During April and May 2021, no vaccinated patients died after becoming re-infected with Covid-19, according to a study undertaken by the All India Institute of Medical Sciences (AIIMS) in Delhi.
This was the first genomic sequence study conducted on “breakthrough infections” in India during the second wave. Breakthrough infections are Covid-19 re-infections in vaccinated persons.
The AIIMS study confirmed that even in re-infected Covid-19 patients with a very high viral load, no death was reported among those who had received even one dose of the coronavirus vaccine.
AIIMS studied 63 breakthrough infection cases, out of which 36 patients had received both doses of Covid-19 vaccine, and 27 had got the first dose. Most of these patients had got the Covaxin jab (53), and 10 re-infected patients had taken Covishield shots.
As per the study, SARS-CoV-2 lineages were assigned to 57.1 percent of the samples, i.e., 36 of them. Out of these, 52.8 percent (19) were in patients who were fully vaccinated and 47.2 percent (17) in patients who had got just the first dose of the coronavirus vaccine.
The AIIMS researchers divided the B.1.617 variant or Delta strain—which was first detected in India — into three lineages: B.1.617.1, B.1.617.2, and B.1.617.3. They found the B.1.617.2 variant to be predominant in 23 samples or 63.9 percent of the samples. Out of these, 12 were in fully vaccinated persons and 11 in partially vaccinated persons. Meanwhile, the B.1.617.1 and B.1.1.7 lineages were found in four persons or 11.1 percent of the samples and one person, i.e., 2.8 percent of the samples, respectively.
Notably, none of the samples studied had comorbidities that could pose as predisposing factors in such cases.
The AIIMS study read: “Viral load at the time of diagnosis was high in all the patients irrespective of vaccination status or type of vaccine received and the initial course of disease with high-grade non-remitting fever lasted for five to seven days in the vaccinated group, similar to the clinical presentation in unvaccinated patients.”
The patients ranged in age from 21 to 92 years old, with 41 men and 22 women. There were no comorbidities in any of the participants that could have acted as a risk factor for infection.