India, along with the WHO and the US, has said a vaccine with more than 50 percent efficacy will be acceptable, which means the vaccine must demonstrate it is at least 50 percent more effective than a placebo.
It is arguably the most awaited and widely tracked breakthrough in medicine in modern times. With known global coronavirus cases topping 32 million on September 25, a vaccine for the highly contagious viral infection cannot come sooner.
Several Covid-19 vaccine candidates have entered late-stage clinical trials and some are getting ready—the possibility of an effective vaccine in the new year is beginning to look more real.
Around a million people have lost their lives to the outbreak that started in China’s Wuhan in late 2019. India is the second-worst hit country, with 92,290 deaths and more than 5.8 million reported infections. For the last several days, India has been reporting the most cases anywhere in the world, with the outbreak showing no signs of abating.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
India, along with the WHO and the US, has said a vaccine with more than 50 percent efficacy will be acceptable. It means the vaccine has to be at least 50 percent more effective than a placebo to be considered for approval.
Officials in the US say that at least 150 COVID-19 infections must be recorded among trial participants, with at least twice as many occurring among the placebo group.Here is the lowdown on some of the leading vaccine candidates:
Moderna had developed a Covid vaccine based on genetic material or mRNA that instructs human cells to make SARS-CoV2 antigen, eliciting an immune response that had a clear head start over rivals.Status update
The company initiated phase-3, or late-stage, clinical trials on July 27. In Phase-3, the vaccine is being tested on 30,000 participants. As of last week, it had enrolled about 25,000 participants. Moderna’s first interim analysis will come after 53 trial subjects become infected. The company plans to seek emergency authorisation for high-risk groups if the vaccine proves effective. The approval is expected in the first half of CY2021 but the possibility of an early approval can’t be ruled out.India availability
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Pfizer and German firm BioNTech have developed a Covid vaccine candidate based on genetic material or mRNA that instructs human cells to make SARS-CoV2 antigen, eliciting an immune response. Though they had a late start, the two companies have covered a lot of ground and could create history by being the first vaccine to get US approval.Status update
They initiated Phase-2/3 or clinical trials on July 27. The vaccine is being tested on 30,000 participants in the US and countries like Argentina Brazil, and Germany.
On September 12, Pfizer and BioNTech announced they would seek to expand their US trial to 43,000 participants. Pfizer's first interim analysis will come after 32 coronavirus trial subjects become infected. By the end of October, it will come to know whether the vaccine works, the company has said. It plans to seek emergency authorisation for high-risk groups if the vaccine proves effective. The approval is expected in the first half of CY2021, but there is a strong possibility of it coming in before the end of 2020.India availability
AstraZeneca-University of Oxford: AZD1222
The British-Swedish pharma major AstraZeneca and the University of Oxford are developing a Covid-19 vaccine based on a chimpanzee adenovirus called ChAdOx1 as vector that has been modified to carry coronavirus genes and deliver them into human cells. The vaccine had a headstart, with phase-1 initiated in April. Interim data was published in July.Status update
Phase-2/3 clinical trials were initiated in May. The vaccine is being tested on more than 12,000 volunteers in the UK and another 5,000 participants in Brazil and South Africa. In India, Serum Institute of India is testing it on 1,700 participants. The company is enrolling 30,000 participants in the US for phase-3. The trial was paused in the first week of September due to an adverse reaction in a volunteer who developed brain inflammation. The trial resumed in all other countries except the US.
AstraZeneca said its first interim analysis will come after 75 coronavirus trial subjects become infected. This will give a fair idea of the effectiveness of the vaccine. The data is expected by the Q4CY20. The approval is expected in the first half of 2021.India availability
The vaccine would be distributed through Serum Institute of India.
Johnson & Johnson: JNJ-78436735
Johnson & Johnson developed Covid-19 experimental vaccine based on adenovirus vector Ad26. The company has used the same viral platform to develop vaccines for Ebola and other viruses such as Zika, RSV and HIV. What sets it apart is that it is a one-dose vaccine compared to two for other vaccine candidates and doesn’t need to be frozen for distribution, which will make transportation easy and save costs.Status update
Johnson & Johnson became the fourth company to initiate a global phase-3 trial. It took just three months for the company to move from phase 1/2 to a late-stage trial. The company plans to enrol up to 60,000 volunteers across three continents and will study the safety and efficacy of a single vaccine dose versus placebo in preventing COVID-19. If proven to be safe and effective, the first batch of the vaccine should be available for emergency use in early 2021.India availability
The vaccine would be distributed through J&J partner Biological E.
