Kerala’s COVID cases are high, and over half are breakthrough infections

Over recent weeks, Kerala has held the dubious distinction of registering more than 50% of the total new daily COVID cases in the country. On Diwali day, November 4, Kerala saw 7,545 new COVID cases, against the 12,885 new cases pan-India reported on November 3. As on Thursday, the test positivity rate was 10.5%, stated Chief Minister Pinarayi Vijayan.

Presenting some cheer is the vaccination drive, with 95% of the adult Kerala population having received at least one shot, while 52.5% has taken both. Reflecting this trend, breakthrough infections in the State have accounted for a substantial portion of the daily COVID cases over the past two weeks, suggest government data.

Breakthrough infections are those caught by the fully vaccinated, and tend to be less severe than the regular infections. Just a fraction of these cases calls for hospitalisation with oxygen beds or ICU facilities. The mortality rates, too, are far lower.

Virulence of infection

Citing government data, an Indian Express report said 1,19,401 positive cases were recorded Kerala from October 19 to November 2. Of these, 67,980 people, or nearly 58% of the total cases, was either fully or partially vaccinated. While 40,584 people came under the former category, 27,396 came under the latter.

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Kerala Health Minister Veena George noted that over the past week, just 2% of the 77,516 active cases had required oxygen beds and 1.5% required ICU admission. It may be recalled that when the second wave of COVID was peaking, in April-June, there was a severe scarcity of oxygen and ICU beds nationwide.

George observed that breakthrough infections were not surprising and were, in fact, anticipated. They go to prove that vaccination can significantly reduce the severity of — and morbidity due to — the infection, she added.

“Kerala has got immunity mainly from vaccination rather than infection as revealed by the State’s recent seroprevalence survey. In many other States, high prevalence of antibodies was mainly due to the widespread infection,’’ she further said. “Although fully vaccinated persons are getting infected, deaths among them due to COVID are very rare. In cases where fully vaccinated people died, the victims had been either very old or had severe comorbidity factors.”

Continued caution

The report quoted State officials as saying that health workers form a large proportion of people getting infected now. They’d been the first to get the shots when India began its vaccination drive early this year.

However, Dr TS Aneesh, who’s part of Kerala’s expert panel on COVID, said: “Health workers, who are among those with breakthrough infections, have better access to testing.’’ That might explain the high number of cases among them, he noted while adding: “The data on infection among the fully vaccinated is a reason to suspect whether the immunity level in the fully vaccinated is going down.”

Experts globally have advised the public to be cautious even after vaccination. Mandatory masking, social distancing and other COVID-appropriate behaviour are seen to be essential even in near-fully vaccinated populations.