Experts fear a new South African strain of COVID might be resistant to the vaccines

Some medical experts have been expressing confidence that the COVID-19 vaccines from Moderna, Pfizer and others will be effective against a new, highly contagious COVID-19 variant that has been slamming the United Kingdom. But U.K. Health Secretary Matt Hancock has a dire warning about a COVID-19 variant that has been spreading in coastal areas of South Africa. That variant, according to Hancock, might be resistant to the vaccines.

Hancock told BBC Radio, "I'm incredibly worried about the South African variant. This is a very, very significant problem…. It's even more of a problem than the U.K. new variant."

John Bell, an immunologist at Oxford University in the U.K., is worried as well. Bell helped develop AstraZeneca and Oxford's COVID-19 vaccine, and according to Bell, there is a "big question" mark over whether or not that vaccine and others will protect against the South African variant.

CBS News' Sarah Carter reports that Bell said it was "unlikely" that the South African variant would render the vaccines from AstraZeneca/Oxford and others ineffective, but he did say that there might need to be adjustments so that the vaccines will be as effective as possible against that variant.

Oxford Professor Shabir Madhi, who worked on the AstraZeneca/Oxford vaccine, told CBS News that more than 13 different COVID-19 variants have been identified in South Africa since the pandemic began — and the new one, 501.V2, is by far the most disturbing mutation he has seen.

Madhi warned, "It's not a given that the vaccine will not work on this variant, but it is a consideration that the vaccine might not have the full efficacy."

Human trials of the AstraZeneca vaccine as well as a Johnson & Johnson vaccine have been conducted in South Africa, and Madhi is glad that some of them were conducted after the 501.V2 variant was discovered.

"Those on our trial received the second dose during the time of this new variant, which is extremely fortunate," Madhi explained.

Glenda Gray, who serves as president of the South African Medical Research Council and headed the Johnson & Johnson trial's team, told CBS News, "It is fortunate that this timing will allow us to see whether there is any change with this new variant…. This new variant should not delay vaccine access, but it also means we need to keep our eye on breakthrough infections."

South Africa, Carter notes, has had the highest COVID-19 infection rates in Africa, and the country's minister of health, Dr. Zweli Mkhize, has said that he hopes to see two-thirds of the country's population vaccinated by the end of 2021. According to Mkhize, "We are targeting a minimum of 67% of the population to achieve herd immunity."