Coronavirus Hong Kong: BioNTech vaccine recipients have antibody levels 10 times higher than those who opted for Sinovac, researchers find

Though quantity of coronavirus-targeting proteins does not directly correlate to level of immunity, findings may suggest ‘substantial differences in vaccine effectiveness’

But study’s lead author notes moderate levels of protection are better than none at all, saying: ‘Don’t let the perfect be the enemy of the good’

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People arrive for their BioNTech vaccination appointments at Sun Yat Sen Memorial Park Sports Centre on Thursday. Photo: Felix Wong

Published: 6:30am, 16 Jul 2021Updated: 8:11am, 16 Jul 2021

A new Hong Kong study has found that recipients of the BioNTech Covid-19 vaccine have 10 times more antibodies than those who took Sinovac, with the latter generating levels of the virus-targeting proteins that were “similar or lower” than the naturally occurring ones seen in recovered patients.

The findings by the University of Hong Kong, published in Lancet Microbe on Friday, could suggest the need for “alternative strategies” – including booster shots – to increase Sinovac recipients’ antibody concentrations and protection against Covid-19, according to the researchers.

The presence of antibodies is a sign of a previous infection, or that a vaccine is working to protect an individual, but the quantity of the proteins generated by the body to identify and neutralise the coronavirus does not directly correlate to the level of immunity.

However, there is increasing evidence that higher levels generally correspond with stronger and longer-lasting protection against infection, according to experts.

In their study, leading epidemiologists Benjamin Cowling and Gabriel Leung, and virologist Malik Peiris wrote: “The difference in concentrations of neutralising antibodies identified in our study could translate into substantial differences in vaccine effectiveness.”

In an exclusive interview with the Post, lead researcher Cowling noted that moderate levels of protection were still better than none at all, and urged Hongkongers to get vaccinated.

“Don’t let the perfect be the enemy of the good,” he said.