BANGKOK - Since April, Thailand has been caught in a spiralling wave of Covid-19 infections, largely fuelled by a more transmissible Delta variant that threatens to overwhelm its healthcare system.
As caseloads log about 20,000 new infections daily, the country has been scrambling to secure more Covid-19 vaccine shots.
Thailand's inoculation drive currently relies on shots by foreign vaccine developers - Sinovac, AstraZeneca, Sinopharm and Pfizer.
To reduce the reliance on imported vaccines and shore up the nation's supply of shots, local scientists have been working on a number of home-grown jabs. Three of six vaccine candidates started clinical trials earlier this year.
While none of the candidates has been approved for use yet, vaccine developers hope the shots will serve as booster jabs in the near future.
So far, scientists have reported favourable results for two of the vaccines that have entered clinical trials - the mRNA-based ChulaCov-19 and the NDV-HXP-S shot that uses an inactivated virus.
ChulaCov-19, which will begin phase two clinical trials next week, yielded a high efficacy rate in preventing Covid-19 infections, said Chulalongkorn University researcher Kiat Ruxrungtham.
The NDV-HXP-S vaccine, by the Government Pharmaceutical Organisation, has started its next phase of trials.
The third, the DNA-based Covigen vaccine, is in phase one of human trials.
Another candidate that will begin human trials next month is the plant-based Baiya Sars-CoV-2 Vax 1. One of the scientists behind it, Dr Suthira Taychakhoonavudh, said there is a sense of urgency for home-grown jabs, but the process cannot be rushed.
"We hope to tackle issues to do with sustainability and security of vaccine supply," she said.
Human trials will start later this year for two vaccines that are administered via nasal spray.