According to Matthew Ferrari, director of the Center for Infectious Disease Dynamics at Penn State University in the US, omicron contains more mutations in more locations of the genome than any of the previous SARS-CoV-2 variants, and some of these mutations are in parts of the virus that may affect the virus’s transmissibility and ability to evade the immune system.

However, he said, there is no evidence yet that the severity of disease that omicron causes is any worse than delta.

“We haven’t seen enough cases yet to know either way,” he said, noting that it also may take some time to understand the extent to which omicron can evade the immune system.

“We won’t know about the practical consequences of omicron in real populations for a few weeks, after which we will begin to see whether there are increases in case numbers or in the proportion of cases among those who were vaccinated,” said Ferrari. “In the meantime, it is important to get your vaccination and your booster.”

Are the current vaccines and boosters effective against omicron?

Ferrari said that all indications are “yes.”

“The current vaccines and boosters will absolutely help to reduce the risk of transmission, infection and severe disease of omicron, although it remains to be seen whether the current vaccines are less effective than for delta,” he said.

 Ferrari noted that updated boosters can be made against the omicron variant.

“They won’t come fast,” he said, “but they will come significantly quicker than the first vaccines. It will only require a change in production, not a full voyage of discovery for a new vaccine.”

In the meantime, he said, people should not delay their plans for the current booster.

“The best protection against the omicron variant,” he said, “is to get your vaccine and your booster, and to take precautions, including wearing a mask, when in public.”