PHILADELPHIA (WPVI) -- An internal document from the United States Centers for Disease Control and Prevention says that the delta variant is as transmissible as chickenpox, with each positive person infecting eight or nine others on average.
"Continue to think of that mask as being like your pair of pants," says Dr. Rachael Evans, chief medical officer of Henry J. Austin Health Center in Trenton.
Essentially, don't leave home without a mask. Especially if you're unvaccinated or in a space where you don't know everyone's vaccine status.
Evans says case numbers are rising, as are breakthrough cases for people who have been inoculated.
"We know that the delta variant is at least three to four times more infective other than variants that we saw," said Evans.
Vaccinations are still helpful in keeping people from getting seriously ill or hospitalized.
In North Philadelphia, Vax Up Philly outreach teams are going door-to-door looking to convince as many people as possible to get their shot.
Philadelphia Schools Superintendent Dr. William Hite says mitigation measures like air purifiers, mask mandates and sterilizing are in place, as schools return to fill-tile in person in the fall.
Though, social distancing is tough.
"We would not be able to, if all children showed up, we wouldn't be able to keep 3-foot distancing," said Hite.
Hite is encouraging all eligible students to get the shot. The school district has had discussions with counsel and is not yet ready to require vaccines for staff.