Vaccines usually undergo three rounds of testing
The first two trials are performed on small groups for checking adverse reactions.
Over 150 covid-19 vaccines being tested around the world she expects vaccine should be ready by 2021, Soumya Swaminathan, chief scientist at the World Health Organization (WHO), said.
“We can be optimistic that there will be one or more safe and efficacious vaccines by next year,” Swaminathan opined
She said the WHO has already started discussions with member-countries on a viable framework for “fair distribution of the vaccine”. A vaccine candidate developed in the UK by the University of Oxford is currently at the most advanced stage, with phase-3 trials recently commencing in hospitals in Brazil and South Africa.
Vaccines usually undergo three rounds of testing. The first two trials are typically smaller, testing only for the possibility of adverse reactions, not on efficacy. Phase-3 trials are a lot more difficult, requiring thousands of volunteers to gauge whether the vaccine actually works in the real world.
India’s own vaccine development efforts have come under a cloud of controversy after the Indian Council of Medical Research (ICMR) made a case to get a vaccine candidate ready by 15 August, effectively giving six weeks for clinical trials to test for safety and efficacy. On the feasibility of such a deadline, Swaminathan said: “Trials take time and must be conducted according to well-established regulatory processes.”
The WHO will be closely monitoring the phase-3 results of all vaccine trials, she said, because it is possible that some vaccines may be more suitable for one age group, or one type of population group than others. “The WHO, through its expert committees, has put forward criteria for selection of vaccines for further development,” she said.
Until an effective vaccine is identified, treatment options for those who are in hospitals will remain critical, and it is fairly clear that several re-purposed drugs which were initially widely used—like hydroxychloroquine and HIV drug Lopinavir—aren’t effective on hospitalized covid-19 patients, Swaminathan said.
Remdesivir seems to reduce the duration of hospitalization, but its impact on lowering mortality is yet to be established. The efficacy of Favipiravir has also not been established, and, furthermore, it can be teratogenic (may cause birth defects) and must be used with caution.”
For the subset of covid patients who are hospitalized and require treatment, a broad scientific consensus seems to be emerging about the likely mortality or death rate. At a research and innovation forum held at WHO last week, Swaminathan said actual covid cases at any point are roughly 10 times the officially recorded figure and the overall death rate is 0.6%. With India’s recorded covid caseload at over 700,000, that would put the actual death toll at 42,000, more than double the officially recorded number of around 20,000.
Most countries are not able to report deaths accurately in real-time, she said, and India may well be missing some covid-related deaths. “We will have to wait for several months to know the true death count.”
