Early Side Effects after Administration of the 1st Dose of Oxford-AstraZeneca Vaccine

Abstract Vaccines have played a central role in minimizing new infections, the rate of hospitalizations, and the overall burden on the health sector. Fear of side-effects is the biggest and commonest reason for avoiding getting vaccinated. It is, therefore, essential to maintain the clarity and consistency of message, to support and encourage people to get vaccinated. This study aims to contribute in that regard, by registering and quantifying the early side-effects of the Oxford-AstraZeneca COVID-19 vaccine in Pakistan. This study employs a non-random cross-sectional design. Data collected from 477 participants using a structured questionnaire was used to investigate the relationship between socio-demographic characteristics and side effect profiles of the participants. Binomial Logistic Regression was used to analyze the data. Odds Ratio (OR) gives the likelihood of having a side effect versus the reference group. Significance level (α) for the probability value (p-value) is set at 0.05. Fever (30.19%) was the most commonly experienced side effect, followed closely by fatigue (22.01%). 71.11% of those with fever experienced low grade fever (99-100F) while 62.69% of body aches experienced were moderate in intensity (Grades 4-6). In general, younger people are significantly more likely (p=0.023) to experience side effects (OR-1 = 1.023: interpreted as 1.023 times increase per unit decrease in age). Similarly, they are more likely (p= 0.029) to have a headache (OR-1 =1.039). Also, they are more likely (p= 0.007) to have a body ache (OR-1 =1.038). The Oxford-AstraZeneca COVID-19 vaccine side-effects seem to be more prevalent among younger age groups, which points to increased vaccine safety among older individuals that are usually more susceptible to severe COVID-19 infection. In addition, we found a substantially reduced number of side-effects, as compared to the clinical trials, which is an encouraging indicator for vaccine safety.