On Friday, immunologist Dr Prapaporn Pisitkun explained on Facebook that she caught Covid-19 from a positive case despite having already receiving two Chinese-made Sinovac jabs.
Prapaporn said she had checked her neutralising antibodies (NAb) to monitor her immune response after vaccination.
Two weeks after her second dose, her NAb was high at 92.9 per cent. However, after two months her NAb dropped to 65.7 per cent.
She said that although her antibody level was not low, it was not high enough to protect her from the Delta variant.
Prapaporn noted there are two ways to generate herd immunity among people. One is vaccination and the other is allowing the virus to infect them so they build natural immunity.
If the government chooses the first option, adequate vaccine brands must be provided, or else herd immunity will be generated in the second way, said Prapaporn.
Sinovac registered just 50.4 per cent efficacy in Brazilian trials, barely reaching the 50-per-cent efficacy needed for World Health Organisation approval.
She said more doses of Covid-19 vaccine should be procured to boost the immunity of medics, and the vaccines should be mRNA brands such as Pfizer-BioNTech and Moderna.
“Sinovac vaccine can protect us from severe illness and death. If there is no better choice, the Chinese vaccine is okay. However, people jabbed with Sinovac can still be infected and spread Covid-19 to others, which means the outbreak will not end and everyone will contract the virus,” she said.
Published : July 02, 2021
By : The Nation