Global Scenario For Covid-19 Vaccines

On August 04, India has recorded one of the highest spikes with over 1.91 million cases in the number of the newly detected COVID-19 disease. According to the Ministry of Health Affairs, the death toll has increased from 39,795 to 40,699. Globally, over 18.7 million people have been infected with the United States being the worst-affected followed by Brazil and India.

Several top pharmaceutical companies are making developments at a steady rate to meet with the surging cases and fast-tracking their efforts to come up with an effective vaccine against the novel coronavirus.

In February 2020, the World Health Organization (WHO) did not expect a vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to be available in less than 18 months. However, several wealthy countries and biomedical research industries are progressing towards creating a vaccine to provide acquired immunity against the novel coronavirus.

While global vaccine makers such as Oxford-AstraZeneca, Pfizer-BionTech, and Moderna Inc. have advanced to later stages of testing, India's two homegrown vaccines have now been given the go-ahead to start phase II of their vaccine trial.

This is a brief review comparing the four most globally popular COVID-19 vaccines in the making and the ways in which it could contribute to global health in the future ahead.

Developments by AstraZeneca PLC and CanSino Biological Inc. 
AstraZeneca PLC is a British-Swedish multinational pharmaceutical and biopharmaceutical company having a portfolio of products for major disease areas including cancer, respiratory, cardiovascular, infection, gastrointestinal, neuroscience, and inflammation. In July 2020, AstraZeneca partnered with a clinical research company, IQVIA to speed up U.S. clinical trials on its potential COVID-19 vaccine.

CanSino Biologics is a Chinese vaccine company that has developed Ad5-nCoV, the first novel coronavirus vaccine in a clinical trial in China. It is the only company that has released clinical trial data, with Ad5-nCoV already in a Phase II trial with a primary completion date of January 2021.

Overall, both the results of these potential vaccines are broadly similar and encouraging. Both groups have used an adenoviral vector and have achieved a positive response to their SARS-CoV-2 spike glycoprotein strategy. However, in the case of COVID-19 vaccines, there were concerns about whether the immunity would last, what are the side-effects and which provides better protection from the virus.

Adenovirus vectors can be divided into human and nonhuman adenovirus groups, Ertl said.
AstraZeneca’s AZD1222 Covid-19 vaccine uses a replication-deficient chimpanzee viral vector based on a weakened version of non-human adenovirus (common cold virus) that causes infections in chimpanzees and contains the genetic material of the SARS-CoV-2 virus spike protein. After vaccination, the spike protein is produced, triggering the immune system to attack the SARS-CoV-2 virus if it infects the body in the future.

A possible way to improve its effectiveness is to add a booster shot using a different vaccine technology. But with adenovirus-vectored vaccines, any more than two doses over a lifetime could generate neutralizing antibodies in the immune system to attack the vector. Perhaps AZD1222 only carrying SARS-CoV-2’s spike protein may not be enough. Phase II/III trials are currently underway in the UK, South Africa, and Brazil with an agreement of supplying more than two billion doses of the vaccine with the UK, US, Europe’s Inclusive Vaccines Alliance, the Coalition for Epidemic Preparedness, Gavi the Vaccine Alliance, and Serum Institute of India.

On the other hand, the potential vaccine, Ad5-nCoV  of the CanSino Biologics uses human adenovirus types 5 (Ad5) and 26 (Ad26), a modified adenovirus that carries the genetic material from the new coronavirus into the human body, but the only disadvantage is many people may have already developed a pre-existing neutralizing antibody against the vector which eventually decreases the vaccine’s efficacy prospects.

At present, CanSinoBIO’s adenovirus vaccine production line is ahead of AstraZeneca. However, the Oxford team working for AstraZeneca is expected to be "accelerated" with the aid of huge funding and the support of the global vaccine distribution network.

Developments by Moderna Inc. and Pfizer Inc-BioNTech 
Moderna Inc is an American biotechnology company focused on drug discovery, drug development, and vaccine technologies based exclusively on messenger RNA (mRNA)
It is working towards making the mRNA-1273 (the vaccine candidate against the novel coronavirus) more advanced. On the 16th of April Moderna announced an award from the US Government Agency BARDA for up to $483 million to accelerate the development of mRNA (mRNA – 1273) against Novel Coronavirus. Moderna – started phase III, Platform – RNA – USA.

Moderna Inc has started Phase III trials of its mRNA-1273 vaccine involving 30,000 human volunteers. The vaccine uses messenger RNA, a synthetic form of genetic material from the virus designed to nudge the body’s immune system into attack mode. Phase I results have shown the vaccine is safe and provoked immune responses in 45 healthy volunteers.

Data of Phase III trials to determine the safety and efficacy of the vaccine will start coming in by November and the vaccine may be available by the end of December.

The US government is supporting Moderna’s vaccine with nearly half a billion dollars and the firm has signed an agreement with drugmaker Catalent Inc to make an initial 100 million doses. It has also signed an agreement with Spain’s Laboratorios Farmaceuticos Rovi SA, Swiss contract drugmaker Lonza Group AG and the Israel government. Moderna vaccine price: Moderna is planning to price the vaccine at $50-60 (Rs 3,700-Rs 4,500) for the entire course. This would mean that per dose would be priced at $25-30 (Rs 1,800-Rs 2,300). Moderna’s proposed price will apply to the United States and other high-income countries, a Reuters report said.

Zurich, Switzerland is close to signing a deal to secure access for a coronavirus vaccine being developed by Moderna of the U.S., a government official has said. Switzerland will soon sign a reservation and supply deal, Pascal Strupler, the director of the Federal Office of Public Health, told the Swiss TV programme Club late on Tuesday.

On the other hand, Pfizer Inc-BioNTech’s (which is a pharmaceutical company headquartered in USA) representatives have said that the pricing has been done after monitoring previous flu doses and attending to public health needs during times of crisis. Pfizer's $20 (roughly, Rs. 1496) will set a precedent for its competitors to manufacture and cap the price of their vaccine in a similar fashion. BNT-162 – Pfizer Inc-BioN Tech. Phase I/II – Platform – RNA – USA and Germany

“Interim results from the German study, combined with initial data from the U.S. study, highlight the potential of this mRNA-based vaccine approach and represent an important step forward in our development efforts for the BNT162 program,” said Kathrin U. Jansen, Ph.D., Senior Vice President and Head of Vaccine Research & Development, Pfizer.

CONCLUSION
The US government has chosen three vaccine candidates to fund for Phase III trials under Operation Warp Speed: Moderna’s mRNA-1273 in July, The University of Oxford, and AstraZeneca’s AZD1222 in August, and Pfizer and BioNTech's BNT162 in September. Researchers are working worldwide to find a vaccine against SARS-CoV-2, the virus causing the COVID-19 pandemic. Experts estimated that the vaccine development process could speed a successful candidate to market in approximately 12-18 months.