The new method was used yesterday to administer third-dose ‘booster’ injections of AstraZeneca to those who had already received two injections of the Sinovac vaccine in what is now the new policy for the provincial government in administering booster injections.
Phuket is the first province in the country to use the new method, following approval by the Ministry of Public Health.
The approval was granted following a study conducted by medical officers at Vachira Phuket Hospital that showed using just 20% of the standard dose of AstraZeneca vaccine by injection the vaccine just under the skin proved just as effective in boosting immunity to the SARS-CoV-2 virus.
In announcing the results of that study on Sept 15, Dr Chalermpong Sukontapol, Director of Vachira Phuket Hospital, together with Dr Supalak Laongpetch and Dr Withita Jaeng-iam, initiators of the research project, explained that the study involved 242 volunteers aged 18-60 who had received two doses of Sinovac vaccine.
The results showed that the immunity of those who received the subcutaneous vaccination was on average slightly higher than that of those who received the conventional vaccination.
Participants who received subcutaneous injections had approximately 17,662.3 AU/ml, while participants who received intramuscular injections had 17,214.1 AU/ml. Both groups had a higher rate of immunity than the minimum threshold or 840 AU/ml.
The side effects of subcutaneous vaccinations were less common than with conventional injections, such as fever or headache, the researchers noted.
“The subcutaneous injection causes more irritation and redness at the injected area, it is not worrying,” Dr Withita said.
Doctors will vaccinate around 200,000 residents and those people living on the island without the house registration, aiming to complete the process by the middle of October, Dr Withita said.
“When done, said a second group consisting of migrants and foreign residents will be inoculated,” she added.
The post-injection time is now also less, Dr Withita said yesterday.
“Only 10-15 minutes of observation is needed following the jab, instead of the previous 30 minutes, as acute side effects, such as low temperature, exhaustion, and headaches are less likely than in the conventional method, with an equivalent immunity boost, based on scientific research,” she said.
The subcutaneous injection will allow doctors to administer approximately four times more shots of vaccine than in the conventional method, speeding up the prevention of the spread of the Delta variant of the COVID virus, Dr Withita added.
As of yesterday, according to the Phuket Provincial Public Health Office (PPHO) 66,383 people in Phuket have received a third-dose booster jab.
The PPHO also reports that 389,163 people in the province have received two vaccination injections, while 426,387 still have received only one vaccination injection.