Novavax has spent three decades and burnt $1.5 billion trying to develop vaccines based on its recombinant nanoparticle technology and Matrix adjuvant platform without much success. It’s hoping Covid-19 will turn the tide. Novavax vaccine is a protein sub-unit vaccine that uses part of the virus and combines with adjuvant, or booster, to deliver it as a vaccine. The vaccine doesn’t need to be frozen for distribution, making it much easier to handle.Status update
Novavax initiated phase-3 trial on September 24 in the UK. The trial is being conducted in partnership with the UK government’s Vaccines Taskforce, and is expected to enroll up to 10,000 individuals between 18-84 years of age over the next four to six weeks. The company expects to roll out the vaccine by mid-2021. In September, Novavax reached an agreement with the Serum Institute of India to produce as many as 2 billion doses a year. The vaccine has to be given in two doses.India availability
Vaccine would be manufactured and distributed by its partner Serum Institute of India
Sputnik V, the Covid-19 vaccine developed by Moscow’s Gamaleya Institute, the Russian Defence Ministry and the sovereign Russian Direct Investment Fund, became the first vaccine to be cleared for public use even before being tested for safety and efficacy. The vaccine is based on a modified human adenovirus as vector, which carries the protein of the SARS-CoV-2 virus. On September 16, RDIF reached an agreement with Dr Reddy’s to conduct clinical trials and distribute 100 million doses of vaccine in India.Status update
The results of Sputnik V of Phase 1/2 clinical trials on 76 people were published in The Lancet early September, showing that the vaccine candidate triggered a strong immune response. Russia is enrolling 40,000 volunteers as part of phase-3, starting September. The trial will take six months to complete. Media reports suggest that the vaccine is available for public in Russia but the vaccine may not be available in other countries at least until the first half of CY21. The vaccine has to be given in two doses.India availability:
Vaccine would be distributed through Dr Reddy’s.
Bharat Biotech: Covaxin
Bharat Biotech is developing a Covid vaccine in collaboration with the Indian Council of Medical Research (ICMR). ICMR’s National Institute of Virology (NIV) had transferred the SARS-CoV-2 virus strain. Bharat Biotech has developed an inactivated vaccine based on the strain. The vaccine has been found to have elicited immune response in monkeys.Status update
Bharat Biotech initiated Phase– 1 and 2 trials in July. The company plans to launch Covaxin Phase -3 trials in October, where it will test the vaccine on about 25,000-30,000 volunteers in India and other countries. The vaccine is unlikley to be launcheduntil the first half of 2021. Bharat Biotech is making the vaccine at risk. Currently, it has capacity to manufacture 100-200 million doses at two of its Biosafety Level (BSL) -3 facilities in Hyderabad. It is trying to rope in partners who can increase the capacity to 1 billion doses per annum. The vaccine has to be given in two doses.India availability
The vaccine will be distributed by Bharat Biotech
Zydus Cadila: ZyCoV-D
Zydus Cadila has taken a novel approach to its potential Covid-19 vaccine. Called plasmid DNA, the vaccine consists of genetic material of SARS-CoV-2 proteins that instructs human cells to make SARS-CoV2 antigen, eliciting an immune response. The company says that this approach is easily replicable and scalable, requiring just Biosafety Level (BSL)-1.Status update
Zydus Cadila initiated Phase–1 and 2 trials in July. The company plans to test the ZyCoV-D vaccine on about 15,000-20,000 people in Phase-3. The launch of the vaccine is expected in the first half of 2021.India availability
Vaccine would be distributed by Zydus Cadila
Sanofi-GSK Covid vaccine lags behind but given that the vaccine comes from Sanofi, which has a huge manufacturing and distribution presence in India, its progress will be closely watched. The vaccine is based on a protein subunit, with adjuvant (booster) provided by GSK.Status update
The companies said the pre-clinical studies showed promise regarding safety and immunogenicity of the vaccine. On September 3, Sanofi and GSK announced the initiation of Phase 1/2 clinical trials. Over 400 participants are enrolled for Phase 1/2 study. Pending positive Phase 1/2 data, companies aim to move into Phase 3 by the end of 2020. Sanofi and GSK are scaling up manufacturing of the antigen and adjuvant with the target of producing up to one billion doses in 2021. The vaccine is likely to be available in the second half of CY21.India availability
The vaccine could be available to India through Covax.
The Chinese vaccine candidate based based on human adenovirus Ad5 vector developed by CanSino Biologics and Beijing Institute of Biotechnology and Academy of Military Medical Science has become a major tool for China's vaccine diplomacy. The vaccine has been approved by the Chinese military on June 25 for a year as a “specially needed drug”.Status update
Cansino vaccine entered phase-3 in August with plans to enrol 40,000 participants. China has got approvals in Russia, Pakistan, Saudi Arabia, for conducting phase-3 trials. Possible launch in second half of CY21.India availability