Massachusetts public health officials reported 3,704 new COVID-19 breakthrough cases in fully vaccinated individuals in the past week, data from the Department of Public Health shows.A breakthrough case is when an individual tests positive for COVID-19 after they’ve been fully vaccinated against the disease.During the same time period between Aug. 21 and 28, the state reported 9,409 new COVID-19 cases among the state’s whole population.Numbers from the Massachusetts Department of Public Health show there have been 19,443 cases of COVID-19 in fully vaccinated individuals as of Aug. 28. Last week, the DPH reported 15,739 total breakthrough cases through Aug. 21.The 3,704 positive COVID-19 cases are among the 4.48 million residents considered fully vaccinated in Massachusetts, or about 0.43% of those individuals. The state health department said 651 breakthrough cases resulted in hospitalization, an increase of 80 over the previous week. The state said 144 cases resulted in death based on information reported to date, an increase of 13 in the past week. Massachusetts hospitals have seen a surge in hospitalizations since the Fourth of July, with the number of COVID-19 patients jumping from a low of 80 on July 4 to over 600 as of Monday.The seven-day average of hospitalizations has increased from a low of 85 on July 9 to its current mark of 576.