Pfizer BioNTechA Pfizer-BioNTech preprint published today suggests that their BNT162b2 vaccine will be effective against SARS-CoV2 variants from the U.K. and South Africa, leading to “small differences in viral neutralization” compared with earlier variants. 

The U.K variant has been identified in 26 states in the U.S., while the South Africa variant has been found circulating in South Carolina.

The Pfizer and University of Texas Medical Branch scientists conducting the research concluded that modifying the BNT162b2 was unnecessary.

The researchers, however, acknowledged that the study involving engineered viruses did “not include the full set of spike mutations found in the UK or SA variants” and that clinical data are required to better understand the impact of viral mutations on the vaccine.

The Pfizer findings are broadly similar to those from Moderna, whose experiments indicated that its mRNA-1273 vaccine is effective against emerging variants from the U.K. and South Africa. The U.K. variant, in particular, seems to pose little threat of escape vaccinated immunity, according to Dr. Anthony Fauci, director of the National Institute on Allergy and Infectious Diseases. “When you’re looking at the U.K. variant, what we’re seeing is very slight, if any impact, on vaccine-induced antibodies and very little impact on anything else, so we’re covered with that,” Fauci said in a recent media briefing.

Moderna is also preparing a modified version of its vaccine known as mRNA-1273.351 designed to work against the South African variant and other similar versions of the virus that threaten to become dominant across the world in coming months.

“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 to boost titers against this and potentially future variants,” said Moderna CEO Stéphane Bancel in prepared remarks.