The global pandemic Covid 19 has created immense havoc. The first case of Covid 19 in India was reported in kerala in January 2020.The Palakkad district in Kerala had been going through the struggling phase of tackling this disease since March 2020.Covid 19 is a viral infection caused by corona virus,an RNA virus.Corona viruses in humans mainly causes respiratory infection.In most of the cases it results in minor or self limiting illness in the form of fever,cough,sorethroat,sneezing etc similar to other viral respiratory illnesses.But in some patients,especially high risk individuals,the disease is not limited to upper respiratory tract and they develop viral pneumonia,ARDS like picture or in severe cases respiratory failure and death.Some patients recovering from the illness have fibrosis and scarring as long term sequelae which will cause serious impairment in their quality of living.In India,the first vaccines approved for use were COVISHIELD-a genetically engineered adenoviral vector vaccine and COVAXIN-inactivated coronavirus vaccine.Here in our study,we are focussing on breakthrough infections in high risk population who are completely vaccinated with the above vaccines as per present national protocols.The serum institute of India could manufacture covishield which is the version of oxford Astrazeneca which has 76% efficacy after two doses.Genetic studies have shown that covishield is effective against different variants of SARS- CoV -2 including the delta strain which caused severe disease.Covaxin is developed by Bharat Biotech in collaboration with ICMR-NIV Pune.This is an inactivated virus based COVID 19 vaccine.The vaccine is reported to be 64% effective against asymptomatic cases,93% effective against symptomatic cases and 65% effective against Delta variant.Observational studies conducted by Lancet consistently demonstrated that vaccinations are extremely effective against severe illness including those caused by all major viral strains.Only a few studies have been conducted on breakthrough infections in high risk population.A similar study conducted by Lancet concluded that vaccination is effective against severe disease in those with comorbidities.Its highlighted in another study that even if the antibody levels in vaccinated people decline overtime the effectiveness against severe illness will persist.This means that the protection provided by vaccines is not only mediated by antibody but also by memory responses and cell mediated immunity.It is critical to vaccinate all individuals to combat the disease. A study on the clinical course and outcome of confirmed cases of vaccinated Covid 19 in high-risk population will provide a clear idea about the disease-host interplay in vaccinated people. This study is to find out the disease severity based on clinical, biochemical and radiological features in the above-mentioned population. This study will help in categorising and characterising the disease severity in high risk vaccinated people and help in providing an early assessment and better clinical care for them.

Objective: To assess the severity of Covid 19 affected in high-risk groups who are vaccinated with two doses of any vaccine against Covid 19 based on the clinical, laboratory and radiological parameters.

The study was conducted at District Hospital Palakkad where the clinical department of Government Medical College Palakkad has been functioning.

• Eligibility criteria: patients admitted to covid hospital who are high risk individuals and has taken two doses of any vaccine against Covid 19 .
• Criteria for high-risk category: age above 60years, diabetes mellitus, obesity, chronic kidney disease, chronic respiratory illness, malignancy, sickle cell anemia, organ transplant recipient, chronic liver disease, cardiac failure, coronary artery disease, systemic hypertension, old cerebrovascular accident, immunocompromised state and any other significant comorbidity which can alter the outcome of COVID
• Inclusion criteria: Patients admitted and treated completely from District Hospital Palakkad.
• Exclusion criteria: Pregnant patients and those adults with past history of COVID 19, those who were not willing to be included are excluded from the study

Variables:

Age, sex, comorbid illness, Respiratory rate, oxygen saturation, CRP, D Dimer, Neutrophil Lymphocyte Ratio, Absolute Neutrophil Count, HRCT scoring or chest X ray findings (whichever is available), requirement of oxygenation and/or ventilator support, disease outcome.

The source of data is the patient himself/herself and medical records.

Appropriate statistical tests are used during the study.

Data sources: patient, medical records No bias encountered Study sample size is 51 .

All the patients admitted and completed treatment during the period of study satisfying the eligibility and inclusion criteria are included in the study.

Statistical methods: Quantitative variables are expressed as mean with standard deviation.

Qualitative variables are expressed as percentage. The first step was identification of eligible cases, second was assessing the clinical, laboratory and radiological parameters and the third was to assess the outcome of the disease.

In our study more than 70% of patients were above 60years of age with male sex predeliction.CRP was elevated in 80% of patients and D Dimer was elevated in 70% of patients.57% of patients were of category B and 43% developed pneumonia, hence included under category C .Out of category C patients, 29% had moderate disease and 14% had severe disease.20% of patients required ventilator support of which 95% were under non invasive ventilation. Out of 51 patients only single patient was put on mechanical ventilation and he expired.

Table 1 sociodemography

Table 2Comorbidities

Table 3 Vaccine

Table 4 physical parameters

Table 5 according to Oxygen saturation

Table 6 mode of ventilation

Table 7 according to CRP and d - dimer

Table 8 According to hematological parameters

Table 9 Radiological investigations

Table 10 outcome

In the present study the patients belonging to age group 32-85 years were included. Covid 19 always showed male sex predeliction irrespective of genotype. Most common comorbid illness which needed hospital admission was diabetes mellitus followed by chronic obstructive pulmonary disease. Covishield is the vaccine received by 84% of patients in our study and other studies have shown that it is 99% effective in preventing complications in general population. The presence of tachycardia and tachypnoea indicates disease progression in covid19.Bloodpressure has no significant role in predicting the outcome of the disease. The outcome of mechanical ventilation is worse in covid 19.CRP as an inflammatory marker directly correlated with disease progression. D Dimer is a marker of both inflammation and risk of thrombotic complications. It was markedly elevated in those patients needed ICU admission. A low absolute neutrophil count and high neutrophil lymphocyte ratio were found in those with moderate to severe disease. Chest X ray in available cases showed bilateral lower zone non homogenous opacities. Based on HRCT chest scoring out of 25, 30% had severe disease at the time of admission. Severe disease at the time of admission showed a very poor outcome compared to those who progress to severe disease after hospitalisation. This study revealed that diabetes mellitus, chronic obstructive pulmonary disease and chronic kidney disease are the most important risk factors determining severe disease with high risk for mortality. Other comorbidities found in our patients include obesity, hypothyroidism, peripheral vascular disease, Parkinson plus and psychiatric illness. The study concluded that covishield provides 57% protection against severe disease and 80% protection against mortality in high risk group of individuals.

Acknowledgement:  Nil

Conflicts of interest: Nil

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