The infectious disease expert warns that non-vaccinated people Covid-19 can become an environment that produces new viruses.

Vaccine has not been a potential vaccine, Dr. William Schaffner, professor at the infectious disease department of Vanderbilt University Health Center, Tennessee, USA, warning.

Dr. Schaffner said the human body was the environment that the virus was constantly transformed and could produce more dangerous transactions than the original.

Although most changes have no effect on the virus and some may even make the virus weakened.

A vaccine vaccination point in Newark, New Jersey Bang May. Photo: Nytimes.

When transformations occur in the virus, persistent survival mutations often make the virus easily spread in the community, Andrew Pekosz, microorganisms and immunology at Johns Hopkins Bloomberg Public Health School.

Mutations will make the virus more dangerous than the original strains appear in China.

Available vaccines can still protect people before the current types of transformations, but experts warn this can change anytime if the virus continues to have a mutation opportunity.

We let the virus spread as much, the more viral viruses have changed opportunities, the World Health Organization (WHO) says last month.