Decoding the science behind the Covid 19 vaccine

COVID19 vaccine

As covid 19 continues to keep economic activity to the minimum with the rising cases and continued threat, hopes are pined on finding a safe and effective vaccine as soon as possible to contain the virus. Will we have vaccines to prevent corona virus by the end of 2020, is a question the entire world is asking. Looking at the way, the scientists are racing to develop a safe and effective, the answer is an optimistic ‘YES’.

While a lot is at stake since the vaccine is the greatest hope for people to protect themselves from this dreadful virus, it is important to understand, the story of COVID-19 vaccine and progress made so far. So, let’s get started and learn the facts about the vaccine, how it has been developed and how important are the safety and efficacy parameters?

Identifying the antigen/pathogen that prevents the disease

Let’s first understand, what are antigens? Antigens are usually proteins, that arouses the body to create an immune response to safeguard itself from attacks when it comes in contact of any disease.The researchers in the past have taken many years to first identify the antigen in other words, the structure of the virus thereafter decades together to develop a vaccine against diseases. Like for instance, it took scientists more than two decades to develop vaccine against rotavirus. In fact, they are still trying to discover a vaccine against respiratory syncytial virus since over 50 years now.

Then, what makes COVID-19 an exceptional case? Why are the experts including scientists’ microbiologists and public health experts so confident about the fast-tracking process and a safe and effective vaccine expected to roll out at the end of the year?

“The scientists were quick to understand the origin of the virus. It was in January that the researchers had comprehended the structure of the COVID 19 and identified parts of the virus, to be used to develop the antibodies in the vaccine. Therefore, it made the process of producing the vaccine faster even though there is a stark difference in the way different people show the symptoms once contracting the disease. This has instilled a sense of confidence and hope in us that the safe and effective vaccine is in the making,” says, Dr. Sanjiv Kumar, Chairperson of the Indian Academy of Public Health and Indian Alliance of Patients Group, Former Senior Advisor at UNICEF and Former Director at IIHMR.

To which Dr. Debkishore Gupta, Consultant Clinical Microbiologist and Head of Infection Control, CK Birla Hospitals, India adds, “All the vaccines (options) undergoing the clinical trials should be subjected to the most severe scrutiny. It is noteworthy, that the Lancet, one of the renowned medical journals, has set rigorous benchmarks that involve the publications to be reviewed by the peers. Sputnik V is one of the very few vaccines, whose phase 1/2 results based on safety and efficacy were published in the journal. It clearly, stated that no bad effects were found, and the vaccine displayed good response among humans. It also encouraged an effective immune response in 76 respondents in all.[This talks volume of the Russian vaccine as an ideal choice amongst the various vaccines that India is looking at today.”

“The second interim results of Sputnik V conducted on 18,794 volunteers 28 days post receiving the first immunization (seven days after the second one) proved the Sputnik V’s efficacy at 91.4 percent. This is way too good as compared to a minimum 50 percent efficacy mark decided by the Indian Council of Medical Research and the World Health Organisation. Preliminary data on respondents on the 42nd day post the first dose (equal to 21 days post the 2nd dose), when a stable immune response is already instilled in them directs the efficacy rate of the vaccine that is above 95%. As of November 24, 2020, no unexpected ill events have shown during the trial process[ii],” adds Dr. Gupta.

What does a safe and effective vaccine mean, then?

Any new medical intervention must qualify the litmus-test especially when it is about the million lives across the globe. Following are the certain parameters basing on which the scientific community decides whether a certain vaccine has the potential to protect one from COVID-19 infection or not:

Proven platform: After the identification of the structure of the virus, the vaccine enters the pre-clinical stage, where, the development process must be based upon a certain proven platform. Dr. Gupta asserts, “Sputnik V is based on a well-established two-vector human adenovirus-based platform designed by the Gamaleya Research Center. The same platform was used to manufacture Gendicine six years ago in order to fight against Ebola and J&J. Over 250 clinical trials and 75 global publications have confirmed the safety of vaccines and medicines that are based on human adenoviral vectors. The vaccine based on this platform is far more reliable than mNRA-based ones from Moderna and Pfizer and chimpanzee adenovirus-based ones used by AstraZeneca as both mNRA and chimpanzee adenovirus don’t have long-term safety studies.”

