H.Health officials have identified the first U.S. cases of Covid-19 caused by a rapidly spreading form of the coronavirus that was originally observed in South Africa in two people in South Carolina.
Neither person has ever traveled to countries where the variant has been confirmed and there is no link between the two, South Carolina health officials said Thursday. This indicates that the variant began to spread locally after it arrived in the United States. One case was found in the Pee Dee area of South Carolina and one in the Lowcountry.
Thursday’s announcement means three coronavirus variants that appear more contagious and have emerged in recent months have all been documented in the United States. But in some ways the news came as no surprise to experts. They had said for weeks that the variant that first appeared in South Africa, called B.1.351, was likely already in the US, but that country’s limited surveillance system for different iterations of the coronavirus meant the variant likely went unnoticed after import a traveler and could even have spread.
Earlier this week, Minnesota health officials confirmed the first Covid-19 case caused by P.1, a variant first identified in Brazil. There have been a few hundred US cases of variant B.1.1.7 that originally occurred in the UK.
It is believed that all three variants are more transmissible than previous forms of the coronavirus and, if not activated, can lead to more cases overall by infecting more people faster. The Centers for Disease Control and Prevention has estimated that B.1.1.7 could become the dominant form of coronavirus in the United States by March.
“It’s important that we all continue to do our part by taking small steps that make a big difference,” Brannon Traxler, interim director of public health for South Carolina, said in a statement. “This includes wearing our masks, staying at least two meters away from others, avoiding large crowds, washing our hands, having frequent tests and, if we can, vaccinating. These are the best ways to prevent the virus from spreading, regardless of the strain. “
The three variants evolved independently – all viruses mutate and occasionally pick up changes that give them a transmission advantage – but happen to share some of the same mutations.
In particular, B.1.351 and P.1 have triggered different alarms than B.1.1.7. Studies have shown that mutations that occur in both variants can help the virus partially bypass the human immune response, potentially making it more likely that the variants can re-infect people who have had a first case of Covid-19.
Such studies raised concerns that existing Covid-19 vaccines – based on previous iterations of the virus – may not be as effective against the variants.
For example, on Thursday Novavax said its experimental Covid-19 vaccine was 90% effective in a study in the UK but 49% effective in a separate study in South Africa. Of the cases in the South Africa study for which sequencing data were available, 93% were caused by B.1.351.
Other vaccines made in different ways may have less of a decline in effectiveness, although more studies are ongoing. In the mRNA vaccines from Pfizer-BioNTech and Moderna, the shots against some of the mutations observed in P.1 and B.1.351 seem to lose some of their neutralizing effect, but the immune response triggered by the vaccines is also predominantly powerful that the Being able to withstand a loss of some oomph while protecting people from getting sick with Covid-19 at the same time.
On Monday, Moderna said his shot against B.1.351 should still be effective, even though the neutralizing antibodies produced by the vaccine do not recognize the shape of the virus as well as other forms. Essentially, the antibody response induced by the shot should still be enough to help people fight Covid-19. However, the question arises as to whether the immune response of the vaccines against the variants will last as long as previous viral iterations.
So far, studies examining the effects of variants on Pfizer and Moderna vaccines have largely focused on neutralizing antibodies. However, experts note that the shots also bring together other parts of the immune system – including T cells, B cells, and other types of antibodies. Provide additional reasons that the current vaccines should continue to work largely against the variants.
However, experts believe that one day the coronavirus could pick up a certain set of mutations that threaten the overall effectiveness of the shots. Therefore, vaccine manufacturers and regulators should consider what will be needed to update vaccinations to better match the circulation.Forms of SARS-CoV-2, the scientific name of the coronavirus, cause Covid-19.
Moderna and Novavax have stated that they are investigating booster shots designed specifically against B.1.351.
The most pressing concern about the variants, experts emphasize, remains their infectiousness for the time being. For example, the World Health Organization warned Thursday that B.1.351 sparked spikes in some cases as it spread from South Africa to other African countries. Matshidiso Moeti, WHO regional director, said the continent was at a crossroads. ”
Cases in the United States remain sky high, but they come from spikes earlier this month. If either variant takes off, the country could see another surge. It will also take more of the population to become immune to the virus, slow the spread of more contagious variants, and put even more pressure on the US vaccination campaign.
Last week, scientists in the UK reported that variant B.1.1.7, first shown there, may also be more deadly than other forms of the virus, although it is still analyzing national data.
In general, experts actually fear that a communicable virus is more than a virus, which is correspondingly more deadly. More infectious variants could result in more deaths overall, even if they aren’t more fatal just because they result in so many more cases.
But with B.1.1.7 “unfortunately it looks like this virus could be both,” said John Edmunds of the London School of Hygiene & Tropical Medicine.
This story has been updated with details from Novavax’s clinical trials.