SINGAPORE - Dr Shefaly Shorey remembers when her husband, a Singapore Armed Forces officer, would grumble about how much she was working.

But ever since she started training nurses who oversee the administration of the Covid-19 vaccine, he has nothing but praises for her.

Dr Shorey, 42, an assistant professor at the NUS Alice Lee Centre for Nursing Studies, said: "He told me, 'Actually I envy your work. I see how happy you are, making a difference in people's lives.'"

Since Feb 8, Dr Shorey has trained more than 80 nurses who oversee the day-to-day operations at vaccination centres across the island.

She said given that the Covid-19 vaccine is new, it is important that nurses are familiar with the unique steps needed to dilute and administer the vaccine.

For instance, the Pfizer vaccine must be kept at between 2 deg C and 8 deg C, and injected using an unusual technique, said Dr Shorey.

Named "Train the Trainers", the course comprises a theory portion, and hands-on practice in administering the vaccine.

Nurses are also taught to assess those giving the vaccines to ensure they are competent and follow protocol.

Dr Shorey said it is crucial that procedures across the vaccination centres are consistent, so those receiving vaccines are assured of their safety.

"We don't want one person who's received the vaccine saying it was done differently from a family member. People's trust in these vaccines would dwindle like that," she said.

Many nurses were thankful for what they had learnt during the course, said Dr Shorey.

"The feedback was so overwhelming, I had tears in my eyes."

And although she has worked through every weekend since the start of her training course, she said her work has been very satisfying, and she was honoured to be a part of the nation's fight against Covid-19.

"It's a proud moment. I'm glad I've been given this opportunity," said Dr Shorey.