Fatality rate among the unvaccinated in third wave three times higher than vaccinated lot

Out of 8,266 Covid-19 infected patients surveyed for the study across 36 districts, 943 were partially vaccinated, 4,359 had taken both the doses while the remaining 2,964 were unvaccinated. The study revealed that 35 patients who were inoculated with either of the two available vaccines succumbed to the infection with a fatality rate of 0.66 per cent. On the other hand, the fatality rate was 2.1 per cent among unvaccinated patients with 63 deaths recorded during the survey which concluded on January 15.

This study was conducted to gauge the impact and efficiency of the available vaccines among the infected population.
“The existing vaccines, which were designed for the original SARS-CoV-2, do not provide 100% protection against the variants of Covid-19 as its durable response is not guaranteed. But as witnessed, they do reduce the risk of hospitalisation and death,” said Dr Avinash Supe, in-charge of the Covid-19 death committee.

As of now, the Centre has allowed vaccination for children only above the age of 15 years. Due to this, most of the infection or 21.83 per cent was recorded in the age group of 11-20 years, as per the study. The breakthrough infection among vaccinated persons was mostly witnessed in young adults and the elderly—31-40 years (19.31 per cent), 41-50 years (17.33 per cent) and 51-60 years (17.11 per cent).

Omicron, the new variant of SARS-Cov-2, which largely dominated over its predecessor Delta variant in the third wave due to multiple mutations in its spike protein, is able to evade immunity from past infection and vaccines.

Also, with the gradual dropping of the neutralising-antibody levels in people acquired through vaccination, the breakthrough infection increased more among fully vaccinated beneficiaries who had taken their doses during the start of the mass immunisation programme in January 2021. The data from the study showed that out of surveyed patients, 11.41 per cent breakthrough infection was recorded among people with one dose and 52.73 per cent among patients who had taken both the doses.

“Several studies across the globe have shown that antibodies produced against SARS-Cov-2 gradually fade off with time. So, the elderly and the frontliners, who are most vulnerable to contracting Covid-19, reported a higher number of breakthrough infections,” said Dr Gautam Bhansali, in-charge of Covid-19 beds in private hospitals. “Thus, the Centre gave approval for the booster shots. I think the government needs to expand it to the general population also,” he added.

A pre-printed study by the UK health security agency stated the second-dose vaccine efficiency against Omicron infection was 42.8 per cent which declined quickly thereafter. The third-dose vaccine efficiency was 94 per cent and 67.7 per cent against Delta and Omicron infection, respectively. However, the third-dose vaccine efficiency against hospitalisation with Delta or with Omicron was above 99 per cent.

The state’s study also showed that a total of 504 surveyed patients who had one dose of vaccine required admission, while 2,925 patients with both doses were admitted to hospitals. Overall, 64.6 per cent of the vaccinated people with either of the doses required hospital admission. Out of the unvaccinated patients, a total of 1,935 or 65.2 per cent needed admission.

An analysis of the data showed that out of the targeted patients, 55.9 per cent of the vaccinated patients were asymptomatic compared to 60.6 per cent of unvaccinated patients. But, public health officials observed, chances of developing severity among unvaccinated patients especially with comorbidities was high as 22 such patients turned out to be more critical than 14 of their vaccinated counterparts.

“The third wave holds the testimony that vaccines do help in controlling severity among patients. So, the eligible population should get their booster shots,” said Dr Shashank Joshi, member of the state task force.