[Updated at 06:39 p.m. on Sunday, Jun 20, 2021, add information about the government's vaccination program in the 16th paragraph]

Jakarta. Most of the 308 health workers vaccinated with Sinovac's Coronavac vaccine in Kudus, Central Java, a district recently hit hard by the novel coronavirus Delta variant, recovered from the disease last week, an encouraging indication of how the Chinese-made vaccine fare against the more infectious variant. 

Badai Ismoyo, the Kudus district health department head, said administering the Covid-19 vaccine to health workers in the local area has proven effective in protecting them from the worst conditions.

"Today, 90 percent of health workers who are self-isolating can return to work and return to serving the community," Badai said in a statement on Friday. 

"This is encouraging news. In addition, it also shows that the vaccine given to them is really effective in protecting against the worst conditions," he said. 

As of June 12, 308 health workers in Kudus were tested positive for Covid-19 after treating patients with the disease in the region.

The Covid-19 spread in Kudus was rapid and massive, leading health officials to suspect that a new, more infectious virus variant had come to the region brought by Indonesian migrant workers returning from abroad. 

A gene sequencing by the Gajah Mada University in Yogyakarta confirmed the suspicion. The university conducted gene sequencing on 34 virus samples from the district last week, finding 28 of them were of the Delta variant, a SARS-CoV-2 mutation first detected in India. 

Still, the health officials take confidence in the limited spread of the virus among vaccinated health workers and the speedy recovery of those two who contracted the virus. 

Badai said most of the health workers in the region received the Covid-19 vaccine during the government's vaccination program from January to March.

Kudus district used the Sinovac Covavac vaccine, which so far still accounts for more than 89 percent of Indonesia's vaccine supply. 

As of June 17, 6,085 health workers and health support personnel in Kudus had been vaccinated with the first dose, and 5,888 people had received the second dose.

“Almost 100 percent of the health workers in Kudus, amounting to around 6,000 people, have received the first and second doses of vaccination," Badai said. 

"Of this number, only 308 health workers were exposed or around 5.1 percent of the total number of health workers. Most of them have recovered and have started working again," he said.

Abdul Aziz Achyar, the director of Kudus's dr. Loekmono Hadi Regional General Hospital, said a total of 153 health workers at the hospital confirmed to have Covid-19. Only 11 people, or 7.1 percent, needed hospitalization. The other 86 (56 percent) used to be in self-isolation but now ready to work, following the rest of their colleagues who had recovered earlier.

The government's vaccination program focused on immunizing health workers first, before vaccinating workers in the services industry, civil servants, and the elderly. The government will start nationwide vaccination for the general population next month, although several provinces, like Jakarta, had done so last week.  

In an attempt to stem the Covid-19 spike in Kudus, the Ministry of Health has dropped 50,000 doses of the Covid-19 vaccine to accelerate vaccination coverage in the region.

"For now, we have intensified mass vaccinations in Kudus so that later we can slow down the transmission of Covid-19," H.M. Hartopo, Kudus district head, said. 

Hartopo said the spike in Covid-19 cases started with homecomers returning to Kudus.

"We need to inform people that people should not ignore health protocols even though they have been vaccinated. The vaccination itself is actually only a means of increasing immunity. So that if exposed to Covid-19, there are no severe symptoms," he said.