Scientists, researchers, hospitals and similar healthcare professionals and entities are on the constant lookout for an effective solution to ride the coronavirus, with vaccination experiments being the current area of focus. Although a unique plant-based protein chewing gum is grabbing the limelight of late, vaccination experimentation is one that’s new, restoring new hope in humanity against the seven variant virus.
Peculiar substances rich in combating viruses in general to mixing chemicals, a lot of efforts are being brewed to find out whether the virus can be annihilated at ground level or lessen its potential of spreading. One that’s been making headlines is the plant-based vaccine showing remarkable results and the mixing of vaccines showing better response among people.
Starting with the plant-based vaccine, drug developer, Medicago, developed a plant-based COVID-19 vaccine candidate enhanced by GlaxoSmithKline’s booster showed 75.3 percent success rate against the Delta variant and is currently seeking regulatory approval to share its success for the world.
World’s First Plant Based Vaccine
For two decades, Medicago has been developing plant-based technology to manufacture virus-like particles (VLP) for its protein vaccines. VLPs are engineered to look like viruses in their natural state, helping the immune system to recognize them more easily. The VLPs are noninfectious and unable to reproduce as they lack core genetic material, according to the company, which said that VLP vaccinations made using different methods have been used internationally for more than 30 years.
Made with virus-like particles, the vaccine comprises a similar structure to that of the coronavirus but does not contain any of its genetic information. The vaccine's overall success rate against all coronavirus variants was 71 percent, with the exception of Omicron, which was not in circulation at the time the trial was conducted. The vaccine candidate was well-tolerated, according to Medicago and GSK, with no significant side events identified in the vaccine group.
“The results of our clinical trials show the power of plant-based vaccine manufacturing technology”, says Takashi Nagao, CEO and president of Medicago. “If approved, we will be contributing to the world’s fight against the COVID-19 pandemic with the world’s first plant-based vaccine for use in humans”.
The trial's results are positive, according to Thomas Breuer, GSK's global COVID-19 adjuvanted vaccines lead and chief global health officer, considering data was collected in an environment where no original SAR-CoV-2 virus was circulating, therefore everything shown in the study is for a new variation.
Currently, Medicago is seeking regulatory approval from Health Canada as part of a rolling proposal. It has also started the FDA and the UK's Medicines and Healthcare Products Regulatory Agency regulatory filing process (MHRA). Preliminary conversations with the World Health Organization (WHO) for the drafting of a proposal are also underway, according to the business. Medicago also said that it has begun a phase 1/2 trial in Japan, which it intends to submit for regulatory approval in conjunction with the results of the phase 2/3 worldwide study next spring.
Another significant experimentation that has been making headlines is by a British study which used a combination of Covid-19 vaccinations and discovered that participants had a greater immune response when they had an AstraZeneca or Pfizer-BioNTech injection first, followed by Moderna nine weeks later.
Better Immune Response from a Mixture of Vaccines
The findings in support of variable dosing are providing some promise to low- and middle-income countries, which may need to combine different brands between their first and second shots if supplies run out or become unstable.
“We found a really good immune response across the board…, in fact, higher than the threshold set by Oxford-AstraZeneca vaccine two doses,” Matthew Snape, the Oxford professor behind the trial dubbed Com-COV2.
“I think the data from this study will be especially interesting and valuable to low- and middle-income countries where they’re still rolling out the first two doses of vaccines”, Snape said. “We’re showing…you don’t have to stick rigidly to receiving the same vaccine for a second dose…and that if the programme will be delivered more quickly by using multiple vaccines, then it is okay to do so”.
According to researchers at the University of Oxford, when the AstraZeneca-Oxford vaccination is followed by a Moderna or Novavax shot, greater antibodies and T-cell responses are generated compared to two doses of AstraZeneca-Oxford.
A dosage of the Pfizer-BioNTech vaccination followed by a Moderna shot was also found to be superior to two doses of the normal Pfizer-BioNTech course in a study of 1,070 volunteers.
The two-dose Oxford-AstraZeneca schedule elicited greater antibodies than the Pfizer-BioNTech followed by Novavax schedule, however this schedule induced lower antibody and T-cell responses than the two-dose Pfizer-BioNTech schedule.
According to an Oxford University study published in the Lancet medical journal, no safety issues were identified.
Many countries have been using a mix and match approach even before reliable data was available, due to high infection rates, poor supplies, and sluggish immunization due to safety concerns.
Vaccines' duration of protection has been questioned, and booster doses are being considered in the wake of an increase in cases. New variations, such as Delta and Omicron, have increased the pressure on vaccine campaigns to be accelerated. Researchers from the Com-COV2 study noted that blood samples from participants were tested against the Wild-Type, Beta, and Delta variants, and that vaccine efficacy against the variations had diminished, but that this was consistent across mixed courses.
Using technologies from several platforms – such as Pfizer and Moderna's mRNA, AstraZeneca's viral vector, and Novavax's protein-based injection – and deploying vaccinations on the same timetable is a first.
According to Snape, the findings could lead to new techniques to vaccination against other diseases.
The study was dubbed as a ‘non-inferiority’ study, with the goal of demonstrating that mixing isn't significantly worse than regular regimens, and compares immune system responses to gold-standard responses observed in past vaccination clinical trials. The study also discovered that a first dosage of the AstraZeneca-Oxford vaccine followed by any of the other trial candidates resulted in a very strong response, which is consistent with data from June.