A small study published this week shows the Pfizer vaccine has the ability to “neutralize” common mutations of the coronavirus found in the United Kingdom and South Africa variants.

A collaborative research team from the University of Texas Medical Branch at Galveston and vaccine maker Pfizer looked at blood samples taken from 20 patients who had received both doses of the COVID-19 vaccine.

They tested serum taken from the blood samples against the mutations found in the variants currently identified.

Their study, published in the journal Nature Medicine, shows “evidence of neutralization of the mutant viruses”, according to UTMB. They found there was slightly less neutralization against the South Africa variant compared to the neutralization of the blood samples against the UK variant.

“One limitation of the current study is that we have not included all the mutations from the spike gene of the new variants. Such experiments are ongoing,” Pei-Yong Shi of UTMB said in a written statement.

The team of researchers note clinical data is needed to provide firm conclusions about vaccine efficacy against variants.