A booster shot of the two-dose Sinovac inactivated vaccine provides effective protection against From Delta Variant of coronavirus.


According to a report in Chinese media, the third dose would increase the potency, scale, and duration of anamnestic responses against Covid-19. It further reported that a full course immunization with Sinovac inactivated vaccines could effectively protect against severe illness caused From Delta Variant. It said the administration of a third dose can raise a “better neutralization breadth and long-lasting humoral response in warding off COVID-19”.

According to the report, the third dose booster of “inactivated vaccine can elicit an expeditious, robust and long-lasting recall humoral response which continues to evolve with an ongoing accumulation of somatic mutations, emergence of new clones and increasing affinities of antibodies to antigens, conferring enhanced neutralizing potency and breadth”.

Collectively, the findings rationalise the use of three-dose vaccination regimens, it was reported. Furthermore, the newspaper quoted another paper that suggested that the risk of progression to severe illness had substantially decreased in fully vaccinated patients infected with the Delta variant.

The newspaper termed it “the largest real-world study confirming the effectiveness of inactive COVID-19 vaccines against severe illness in patients infected with the Delta variant in Jiangsu, China”.

It further said that severe illness didn’t occur in fully vaccinated patients who didn’t have any underlying health conditions. Both of the two fully vaccinated patients who developed severe illnesses had underlying diseases. And 100-percent protection was also found in elderly patients that had been fully vaccinated, the paper said.

“The protective effect is affected by underlying medical conditions. Partial vaccination does not offer clinically meaningful protection against severe illness. Our study highlights the importance of continuing efforts on a full course of vaccination,” the research concluded.

The report said that the severe illness was 100 per cent prevented in fully vaccinated women whereas only 81 per cent men were at reduced risk. It said more research was needed on whether sex disparities existed in Covid-19 vaccine efficacy.

Source The Express Tribune