Explained: Johnson & Johnson says its COVID-19 vaccine is effective against Delta variant; what this means

Johnson & Johnson (J&J)’s vaccine works against the fast-spreading Delta variant and other highly prevalent viral variants of Sars-CoV-2, the virus that causes COVID-19, the company has said. J&J said it had submitted the data as a preprint to the website bioRxiv ahead of peer review. The announcements: The company said the single-shot vaccine generated a strong response against the coronavirus, and data showed “the durability of the immune response lasted through at least eight months”.

• J&J said a study showed the vaccine was 85 percent effective against “severe/critical disease and demonstrated protection against hospitalisation and death”.
• The vaccine was effective across regions studied globally, including in South Africa and Brazil, “where there was a high prevalence of rapidly emerging Beta and Zeta (P.2) variants during the study period”, according to the company.
• A single dose of the vaccine generated neutralising antibodies against a range of Sars-CoV-2  variants of concern, including against Delta (B.1.617.2), Beta (B.1.351), Gamma (P.1)

What it means for India? J&J has indicated that it is in talks with the Indian government to bring its vaccine to the country of 1.3 billion people. There have been reports that the firm will not carry out local trials after India okayed scrapping bridging trials for vaccines approved by the West and the World Health Organization.

• A launch in India will bolster the country’s vaccine arsenal even as authorities prepare for a possible third wave.
• The data showing J&J’s vaccine is effective against the Delta variant, which was first identified in India, is encouraging in that context.
• J&J’s inclusion in India’s vaccine list will not only give India one more option but also boost the availability of the shots. Experts say the key to ending the pandemic lies in an efficient and fast vaccination campaign.
• India is already using Covishield (the made-in-India version of the Oxford-Astrazeneca vaccine), the indigenous Covaxin and Russia’s Sputnik V.
• Moderna’s vaccine, which is being widely used in the US, too, has received regulatory approvals in India.
• Vaccines by Ahmedabad-based Zydus Cadila and Hyderabad-based Biological E are expected in the coming months.

Where do others stand? Before J&J’s announcement that its candidate is effective against the Delta variant, a section of infectious disease experts has backed the need for booster shots of the Pfizer/BioNTech or Moderna mRNA-based vaccines for Americans who received the J&J jab, primarily due to the prevalence of the more contagious Delta variant, according to a Reuters report.

• Both Pfizer and Moderna have earlier said their vaccines were effective against the Delta variant.
• The Indian government has said Covishield and Covaxin were effective against Alpha, Beta, Gamma and Delta variants.
• Sputnik V’s developers, too, have said the Russian vaccine was 90% effective against the Delta variant.

The fine print: The new data could be a booster shot for the vaccine itself. The single-shot vaccine was once considered a game-changer with hopes rising over faster rollout in shorter spans. But there have been obstacles. “Supply problems, safety concerns, improved deliveries of rival vaccines and countries’ inoculation strategies have all played a part in holding back usage,” says another Reuters report.

• According to the June 23 Reuters report cited above, “only about 12 million doses have been delivered to the EU (European Union) out of the 55 million expected by the end of June”.
• A New York Times report on June 18 said authorities feared that they might not find recipients for “millions of doses that will soon expire”, after the vaccine’s appeal dropped due to a rare blood-clotting disorder that put a brief pause on the injections in April.

So is J&J’s vaccine safe and effective? According to the US Centers for Disease Control and Prevention (CDC), the vaccine had high efficacy at preventing hospitalisation and death in people who did get sick in clinical trials.

The J&J/Janssen COVID-19 Vaccine was 66.3% effective in  clinical trials (efficacy) at preventing laboratory-confirmed COVID-19 infection in people who received the vaccine and had no evidence of being previously infected.

• CDC and the US Food and Drug Administration (FDA) have already recommend the resumption of the J&J vaccine in the US after a temporary pause.
• CDC’s website says reports of adverse events suggest an increased risk of thrombosis with thrombocytopenia syndrome (TTS) — a rare but serious risk that involves blood clots with low platelets, mostly in adult women below 50 years.
• Most importantly, CDC also says a review of all available data shows the vaccine’s known and potential benefits outweigh its known and potential risks.