Vaccine immunity study finds 30% people lose immunity against Covid after 6 months

Mangalore Today News Network

Hyderabad, Jan 19, 2022: Hyderabad’s AIG Hospitals, along with the Asian Healthcare Foundation, has published results of another significant research in which long-term durability of vaccine immunity was assessed with respect to the antibody levels.

 

The study found that almost 30% of individuals had antibody levels below the protective immunity level of 100 AU/ml after 6 months.

The study was conducted on a large pool of 1,636 healthcare workers who were fully vaccinated.

“The study aimed to understand the effectiveness of current vaccines over the long-term and see if there are specific population demography who need a booster at the earliest,” explained Dr D Nageshwar Reddy, Chairman, AIG Hospitals.

Researchers involved in the study measured the IgG anti-S1 and IgG anti-S2 antibodies to SARS-CoV-2 in 1,636 individuals.

“Those who had antibody levels less than 15 AU/ml were considered Antibody negative, which means they didn’t develop any protective immunity against the virus,” explained Dr Reddy.

The study estimated that an antibody level of 100 AU/ml is the minimum level for protection against the virus.

“Any individual with less than 100 AU/ml antibody level is susceptible to getting infected,” said Dr Reddy.

Of the 1,636 study participants, 93% received Covishield, 6.2% received Covaxin, and less than 1% received Sputnik vaccines.

“These individuals were majorly above 40 years with co-morbidities like Hypertension and Diabetes. Out of the total, 6% did not develop any immune protection at all,” said Dr Reddy who is also amongst the researchers.

The results clearly indicate that younger people have more sustained antibody levels than the elderly population. People above 40 years with co-morbidities like Hypertension and Diabetes have significantly less antibody response after 6 months of getting fully vaccinated.

Individuals above 40 years with diabetes and hypertension of both genders may be at a higher risk of SARS-CoV-2 infection and these individuals should be prioritised for a booster dose after 6 months, the study suggested.

According to Nageshwar Reddy, the 9-month gap for prevention dose benefits 70% of the population who can retain enough antibody levels beyond 6 months.

“However, considering the scale of our country, the 30% people especially those with comorbid conditions like Hypertension, Diabetes, etc., who are more prone to develop an infection after 6 months of getting fully vaccinated should also be considered for the prevention dose,” he further added.