The Ministry of Health and Family Welfare on Tuesday said that there is no evidence yet to definitively say that plasma therapy can be used to treat Covid-19. The procedure involves the transfusion of blood plasma from a Covid-19 patient who has recovered to another patient who is critically ill.

Plasma therapy is in an experimental stage in India. Last week, plasma therapy trials had been conducted on four Covid-19 patients in Delhi. Chief Minister Arvind Kejriwal had said that the results were encouraging and expressed hope that plasma therapy could help save critically ill patients.

“The Indian Council of Medical Research has stated this very clearly that there are no approved therapies of Covid-19, including plasma therapy,” health ministry Joint Secretary Lav Agarwal said at the Centre’s press briefing. “Plasma therapy is one of the therapies that is being experimented with. However, so far there is no evidence to support it as a treatment.”

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Agarwal added that the ICMR was studying the effectiveness of plasma therapy. “Till the time there is no robust scientific proof to prove the effectiveness of plasma therapy, we can only use it for research and trial purposes,” Agarwal added. He warned that the procedure could lead to “life threatening” consequences if proper guidelines are not followed.

The Indian Council of Medical Research, the country’s nodal body for coronavirus testing, also said that there is no approved or definitive therapy for the infection, adding that convalescent plasma is one of the several emerging ones. “However, there is no robust evidence to support it for routine therapy,” ICMR tweeted. “US Food and Drug Administration has also viewed it as an experimental therapy.”

The medical body also listed the technical challenges arising out of the plasma therapy. “There are also several risks of using this therapy including life-threatening allergic reactions and lung injury,” it added. “Given the serious uncertainties around Covid-19 convalescent plasma therapy, ICMR has initiated a multi-center clinical trial to evaluate the safety and efficacy of using this therapy in Covid-19 patients in India. Despite the threat of Covid-19 pandemic, there’s a need to ensure the ethical integrity and establish the scientific basis of using Covid-19 convalescent plasma therapy in patients.”

At the press briefing, Agarwal said India’s Covid-19 recovery rate is now 23.3% and that the doubling rate of cases has also improved. “We have reported fewer cases because of the lockdown, as our doubling rate shows,” Agarwal said. “The doubling rate, which was around 3.5 before lockdown, is currently around 10.2.”

Citing data from the World Health Organization, Agarwal said that 20 countries whose combined population equals India’s have 84 times more Covid-19 cases. He added that the nationwide lockdown and containment measures had proven to be effective.

The number of coronavirus cases in India has risen to 29,974, according to the health ministry’s Tuesday evening update. Covid-19 has killed 937 people in the country.