Two widely anticipated new COVID-19 vaccines — from Johnson & Johnson and Novavax — appear to halt infections in places where more contagious variants are circulating, new trials show.

But there was one key exception: Each loses a significant amount of its protective power when used where the new South African variant is circulating.

The news is ominous, since the first two known U.S. cases of infection with the South African variant were reported in South Carolina on Thursday.

For the Johnson & Johnson one-dose vaccine, the efficacy rate fell from a robust 72 percent in the United States arm of the trial to 57 percent in the trial conducted in South Africa, where the highly contagious variant is driving most cases.

Still, Dr. Paul Stoffels, chief scientific officer at Johnson & Johnson, said the company plans to proceed with applying for emergency use approval in the United States. “This is the pandemic vaccine that can make a difference with a single dose,” he told The New York Times.

Novavax’s vaccine trial in Britain was far more successful than its South African trial: The company said that its initial analysis in the U.K. showed that out of 62 participants who developed the illness, 56 had received a placebo and 6 had gotten the vaccine. The more infectious British variant was found to have caused about 50 percent of the cases in that trial, Novavax said.

If those results bear out in a larger clinical trial being conducted in the United States and Mexico, which has enrolled about 16,000 out of a goal of 30,000 people, that would put the vaccine on par with the Moderna and Pfizer vaccines, which have been shown to be about 95 percent effective.

However, Novavax’s smaller trial in South Africa also found the vaccine to only have a 49.4 percent efficacy overall. The company reported that about 6 percent of the trial’s participants were positive for HIV, and for those who were not HIV-positive, the vaccine had a 60 percent efficacy.

The Novavax trials revealed another troubling fact: A third of the participants in its South African trial appeared to have already been infected with the original coronavirus and some of those people became infected again, suggesting natural immunity might not fully guard against the newly emerged South African variant.

‘Worrisome’

Novavax has said it is already in discussions with regulators in Britain about authorizing its vaccine, and that it could submit a similar application to the United States in April, when results from its U.S. trial are expected.

Other vaccine developers have been scrambling to determine whether their vaccines would remain effective against the South African variant and are designing new versions in case the virus can break through the protection provided by the shot, the Times reported.

Stanley Erck, president and CEO of Novavax, said that researchers expected the variants could change the trial results, but “the amount of change has been a bit of a surprise to everyone.”

The South African trial was relatively small — with just 4,400 volunteers — and was not designed to come up with a precise estimate of how much protection the vaccine provides, the Times reported. Still, the company said it would soon begin testing a new vaccine tailored to protect against the troubling variant.

“This is really worrisome,” Dr. Peter Hotez, a vaccine expert at the Baylor College of Medicine and the inventor of a coronavirus vaccine, told the Times. “We have to have the American people vaccinated by late in the spring or early summer to have any hope in preventing the South African and the U.K. variants from taking over.”

Another expert said vaccine makers will need to be ready to pivot with their vaccines, changing them as needed.

“This virus is throwing us curve balls every day, so I think we just need to be prepared for that and realize that the first generation of vaccines may need to be updated,” Dr. Jesse Goodman, a professor of medicine and infectious diseases at Georgetown University, told the Times.

South African COVID variant surfaces in South Carolina

Two South Carolina residents who have not traveled have been infected with the highly contagious South African coronavirus variant, state health officials reported Thursday.

The variant is perhaps the most worrisome to public health experts, because it might have some ability to evade COVID-19 antibody treatments or vaccines.

These are the first cases in the United States involving the new B.1.351 variant, and the patients’ lack of travel or a connection to one another suggests the variant is already spreading in the community, experts said.

“The arrival of the SARS-CoV-2 [South African] variant in our state is an important reminder to all South Carolinians that the fight against this deadly virus is far from over,” Dr. Brannon Traxler, interim public health director of the state’s Department of Health and Environmental Control, said in a statement. “While more COVID-19 vaccines are on the way, supplies are still limited. Every one of us must recommit to the fight by recognizing that we are all on the front lines now. We are all in this together.”

State officials did not release the names of the people infected, saying only that one is from the Low Country, along the South Carolina coastline, and one is from the northeastern corner of the state.

The B.1.351 variant, first identified in South Africa in December, is considered by scientists to be even more worrisome than the more widely publicized British variant. And earlier this week, a more infectious Brazilian variant was diagnosed in a Minnesota resident who had recently traveled to Brazil.

Public health experts had feared that the variants were already in the United States, undetected until now because of limited surveillance. Efforts are being made to ramp up surveillance through partnerships among the U.S. Centers for Disease Control and Prevention, academic institutions and private companies.

“At this time, we have no evidence that infections by this [South African] variant cause more severe disease,” the CDC said in a statement released Thursday. However, “like the UK and Brazilian variants, preliminary data suggests this variant may spread more easily and quickly than other variants.”

The B.1.351 variant also contains a key mutation that appears to allow the virus to elude the full power of antibody treatments and vaccines. At least one antibody therapy will not work against the new variant, and lab studies recently found the mutation in the variant diminishes the ability of vaccine-induced antibodies to neutralize the virus. Whether that translates into decreased vaccine effectiveness remains to be seen, but vaccine makers are already racing to make new vaccines and “booster” shots to handle the new mutations.

Moderna announced Monday it was already working to develop and begin human tests of a vaccine specific to the South African variant, as a precaution. The company will also test a third booster shot of its current vaccine, to see if boosting immunity to the original virus could protect against the variant, the Washington Post reported.

The emergence of coronavirus variants has made the campaign to vaccinate all Americans even more urgent. As of Friday, more than 26.2 million Americans have been vaccinated, while over 48.4 million doses have been distributed, according to the CDC. More than 4.3 million people have received their second shot.

A global scourge

By Friday, the U.S. coronavirus case count passed 25.8 million while the death toll passed 433,000, according to a Times tally. On Friday, the top five states for coronavirus infections were: California with nearly 3.3 million cases; Texas with more than 2.3 million cases; Florida with nearly 1.7 million cases; New York with nearly 1.4 million cases; and Illinois with over 1.1 million cases.

Curbing the spread of the coronavirus in the rest of the world remains challenging.

In India, the coronavirus case count was over 10.7 million by Friday, a Johns Hopkins University tally showed. Brazil had over 9 million cases and more than 221,000 deaths as of Friday, the Hopkins tally showed.

Worldwide, the number of reported infections passed 10.5 million on Friday, with nearly 2.2 million deaths recorded, according to the Hopkins tally.

More information

The U.S. Centers for Disease Control and Prevention has more on the new coronavirus.

SOURCES: Washington Post;The New York Times; Associated Press

Source: HealthDay