Even as the investigation is underway to find out the reasons for the breakout of fire on January 21 at Serum Institute of India (SII) vaccine factory in Pune that killed at least five people and gutted equipment worth hundreds of crores of rupees, experts and industry executives have expressed shock and called the fire incident of this scale "unusual".
The fire broke out at a building that makes Rotavirus and BCG vaccines, near the company's existing production plant at Manjri, a Pune suburb, where vaccine manufacturing equipment was being installed for the upcoming production of non-COVID vaccines.
Adar Poonawalla, CEO of SII, told CNBC-TV18 that new product launches will be hit, and there will be major equipment damage and more than Rs 1000 crore in revenue loss over the next one to two years due to the fire.
Maharashtra Chief Minister Uddhav Thackeray tweeted that an "electrical fault" caused the fire at the plant.
To be sure, SII is the largest vaccine maker in the world by volume, with a strong track record of regulatory and quality compliance and industrial safety.
"If you have a facility where let's say an expansion or construction is going on -- this is a facility which has been producing rotavirus vaccine -- there could be some renovation, repair or expansion that might have been going on; we don't have exact details, but this (fire) is quite unusual," said Davinder Gill, former CEO of Hilleman Laboratories. Gill was previously global head of Biotherapeutics at Pfizer.
Gill explains that unlike the pharmaceutical industry, especially bulk drug units that have chemical reactors involving risky chemical reactions that are prone to fire accidents, vaccine facilities have bioreactors to grow microorganisms and are generally safe from a fire standpoint. But they also have tanks that hold solvents and buffers.
"The inflammable thing that vaccine manufacturing uses is ethanol (alcohol), and the manufacturers are trying to limit or eliminate the use of it," Gill said.
Ethanol is used as a solvent in certain vaccines like Haemophilus influenzae type B HIB, for precipitation of DNA (or washing) in vaccine manufacturing.
Another top executive of a vaccine company who didn't want to be named said that he was surprised at the intensity of the fire.
"We still don't have details, electrical fault is claimed as a possible reason. Electric short circuits or build-up of static electricity can happen, but are rare," the executive said.
"This isn't any old legacy plant; it is a newly built state-of-the-art manufacturing site making WHO prequalified vaccines - there will be a fire safety plan. Even the workers couldn't escape from fire to safety is both sad and bizarre," the executive added.
Accident or Sabotage?
Experts say the companies that are making COVID-19 vaccines can be highly vulnerable targets for cyber attacks and other sophisticated attempts of sabotage.
"I think we have to be careful not to rush to conspiracy theories, but those investigating should examine the angle of sabotage, given the circumstances that we live in," Gill said.
The vaccine executive quoted above said that when he saw the visuals of the fire at the SII plant on TV, the first thing he did was to immediately call his relevant department head and instructed him to beef up the security at the plants.
"Security and surveillance at vaccine manufacturing plants are taken very seriously because we deal with biohazard material," the executive said.