Two new COVID-19 vaccines may soon be on the market, as vaccine producers Novavax and Janssen both report positive Phase III results this week.
The Novavax protein subunit vaccine and the Janssen recombinant, non-replicating adenoviral vector vaccine were previously predicted to be approved soon in the U.S. and these results seem to confirm that approvals are on the near horizon.
Novavax reported results from its phase III UK trial, which recruited more than 15,000 participants between 18-84 years (27% over 65 years). The Novavax vaccine is given in two doses with a vaccine booster called an adjuvant and can be kept in a fridge at 2-8°C. Overall, 56 cases of COVID-19 were recorded in the placebo group versus 6 in the vaccine group with an overall efficacy for preventing infection of 89.3%.
Novavax’s candidate seems to be more effective than Sanofi and GlaxoSmithKline’s protein subunit candidate, which failed to trigger a sufficient response in early trials.
Amid concerns about more infectious variants of the virus, the company analyzed the study data to assess whether the vaccine was also effective against the recent UK variant strain. They estimated that the vaccine was effective against both the original and recent UK variant strains with efficacy estimates of 95.6% and 85.6%, respectively.
On a similar note, the company also reported results from a phase IIb trial in South Africa, where there has also been a recent SARS-CoV-2 strain causing concern. This trial was smaller at just over 4400 participants and reported 60% efficacy against mild-severe COVID-19 in individuals without HIV. The large majority of cases recorded in the trial were the South Africa escape variant.
Although this rate of protection is lower than that seen for the other strains of the virus, it is a step in the right direction. “This is the first COVID-19 vaccine for which we now have objective evidence that it protects against the variant dominating in South Africa,” says Shabir Madhi, M.D., Ph.D., a professor and Executive Director of the Vaccines and Infectious Diseases Analytics Research Unit at Wits, and principal investigator in the Novavax COVID-19 vaccine trial in South Africa.
Novavax is also running a bigger phase III study in the US and Mexico. The start of this trial was delayed, due to manufacturing issues, but the company reports it is progressing fast and has already recruited 16,000 of its 30,000-participant goal. According to a press statement, the company hopes to finish recruitment in the first half of next month.
It seems likely that the data from the larger study will be needed for FDA approval, although the company says it plans to file for authorization in the U.K. very soon. Whether the company has solved its previous manufacturing issues and is now able to produce vaccine on a large scale remains to be seen.
Johnson and Johnson subsidiary Janssen Pharmaceuticals also released results for its single dose recombinant, non-replicating adenoviral vector vaccine. Notably this vaccine, which is similar to the AstraZeneca/Oxford University vaccine (not yet approved in the U.S.), only needs one dose and can also be kept in a fridge rather than a freezer.
This vaccine uses the same vector as Janssen’s EU approved Ebola vaccine and its HIV, RSV and Zika vaccine candidates.
The results reported this week are from one of two large phase III trials the company is running. The initial results are reported for a trial of 44,325 participants carried out in Latin America, the, South Africa and the U.S. The vaccine was 66% effective at preventing moderate and severe COVID-19 at 28 days after vaccination including all countries and variants, but 85% effective at preventing severe or critical disease.
When split by country, the vaccine was 72% effective in the U.S., 66% effective in Latin American countries and 57% effective in South Africa at preventing moderate to severe disease at 28 days. No deaths related to COVID-19 occurred in the vaccine group versus 5 in the placebo group.
The company is also running a 30,000-participant phase III trial of the same vaccine that is recruiting in several European countries, as well as South Africa and the U.S. but this has yet to report results.
Johnson and Johnson plan to file for U.S. Emergency Use Authorization from the FDA in early February and “expects to have product available to ship immediately following authorization,” according to a press statement.