The fast-spreading Omicron variant that causes milder illness compared with previous versions of the coronavirus has fuelled the view that COVID-19 now poses less of a risk than in the past.
In which case, some ask, why go to great lengths to prevent getting infected now, since everybody will be exposed to the virus sooner or later?
Here is why experts say it is not time to be complacent about Omicron:
You could still become very ill
Research has indicated that Omicron may be more likely to lead to an asymptomatic case of COVID-19 than prior variants. For those who do have symptoms, a higher proportion experience very mild illness, such as sore throat or runny nose, without the breathing difficulties typical of earlier infections.
But the extraordinary spread of Omicron in many countries means that in absolute numbers, more people will experience severe disease. In particular, recent data from Italy and Germany show that people who are not vaccinated are far more vulnerable when it comes to hospitalization, intensive care and death.
"I agree that sooner or later everyone will be exposed, but later is better," said virus expert Michel Nussenzweig of Rockefeller University.
"Why? Because later we will have better and more available medicines and better vaccines."
You could infect others
You might become only mildly ill, but you could pass the virus to someone else at risk for critical illness, even if you have antibodies from a prior infection or from vaccination, said Akiko Iwasaki, who studies viral immunology at Yale University.
Omicron's long-term effects are unknown
Infections with earlier variants of the coronavirus, including mild infections and "breakthrough" cases after vaccination, sometimes caused the lingering, debilitating long-haul COVID syndrome. "We have no data yet on what proportion of infections with Omicron... end up with Long COVID," Ms Iwasaki said.
"People who underestimate Omicron as 'mild' are putting themselves at risk of debilitating disease that can linger for months or years."
Also unclear is whether Omicron will have any of the "silent" effects seen with earlier variants, such as self-attacking antibodies, sperm impairments and changes in insulin-producing cells.
More infections mean more new variants
Omicron is the fifth highly significant variant of the original SARS-COV-2, and it remains to be seen if the ability of the virus to mutate further will slow down.
High infection rates also give the virus more opportunities to mutate, and there's no guarantee that a new version of coronavirus would be more benign than its predecessors.
"SARS-CoV-2 has surprised us in many different ways over the past two years, and we have no way of predicting the evolutionary trajectory of this virus," said David Ho, professor of microbiology and immunology at Columbia University.
