Covid-19 vaccine may be required to be taken annually: taskforce chair

Dr Sanjay Oak, chairman of the state’s Covid-19 taskforce, during a ‘live’ Facebook session on Sunday, said that over time, neutralising antibodies decrease, so the Covid-19 vaccine would be required to be taken annually.

“A second dose of the vaccine against Covid-19 would be required to be taken again in the next 10-12 months,” said Dr Oak, adding that just like influenza vaccine, which needs to be taken seasonally, the Covid-19 vaccine may also be required at regular intervals.

Dr Oak said, “It looks like we will have to take the vaccine every year. We are yet to complete one year since the Covid-19 vaccination drive began, not just in India, but in western countries too. We began the drive from January 16. As of now, it is quite possible that with time, the level of neutralising antibodies decreases. With other vaccines, like those given against influenza, the neutralizing antibodies remain for about 10-12 months. For now it looks like we might have to take a second dose of Covid-19 vaccine next year.”

The influenza vaccine is a seasonal shot given to protect against three to four influenza viruses.

Dr Oak also said that the new variants have to be taken seriously as mutation is seen in protein spikes.

He said, “Now we have enough oxygen supply and enough isolation beds, but ICU beds are full. A particular mutation is considered to be a variant of concern after considering three factors - infectivity, virulence and its impact on vaccination and our Covid-19 appropriate behaviour. While the first two are not within our control, the last one is most important. Even today, there is vaccine hesitancy in rural areas which needs to be addressed. Even after vaccination, a mask is the best preventive method.”

Explaining the difference between Covishield and Covaxin, he said that while Covaxin is made from a completely dead virus, Covishield is made from an attenuated or a weakened virus.

He added, “It is partly true that the gap between two Covishield doses has been increased because of a shortage in supply. However, even in western countries the gap has been increased to more than eight weeks.”

In view of the anticipated third wave which is likely to infect children the most, as the age group is yet to be vaccinated, Dr Oak said, “In the trials for those aged between 12-18 for Covaxin, it was found that there were no major side effects and that the results were satisfactory. I believe that vaccination for those aged between 12-18 years can begin shortly.”