CHICAGO (NewsNation Now) — As reports of the omicron variant raging around the country circulate, how do different coronavirus vaccines respond to the variant?

The vaccine that all but 11 countries use, the AstraZeneca vaccine, has been found to provide roughly zero protection against the omicron variant. AstraZeneca’s two-dose vaccine, which is the vaccine 184 countries use, was zero percent effective against the variant after just two doses.

The same data was reported for China’s Sinopharm vaccine, Russia’s Sputnik V vaccine and the single-dose Johnson & Johnson.

When you compare that to two doses of Moderna or Pfizer, the results are better but still have lowered efficacy. According to a Pfizer study, the two-dose Pfizer vaccine is 70% effective against severe illness and 33% effective against mild illness.

Moderna is a similar story; it is 50 times less effective against omicron than other variants with two doses. However, on Monday Moderna announced that a booster dose of its COVID-19 vaccine should offer protection against the rapidly spreading omicron variant. Moderna said lab tests showed the half-dose booster shot increased by 37 times the level of so-called neutralizing antibodies able to fight omicron.

About one in six Americans have received their booster shot, according to data to compiled by the Centers for Disease Control and Prevention. More than 60% of the population has received two coronavirus vaccine doses, according to CDC data.