30% people losing vaccine-acquired immunity after six months: AIG study | India News – Times of India

HYDERABAD: Nearly 30% individuals lose their vaccine-acquired immunity after six months, a study conducted to understand the longevity of vaccine immunity in Indian population with respect to antibody levels has found.
The study was conducted by AIG Hospitals along with the Asian Healthcare Foundation on 1,636 healthcare workers fully vaccinated with three of the Covid-19 vaccines currently being administered in the country. Of the 1,636 participants in the study, 93% (1519 individuals) had received Covishield, 6.2% (102) got Covaxin and less than 1% (13) had been administered the Sputnik jab.
The results of the study were uploaded on Wednesday on pre-print server Research, which is a preprint platform where research papers are uploaded before they are peer-reviewed.
Researchers involved in the study measured the IgG anti-S1 and IgG anti-S2 antibodies to SARS-CoV-2 in these 1,636 individuals. Those who had antibodies levels less than 15 AU/ml were considered Antibody negative, which means they didn’t develop any protective immunity against the virus.
Further, it was estimated that an antibody level of 100 AU/ml is the minimum level for protection against the virus, which means any individual with less than 100 AU/ml antibody level is susceptible to getting infected.
“Our study results were at par with other global studies where we found that almost 30% individuals had antibody levels below protective immunity level of 100 AU/ml after six months. 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 D Nageshwar Reddy, Chairman, AIG Hospitals, who is one of the researchers.
The researchers pointed out that these results clearly indicate that with age, immunity wanning is directly proportional which means that younger people have more sustained antibody levels than the elderly population.
With those above 40 years with co-morbidities like Hypertension and Diabetes showing significantly less antibody response after six months of getting fully vaccinated, individuals of both genders aged above 40 years and suffering from co-morbidities like hypertension and diabetes may be at higher risk of infection and hence should be prioritised for a booster dose after six months.
“At present, the nine-month gap for Prevention Dose benefits 70% of the population who can retain enough antibody levels beyond six months. However, considering the scale of our country, the 30% people especially those with co-morbid conditions like Hypertension, Diabetes, who are more prone to develop an infection after six months of getting fully vaccinated should also be considered for the prevention dose,” Dr Reddy added.
Pointing out that the country is currently seeing a surge in infections, he said: “Fortunately, the severity of the disease is mild because of multiple factors including the effect of vaccination, the intrinsic character of the variant itself, and natural immunity amongst the population. However, we need to devise strategies that can ensure minimal spread and protect as many people as possible. 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,” Reddy said.