A man receives his booster shot with the Pfizer COVID-19 vaccine in Hartford, Connecticut.
  • Pfizer and BioNTech released lab-test data about how their vaccine works against the Omicron variant.
  • It said two doses still appear to protect against death and severe illness.
  • But it said people's protection from infection was weakened, and getting three doses is more effective.
  • For more stories visit Business Insider.

Pfizer and BioNTech said on Wednesday that three doses of their Covid-19 vaccine work against the new Omicron variant, but that getting two doses was less effective.

It released the results of preliminary laboratory studies on Wednesday, comparing the effect of two doses with two doses combined with a third booster dose.

Albert Bourla, Pfizer's chairman and CEO, said in the statement that two doses appear to still be able to protect vaccinated people from severe death and illness, but a third dose improves protection.

"Although two doses of the vaccine may still offer protection against severe disease caused by the Omicron strain, it's clear from these preliminary data that protection is improved with a third dose of our vaccine," he said.

Scientists are concerned at the high number of mutations the Omicron variant has. Mutations could mean that the virus is more deadly, more infectious, and make vaccines less effective.

The variant was only recently discovered, and experts are rushing to understand it better.

But early evidence suggests the Omicron variant may be easier for people to catch than the Delta variant, but could result in less serious infections.

Pfizer is working on an updated vaccine to target the Omicron variant.

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