https://www.nejm.org/doi/pdf/10.1056/NEJMoa2103055
Here's a report of the Novavax trial in South Africa. They found 60% efficacy 7 days after the second shot for HIV-negative people. This was in a background of almost all B.1.351 variant. This variant is especially good at avoiding the antibodies made in response to earlier variants, including the one in the vaccine. You can see in the chart on the bottom left that people who had antibodies from a prior infection had basically no protection from them at all. That's a pretty strong argument for getting vaccinated, even if you have had prior covid.
If you look closely at the top graphs showing covid in vaccinated vs unvaccinated people, it's clear that efficacy of the vaccine continues to increase up until day 40 or so. The second shot was day 21, so they started to measure the difference at day 28. So if they had set up the experiment to start counting later, they would have gotten better efficacy.
This result shows strength for Novavax.
Novovax is the next vaccine candidate in the pipeline for the US. It may be the last approved here, as it gets much harder once Pfizer and Moderna get full approval, which they have started the process for.
A few bullet points on it:
- Made using moth cells (no fetal tissue).
- Lower day after side effects than Pfizer/Moderna
- It appears effective, even against the South African Variant (B1.351), which shows little response to natural immunity, or the A-Z vaccine (not available here). While 60% effectiveness against symptomatic disease there does not seem great, it was 100% effective in the study population against severe disease and death. Also they chose to start measuring only 1 week from the last injection, which handicaps results, as effectiveness is not optimal by then.
