Indonesia gave Sinovac Biotech's COVID-19 vaccine its first emergency use approval outside China on Monday as the world's fourth most populous country launches nationwide inoculations to stem surging infections and deaths.
A lack of data and varying efficacy rates reported for the vaccine from different countries could undermine public trust in the rollout, according to public health experts.
Interim data from a late-stage human test of CoronaVac showed it is 65.3 per cent effective, Indonesia's food and drugs authority BPOM said - lower than figures in Brazil and Turkey which have yet to launch mass vaccinations. "These results meet the requirements of the World Health Organization of minimum efficacy of 50 per cent," BPOM head Penny K. Lukito told a news conference.
President Joko Widodo is set to get his first dose on Wednesday in a sign of the priority placed on immunisation in a country of 270 million people that has done far less than Southeast Asian neighbours to contain the virus.
But some public health specialists question how effective the rollout will be given the limited number of doses available, logistical challenges across thousands of islands and scepticism over the vaccine.
A BPOM official said 25 infections were found to get the efficacy rate, but without giving further details.
Dale Fisher of the National University of Singapore told the Reuters Next conference on Monday that not releasing detailed data could be problematic for a fast rollout.
"Messaging is more important than ever," he said.
Indonesia has suffered more than 24,343 deaths from 836,700 cases. Over a tenth of deaths were in the last two weeks.
A Brazil-based study last week showed Sinovac's vaccine is 78 per cent effective. Turkish researchers said in December it showed 91.25 per cent efficacy based on interim analysis.
To start, only three million doses of CoronaVac will be available in Indonesia. Some 1.2 million doses have been dispatched to 34 provinces, which span an area wider than the continental United States.
15-MONTH CAMPAIGN
Indonesian authorities say they have also secured a total of nearly 330 million doses of vaccine from Sinovac and other companies for a campaign they expect to take 15 months to reach herd immunity once two-thirds of Indonesians are vaccinated.
Sinovac has been overseeing late-stage clinical trials in Indonesia along with local state-owned drugmaker Bio Farma.
Some 1.3 million frontline workers are due to be among the first to receive the vaccines. But as it seeks to revive its economy, Indonesia then plans to prioritise younger workers rather than the vulnerable eldely as in many countries.
In a possible boost for acceptance in the world's largest Muslim majority nation, the vaccine was declared "holy and halal" last week by the Indonesian Ulema Council.
But public health workers report scepticism, particularly given that it is the first major international campaign using the Sinovac vaccine.
Irma Hidayana, co-founder of Indonesia's LaporCOVID-19, an independent coronavirus data initiative, said at the Reuters Next conference on Monday public trust in vaccines was a major issue.
A recent survey by the group found 69 per cent were uncertain about getting vaccinated.
Based on traditional vaccine technology that uses inactivated coronavirus, CoronaVac can be stored at normal fridge temperatures of 2-8 degrees Celsius (36°-46°F) and may remain stable for up to three years.
Vaccines offered by Pfizer/BioNTech and Moderna use the novel synthetic messenger RNA (mRNA) technology but require more demanding temperature control for storage and transportation.
