This voluntary survey of healthcare workers in India found a 43% rate of reported SARS-CoV2 infection following vaccination. This relatively high rate of reported infection was further reported as predominantly symptomatic COVID19 disease. Of patients with symptomatic disease, 28% required non-ICU hospital admission and 13.2% required ICU admission.
Understanding relationships between emerging variants and vaccination status has become paramount in our understanding of this new wave of the pandemic and its global implications. Given this scarcity of available information, any early sense of impact of this new wave of the pandemic on vaccinated patients is crucial to our understanding of the development of this pandemic. As such, this study aimed to provide an initial glimpse into the experience of healthcare workers in India who are currently confronting this staggering new wave of the COVID19 pandemic.
The protection offered by vaccination against new strains of SARS-CoV2 is a central question to which there remains an unclear answer. It has become clear that SARS-COV-2 variants, such as B.1.617, are spreading rapidly in India and are the predominant strains responsible for much of the morbidity and mortality associated with this latest wave. Several in vitro studies have suggested neutralizing potential of these vaccines against new variants 3. Unfortunately, there have been little to no in vivo studies that have examined clinical vaccine efficacy in these new environments. The results from this survey suggest that, in vivo, vaccine efficacy to prevent both asymptomatic and symptomatic SARS-CoV2 infection may be significantly reduced. Notably, there was a significant proportion of patients who reported only mild symptomatic disease, indicating there may be a role in mitigating severe disease. The intrinsic and extrinsic factors that may be responsible for this reduction in efficacy require further study. Additionally, the focus on healthcare workers in this study may aid in understanding a subpopulation with the highest exposure risk. Vaccine efficacy data obtained via clinical trials involving the general population may not be representative of vaccine efficacy in this subgroup.
There are several limitations to this study inherent to voluntary survey response studies. Respondents who had infection or had more severe infection may be more inclined to respond, leading to selection bias. Additionally, recall bias in recounting severity of illness may lead to overstatement of the severity of illness. This study did not include factors such as geographic location, immunocompetent vs immunocompromised status, comorbidities, and several other factors. This study also did not include members of the general population, which may limit generalizability. Regardless of these limitations, this study offers an initial glimpse into the impact of this new wave of the COVID19 pandemic on vaccinated healthcare workers in the Indian subcontinent.
In summary, this survey of healthcare workers in the Indian subcontinent reported high rates of both symptomatic and asymptomatic disease despite reporting receiving vaccination. Despite this higher rate of disease, most respondents only reported mild disease. The destruction produced from this latest wave of the COVID19 pandemic may be a call to the international community to unite to not only aid India, but to understand these variants and prepare for their potential spread. As the pandemic rages forward, systematic, and focused in vivo studies into vaccination efficacy to further confirm the effects found in this initial survey are necessary.