Scientists from the US have said vaccinated people appear to be contracting the coronavirus at a surprisingly high rate, according to a report in Bloomberg. While it is evident that vaccination provides powerful protection against the virus, there is growing concern that vaccinated people may be more vulnerable to serious illness than previously thought.
When a fully vaccinated person gets infected with coronavirus, it is termed a breakthrough case. According to the US Centers for Disease Control and Prevention (CDC), vaccine breakthrough cases are normal as no vaccine is 100 per cent effective.
In the Bloomberg report, Tom Frieden, a former director of CDC and head of the non-profit Resolve to Save Lives, has been quoted as saying, “We have to be humble about what we do know and what we don’t know. There are a few things we can say definitively. One is that this is a hard question to address.”
Vaccinated people, meanwhile, are confused about how to protect themselves due to lack of information and clear public health messaging. In the middle of all of this, studies giving different pictures of breakthrough infections have emerged. “It’s quite clear that we have more breakthroughs now,” Monica Gandhi, an infectious disease expert at the University of California, San Francisco, is quoted by Bloomberg as saying. “We all know someone who has had one. But we don’t have great clinical data,” she added.
DELTA VARIANT RESPONSIBLE?
The New York Times recently reported that with the arrival of the contagious delta variant, Covid hospitalisations and deaths among vaccinated Americans also may have increased, according to preliminary figures. The report analysed preliminary data from seven states — California, Colorado, Massachusetts, Oregon, Utah, Vermont and Virginia — in the US with respect to the arrival of the delta variant in July. The figures gathered by the report show that breakthrough infections in vaccinated people accounted for at least one in five newly diagnosed cases in six of these states and higher percentages of total hospitalisations and deaths than had been previously observed in all of them.
In India too, a small study by Indian Council of Medical Research (ICMR) on Covid-infected individuals in Chennai, Tamil Nadu, indicated the prevalence of B.1.617.2 (delta variant) “was not different between vaccinated and unvaccinated groups”. The delta variant was the dominating circulating strain and one of the primary drivers for India’s second wave, said the study, approved by ICMR-National Institute of Epidemiology, Chennai. Covid-infected persons, both vaccinated and unvaccinated ones, who visited Greater Chennai Corporation’s triage centres between May 3 and 7, were enrolled in the study. “Studies have documented reduction in neutralisation titres among Covishield and Covaxin recipients after infection with delta variant. This might be the reason for breakthrough infections observed in fully vaccinated individuals,” the ICMR study stated.
A lot of this may be also be attributed to a change in Covid-appropriate behaviour among vaccinated people, as many have started to mingle socially or even travel. However, experts still hold the position that vaccinated people infected with the virus were much less likely to be hospitalised, much less likely to need critical care and much less likely to die. Last week, Indian SARS-CoV-2 Genomics Consortium also said while India was reporting a significantly high number of breakthrough infections, the vaccination has shown to be effective against severe illness, hospitalisation and death.
With India bracing for a possible third wave, much of it, however, hinges on vaccination that is crucial to protecting people against Covid-19. According to a recent study done by professors and alumni from Pandit Deendayal Energy University (PDEU) in collaboration with Nirma University, the vaccination rate of India is currently 3.2 per cent and if does not improve, India can witness six lakh cases per day in the third wave. But if the government’s proposal to increase this rate by five times (1 crore doses per day) comes to fruition, India will see only 25 per cent cases (seen in the second wave) during the third wave peak.
The Biden administration recently allowed booster shots for immunocompromised, and the government said it planned to make vaccine booster shots widely available to all Americans starting September 20. According to a report in Reuters, the UK has also decided to give a booster shot to the immunocompromised and elderly as it induces antibodies. Clinical scientist Dr Gagandeep Kang, however, in an interview to CNBC, said Covid-19 vaccines were working against the delta variant and people should not rush for booster shots in India.