Durban, South Africa — The race to vaccinate people against COVID-19 has been made even more urgent by the emergency of new, more contagious variants of the coronavirus. CBS News got rare access to a lab in South Africa studying one of the more worrying new strains of the virus, which appears to have at least some resistance to the antibodies that vaccines create in the human body to fend off the bug.

Virus hunters in the high-risk biohazard lab in Durban are hot on the trail of the mutant strain spreading at breakneck speed across South Africa. The virus has mutated to attach itself more easily to human cells, making the disease no more deadly, but helping it spread a lot more easily.

“We do believe that we are going through a new pandemic with this variant that not only transmits much faster, but that also potentially has less neutralization,” genetic scientist Tulio de Oliveira tells CBS News. 

De Oliveira discovered the new variant after observing a dramatic uptick in infections in November. His colleagues in the highly secured lab have developed a live culture of the strain to speed up their research.

Alex Sigal is a senior researcher at the Africa Health Research Institute and at Germany’s Max Planck Institute for Infection Biology. He says the new strain discovered in South Africa appears to have the ability to reduce the effectiveness of antibodies in people infected with the original version of the virus significantly. 

“Ten-fold would be conservative,” he tells CBS News, but “you can also have complete knock-out,” meaning a person’s natural defenses to the original strain of the virus could prove useless against the variant in South Africa. 

That means those infected in the first wave could have little protection from the new strain, and even more troubling, it could render some of the vaccines less effective.

“It’s clear that we’ve underestimated this virus,” he says. “On the other hand, the evidence is not there yet that vaccines will be affected, and certainly people should keep vaccinating because that’s the solution to this pandemic.”

At the country’s central lab, scientists stress that immunity is only part of the picture. Data on just how effective the vaccines are against the new strain won’t be available for a couple weeks, but in the future, vaccines may have to be tweaked every so often to protect against mutant strains — much as the annual flu shot has been for years.