New Delhi, Just when the world breathed a bit easy after countries like the UK and the US starting the process of vaccination against Covid-19, reports of a new strain found in the UK with properties to spread much faster than the dominant strain triggered many questions including whether the new strain has the ability to evade vaccine-induced immunity.

This crucial question comes at a time when India is also expected to approve the use of a Covid-19 vaccine soon.

According to the US Centers for Disease Control and Prevention's National Center for Immunization and Respiratory Diseases (NCIRD), the possibility that the new SARS-CoV-2 strain could have the ability to evade vaccine-induced immunity is of great concern.

This is because once a large proportion of the population is vaccinated, "there will be immune pressure that could favour and accelerate emergence of such variants by selecting for 'escape mutants,'" it said.

"There is no evidence that this is occurring, and most experts believe escape mutants are unlikely to emerge because of the nature of the virus," NCIRD said in an update last week.

Vaccine makers like Pfizer and AstraZeneca also said that their vaccines against Covid-19 should work against the new strain.

However, results of any tests proving the efficacy of these vaccines against the new strain have not come out.

In such a situation, should regulators in India wait to see proof of efficacy of Covid-19 vaccine against the new strain before approving one for use?

Health experts in India believe that approving vaccines that at least work against the dominant strain is the need of the hour as it is natural for virus to mutate.

"Theoretically speaking, the vaccines that Pfizer and AstraZeneca have rolled out they contain effective antibodies against the virus even if the strain is a different one. So ideally, they should work against the new strain," Puneet Khanna, HOD and consultant - Respiratory Medicine, HCMCT Manipal Hospitals in New Delhi, told IANS.

"I think the vaccines, whenever they are available, should be given an approval for mass vaccination," he said.

Avi Kumar, Consultant, Pulmonology at Fortis Escorts Heart Institute in New Delhi also believes the vaccination programme is very important and should be undertaken.

"It is definitely a good idea to follow all protocols concerning the vaccination, irrespective of which strains come up in the future. We need to start somewhere and this is a good beginning," he said.

India currently has eight Covid-19 vaccine candidates, including three indigenous vaccines, under different stages of clinical trials which could be ready for authorisation in near future.

Serum Institute-Oxford's Covishield, Bharat Biotech's Covaxin and Pfizer vaccine are in the fray for emergency use authorisation.

"There is no point in waiting and testing the vaccine's efficacy for the new strain. If the trials prove to be successful in efficacy and safety, it should be given a green signal for mass vaccination, without waiting," said Akshay Budhraja, Consultant, Department of Pulmonology, Aakash Healthcare Super Speciality Hospital in New Delhi.

"India should definitely go ahead with vaccines with good efficacy and strategise on mass vaccination since coverage is not very easy to achieve," said Akhila Kosuru, Senior Physician, Apollo Telehealth.