KUALA LUMPUR: Two doses of Sinovac's Covid-19 vaccine followed by a booster Pfizer-BioNTech jab has proven to be highly effective against the coronavirus and at preventing symptomatic disease, hospitalisation and intensive care units (ICU) admission.
Health director-general Tan Sri Dr Noor Hisham Abdullah said existing data showed that the Sinovac (CoronaVac) - Pfizer (Comirnaty) mix offered longer-term protection against getting seriously ill from Covid-19.
He therefore advised eligible recipients, especially those who had received Sinovac as their primary vaccine, to get booster doses as its effectiveness starts to wane after a few months.
"Data showed a mix of Sinovac and booster Pfizer is much better in efficacy (as seen in Sarawak).
"Undoubtedly vaccines work. Look at last year July and August, for instance, when coverage of vaccination in the Klang Valley was low.
"It was mayhem in our hospital admission and ICU utilisation. Now, health facilities are much better daily," he told the New Straits Times today.
Sarawak (where the majority of the population received Sinovac as the primary vaccine) is the first state to implement booster doses and additional doses starting from Oct 13.
The state has the most number of booster shot recipients in the country to date, the majority of whom received Pfizer's Comirnaty as the third/ booster jab.
According to data from the Health Ministry's CovidNow portal, Sarawak recorded an average of 500 daily admissions to hospitals on Aug 31 last year (seven-day average) and peaked at 611 on Sept 12. The figure dropped to a mere 54 admissions on Jan 1 (seven-day average).
Meanwhile, active ICU admissions stood at 119 (seven-day average) on Sept 28 and declined to eight (seven-day average) on Jan 1.
According to a Chilean study, efficacy in preventing SARS-CoV-2 infection among Sinovac recipients stood at 93.18 per cent for a third dose with Pfizer, 90.53 per cent for AstraZeneca, and 70.89 per cent for Sinovac.
Dr Noor Hisham further said at present, there is no change in the Health Ministry's policy and Clinical Guidelines on Covid-19 vaccination in Malaysia with regards to the number of vaccines boosters required.
"At the moment, it's status quo, no change in our policy and guidelines. We are getting more data on the response of vaccination. Our expert panels are reviewing all the data for now and (there is) no policy change as yet.
"What is obvious is in Sarawak as the majority had Sinovac (as the primary vaccine) and with booster dose more than 56 per cent, the cases are less now than before.
"Let our expert panels do the needful first before providing any recommendations based on facts and data. From day one, our action and guidelines are based on science facts and data."
He was commenting on a preprint study by Yale University, US which showed that two doses of the Sinovac vaccine with a booster shot of Pfizer look to be less effective against the Omicron variant compared with other strains.
According to the study, receiving two doses of Sinovac as the primary vaccine along with a booster Pfizer jab produced an antibody response similar to a two-dose mRNA vaccine.
Antibody levels against Omicron were 6.3-fold lower when compared with the ancestral variant and 2.7-fold lower when compared with Delta, it said.
Professor Akiko Iwasaki, who is one of the authors of the study, on Dec 30 tweeted that CoronaVac recipients may need two additional booster doses to achieve protective levels needed against Omicron.
Health Minister Khairy Jamaluddin on Jan 1 said the ministry's technical committee is studying the need for a possible fourth dose for those who received Sinovac as their primary vaccine to ensure recipients achieve the protective levels needed against the more transmissible Omicron variant.
As of Jan 1, 25,616,109 individuals in Malaysia have been fully vaccinated and 6,329,155 had received their booster shots.
Dr Noor Hisham added that it is essential to use common sense and take all precautionary public health and social measures, especially since Malaysia now has the tools, resources and strategies in place to protect ourselves.
"Today, we are in a crisis within a crisis as the nation is facing devastating floods during a pandemic.
"We are not out of the woods yet and must come together to soldier on as we continue the care of our patients and the rakyat.
"We will encounter further tough weeks ahead. But as much as we care for our patients, remember to look out for one another.
"As we enter the third year of the pandemic, we have learned that what is certain is uncertain, what is predictable is unpredictable, but we can at least be prepared and hope for the best."