United States-based pharmaceutical company Moderna Inc. on Monday claimed that its vaccine against COVID-19 has an efficacy of about 94.1% with no serious concerns over safety. The pharma company also said that its vaccine appears to be safe and effective across age, race, ethnicity and gender. Moderna will be the second vaccine candidate that would have applied for US and European emergency use authorisation after Pfizer.
Moderna’s trial consisted of 30,000 volunteers and among those 196 contracted COVID-19 in the trial. And among the 196 people, 185 belonged to a placebo group while 11 got the actual vaccine.
Moderna and Pfizer (with its German partner BioNTech) have declared over 90% efficacy of their vaccines. Moderna is just behind Pfizer in seeking to begin vaccinations in the US in December. Across the Atlantic, British regulators also are assessing the Pfizer shot and another from AstraZeneca.
The other candidate that showed a reasonable efficacy is that of AstraZeneca with an average of 70% efficacy. The efficacy of the vaccine candidate varied as 62% efficacy was found in those administered two full doses and 90% in those who received a half dose followed by a full dose.
However, AstraZeneca has been in controversy over adverse effects of its vaccine many times—once each in US and United Kingdom, and recently in India in the trial run by Serum Institute of India (SII).
Last week, a trial volunteer in Chennai claimed to have suffered serious neurological and psychological symptoms after taking the experimental shot and sued AstraZeneca along with others and a sought compensation of Rs 5 crore. The Pune-based SII on Tuesday denied allegations that the volunteer suffered side effects from the Covid-19. "We would want to assure everyone that the vaccine won't be released for mass use unless it is proven immunogenic, and safe," it said in a blog.
Both Moderna and Pfizer vaccines are mRNA (Messenger RNA) vaccines while AstraZeneca used an adeno vector for its vaccine.
However, apart from these most highlighted vaccine candidates, the number of vaccines being developed around the world is growing day by day. Alongside, the vaccines that have entered clinical trials have increased as well.
Among the vaccine candidates under phase-II trials, India’s COVAXIN, developed by Bharat Biotech, uses the most conventional way of vaccine manufacturing, which is done by administering a whole inactivated virion. However, India has vaccine candidates under clinical trials that are developed by companies outside the country. Prominent ones are the candidates of AstraZeneca and Zydus Cadila.
One of the important countries in the vaccine production appears to be China with 11 candidates entering clinical trials, out of which four are in phase III and the trials are proceeding smoothly. China is also seeing a massive production of the vaccine; reportedly, the country expects production of 610 million doses by the year-end. And by next year, it expects to increase its production capacity by a billion doses.
Worldwide, a total of 48 vaccine candidates are under clinical trials, while those in preclinical evaluation amount to 164, as per the recent World Health Organization (WHO) vaccine landscape.
Among the 48 clinically tried vaccines, The Republic of Kazakhstan has one candidate under phase I/II. This is developed by Research Institute of Biological Safety Problems and is an inactivated viral vaccine. Cuba has two candidates whose phase I trials have recently started. Apart from Sputnik V, Russia also has other vaccines under clinical trial (FBRI SRC VB VECTOR, Rospotrebnadzor, Koltsovo).
Typically it can take a vaccine 15 years of clinical evaluation before its availability in the market for mass use. The fastest vaccine to have been developed till now was the mumps vaccine in 1960s and even that took four years. However, amid the global pandemic, the development process of a vaccine against COVID-19 has gone through a compressing of the clinical evaluation and thus, there has already been news of several successful trials.
(With inputs from PTI)
Also Read: Even with Vaccines, It is a Long and Rocky Road to Immunity