COVID: Hybrid immunity to stave off Delta variant in Kerala, feel experts

THIRUVANANTHAPURAM:   The lower immunity of population against Covid has come in the way of achieving herd immunity against delta variant when the spread of infection subsided in other states.

While the state managed to delay the curve, it also resulted in delaying the opening up of the normal life.

However, the situation is likely to change soon with the developments after the Onam holidays.

One is the surge in the number of new infections and its recoveries. The second is the faster vaccination coverage surpassing the national average during the period.

The combination of these two factors have made the health experts to count on the effectiveness of hybrid immunity that sort catapult the state to achieve the desired herd immunity level soon.

Achieving the herd immunity level is important in checking the future waves.

Hybrid immunity is an immunity gained by a combination of antibodies developed from natural infection and from those induced through vaccination.

A better vaccination coverage has helped the state to manage the late surge as most of the infection among turned out to be mild.

Besides the infection gave a sort of booster immunity to those who recovered from the infection, according to health experts.

The serious infection and deaths were mostly (95 per cent) observed among unvaccinated people.

There were concerns of breakthrough infections because the delta variant resulted in infecting people who were fully vaccinated.

But these infections were found to be mild in most cases except in those with more than two co-morbidities, said chief minister Pinarayi Vijayan on September 10.

“The increase in mild Covid cases in the recent surge is a positive trend. It not only helped us to manage the surge but also boosted the overall immunity level with hybrid immunity,” said deputy superintendent of Thiruvananthapuram medical college and hospital, Dr SS Santhosh Kumar.

A study conducted Dr Padmanabha Shenoy, a clinical immunologist and rheumatologist, in 1,500 people found that even a single dose of vaccine produces a very high level of immunity for a previously Covid infected person.

This high level of hybrid immunity (hybrid of natural infection with one dose of vaccine) is anticipated to last in the person’s body for a longer time, providing long lasting immunity, he said.

“Studies show that infection followed by both doses of vaccines offer the best protection followed by infection and a single dose. The immunity developed from just two doses comes next to it. The hybrid immunity develops even when a vaccinated person gets infection,” said an internal medicine specialist and public health activist Dr N M Arun.

Hybrid immunity or Super immunity

A combination of immunity gained from natural infection and vaccines.

Infection and single-dose vaccine give more immunity than a double dose.

Hybrid immunity gives better immunity against new variants.

The recent surge in daily new cases and increase in vaccination to boost overall immunity.

81.9% of the eligible population received the first dose and 33.4% the second dose till September 17.

6% of the Covid patients reported in June-August had eceived one dose and 3.6% received both.

Kerala tops vaccination per million (9,27,588).

Only 2% of the 2,25,022 Covid patients between September 8 and 14 required oxygen beds and 1% ICU beds.