The Novavax vaccine uses a traditional method to train the immune system to make antibodies to Covid’s spike proteins.It differs from mRNA vaccines like Pfizer and Moderna that use genetic code to create an immune response.Researchers began by modifying the spike gene, which was inserted into a virus called baculovirus and allowed to infect moth cells. The infected cells produced the spikes seen on the SARS-CoV-2 virus, which were then harvested and assembled into nanoparticles. These nanoparticles mimic Covid’s molecular structure but do not cause it.Immune cells, with the assistance of helper T cells, then take on the spike proteins and tear them apart.B cells can encounter the vaccine nanoparticles and if they are congruously shaped, will latch on to the spike protein and proliferate, producing antibodies of the same shape.The production of these correctly shaped antibodies is what stops coronavirus from entering the body’s cells.The same method is used to make vaccines for flu and HPV.
Novavax said on Monday that its two-shot Covid-19 vaccine was 90 per cent effective at preventing symptomatic cases and 100 per cent effective at preventing moderate and severe symptoms.The US-based biotech firm said it was also 93 per cent effective against variants of concern such as the Alpha strain that originated in the UK.Findings on its efficacy were based on trials involving nearly 30,000 people in the US and Mexico who were injected at random with either the Novavax vaccine or a placebo.The study produced 77 cases of the virus. Of these, 14 people had received the vaccine and 63 the placebo.The infections were all mild but with only one case of the highly infectious Delta strain among these 77 infections, the vaccine’s efficacy against the most concerning of all variants is not assured.

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