The Johnson and Johnson vaccine stands apart as the only single-shot dose that has been approved in the global fight against the Covid-19 pandemic. It is also relatively easy to store and transport, which means that poorer countries have shown an interest in using it for their inoculation drives. With the emergency nod in India, it has become the fifth vaccine to join India’s vaccine arsenal. Even before it had received clearance from Indian health authorities, the Hyderabad-based pharma firm Biological E had said it was set to produce 600 million doses of the vaccine annually. Here’s all you need to know.
What kind of vaccine is J&J? How Does It Work?
The J&J shot is built on the viral vector platform, which is used by some of the most common and widely administered vaccines against the novel coronavirus, which causes the Covid-19 disease.
The key principle on which any vaccine works is to introduce the immune system to the pathogen that causes the disease so that it can train itself to recognise the same pathogen in the future and counter it.
For a viral vector vaccine, scientists use a modified, and harmless, version of a different virus (which is the vector, or carrier) to insert molecular instructions into human cells. In the case of Covid-19 vaccines, the human cells read this instruction to produce the spike protein of the novel coronavirus — which it uses to infect humans. Once the body starts producing the spike protein, the immune system is activated and it gets to work manufacturing antibodies against the virus.
This J&J vaccine uses an adenovirus, which causes the common cold, to carry the spike protein into human cells.
However, the adenovirus is inactivated, which means there is little risk of it causing an actual infection.
The Oxford-AstraZeneca vaccine, which is being used in India as Covishield, and the Russian-made Sputnik V vaccine, too, are viral vector shots.
What Is The J&J Vaccine’s Efficacy Rate?
The vaccine, also known as the Janssen vaccine after the Belgium-based J&J subsidiary that anchored its development, was shown to have 72 per cent efficacy in early clinical trials in the US and 64 per cent and 68 per cent efficacy in South Africa and Brazil. For comparison, the Oxford-AstraZeneca dose had a 76 per cent efficacy rate in a US trial while Covaxin had shown an over 77 per cent efficacy. Sputnik V and Moderna, the two other vaccines cleared for use in India, have efficacy rates of over 91 per cent and more than 90 per cent, respectively.
However, J&J has recently reported that its vaccine “generated strong, persistent activity against the rapidly spreading Delta variant and other highly prevalent Sars-CoV-2 viral variants". In a statement on July 1, it had also said that “the durability of the immune response lasted through at least eight months", which covers the period since the vaccine was first rolled out in the US and elsewhere.
In fact, the company claimed that its shot “elicited neutralizing antibody activity against the Delta variant at an even higher level than what was recently observed for the Beta (B.1.351) variant in South Africa". It said data showed the vaccine was “85 per cent effective against severe/critical disease and demonstrated protection against hospitalisation and death".
What Have Been Issues Affecting J&J Vaccine?
Right at the outset, after it was okayed in the US, drugs regulators flagged issues with the key production site for the vaccine in the country and made the company throw out millions of doses citing unsatisfactory standards. The New York Times in June, in fact, reported that US authorities had asked the company to trash 60 million doses.
Then there were issues with blood clots. In April, the US called a pause on vaccinations with the J&J shot as health authorities investigated cases of rare blood clots linked to it. After the CDC found 15 cases of the clots in nearly 8 million people who got the J&J vaccine, it decided to lift the suspension but added a warning that younger women may run a slight risk of the severe side effect.
Authorities in the European Union (EU), too, have identified blood clots as a “very rare" side effect of the J&J vaccine but reports in April said it was ruled that the benefits of the vaccine outweighed the risks.
More recently, US authorities said they had identified cases of the Guillain-Barre syndrome (GBS) among people who were vaccinated with the J&J shot. The company was informed that preliminary reports showed 95 of the cases were classified as serious and required hospitalisation and there was one death.
The US diseases watchdog, the Centre for Disease Control and Prevention (CDC) said that most of the GBS cases were in men and many of them were aged over 50 years or older. J&J added in a statement that most of the GBS cases emerged within 42 days, or 6 weeks, after vaccination.
The FDA said that the chances of getting GBS post vaccination were “very low" but advised J&J vaccine recipients to seek medical attention if they show symptoms like weakness or tingling sensations or have difficulty walking or difficulty with facial movements after receiving their shot.
Who Is Making The Vaccine In India? How Many Shots Will Be Available For Indians?
In August last year — well before it had received any emergency clearances — J&J had announced that it would collborate with Biological E for manufacturing the vaccine in India. Then in March this year, reprts said that the Quad — comprising India, Australia, Japan and the US — would support the manufacture of the vaccine in India.
Biological E had said in May this year that it was looking to produce 600 million doses of the vaccine annually although it was reported at the time that the Centre had not accounted for any J&J shots as part of the country’s vaccine stocks.
A tweet announcing the emergency approval to India, Union Health Minister Mansukh Mandaviya did not share any details about the vaccine’s rollout and launch in the country.
Earlier, in May, it was announced that an advance order for 200 million doses of the J&J shot had been placed for the COVAX Facility, which is working to ensure equitable vaccine supply around the world. The vaccines thus procured were to be available for both self-financing partners and COVAX Advance Market Commitment (AMC)-eligible participants, which includes India. It was also reported that the scope of supply of 300 million additional J&J doses in 2022 was being explored by COVAX.
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