Recent releases of Novavax and Johnson & Johnson on coronavirus 2019 vaccines (COVID-19) show efficacy, but there are still concerns about new variants that have recently become more common.
The protein-based coronavirus 2019 (COVID-19) vaccine candidate NVX-CoV2373, from Novavax, reported phase 3 findings that showed 89.3% efficacy in the prevention of COVID-19 in UK participants.
The experimental findings – carried out during a significant transmission in the country and an emerging, more transmissible variant that is spreading worldwide – coincide with phase 2b findings that show less prevention of the variant originally observed in South Africa.
The vaccine
NVX-CoV2373 is a vaccine consisting of a full-length, perfusion-vein protein, made from proprietary nosocomial nanoparticle technology and the saponin-based Matrix-M additive.
The purified protein is produced in insect cells and is encoded by the SARS-CoV-2 protein genetic sequence.
With the emergence of new mutated strains of SARS-CoV-2 in regions, including southern England and South Africa, Novavax began developing new vaccine structures specified according to the genetic codes of the strains, with the expectation that ideal candidates via booster or in combination as a divalent vaccine will become clear in the coming days.
Testing for these newer vaccines will begin in the second quarter of 2021.
“A primary advantage of our complementary platform is that it uses a very small amount of antigen, enabling the rapid creation and large-scale production of combination vaccine candidates, which could potentially address multiple circulating strains of COVID-19,” said Gregory M Said Glenn. , Managing Director, Novavax President of Research and Development, in a statement.
British trial
Investigators enrolled 15,000 plus adult participants aged 18-84 years to determine the vaccine for a primary endpoint of occurrence of PCR-confirmed, symptomatic COVID-19 starting at least 7 days after the booster vaccine dose in participants. which was serologically negative for SARS. -CoV-2 at baseline.
More than one fourth (27%) of the participants in the trial were older than 65 years.
In the first interim analysis of 62 COVID-19 cases, 56 (89.2%) were observed in the placebo arm, compared to only 6 in the vaccine group (95% GI, 75.2 – 95.4). Of the 62 cases, only 1 was serious – from a placebo patient.
The highly transmissible strain of the British variant was observed in more than half of all cases, investigators noted (n = 32). In a post-hoc review, investigators reported that NVX-CoV2373 was 95.6% effective against the original COVID-19 strain and 85.6% effective against the British variety.
In an interim analysis of the safety database, investigators observed low, balanced doses of severe and medically-adverse side effects in both treatment arms.
Clive Dix, chair of the UK Vaccine Taskforce, praised the results as “spectacular” and encouraged 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 individuals in the UK and the rest of the world from this virus,” Dix said in a statement. “Novavax expects to share further details of the UK test results as additional data become available.”
South Africa trial
In the phase 2b clinical trial evaluating the vaccine against placebo in 4400 plus adult participants from August 2020 to mid-January 2021, investigators reported an efficacy of 60% (95% AI, 19.9 – 80.1) for prevention of COVID-19 among participants who were HIV-negative.
Overall, they observed 29 cases in the placebo group and 15 in the NVX-CoV2373 group. Again, only 1 serious case was reported in the placebo group.
In the overall trial population, consisting of both HIV-positive and HIV-negative participants, researchers reported an efficacy of 49.4% (95% AI, 6.1 – 72.8).
Preliminary sequence data show that 92.6% of the cases were the South African variant for 27 of the 44 total COVID-19 diagnoses.
However, investigators stressed that a third of the enrolled participants were seropositive, which already showed a COVID-19 infection at baseline. Pre-trials, according to temporary epidemiology data for the assessed region, these cases indicate the original COVID-19 strain.
Whether the current Novavax product can completely protect against the worldwide South African variant is debatable, but researchers emphasize its value in reducing COVID-19 severity.
“The 60% reduced risk of COVID-19 disease in vaccinated individuals in South Africans underscores the value of this vaccine in preventing disease due to the very worrying variant currently spreading in South Africa, which is spreading worldwide,” said Shabir Maddi. , chief investigator professor, executive director of the research unit for the analysis of vaccines and infectious diseases (VIDA) at Wits, said in a statement. “This is the first COVID-19 vaccine for which we now have objective evidence that it protects against the variant that prevails in South Africa.”
US trial
According to Novavax, the enrollment PREVENT-19 clinical trial in the U.S. and Mexico has already targeted more than 16,000 participants at random, with the expectation that 30,000 targeted enrollments would be in early February.
Phase 3, randomized, placebo-controlled, observation-blind assessment, is performed in support of federal agencies, including Operation Warp Speed (OWS), and the efficacy, safety, and immunogenicity of NVX-CoV2373 with Matrix-M in adults versus placebo.
Johnson & Johnson
Johnson & Johnson (J&J) announced today that the JNJ-78436735 COVID-19 vaccine was 85 percent effective in preventing serious diseases in all regions studied – 28 days after vaccination.
These regions included the USA, Latin America and South Africa. Efficacy against serious diseases increased over time, with no cases in vaccinated participants reported after day 49 in all adults aged 18 years and older.
In addition, the protection level of the vaccine against moderate to severe 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, developed by Johnson & Johnson’s Janssen Pharmaceutical Enterprises, is more commonly called the Ad26.COV2.S vaccine, and is a recombinant, replication-incompetent adenovirus serotype 26 (Ad26) – vector encoding. a complete and stabilized SARS-CoV-2 ear protein (S).
‘These results from the top line with a COVID-19 single-admission vaccine candidate are a promising moment. The potential to significantly reduce the burden of serious illness by delivering an effective and well-tolerated vaccine with just one vaccination is a critical part of the global response to public health, ” Johnson & Johnson Vice President and Chief Scientist officer Paul Stoffels, managing director, said. ” The single-use vaccine is considered by the World Health Organization to be the best option in pandemic conditions, improving access, distribution and compliance. Eighty-five percent efficacy in preventing severe COVID-19 disease and preventing COVID-19-related medical interventions can protect hundreds of millions of people from serious and fatal consequences of COVID-19. It also offers the hope of easing the huge burden on healthcare systems and communities. ”
These results come from the company’s Ensemble study conducted in eight countries and three regions.
“The J&J vaccine is a fantastic result,” said former FDA Commissioner Scott Gottlieb, MD. tweeted this morning. “We now have three extremely effective vaccines. This vaccine has shown sustained (and increasing!) Immune protection over time, perhaps through a robust early induction of immune cells into memory (CD4 and CD8). The protection was strong and durable. ”