Anthony Fauci, a leading US expert on infectious diseases, said up to 90 percent of the population may need to be vaccinated to achieve herd immunity against coronavirus.

Fauci told the New York Times that he is gradually increasing his estimate of herd immunity scores. According to him, Americans may already realize that it may take longer than expected to restore normal life, and fewer Americans report that they are skeptical about vaccinations.

Fauci noted they will develop an umbrella of immunity. It will be able to protect even the vulnerable who have not been vaccinated.

The more contagious the disease, the higher the level of vaccination required to reach the herd immunity threshold. For example, measles, which is considered the most contagious disease in the world, requires a herd immunity of at least 90 percent.

Fauci noted that experts don't really know what level of vaccination is required for herd immunity, but initial estimates of 60 to 70 percent were based on early data.