Covid-19 booster shot enhances waning immune response - Pharmaniaga

 

A booster shot of the Covid-19 vaccine will help boost a waning immune response and induces a significant increase in neutralising antibodies against highly infectious variants.

Pharmaniaga in a statement today said the same Covid-19 vaccine booster shot is highly recommended based on the evidence from boosting studies in the adult and elderly populations. 

The pharmaceutical company said the conclusion was made by experts in a virtual webinar organised by Pharmaniaga entitled “Covid-19 Booster Shots and Vaccination for Children: Moving forward with experiences from China, Chile, and Indonesia” held today.

“The panel experts concurred that taking booster shots will substantially increase antibodies which have started to decline six months after the second dose, according to the studies,” it said.

Among the panellists was Sinovac Biotech Co Ltd senior director of overseas business Weining Meng who said a booster shot given at an interval of between six and 12 months after the second dose led to a strong boost in immune response, with geometric mean titers (GMTs) increasing to approximately 140.

He said according to research conducted at the Chinese Academy of Sciences, Peking University and Sinovac Biotech, their data also indicated that a third dose would allow vaccine protection to last longer and have better persistence.

Booster timing 

Meng said the timing of a booster dose should take into account the existing Covid-19 infection in the country and breakthrough cases after the primary vaccination.

“The GMT six months after the third dose is higher than the peak of the second dose. In addition, the studies also showed higher persistence of antibody six months after the booster dose compared to the second dose, indicating a longer duration of protection from Covid-19 and other new variants,” added Meng.

To date, Sinovac Biotech has supplied more than two billion doses of CoronaVac to the world. Over 810 million doses were delivered to countries outside China by Oct 12, while more than 1.2 billion doses were used in China.

A speaker from Chile, Millennium Institute Immunology and Immunotherapy professor and director Dr Alexis M Kalergis noted that the vaccines received by the Chilean population were mostly from Sinovac.

“In Chile, the regulator has approved the use of CoronaVac vaccine starting from six years, and older children and this vaccine campaign is moving smoothly so far due to better safety profile in the paediatric population,” he said, adding that the Sinovac vaccine had been proven to be safe and effective in the Chilean population.

Sinovac vaccine as booster 

He noted that booster shots are safe and provide significant enhancement of neutralising antibodies in healthy adults.

“The effectiveness of the booster shots is expected to be high for the Sinovac vaccine. Chilean health fertility experts are more comfortable using the Sinovac vaccine as it is made using an inactivated virus platform that has been extensively used in the past, such as the polio vaccine.

“No doubt other vaccines are effective as well, but the main reasons why we decided to work with inactivated vaccine - Sinovac, is because data shows it is more comprehensive in terms of an immune response,” he said.

- Bernama