Two of the nine Princeton residents who had complained of symptoms of coronavirus after being exposed to it at a party in Princeton have shown improvement, Princeton Health Department officials said.

While the two residents’ symptoms have subsided, the other seven residents have been directed to obtain testing for coronavirus, also known as COVID-19, Princeton Health Officer Jeffrey Grosser said March 12.

The nine residents who had complained of COVID-19 symptoms -including the two whose condition has improved – were among 14 Princeton residents who attended the Feb. 29 party, Grosser said.

The 14 Princeton residents have been advised to self-quarantine, Grosser said. All are being followed for the development of signs and symptoms of COVID-19, which include cough, fever and shortness of breath.

Close contacts of the 14 residents also are being assessed and monitored for signs and symptoms of COVID-19 and have also been asked to self-quarantine, he said. Close contacts includes any friends, family or health care professionals.

In addition, three Pennsylvania residents who attended the same party have presumptively tested positive for COVID-19. The test results are pending confirmation by the Centers for Disease Control and Prevention. Princeton health officials were notified March 11.

The Pennsylvania residents were among 47 guests at the Princeton party, which also included two Massachusetts residents who attended the Biogen conference in Boston and who tested positive for COVID-19, Grosser said. The conference has been linked to COVID-19 transmission.

“As more cases are observed throughout New Jersey, we are urging people with underlying health conditions, pregnant women and the elderly to practice social distancing,” Grosser said.

They are being advised to avoid non-essential travel, public events, community gatherings and indoor venues, he said.