As Variants Circulate, Moderna Announces its Updated COVID-19 Vaccine Results

According to the CDC, the most dominant strain being reported in the US is the EG5 variant with 21.5% of the cases followed by the FL151 with 14.5% of reported cases. These variants are of Omicron lineage.

Another variant that has sparked interest among virologists, infectious disease providers, and public health officials is the BA286 (Pirola) variant. It is classified as a "variant being monitored" by the CDC, and may be more capable of causing infection in people who previously had COVID-19 or were vaccinated with previous vaccines. This variant has over 30 mutations, according to an Al Jazeera report. And this fact alone has people concerned, especially with BA286 having a much greater number of mutations than other variants circulating currently.

However, more research is showing BA286 may not be as contagious or as evasive as previously thought according to a CNN report. For now, the reported case loads for BA286 are very low in the United States, and it remains to be seen what will happen and if it has the durability to last and increase COVID-19 incidence rates.

Addressing Circulating Variants

This morning, Moderna announced its updated COVID-19 vaccine, mRNA-1273.815, generated an 8.7-fold increase in neutralizing antibodies in humans against BA286.

"These results demonstrate that our updated COVID-19 vaccine generates a strong human immune response against the highly mutated BA.2.86 variant,” said Moderna President Stephen Hoge, MD, in a statement. “Taken together with our previously communicated results showing a similarly effective response against EG5 and FL151 variants, these data confirm that our updated COVID-19 vaccine will continue to be an important tool for protection as we head into the fall vaccination season."

Pfizer has also updated its COVID-19 vaccine to protect against variants including multiple XBB-related sublineages (XBB15, XBB116, XBB23, and EG51).

Awaiting the Updated Vaccines

In the northern hemisphere, the start of the seasonal respiratory season is just weeks away, and the updated vaccines are awaiting FDA approval. There are expectations it will happen soon, but no official dates have been announced.