Interchangeability of COVID-19 vaccines is not permitted and pregnant and lactating women should not be administered the shots as they have not been part of any anti-coronavirus vaccine clinical trial so far, the health ministry said on Thursday.

If required, COVID-19 vaccine and other vaccines should be separated by an interval of at least 14 days.

"Interchangeability of COVID-19 vaccines is not permitted. Second dose should also be of the same COVID-19 vaccine which was administered as the first dose," the letter written by Manohar Agnani, Additional Secretary, Union health ministry said.

The ministry has listed precautions and contraindications for COVID-19 vaccination along with a comparative factsheet for both the vaccines (Covishield and Covaxin) which contains information on vaccine platform, physical specifications, dosage, cold-chain storage requirements, contraindications and minor AEFIs (adverse event following immunization).

It said this information should be disseminated to programme managers across all levels and through them to cold-chain handlers and vaccinators for ready reference.

Listing the contraindications, the health ministry cautioned against administration of the vaccine in persons with a history of anaphylactic or allergic reaction to a previous dose of COVID-19 vaccine, and in those with immediate or delayed onset anaphylaxis or allergic reaction to vaccines or injectable therapies, pharmaceutical products, food items, among others.

According to the letter, in case of persons having active symptoms of SARS-CoV-2 infection, coronavirus infected patients who have been given anti-SARS-CoV-2 monoclonal antibodies or convalescent plasma and acutely unwell and hospitalised patients due to any illness, the COVID-19 vaccination is to be deferred for four to eight weeks after recovery.

"Pregnant and lactating women have not been a part of any COVID-19 vaccine clinical trial so far. Therefore, women who are pregnant or not sure of their pregnancy and lactating women should not receive COVID-19 vaccine at this time," the letter stated.

The vaccine should be administered with caution in persons with a history of any bleeding or coagulation disorder (like clotting factor deficiency, coagulopathy or platelet disorder, it said.

"Following conditions are not contraindicated for COVID-19 vaccines --persons with past history of SARS-CoV-2 infection and or RT-PCR positive illness, history of chronic diseases and morbidities and immuno-deficiency, HIV, patients on immune suppression due to any condition," the letter stated.

Prime Minister Narendra Modi will launch India's massive COVID-19 vaccination drive on January 16 via video conferencing, even as adequate doses of Bharat Biotech's 'Covaxin' and Serum Institute's 'Covishield' vaccines have been delivered across the country to all states and Union territories.

The letter also mentions mild AEFIs following vaccination for both the vaccines.

In case of Covishied, some mild AEFI may occur like injection site tenderness, injection site pain, headache, fatigue, myalgia, malaise, pyrexia, chills and arthralgia and nausea.

Some mild AEFIs in case of Covaxin include injection site pain, headache, fatigue, fever, body ache, abdominal pain, nausea and vomiting, dizziness-giddiness, tremor, sweating, cold, cough and injection site swelling.

Paracetamol may be used to provide symptomatic relief from post vaccination adverse reactions, the letter added.