Mississippi has its first confirmed case of the B1351 variant of COVID-19, which has shown strong antibody resistance and likely circumvents the immunity gained after natural infections. The new strain, sequenced in a patient in Harrison County this week, is popularly known as the South African variant.
Health leadership explained that, compared to the standard variant of COVID-19, B1351 is more infectious, equally deadly and shows strong evidence of antibody resistance. Antibodies are one mechanism of natural and acquired immunity, through surviving an infection or receiving a vaccination.
The Mississippi State Department of Health’s contact tracing for the case is ongoing. No known out-of-state travel is confirmed for the individual, meaning it could have been acquired in Mississippi. Previously, B1351 cases were detected in Tennessee, Georgia, Florida and Texas.
An accurate understanding of the relationship the new strain has with the currently available vaccines is critical. The best available data, from the Johnson & Johnson clinical trials in South Africa, show that while there is some evidence of slightly less protection against transmission and mild-to-moderate cases of COVID-19, 28 days after vaccination, no cases resulted in hospitalization or deaths.
In simple terms, this means that while one is more likely to catch a mild case of B1351 after vaccination than they are to contract the original strain of COVID-19, strong clinical evidence suggests that full vaccination still prevents the worst outcomes, like ventilation or heart failure.
“It encourages us to get vaccinated,” State Health Officer Dr. Thomas Dobbs said. “But it also reminds us that we’re not out of this.”
Byers stressed that the immediate goal of the vaccine campaign was to “limit our morbidity and mortality from this virus,” which all available vaccinations have proven immensely effective at accomplishing. Because the Pfizer and Moderna trials took place before the widespread emergence of the B1351 variant, public health experts do not have the concrete data that Johnson & Johnson’s extensive South Africa study provided.
Preliminary studies have revealed relatively similar reductions in neutralizing antibodies when examining the effect of the Pfizer and Moderna vaccine on the B1351 strain. However, these antibodies are only one of several immune reactions that the vaccine generates. With comparative trials showing Pfizer and Moderna’s mRNA vaccine is overall even stronger than Johnson & Johnson’s formulation, there is solid reason to expect that the latter’s extreme success at preventing the worst outcomes will be replicated in the other available vaccines.
Much more concerning to experts than the new variant’s interaction with vaccines is its strong resistance to natural antibodies. One of the defining features of the B1351 variant is what is referred to as the E484K mutation, which strengthens the “spike” that lets the virus penetrate human cells, and gives it its crowned shape.
This also threatens the effectiveness of some of the best available treatments for those with severe cases of COVID-19. “We see that there’s some reduced effectiveness in some of the treatments, such as the monoclonal antibodies, to the South African variant,” Byers said.
At multiple times, Dobbs stressed the danger that still remains ahead in the pandemic. “We (still) see this transmission occurring in the community. We need to make sure that we do simple stuff to protect the vulnerable: to protect our families,” he said.
“Get vaccinated. Get protected now. We’re not out of the woods yet,” Dobbs added.
“Now’s not the time to give up,” Byers said.