Safety and efficacy: These are the factors that contribute in the fast development of COVID 19 vaccine: a) Global Urgency: Because of the urgent need to prevent deaths and sickness many international bodies, public and private institutions across countries such as Coalition for Epidemic Preparedness Innovation (CEPI), Covax. Operation Warp Speed in US etc along with WHO, GAVI etc collaborated to make COVID-19 vaccines available to the public as quickly as possible. B) Fast track approval by regulators, such as emergency approvals, have shortened review timelines in order to hasten vaccine development. C) Many steps in vaccines development such as clinical trial phase 2 &3 have been done in parallel which earlier were done sequentially with time gap between these steps, and d) The mass production even before completing trials: Many manufactures including Serum Institute of India started mass production even before clinical phase 2 and 3 trials were completed taking the risk of having to destroy these doses, if trials did not show desired results. All the vaccine trial results are rigorously reviewed by independent peer reviewers when published and carefully screened by regulatory authorities within and outside the countries. The phase I and II trials have been conducted on human respondents to test the safety and first interim efficacy tests. It also determines the dosage and gauges the adverse side effects. The phase I determines the safety of the vaccine. For instance, Sputnik V cleared the safety parameters with no major adverse effects barring light and mild pain at the site of injection, or headache muscular pain and fever. In fact, vaccines such as Sputnik V had the advantage of more than required number of human respondents in phase II that determines the safety and efficacy of the vaccine. The neutralizing antibodies after vaccine is 1.5 times higher than of patients who have contracted coronavirus. As the the Drug Controller General of India has allowed Sputnik V and other vaccines to enter the phase II and III stages of the clinical, the outcomes will further strengthen our trust on the vaccine,” says Dr. Kumar.

According to the National Research Center for Epidemiology and Microbiology, known as the Gamaleya Center, the efficacy of Sputnik V vaccine against severe cases of COVID-19 was 100%. Among the confirmed cases of COVID-19, 20 severe cases were recorded in the placebo group, while there were no severe cases recorded in the group.

Storage: Storage and logistics are two major challenges in India and very few vaccines comply to the conditions in India. “Russian vaccine has proven to be the natural choice even before the phase III trials as it is available in two forms, liquid, which could be stored at -18°C and lyophilised (freeze dried), to be stored at 2°C to 8°C. The lyophilised form is developed keeping transportation constraints to remote places in mind. This is far more appropriate for Indian soil as compared to many other vaccinations such as Pfizer that needs to be stored at a temperature of -70C. The manufacturers have already started the production of the lyophilised form of Sputnik V,” adds Dr. Gupta.

Dosage: In quest of best fit vaccine, we have reached in advanced stage of clinical trials. Along with safety, dosage pattern is another concern. “In the recently released preliminary phase III results, AstraZeneca’s chimpanzee adenovirus-based vaccine’s full dosage efficacy was 62 percent. In case of the vaccinations that use the same vector in both the doses, the immune system is likely to launch defense mechanisms against the second dose, that makes the vaccine less efficient,” says Dr. Gajendra Singh, Public Health Expert.

He further explains, “Sputnik V, however, is vaccine based on late-stage adenovirus. It uses two different vectors for different injections, human adenovirus types Ad5 and Ad26. Two doses of Sputnik V are needed three weeks apart with the result antibodies are developed against S-protein of the virus after administration. It is thereafter that the immunity is triggered against this protein, which prevents the COVID-19 to enter in the cells of the body. This makes the human body immune to the infection.”

Affordable pricing: As Sputnik V is adenovirus vector-based vaccine, it can be considered comparatively safe. Stating how the ideal vaccine should be, keeping India’s vision of affordable healthcare in mind, Dr. Singh says, “Sputnik V is expected to be available at a price around $10 or ₹700 per dose for national and global markets while other vaccines would be costing little higher such as Pfizer at $19.50 or ₹1,401.86 and Moderna $25-37 or ₹ 1,843.93- ₹ 2,729.01 per dose.[iv] India requires a safe and effective vaccine and definitely cheaper than contemporaries as targeted number of beneficiaries is huge.

“Prevention of deaths and cases from COVID-19 is the need of the hour hence the government, national and international agencies have mutually taken the decision to opt for fast-tracking process without compromising on safety and efficacy of the vaccine” concludes Dr. Kumar.

It is noteworthy here that Russia has had major breakthroughs in the field of medicine in the past as well. Soviet scientists in collaboration with their American counterparts had pioneered a freeze-drying technique for the vaccine against small-pox in 1960s. Prior to that, the two countries had collaborated on a polio-vaccine in 1950s.[v] Soon after that on October 4, 1957, Soviet Union launched the world’s first satellite named Sputnik and interestingly, Russian vaccine Sputnik V is named after this satellite. The title signifies Russia’s success as the first country to have a vaccine approved as per the Russian government official.[vi]

As we recall the glorious history of Russia; the world is looking forward to Sputnik V vaccine in the fight against COVID-19. While there is a competition, looking at the huge demand and the history of medical science, the key is to combat this situation with collaboration backing with scientific methods to find meaningful solutions.

(Disclaimer: The authors are Dr. Sanjiv Kumar, Chairperson of the Indian Academy of Public Health and Indian Alliance of Patients Group, Former Senior Advisor at UNICEF and Former Director at IIHMR; and Dr. Debkishore Gupta, Consultant Clinical Microbiologist and Head of Infection Control, CK Birla Hospitals, India. Views expressed are a personal opinion.)

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