Following a flurry of favourable results from human trials of coronavirus vaccines, drugmakers from the world over are now seeking 'emergency use' approvals from regulators, which could see these vaccines deployed in possibly tens of millions of people.
However, researchers are worried that this kind of early operationalisation could undermine the ongoing human clinical trials that seek to demonstrate conclusively how well the coronavirus vaccines work.
After the publication of early data from phase-3 clinical trials on November 9, drugmakers Pfizer and BioNTech have sought regulatory approval to deploy their inoculation under emergency-use rules. American biotech company Moderna is also likely to do the same soon.
Once a vaccine is accorded emergency approval, developers feel pressured to offer the vaccination to study participants who received a placebo. However, if too many people traverse to the vaccine group, the companies might not have sufficient data to determine long-term results, for instance, if the inoculation prevents infection or just the disease, how long vaccine protection lasts?
What does emergency use of COVID-19 vaccine mean?
It's when regulators allow shots to be given to certain people while studies of safety and effectiveness are ongoing. For example, before any vaccine is permitted in the US, it must be reviewed by the Food and Drug Administration, which requires study in thousands of people.
Normally, the process to approve a new vaccine can take about a decade. But the federal government is using various methods to dramatically speed up the process for COVID-19 vaccines. During a health crisis, the FDA can loosen its normal scientific standards to allow emergency use of experimental drugs, devices, vaccines and other medical products.
The first vaccines to get the provisional green light in the US are almost certain to be made available under this process, known as emergency use authorisation (EUA).
Instead of the usual requirement of "substantial evidence" of safety and effectiveness for approval, the FDA can allow products onto the market as long as their benefits are likely to outweigh their risks. It has already used its emergency powers to authorise hundreds of coronavirus tests and a handful of treatments during the pandemic.
However, the agency has almost no experience granting emergency use for vaccines and has laid out extra standards it will use to make decisions on upcoming COVID-19 shots. In October, FDA officials told vaccine makers they should have two months of safety follow-ups from half of the people enrolled in their studies before requesting emergency authorisation.
That data is expected to be enough for the FDA to allow vaccinations of certain high-risk groups, such as front-line health workers and nursing home residents.
Full approval of a vaccine will likely require six months of safety follow-up as well as extensive inspections of company manufacturing sites. The leading vaccine makers are not expected to complete that process until next spring or summer. Only then is the FDA expected to grant full approval, which would allow vaccinations of the general population.
Coronavirus vaccine dilemma
COVID-19 once approved for emergency use, will be meant only for frontline healthcare workers as well as those at immediate risk of contracting coronavirus. Healthy population can't be taken in for mass vaccination under emergency use authorisation as it needs full approval from regulators which will take a lot of time as they assess the clinical trial data in detail.
Emergency Use Assessment and Listing (EUAL) was first approved by the World Health Organisation (WHO) during the Ebola outbreak in Africa during 2013-16. In January 2020, WHO revised its emergency use listing (EUL) to assess whether a vaccine's quality, performance, and safety are acceptable and whether the benefits outweigh risks in the interest of public health. Meanwhile, regulators of WHO's member countries can authorise emergency use of new drugs and vaccines if they believe the benefits outweigh the risks.
Coronavirus vaccines' emergency use approved in Russia and China has not followed the EUA. Hence, it is a big question mark whether the two meet WHO norms as they have only been approved by their respective national regulators for emergency use. Furthermore, Russia applied to WHO for pre-qualification of its Sputnik coronavirus vaccine in October. Although countries' own regulators can use these jabs on their population, they may not have global acceptance without WHO approvals.
This can only be done when regulators issue a full licence after assessing data on multiple thousand people over a longer period of time and have inspected manufacturing sites, etc. However, this could take a minimum of 6-9 months or more until regulators have assessed all data in detail. Mass vaccination of the population can only follow thereafter.
How's the situation in India
The Centre is contemplating over the modalities of EUA of coronavirus vaccines pending conclusion of phase-3 trials. India's COVID-19 caseload has been running in thousands with hundreds of related deaths every day, pushing the government to find a way to provide emergency authorisation to coronavirus vaccine candidates. Prime Minister Narendra Modi also assessed the details about the emergency authorisation process at a review meeting on Friday regarding the procurement and delivery strategy of COVID-19 vaccines.
"Held a meeting to review India's vaccination strategy and the way forward. Important issues related to the progress of vaccine development, regulatory approvals, and procurement were discussed," PM Modi tweeted after the meeting. Vaccine Task Force (VTF) will lay down the principles for EUA in India, and the National Expert Group on Vaccine Administration for COVID-19 (NEGVAC) will take a call on vaccine pricing.
India's existing legal framework, which includes the Epidemic Diseases Act, 2020; National Disaster Management Act, 2005; and New Drugs and Clinical Trial Rules, 2019; provide for granting authorisation.
Pune-based Serum Institute of India (SII) is carrying out the phase-3 trial of the Oxford-AstraZeneca vaccine, while Bharat Biotech and ICMR have started the phase-3 trial of the indigenously developed COVAXIN inoculation. SII CEO and owner Adar Poonawalla recently announced that India will have the COVID-19 vaccine for vulnerable population by January-February if it gets favourable trial results by November or early December.