $200 million federal grant the university obtained in 2003, has been the subject of fierce opposition and failed lawsuits from those who fear that research on deadly organisms for which there are no vaccines or treatments is too dangerous for a densely populated area.
Longtime civil rights leader Mel King, who was a plaintiff along with his wife in an unsuccessful federal lawsuit attempting to block the biolab, said Saturday he was determined to fight to keep the Boston commission from approving the lab.
"We have to take it to the next level," King said. "I think it's an incredibly disastrous thing to put on any community.
"There are lots of places where there aren't people around where they could do that,'' he said "But when you get people ego-tripping, they don't care about what happens to other people."
King, a South End resident and former mayoral candidate, said he would consider another lawsuit, or protests, though he said any efforts to block the biolab had to be organized after careful conversation with other opponents.
The biolab is on the Boston University Medical Campus along Albany Street.
"Basic research, I think, on some of these very dangerous pathogens has to be done. But the center of an urban environment is not the place to do it," said another biolab opponent, Lynn C. Klotz, a Gloucester resident and senior science fellow at the Washington, D.C.-based Center for Arms Control and Non-Proliferation.
But Corley said that a four-and-a-half-year risk assessment study had proven the site was safe. And the location — at the center of a network of scientists, doctors, researchers, and academics — allows for the easy collaboration required to study such complicated pathogens.
"Pathogens evolve. Pathogens give us surprises," said Corley. "One of the advantages of having a facility like this at BU is, it's a research-rich university that has a lot of people who would not think about emerging infectious disease, but who have the expertise and talent to help us to solve the most vexing problems we face."
City Councilor Timothy McCarthy said the decision to put the biolab in the South End had been discussed for more than a decade by city leaders and biolab experts, and he was sure that researchers will be able to safely and efficiently perform Level 4 research there.
"I am very confident that Boston University and this biolab is going to bring scientists and engineers and researchers from around the world and that it's an absolute positive for Boston," he said. "Boston University has done a great job of dotting their i's and crossing their t's."
McCarthy said his constituents in District 5 in Hyde Park and Roslindale have not voiced any major concerns about the research being done there.
The councilor also convened an independent group of researchers to analyze the impact of the lab, and they all encouraged him to support it.
"This is a city that is growing. This is a city that people want to be at," he said. "This is just one more reason to come here."
Scientists at the biolab have been performing Biosafety Level 3 research since January 2014, according to its website. They had been conducting Level 2 research since early April 2012.
The Boston Public Health Commission will review many aspects of the proposed biolab, including its safety manual, risk management plan, disease surveillance plan, and evacuation and emergency response plans.
If the Level 4 research is approved, the commission said in its statement, it will work with city, state, and federal agencies to ensure that all research conducted there complies with "all applicable regulations" to protect the health and safety of workers and residents.
Each research project will have to be approved by the Boston Biosafety Committee.
Boston Mayor Martin J. Walsh said in a statement that he will focus on ensuring the city is safe but did not say whether he supported or opposed the biolab.
"The well-being of our residents is my top priority and I will continue to work closely with the Boston Public Health Commission as they continue their process to ensure that the right safety and training procedures are in place before issuing any permits," Walsh said.
Felice J. Freyer of the Globe Staff contributed to this report. Evan Allen can be reached at firstname.lastname@example.org. Follow her on Twitter @evanmallen. Felicia Gans can be reached at email@example.com. Follow her on Twitter @FeliciaGans.