As mutated strains of the coronavirus represent new threats in the pandemic, vaccine makers are racing to respond.
Moderna, whose two-dose vaccine has been authorized for use in the United States since Dec. 18, said on Jan. 25 that it is now investigating whether a third dose of the vaccine will better prevent the spread of a variant first seen in South Africa, while it also tests a new vaccine formula for the same purpose.
“Out of an abundance of caution and leveraging the flexibility of our mRNA platform, we are advancing an emerging variant booster candidate against the variant first identified in the Republic of South Africa into the clinic to determine if it will be more effective … against this and potentially future variants,” Moderna CEO Stéphane Bancel said in a statement. Pfizer and BioNTech, whose vaccine was also authorized in December, announced on Jan. 20 that their COVID-19 vaccine creates antibodies that could protect vaccine recipients from the U.K. variant B.1.1.7.
Moderna on Jan. 25 said laboratory tests have shown its COVID-19 vaccine could protect against the U.K. strain but that it is less effective – while still meeting efficacy benchmarks – against the strain identified in South Africa. Data from the study were submitted to a preprint server on Jan. 25 but have not yet been peer reviewed.
“This is not a problem yet,” Paul Offit, MD, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, told CNBC.
“Prepare for it. Sequence these viruses,” he said. “Get ready just in case a variant emerges, which is resistant.”
There were at least 195 confirmed cases of patients infected with the U.K. variant, which is believed to be as much as 70% more transmissible, in the United States as of Jan. 22, according to the Centers for Disease Control and Prevention. No cases from the South African variant have been confirmed in the United States. To try to prevent the variant from entering the country, President Joe Biden plans to ban travel from South Africa, except for American citizens and permanent residents.
The U.S. has reported more than 25 million total COVID-19 cases, according to data from Johns Hopkins University, marking another major milestone during the pandemic.
That means about 1 in 13 people have contracted the virus, or about 7.6% of the U.S. population.
“Twenty-five million cases is an incredible scale of tragedy,” Caitlin Rivers, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, told The New York Times. She called the pandemic one of the worst public health crises in history.
After the first U.S. case was reported in January 2020, it took more than 9 months to reach 10 million cases in early November. Numbers rose during the holidays, and 10 million more cases were reported by the end of the year.
Following a major surge throughout January 2021, with a peak of more than 300,000 daily cases on some days, the U.S. reached 25 million in about 3 weeks.
Hospitalizations also peaked in early January, with more than 132,000 COVID-19 patients in hospitals across the country, according to the COVID Tracking Project. On Jan. 24, about 111,000 patients were hospitalized, which is the lowest since mid-December.
The U.S. has also reported nearly 420,000 deaths. As recently as the week starting Jan. 17, more than 4,400 deaths were reported in a single day, according to the COVID Tracking Project. Deaths are beginning to drop but still remain above 3,000 daily.
The University of Washington’s Institute for Health Metrics and Evaluation released a new projection Jan. 22 that said new cases would decline steadily in coming weeks. New COVID-19 cases had fallen about 21% in 2 weeks prior to Jan. 25, according to an analysis by The New York Times.
“We’ve been saying since summer that we thought we’d see a peak in January, and I think that, at the national level, we’re around the peak,” Christopher J.L. Murray, MD, director of the institute, told the newspaper.
At the same time, public health officials are concerned that new coronavirus variants could lead to an increase again. Dr. Murray said the variants could “totally change the story.” If the more transmissible strains spread quickly, cases and deaths will surge once more.
“We’re definitely on a downward slope, but I’m worried that the new variants will throw us a curveball in late February or March,” Ms. Rivers told the newspaper.
A version of this article first appeared on WebMD.com.