Thailand has imposed a nighttime curfew and other new coronavirus restrictions in the capital and several other provinces.

Health officials announced that medical workers will be given booster shots of AstraZeneca vaccine after already receiving two doses of China’s Sinovac vaccine.

Thailand is facing a rise in COVID-19 cases and deaths since April worsened by the spread of the more infectious delta variant that was first identified in India.

Thailand reported 8,656 new cases and 80 deaths on Monday, bringing its total since the pandemic began last year to 345,027 confirmed cases and 2,791 deaths. More than 90 percent of the cases and 95 percent of the deaths have occurred since early April.

Most cases are in Bangkok and nearby provinces and in the country’s four southernmost provinces. The sharp rise in cases has caused a severe shortage of hospital beds for COVID-19 patients, prompting the authorities to allow patients to isolate at home and in community centers.

The head of the Thai Red Cross Emerging Infectious Diseases Health Science Center, Dr. Thiravat Hemachudha, said last week that a study he helped conduct found that Sinovac was less effective at fighting the delta variant, and that a booster dose of AstraZeneca would boost its efficacy, while two doses of AstraZeneca instead was even better.

The Health Ministry announced Sunday that 618 of 677,348 health workers who have received two doses of Sinovac have since tested positive for COVID-19.