Covid vaccines help reduce hospitalisation and mortality even though the Delta variant is capable of breaking through the protection offered by vaccines, showed a study spearheaded by the Indian Council of Medical Research (ICMR).

The study, which is yet to be published, had a total sample size of 677 who were infected during the second wave (between March and June) despite receiving vaccination. The cases came from as many as 17 States.

While 592 had received both doses, 85 had only one dose of Covishield or Covaxin. It also revealed that the majority of the clinical cases in the breakthrough – those who had received both the shots – were infected with the Delta variant.

“The study indicated that the majority of the cases (86 per cent) in the breakthrough were infected with the Delta variant, and only 9.8 per cent cases required hospitalisation, while fatality was observed in only 0.4 per cent cases. This clearly suggests that vaccination does provide reduction in hospital admission and mortality,” said ICMR.

Age of patients

The median age of patients in the study was 44 (31-56), with the breakthrough cases after one dose was 53 (45-61) and after two doses was 41 (30-55). Meanwhile, 65 per cent of the breakthrough cases were males.

A total of 482 cases – 71 per cent – were symptomatic with one or more symptoms, while 29 per cent had asymptomatic SARS-CoV-2 infection. Fever was the most consistent presentation followed by body ache, including headache and nausea, cough, sore throat, loss of smell and taste, diarrhoea, breathlessness, and 1 per cent had ocular irritation and redness.

According to the preprint study, comorbidities were observed in 154 out of 677 cases, which included diabetes, hypertension as well as chronic cardiac, renal and pulmonary diseases and obesity.

The comorbid cases were significantly predisposed to develop symptoms such as cough, sore throat, fever, loss of smell and taste, diarrhoea, and breathlessness, it showed.