The effectiveness of vaccinations against new variants would also dictate when, where, and how often additional shots are needed.
Health experts say that at least 70 percent of the country needs to be vaccinated to ensure herd immunity and completely eradicate the epidemic that killed more than 300,000 Americans.
The latest Covid-19 vaccines from Pfizer and Moderna tend to be exceptionally effective at avoiding severe illness.
More than 4,000 active cases among inmates and 1,430 more among workers in California.
The CDC has updated its guidelines on the spread of COVID-19.
Public health authorities and drug manufacturers need to be open regarding the side effects of coronavirus vaccines, doctors say.
Both the Pfizer vaccine and the Moderna vaccine were developed with new technology that uses messenger RNA.
Coronavirus Covid-19 increased by 467 percent in Kansas counties, requiring masks in public places.
According to the Centers for Disease Control and Prevention, these indoor behaviors are far more dangerous indoors during the pandemic.
Study: immunity from SARS-CoV-2 can last for at least six months, or it may be longer, maybe a matter of years.