VACCINE TRIAL IN WUHAN SHOWS PROMISE, BUT A LONG WAY TO GO

HCQ, Remdesivir, and Oxford, Sino Biotech, Moderna vaccine programmes, though in early stages, bring some hope

NEWDELHI: A vaccine for the SarsCov-2 virus developed by researchers at China’s CanSino Biologics was found to be safe and effective in its first test on humans, becoming the latest trial that raises hope for an early candidate that could help make people immune to the coronavirus disease (Covid-19). The result of CanSino’s Phase 1 trial, reported in The Lancet on Friday, is the first to be published in a peer-reviewed journal. The Chinese researchers reported that their experimental vaccine produced neutralising antibodies — the type of immune cells that kill infected cells — and the rapid immune responses crucial for the body to mount its varied counter-attack. The trials were carried out with 108 healthy participants from Wuhan who were never infected by the virus. The results are based on antibody and immune cell concentrations seen within 28 days of the vaccine being given to the participants in a low, medium or high dose. The ones given the high dose had the strongest immune response but also suffered from the most side-effects, such as high fever, fatigue and headache.

NEW DELHI: Mixed results from clinical trials of several promising treatments and vaccines against the Covid-19 released this week brought both cheer and gloom to a world desperate for a safe and effective treatment or vaccine against a disease that has infected at least 5.3 million people and killed 340,000.

At least 100 vaccines are being developed against Sars-CoV-2, which causes Covid-19, with many using new platforms that have not been used in a licensed vaccine before. Vaccines work by training the body’s adaptive immune system to recognise and neutralise invading viruses, bacteria and other pathogens to prevent infection.

HYDROXYCHLOROQUINE

In the absence of a treatment or vaccine, one of the major drugs being repurposed to treat this new disease against which humans have no immunity are anti-malarial drugs, hydoxychloroquine and chloroquine, which US President Donald Trump said he has been popping daily to prevent infection.

On Friday, a study of 96,000 hospitalised patients in six continents published in The Lancet journal delivered the disappointing news that those treated with the drug had a significantly higher risk of death compared with those who were not. The drug raised the risk of irregular heart rhythm (arrhythmia) that can lead to sudden cardiac death, concluded the analysis.

India is the world’s biggest producer of HCQ, which is approved for use as a prophylaxis to be given to asymptomatic health workers and contacts of Covid-19 patients since March 23. This was expanded to include frontline workers from May 22.

“Several studies are underway in India, and, as the results emerge, we shall be able to provide more insights into the experiences locally...,” said health minister Dr Harsh Vardhan, in an interview to HT earlier this week. “...The Lancet paper that has come out will have implications for treatment regimen, not prophylaxis,” said an official from India’s apex research organisation, the Indian Council of Medical Research.

REMDESIVIR

Remdesivir became the only drug to receive an emergency-use authorisation in the US to treat Covid-19 after early data showed it shortened recovery time from 15 days to 11 days in hospitalised adults with lower respiratory tract infection. A study of 1,063 patients that included 538 who received remdesivir and 521 who were given a placebo showed death in the remdesivir group was 7.1%, compared to 11.9% for the placebo group, but it brought no benefits for severely ill patients on mechanical ventilation, according to a study published in the New England Journal of Medicine.

“These findings support the use of remdesivir in this population, with the largest benefit observed among individuals who required oxygen supplementation but were not mechanically ventilated. We anticipate that results from our Phase 3 SIMPLE-Severe study [randomised, open-label, multicentric trial to evaluate the safety and efficacy of two dosing durations – 5 days and 10 days – in adults diagnosed with Covid-19], which is evaluating remdesivir in a similar population of Covid-19 patients requiring oxygen but not on mechanical ventilation, will be published in the near future,” said the drug’s manufacturer Gilead Sciences, in a statement.

Gilead Sciences has signed non-exclusive voluntary licensing agreements with four generic pharma companies -- Jubilant Life Sciences, Cipla, Hetero Labs, and Mylan – for manufacture and distribution of remdesivir to 127 countries, including India.

The promoters of HT Media Ltd, which publishes Hindustan

Times, and Jubilant Life Sciences are related. There are, however, no promoter cross-holdings.

OXFORD VACCINE

Following preclinical animal studies showing Oxford University’s ChAdOx1 nCoV-19 vaccine protected six monkeys from pneumonia, recruitment of around 10,260 adults and children has begun to assess the immune response to the vaccine across ages. The vaccine is made from a weakened version of a common cold adenovirus (ChAdOx1) that causes infection in chimpanzees, and has been genetically changed so it cannot cause infection in humans. “The Covid-19 vaccine trial team has been working hard on assessing the safety and immunogenicity of ChAdOx1 nCoV-19, and preparing to assess vaccine efficacy...,” said Sarah Gilbert, professor of vaccinology at the Jenner Institute at Oxford

University, on Friday. Oxford University has licensed the experimental vaccine to AstraZeneca, with who the Pune-based Serum Institute of India (SII) is in talks about mass production.

SINO BIOTECH VACCINE

Sino Biotech’s inactivated Ad5vectored Covid-19 vaccine is among at least seven such where teams are using traditional platforms to develop vaccines using a weakened or inactivated form of the virus, such as those used in measles and polio vaccines. The Sino Biotech vaccine was found to be safe, well tolerated, and able to generate an immune response against Sars-CoV-2 in humans, according to new research published in The Lancet.

The Ad5 vectored Covid-19 vaccine is the first vaccine to be tested in humans and demonstrated a strong immune response after 28 days in 108 healthy adults. The final results will be evaluated in six months. If successful, the vaccine will be produced in China and, as of now, India has no role in its development and production.

MODERNA VACCINE

Moderna announced earlier this week that its experimental vaccine mRNA-1273 produced virusneutralising antibodies at levels similar to those found in recovered patients. It said early data showed the vaccine raised the levels of neutralising antibodies in eight vaccinated people to levels found in the convalescent plasma of recovered patients.

“This is not the most advanced mRNA vaccine being developed by Moderna, they have started others much earlier...,” said Dr Anurag Agrawal, director, Council of Scientific and Industrial Research-Institute of Genomics & Integrative Biology, New Delhi.