BANDAR SERI BEGAWAN – Less than half of invitees have agreed to participate in a study on Bruneians’ immune response to COVID-19 vaccines.

Associate Professor Dr Anne Cunningham, one of the immunologists leading the study, said the participant response rate was lower than expected but started to pick up after news reports on the research.

Only one-third of 1,200 who received invitations last week consented to take part in the study, she told The Scoop.

“However, half of our invitees walked in for their blood sample to be taken [on Monday], even though they didn’t reply to the SMS. That’s fine as long as they meet our inclusion criteria and were part of the sample.”

Dr Cunningham, who is the deputy dean of UBD’s PAPRSB Institute of Health Sciences, said another 4,700 SMS invitations were sent out on Monday and 40 percent of the respondents from this batch have agreed to join the study so far.

“Some people did mistake the SMS for spam, so we want to let people know it’s legitimate,” she said. “We have changed the format of our information to make it clearer and we will include an invitation reminder text.”

More text invitations will be sent to randomly selected people across all age groups and different vaccine types in the next three to four weeks. Only participants who received their second dose no more than six weeks ago are eligible for the study.

The study will compare 3,000 participants’ antibody responses to three vaccine types – AstraZeneca (viral vector), Moderna (mRNA), and Sinopharm (inactivated virus).

During his daily COVID press briefing on Tuesday, Health Minister YB Dato Dr Hj Md Isham Hj Jaafar called on the public to step forward and participate in the study as research findings will help the government determine the need for COVID booster shots.

The study is a collaboration between the Ministry of Health; Universiti Brunei Darussalam; Duke-NUS Medical School of Singapore and BruHealth app developer EVYD Technology, which is responsible for managing a database on participants’ details.

Noryanto, an Indonesian citizen living in Brunei, receives his first dose of the Moderna vaccine at Labi Health Centre on Oct 11, 2021. Photo: Ain Bandial/The Scoop

Speaking to reporters in an interview last week, Head of MoH’s Disease Control Division Dr Justin Wong said the main aim of the study was to help the ministry roll out COVID vaccines more effectively.

“There are a number of interesting things about this study that can contribute to health in general, and global health in particular.”

“There’s not much published literature on Sinopharm. So this is one of the steps that directly compares the Sinopharm vaccine to other vaccines like the AstraZeneca and Moderna vaccines,” he said.

Duke-NUS Medical School will provide its virus neutralisation test kit (cPass) to detect and measure participants’ neutralising antibodies — the specific antibodies that are responsible for clearing a person’s viral infection.

The test will help researchers quantify and understand the antibody levels of Bruneians after they were given different types of vaccines, said one of the researchers involved in the study.

Dr Muhd Hazim Hj Abdul Ghani, an immunology lecturer at UBD, said Duke-NUS Medical School’s role is to measure and analyse the antibody levels, while UBD is responsible for collecting blood specimens.

Participants are expected to receive their cPass test results through SMS sometime in February.

The SMS message will indicate whether respondents have positive or negative neutralising antibodies.

Dr Hjh Hanisah Hj Sharif, another researcher involved in the study, said a person who produces a positive cPass result has neutralising antibodies towards the COVID vaccine.

“If you have neutralising antibodies, that’s good because it will offer you some protection against the virus.

“A negative result could indicate that your immune system did not react as well as it should, and not enough neutralising antibodies were produced, so you are more susceptible to infection,” she explained.

She added that if the research sample returns more positive cPass test results, it would suggest that COVID vaccines have been effective in preventing serious illness among the Brunei population.

To date, 83.2 percent of residents are fully vaccinated against the coronavirus.

A nurse extracts a dose of the AstraZeneca vaccine from a vial at the PIHM Hospital in Temburong. Photo: Rasidah Hj Abu Bakar/The Scoop

Dr Wong added that different vaccines will generate different levels of neutralising antibodies, and this can tell us which are the best vaccines to use as booster shots.

“One study alone will not in itself provide a conclusive evidence on the level of boosters needed, or what vaccines are ideal. But taken together, this study forms part of the scientific literature that informs policy making in MoH,” he said.

“And this study will have added weight because it’s a study done on the Brunei population. We know immune responses can vary by age, ethnicity and diet etc, so these are the kinds of things we want to find out.”

The study is one of the largest medical studies ever conducted in Brunei and is funded by the Council for Research and Advancement of Technology and Science and the Tumasek Foundation in Singapore.