A new paper warns that the highly transmissible delta variant may develop mutations that help it escape antibodies developed by the COVID-19 vaccine.

The specific mutations to the virus include the K417N, N439K, E484K and N501Y mutations.

The paper — which was not peer-reviewed but published on bioRxiv, which shares preliminary scientific reports — said two of the four mutations had already appeared in a small number of patients. Around the world, there have been 36 cases where a patient had two of the mutations to the delta variant.

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The researchers for the paper, who worked in Japan, made four changes to the amino acid structure of the delta variant to test out if it could evade vaccines with specific mutations.Three of the mutations — K417N, E484K and N501Y — already exist in the beta variant, which was discovered in South Africa. The South Africa variant has, for the most part, been defeated by the vaccines, though there has been concern about vaccine efficacy and the beta variant.

So the researchers added one more mutation to create an engineered virus — called a pseudovirus, which is harmless and can’t self-replicate — called Delta 4+ and tested it against the Pfizer vaccine.

The antibodies made from the Pfizer-BioNTech vaccine could not stop the man-made virus in the lab, the researchers said.

So, the researchers said, this means the delta variant “is poised to acquire complete resistance to wild-type spike vaccines.”

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The worry over this Delta 4+ variant comes as experts have warned of COVID-19 variants that might evade vaccines and spread so fast that science can’t keep up with them.

So what’s the plan, then? The researchers said it’s important to develop COVID-19 vaccines that could stop these variants.

Developing new vaccines to take on variants is already on the mind of Pfizer CEO Albert Bourla, who told Fox News earlier this week that his company is monitoring new COVID-19 variants in case one escapes vaccines.

“Every time that a variant appears in the world, our scientists are getting their hands around it,” Bourla told Fox News. “And they are researching to see if this variant can escape the protection of our vaccine.

“We haven’t identified any yet, but we believe that it is likely that one day, one of them will emerge,” he added.

Bourla said it would take about three months for Pfizer to produce a new version of its COVID-19 vaccine that could stop a COVID-19 variant.

“We have built a process that within 95 days from the day that we identify a variant as a variant of concern, we will be able to have a vaccine tailor-made against this variant,” Bourla said, according to Insider.