Recent publications by Novavax and Johnson & Johnson data on coronavirus disease vaccines 2019 (COVID-19) show efficacy, but there is still some concern about new variants that have recently become more common.
Novavax Protein-Based Vaccine Candidate NVX-CoV2373 (COVID-19) Candidate 2019 has reported phase 3 findings that show an 89.3% efficacy in the prevention of COVID-19 in UK participants.
The results of the test, performed at a time of significant transmission in the country and an emerging variant, more transmissible that extends worldwide, coincide with the findings of phase 2b that show less prevention of the variant originally observed in South Africa.
The vaccine
NVX-CoV2373 is a vaccine consisting of a long-lasting prefusion ear protein made from patented recombinant nanoparticle technology and the saponin-based Matrix-M adjuvant.
Produced in insect cells, the purified protein is encoded by the genetic sequence of the SARS-CoV-2 ear protein.
With the emergence of new mutated strains of SARS-CoV-2 in regions such as the south-east of England and South Africa, Novavax has begun the development of new vaccine constructs specified in the genetic codes of the strains, in the hope that ideal candidates are provided through booster or in combination as a bivalent vaccine will become apparent in the coming days.
Tests of these newer vaccines would be launched in the second quarter of 2021.
“One of the main advantages of our adjuvanted platform is that it uses a very small amount of antigen, which allows the rapid creation and large-scale production of combined vaccine candidates that could face multiple circulating strains of COVID-19,” he said. say Gregory M. Glenn, MD, president of Novavax Research and Development, in a statement.
UK test
The researchers enrolled more than 15,000 adult participants aged 18 to 84 years to evaluate the vaccine for a primary endpoint of symptomatic PCR-confirmed symptomatic COVID-19 with onset at least 7 days after the booster dose in participants. serologically negative for SARS -CoV-2 at baseline.
More than a quarter (27%) of trial participants were over 65 years of age.
In the first provisional analysis of 62 cases of COVID-19, 56 (89.2%) were observed in the placebo arm, compared with only 6 in the vaccine group (95% CI, 75.2 – 95, 4). Of the 62 cases, only 1 was severe: from one placebo patient.
The researchers noted that the transmissible variant strain of the United Kingdom was detected in more than half of all observed cases (n = 32). In a post hoc evaluation, the researchers reported that NVX-CoV2373 was 95.6% effective against the original COVID-19 strain and 85.6% effective against the UK variant strain.
In a provisional analysis of the safety database, the researchers observed low and balanced rates of serious adverse events and medical care in both treatment arms.
Clive Dix, chair of the UK vaccine working group, praised the results as ‘spectacular’ and expressed his encouragement for the slightly less effective effect observed against the UK variant with the vaccine.
“This is an incredible achievement that will ensure that we can protect people in the UK and the rest of the world from this virus,” Dix said in a statement. “Novavax expects to share more details of the test results in the UK as additional data becomes available.”
South Africa test
In the phase 2b clinical trial evaluating the vaccine versus placebo in more than 4,400 adult participants from August 2020 to mid-January 2021, the researchers reported a 60% efficacy (CI of the 95%, 19.9 – 80.1) in the prevention of COVID-19 among participants who were HIV negative.
Overall, 29 cases were observed in the placebo group and 15 in the NVX-CoV2373 group. Again, only one serious case was reported in the placebo group.
In the overall trial population, made up of both HIV-positive and HIV-negative participants, the researchers reported an efficacy of 49.4% (95% CI: 6.1 – 72.8).
Preliminary sequencing data show that, for 27 of the 44 diagnoses observed for COVID-19, 92.6% of cases were the South African variant.
The researchers noted, however, that one-third of the enrolled participants were HIV-positive, demonstrating a previous COVID-19 infection at first. Pre-trial infections, according to temporary epidemiological data from the evaluated region, indicate that these cases would be the original COVID-19 strain.
It is questionable whether the current Novavax product can be completely protected from the worldwide South African variant, but researchers stress its value in reducing the severity of COVID-19.
“The 60% reduced risk of COVID-19 disease in vaccinated South African individuals underscores the value of this vaccine in preventing diseases of the highly worrying variant currently circulating in South Africa and which is spreading throughout the world, ”said lead research professor Shabir Maddi, the executive director of Wits’ Vaccine and Infectious Disease Analysis (LIFE) Research Unit said in a statement. “This is the first COVID-19 vaccine for which we now have objective evidence that protects against the variant that dominates South Africa.”
American test
According to Novavax, the PREVENT-19 clinical trial enrolled in the United States and Mexico has already randomized more than 16,000 participants, with expectations of 30,000 specific enrollments in early February.
Conducted with the support of federal agencies, including Operation Warp Speed (OWS), Phase 3, randomized, placebo-controlled, blinded evaluation by observers will evaluate the efficacy, safety, and immunogenicity of NVX-CoV2373 with Matrix-M in adults versus placebo.
Johnson & Johnson
Johnson & Johnson (J&J) announced today that its JNJ-78436735 COVID-19 vaccine was 85% effective in preventing serious disease in all regions studied, 28 days after vaccination.
These regions included the USA, Latin America and South Africa. Efficacy against serious disease increased over time, with no cases recorded in participants vaccinated after day 49 in all adults over 18 years of age.
In addition, the level of moderate to severe vaccine protection against COVID-19 infection was 72% in the United States, 66% in Latin America, and 57% in South Africa, 28 days after vaccination. .
The single-dose research vaccine, which is being developed by Johnson & Johnson’s Janssen pharmaceutical companies, is more commonly known as the Ad26.COV2.S vaccine, and is a vector encoder for recombinant and incompetent adenovirus serotype 26 (Ad26). . a complete and stabilized tip SARS-CoV-2 protein (S).
“These top-line results with a vaccine candidate against COVID-19 represent a promising moment. The potential to significantly reduce the burden of serious disease by providing an effective and well-tolerated vaccine with just one vaccination is a critical component of the global public health response, “said Johnson & Johnson, executive committee vice president and chief scientific director. Said Paul Stoffels, MD. “The World Health Organization considers a single vaccine to be the best option in pandemic environments, which improves access, distribution and compliance. Eighty-five percent effectiveness in preventing serious COVID-19 disease and preventing COVID-19-related medical interventions will potentially protect hundreds of millions of people from the severe and deadly outcomes of COVID-19. It also offers the hope of helping to alleviate the enormous burden on health systems and communities. ”
These results come from the Ensemble study conducted in eight countries and three regions.
“The J&J vaccine results in a fantastic result,” said former FDA Commissioner Scott Gottlieb, MD. has tweeted this morning. “We now have 3 highly effective vaccines. This vaccine showed sustained (and increasing!) Immune protection over time, perhaps from a robust early induction of memory immune cells (CD4 and CD8). The protection was strong and lasting. “