September 1, 2021

Delta Variant Surge Continues; Boosters Are Coming Soon

By Donald Gilpin

On Monday, August 30, the Princeton Health Department reported 17 new cases of COVID-19 in Princeton in the previous seven days, 31 cases in the previous 14 days. Princeton Health Officer Jeff Grosser noted that the recent surge, with the spread of the Delta variant, has been about 50 percent as big as the COVID-19 surge Princeton experienced last winter.

The Delta variant is “a much more contagious strain that has spread on a much different scale from what we saw with the Alpha variant,” he said. “With Delta, it felt as if once someone from a household was infected it was a waiting game for everyone else in that house. There was certainly vaccine protection in situations where households were not completely infected, but in low vaccination-rate households infection rates neared 100 percent of the dwelling’s inhabitants.”

Grosser emphasized the need for mask-wearing, social distancing, and vaccinations as the way to reduce transmission of all strains of the virus.

The Princeton vaccination rate, as of August 24, was 79 percent (ages 12 and over) and 98 percent for residents 65 and over. The vaccination rate for Mercer County (age 12 and over) is 65 percent, 75 percent for 65 and over. For New Jersey it’s 72 percent (12 and over), 85 percent for 65 and over, and for the United States as a whole, the vaccination rate is 61 percent (ages 12 and over) and 82 percent for age 65 and over.

At least one in 10 people who live in Mercer County has been infected with COVID-19 since January of 2020, and at least one in 379 in Mercer County has died.

Starting September 20, the Princeton Health Department will begin to offer booster doses to individuals who have had the Pfizer or Moderna vaccine for at least eight months, and will also offer Johnson & Johnson boosters once they are approved by federal health authorities.

The health department over the past two weeks has begun to provide third shots to moderately to severely immunocompromised homebound Princeton residents who have been fully vaccinated with the Pfizer or Moderna COVID-19 vaccine. Those individuals are eligible for a third dose 28 days after their second COVID vaccine.

The health department will continue to provide the vaccine to those individuals in their homes. Eligible residents should schedule a third shot by visiting the municipal webpage or emailing the health department COVID-19 generalist Julie Venema at

Grosser expressed concern that the upcoming school year could be “equally or more of a challenge” than last year. “We have learned a tremendous amount about this pandemic, this virus, and learned what preventative health tactics work to thwart this quick-spreading virus. Unfortunately for our residents under the age of 12, a vaccine, which is our best weapon against the virus, is not yet available and probably won’t be until sometime this fall or winter.”

Princeton University vaccine clinics will take place in Jadwin Gymnasium from 1 to 4 p.m. on Wednesdays in September, starting today, September 1, open to the public with no appointment necessary. 

Mercer County COVID-19 vaccination clinics, in partnership with Capital Health and Penn Medicine Princeton Health, will take place on Friday, September 3 and every Friday throughout the month, as well as October 1 at the Trenton Farmers Market on Spruce Street from 10 a.m. to 5 p.m., also on Monday, September 13 and the following Mondays throughout the month at Millyard Park on Clinton Avenue next to Roebling Market from 10 a.m. to 5 p.m.

Vaccinations are free, regardless of immigration or insurance status, and no appointment is necessary. Registration at the New Jersey Vaccine Scheduling System ( is recommended but not required.

Grosser added that additional combined flu and COVID-19 vaccine clinics will be scheduled at multiple locations throughout the fall. 

New Jersey Gov. Phil Murphy announced on Monday that some vaccine mega-sites will probably reopen to increase capacity as people become eligible for booster shots. It is still not known whether boosters will be recommended six or eight months after the second dose of the Pfizer or Moderna vaccine, and the shots have not yet received final authorization from federal health officials. 

Murphy pointed out that 2.4 million people in New Jersey could be eligible for the booster on September 20 if the six-month window is approved. New Jersey Health Department Commissioner Judith Persichilli added that because of high demand it could take up to four months to distribute the booster.