Novavax Covid-19 vaccine performs well in clinical trials, but variants remain a threat

More than 330 million vaccines have been administered in the fight against Covid-19, and a new vaccine candidate is now ready to enter the ring. Novavax recently completed its final analyzes and will seek approval from the FDA and the international community in the coming weeks. The new candidate uses a mechanism to trigger immune responses that is different from vaccines already in circulation, but remains effective against non-variant forms of the virus. Here, I discuss the results and implications of the Novavax trials and the performance of the vaccine against increasing variants of SARS-CoV-2.

The press release details a UK trial of 15,000 participants. Against the wild strain of the virus, the two-dose vaccine showed an efficacy of 96.4%. Notably, the vaccine was also 100% effective in preventing serious illnesses, which included symptoms such as tachypnea, elevated resting heart rate, required ventilation, hospitalization, among others.

These 15,000 participants also included infections via the highly transmissible UK variant of the virus. The vaccine has consistently shown an impressive 86.3% efficacy against the variant, which corresponds to an overall vaccine efficacy of 89.7% among the 15,000 study participants. In addition, among the non-placebo participants in the trial, only one case of Covid-19 was reported among those aged 65 and over, a demographic group heavily affected by the pandemic.

Novavax also wanted to see how its vaccine would perform against the South African antibody-resistant variant of the virus. Among a group of participants of 2,905 adults, the vaccine demonstrated an overall efficacy of only 48.6% against the predominant B.1.351 variant. Although no serious Covid-19 was noted in the vaccinated group, these figures are less encouraging than in the British group. In HIV-negative adults, the efficacy is 55.4%, which is still well below average. This is a recurring theme in the vaccine landscape. The South African variant, along with its genetically similar counterparts like those from Brazil, Japan, and elsewhere, are significantly resistant to vaccine-induced and naturally formed antibodies.

The Novavax vaccine works by combining a purified spike protein with an adjuvant or a substance designed to enhance a given immune response. In 1984, I used essentially the same formula – adjuvant, shell, and the equivalent of a spike – to create a vaccine that prevents cats from contracting leukemia. It’s old technology, but arguably the most direct line of attack we can mount against a virus. Other FDA-approved Covid-19 vaccines employ methods that are certainly innovative and still effective, but overall more roundabout approaches to achieve the same target. These include the messenger RNA in the Moderna and Pfizer-BioNTech vaccines, which instruct human cells to make advanced proteins, and the adenovirus vectors in the Johnson & Johnson and AstraZeneca vaccines, which contain instructions for making spike. anti-SARS-CoV-2 antibody.

That clinical trials of the Novavax vaccine have yielded such promising results is a great sign, especially given the emergence of new variants. Many pharmaceutical companies have already announced that they are developing second generation vaccines tailored directly to these new variants. The only hesitations to note are the ones they adapt to, and what if new ones pop up in the time it takes to develop, test, and distribute? The illustration below shows some of the many variants that have derived from the wild type of SARS-CoV-2.

Either way, those hesitations shouldn’t hurt the positive news about this story. A new vaccine will soon be available that shows high efficacy against wild type and one of the more prolific variants. Hopefully this vaccine will help reign over the number of cases as new vaccines are developed in the coming months.