A vaccine for COVID-19: So near and yet so far

Shobha Shukla *

With the numbers of those infected with COVID-19 (SARS-CoV-2) escalating everyday globally we are indeed wading through turbulent waters with no end at sight. Scientists around the world are literally burning the midnight oil, searching frantically for a treatment to rid the world of this pandemic. It is a race between humans and the virus.

And although it is too early to predict anything, their efforts for developing a vaccine have met with some initial successes, with 5 candidate vaccines having entered phase-3 of their clinical trials. And as we wait with bated breath for the magic vaccine, a historic moment has already set in with the large scale manufacturing of some of these vaccines already begun, including in India.

saving human lives has primacy over money

This is an unprecedented move - to start producing large quantities of vaccines irrespective of the final outcome of the trials. It is a calculated risk that philanthropic organisations and some governments are ready to take by giving precedence to saving human lives over losing money (in case the vaccine does not make it to the final milestone). It will ensure timely and large-scale availability of doses in case that particular vaccine is successful.

AZD1222

One such candidate vaccine is AZD1222 that is being developed jointly by the University of Oxford and AstraZeneca. The Pune-based Serum Institute of India, the largest vaccine manufacturer in the world, that has entered into a manufacturing partnership with AstraZeneca, has committed to manufacture 1 billion (100 crore) doses of this vaccine and has already commenced production.

"This is a big, yet deliverable, assurance for global health as India is already the biggest manufacturer and supplier of more than 60% different kinds of vaccines worldwide. It is vital to ensure that manufacturing of COVID-19 vaccine remains in countries like India so that the world can have access to cheap and affordable prevention against the dreaded virus, without delay by ensuring equitable distribution", said Dr Ishwar Gilada, senior infectious diseases expert, and Secretary General of Organized Medicine Academic Guild (OMAG). Dr Gilada is also the President of AIDS Society of India, and on the governing council of International AIDS Society (IAS).

India is also likely to participate in phase-3 clinical trial of AZD1222. As per a news report, Serum Institute of India said it will apply for a licence from the Indian regulator to start clinical trials of the vaccine in the country very soon.

Dr S Natarajan, President of Organised Medicine Academic Guild (OMAG) and a Padmashree awardee (among the highest civilian honours in the country) hoped that the Indian Government will play a proactive role and expedite clearance to conduct these trials in India. While cautioning that "the results of phase-3 clinical trial will be very important to decide the safety, effectiveness and roll-out of the vaccine for public health use", he conceded that the initial results of this study give hope and that India should be proud to be a part of this initiative.

The results of the Phase-1/2 trial of AZD1222 published in The Lancet, indicate no early safety concerns and no serious side effects by the vaccine in 1077 trial participants aged 18-55 years. The vaccine produced a dual immune response that lasted till at least 56 days after they were immunised. Not only did it produce antibodies, which are the immune system's natural response, but it also produced T-cells that directly kill virus infected cells and are said to last much longer in the human body as compared to the protective antibodies.

Large scale Phase-3 clinical trials are currently underway in the UK (8000 participants) and Brazil (5000 participants) and are due to start in USA (30,000 participants), South Africa (2000 participants) as well as in India (10,000 participants).

4 more vaccines entering phase-3: WHO

As per WHO, apart from AZD1222, their are 4 other vaccines (out of the 24 candidate vaccines currently in clinical evaluation stages) that have entered phase-3 clinical trials, after successfully completing phases-1 and 2 (phases 1 and 2 evaluate safety, immunogenicity and efficacy of the vaccine in a small number of trial participants while in phase-3 the safety, immunogenicity and effectiveness of the potential vaccine is tested in a broader population - often multicountry - over a longer period of time).

Three of these are by Chinese companies, and one is being developed by an American firm Moderna Inc in collaboration with the US government's National Institute of Allergy and Infectious Diseases (NIAID), part of National Institutes of Health (NIH).

US-based biotechnology company Moderna, supported by the National Institute of Allergy and Infectious Diseases (NIAID) is developing a potential coronavirus vaccine candidate mRNA-1273. In fact, Moderna was the first organization to start human trials of mRNA-1273 on March 16, 2020 - 5 days after WHO had termed COVID-19 as a pandemic. The initial phase-1/2 trial has shown promising results. Phase-3 trials are planned to begin this month (in July) on 30,000 participants in USA.

China's state-run Sinopharm Group Co is working on two COVID-19 vaccines being developed by its subsidiary China National Biotec Group Co. (CNBG). As reported by Bloomberg News, these two experimental vaccines are already being offered to employees of large state-owned companies who intend to travel overseas for work. Administering an investigational vaccine (that is still being evaluated in clinical trials) to people outside of the clinical trial protocol is unusual indeed. China National Biotec Group Co. (CNBG) is aiming to produce 200 million doses of inactivated COVID-19 vaccines a year.

China's Beijing-based Sinovac Biotech has also announced positive results from its Phase-1/2 clinical trials of its vaccine CoronaVac and will start phase-3 trials on 9,000 healthcare professionals working in COVID-19 specialised facilities in Brazil and on 4,200 healthcare workers of 7 COVID-19 dedicated hospitals in Bangladesh.

An ideal vaccine against SARS-CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus-2) should be safe and effective after one or two vaccinations; provide protection for a minimum of 6 months and protect old and young alike, including immunocompromised individuals and those with co-morbidities.

Agrees Dr Ishwar Gilada that while phase-3 clinical trials move ahead for these and other vaccines in the pipeline, it is the duty of all the governments, including the Indian government, to be geared to ensure that scientific breakthroughs translate into public health gains without any unnecessary delays. Whenever a safe and effective vaccine for COVID-19 becomes available for public health use, we must have strong health systems and other regulatory mechanisms already in place to be able to deliver it to those most in need of it globally.

Never before the world has conducted a vaccine research so quickly without compromising safety or scientific integrity. It is important to know if a vaccine is safe, immunogenic and effective in protecting us against coronavirus - and - it is equally important to ensure that everyone of us, especially those more vulnerable, to get it as soon as possible.

Dr Anthony S Fauci, Director of National Institute of Allergy and Infectious Diseases (NIAID) had said: "What happens is that in the standard way of developing a vaccine, you don't jump to invest in the next step until you're pretty sure that the step you're in is working... Given the fact that we needed to do this as quickly as possible without sacrificing safety or scientific integrity, the federal government partnered with multiple of these companies and said, we're going to move fast and we're going to assume we're going to be successful. And if we are, we've saved several months. And if we're not, the only thing we've lost is money. But better lose money than lose lives by delaying the vaccine."