Moderna Develops Vaccine Booster Shot Against New COVID-19 Strain

CAMBRIDGE, MA — Cambridge-based pharmaceutical and biotech company Moderna said Monday it is working on a COVID-19 booster shot after it discovered its COVID-19 vaccine appears to protect against the new strain discovered in South Africa.

"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," Moderna CEO Stephane Bancel said in a statement.

A "titer" is a lab test that measures the amount of antibodies in blood and can be used to prove immunity to disease.

Researchers said in a study — that has yet to be peer reviewed — with the National Institute of Allergy and Infectious Diseases its coronavirus vaccine appears to work against both the highly contagious strain found in the U.K. and the one found in South Africa.

The company said the vaccine showed a weaker immune response against the South African strain than others, but the antibodies still stayed high enough to be protective against the virus.

“As we seek to defeat the COVID-19 virus, which has created a worldwide pandemic, we believe it is imperative to be proactive as the virus evolves. We are encouraged by these new data, which reinforce our confidence that the Moderna COVID-19 Vaccine should be protective against these newly detected variants,” Bancel said in the statement.