Federal health officials have suspended the distribution of the monoclonal antibody cocktail of Eli Lilly in 8 states in response to fears about the efficiency of the COVID-19 variant.

According to the US Department of Health, COVID-19 distribution will be halted in Washington, Oregon, Massachusetts, Indiana, Illinois, Florida, California, and Arizona unless notified due to the increase of variants in these specific states.

As per the announcement, in Washington, Oregon, Indiana, Florida, California, and Arizona, the combined frequency of the P.1 variant (identified initially in Brazil) and the B.1.351 variant (identified initially in South Africa) has surpassed 10%; in Massachusetts and Illinois, the P.1 variant has been repeatedly increased at a speed exceeding 10%.

The suspension is not due to worries about the cocktail’s safety – which combines the medications etesevimab and bamlanivimab – but rather to worries about the cocktail’s effectiveness against the different strains of Covid. According to the report, the suspension will have no effect on distribution in other regions of the US.

The Food and Drug Administration granted emergency use permission for the therapy in February. These monoclonal antibody therapies are intended to be administered in the early stages of COVID-19 infection in non-hospitalized patients at high risk of developing severe disease, in order to assist keep them out of the hospital. It must be given within a few days following diagnosis.

For the time being, the FDA advises health care practitioners in these states to treat COVID-19 patients with the approved Regeneron monoclonal combination.

Thus far, clinical trial results indicate that Regeneron’s cocktail is somewhat more effective against current main variations than Eli Lilly’s, which showed declining potency in all versions saves the B.1.1.7, or U.K. variation, in its own laboratory experiments.

Talking to ABC News, Eli Lilly said that the company is consistently monitoring the environment of Covid-19 and is also assessing antibody therapies’ neutralization against emerging and already existing broad array of variants and mutations. Lilly asserted that it will keep working with the regulatory agencies and the government to make sure patients have access to the available treatment.

Regeneron told ABC News that their cocktail continues to look excellent against known variations, including those seen in India, and that the company would continue testing against new variations as they arise.