KUALA LUMPUR: Experts are split over the decision by health authorities to make booster doses a requirement for citizens aged 60 and above and for all adult recipients of the Sinovac vaccines to retain their fully vaccinated status come February.
While some believed the move was warranted, others, however, were concerned over what could be perceived as a "hard-line" measure, which could lead to similar pitfalls the authorities faced with anti-vaxxers in the early stages of the national Covid-19 vaccination drive.
Epidemiologist Dr Malina Osman said the public had to consider the hardship and challenges faced by the country and the risks the Covid-19 Omicron variant posed.
"The government's vision is fair due to evidence on waning antibodies in those who received Sinovac and Pfizer shots as reported in several journals. And with Omicron, we do not know what the future has in store for us.
"In terms of public health, more people are getting infected and we are seeing a marked increase in Stage 3 and 4 cases, where the immunity for those who received Sinovac and Pfizer shots had lapsed after the three- and six-month coverage threshold.
"What we are fearful of is the burden on the healthcare system, which is barely coping after facing months-long overload to the critical care wards due to multiple surges in infection."
The Universiti Putra Malaysia associate professor expected a similar policy on boosters to be enforced on adult recipients of all Covid-19 vaccines in the coming weeks due to reports of waning antibodies and in anticipation of surges due to Omicron.
This week, researchers in Hong Kong urged people to get a third dose of the Covid-19 vaccine after a study showed insufficient antibodies were generated by those who received Sinovac and Pfizer-BioNTech shots to fend off Omicron.
Health Minister Khairy Jamaluddin announced on Thursday that adults who received the Sinovac vaccine in Malaysia and citizens over 60 would need to get boosters shots by February so that they can keep their fully vaccinated status.
The status allows people to dine in and enter malls, retail stores, cinemas and other recreation areas. Singapore is considering imposing a similar policy.
However, Malaysian Public Health Physicians Association president Datuk Dr Zainal Ariffin Omar saw a possible pushback, similar to what the Health Ministry experienced with vaccine-hesitant groups.
"Forcing people is not a sustainable or good option to encourage them to get booster shots. More people will resist such impositions to revoke their status," he said.
"People are worried about the side effects and long-term complications. They also are balancing the risk of infection while contemplating immunity from boosters and natural infections. It is the same scenario in other countries."
Dr Zainal said even members of the medical fraternity were worried of adverse events following immunisations and the long-term complications as there was insufficient information on such incidents related to booster shots from the ministry.
He said the booster shot promotions had to be in-depth and involve appropriate individuals for targeted groups.
"It is not enough to have celebrities or those from the ministry promoting things."
He said this was needed to address the distrust towards the government generally, which also affected the initiative.
Khairy said the authorities were verifying 18 more suspected cases of the Omicron variant, with results expected soon. At press time these results had yet to be updated.
The second Omicron case involved an 8-year-old travelling with her family from Nigeria, where the family resided, via Qatar.
All close contacts, including 35 passengers on the same flight, had tested negative for Covid-19.
Malaysia reported the first Omicron case earlier this month involving a traveller from South Africa.
Epidemiologist Professor Dr Jamalludin Ab Rahman from International Islamic University Malaysia said the government's decision might be harsh, but it was necessary.
"Despite the advice from the government for people to get booster shots, the uptake is still poor. And if the government wants to protect people, immediate action is necessary.
"I believe the presence of Omicron may have also forced the ministry to take such a stand. Our cases are going down and Omicron can halt this progress. While Omicron has been found to be milder than Delta, if it causes another wave, it can still overwhelm the healthcare capacity."
However, he asked the health ministry to share their evidence on the need for booster shots with the public.
"What the ministry can do is share with the public the local evidence showing that two doses of Sinovac is less effective compared with Pfizer and AstraZeneca."
It was earlier reported that the efficacy of the Sinovac vaccine dropped to 28 per cent against both Covid-19 infections and Intensive Care Unit (ICU) admissions three to five months after completing vaccination.
The report quoted studies by the Real-World Evaluation of Covid-19 Vaccines Under the Malaysia National Covid-19 Immunisation Programme and the National Medical Research Register, which stated that the Sinovac vaccine's efficacy against Covid-19 infections fell to 28 per cent from 76 per cent over the same period.
Pfizer's two-dose Covid-19 vaccine, however, remained 79 per cent effective in preventing ICU admission from 86 per cent three to five months after the primary vaccination.
The study found that the Sinovac vaccine was only 76 per
cent effective against breakthrough deaths after three to five months, falling from 79 per cent two months after the primary vaccination.
Dr Jamalludin said this needed to be clarified as Sarawak, which received mainly Sinovac (around 60 per cent of the state's population), was not showing any increase in number of deaths from the coronavirus.
Nevertheless, he said, experts had been telling people from the very beginning that as the virus mutated, immunity would wane and people might need boosters.