Which vaccine, Covishield (ChAdOx1 nCoV-19) or Covaxin (BBV152), is associated with higher side effects?

Covishield vs Covaxin: Side Effect Profile Comparison

Covishield (ChAdOx1 nCoV-19) is associated with significantly higher rates of adverse events compared to Covaxin (BBV152), with 85.3% of Covishield recipients reporting at least one adverse reaction versus only 17% of Covaxin recipients. 1

Direct Comparative Evidence

The most robust head-to-head comparison demonstrates clear differences in reactogenicity between these vaccines:

• Covishield recipients experienced adverse events at a rate 5 times higher than Covaxin recipients (85.3% vs 17%, respectively) in a large cross-sectional survey of 2,311 participants 1
• After the first dose, adverse events were significantly more common with Covishield (adjusted OR = 3.39,95% CI: 2.24-5.11, P < 0.001) 1
• Both vaccines demonstrated favorable safety profiles without any serious adverse events requiring hospitalization in multiple studies 1, 2, 3

Common Side Effects by Vaccine Type

Covishield (ChAdOx1 nCoV-19)

The most frequently reported adverse events include:

• Pain at injection site (most common) 1
• Fever (30.5% after first dose) 2
• Fatigue 1
• Feeling of unwellness 1
• Malaise and body pain (reported in 73% and 71.1% respectively in dental practitioners) 4

Covaxin (BBV152)

The most frequently reported adverse events include:

• Pain at injection site (most common, but at lower frequency than Covishield) 1
• Local tenderness (39.3% after first dose) 2
• Fatigue 1
• Feeling of unwellness 1

Temporal Pattern of Side Effects

The majority of adverse events occur within the first 24 hours post-vaccination:

• 44.1% of reactions onset within 0-12 hours 4
• 29.0% of reactions onset within 12-24 hours 4
• 75.7% of side effects resolve within 3 days 4
• Only 5.5% of cases reported side effects persisting beyond the first week 4

Demographic Risk Factors for Higher Side Effects

Women experience significantly more adverse events than men (adjusted OR = 1.68,95% CI: 1.24-2.29, P = 0.001) 1

Younger individuals report more frequent side effects compared to elderly recipients (adjusted OR = 0.60 for elderly, 95% CI: 0.36-0.99, P = 0.047) 1

Age shows a significant positive association with adverse events in Covaxin recipients, while the association is only marginal in Covishield recipients 1

Serious Adverse Events and Mortality

Among 2,708 serious adverse events analyzed from nationwide Indian data:

• Covishield accounted for 69.8% (1,891 cases) of serious adverse events 5
• Covaxin accounted for 12.8% (347 cases) of serious adverse events 5
• Overall mortality among serious adverse events was 42.1% (1,114 deaths) 5
• Cardiovascular system involvement was most common (31.3%), followed by respiratory (13%) and neuropsychiatric (13.3%) systems 5

Critical predictors of mortality among serious adverse events include:

• Male sex (higher odds of mortality) 5
• Older age (higher odds of mortality) 5
• Cardiovascular system involvement (significantly higher odds of mortality) 5
• Undetermined or unclassifiable causality (higher odds of mortality) 5

Rare but Serious Complications

Vaccine-induced immune thrombocytopenia and thrombosis (VITT) is a rare but life-threatening complication associated with adenoviral vector vaccines like Covishield:

• Incidence is 14.9 per million after first dose and 1.8 per million after second dose 6
• Symptoms begin 5-30 days post-vaccination and include severe headache, leg swelling, shortness of breath, unexplained bruising/bleeding, and persistent abdominal pain 6, 7
• Cerebral venous thrombosis occurs in 50% of VITT cases, with one-third having multiple thrombosis sites 6, 7
• This complication has been specifically associated with adenoviral vector vaccines (like Covishield/ChAdOx1), not with inactivated vaccines like Covaxin 6

Special Populations

In patients with rheumatic and musculoskeletal diseases (724 patients studied):

• 60.22% experienced at least one adverse event (59.64% with autoimmune disease vs 61.61% with non-autoimmune disease) 3
• All adverse events were self-limiting with no severe events or hospitalizations 3
• Only 4 patients reported disease flare, which resolved within 5 days 3

Clinical Implications

Patients receiving Covishield should be counseled to expect higher rates of common side effects (injection site pain, fever, fatigue) compared to Covaxin, though these are typically mild and self-limiting 1, 2

Healthcare providers must educate all vaccine recipients about VITT warning signs, particularly those receiving Covishield, emphasizing the need for urgent medical evaluation if symptoms develop 5-30 days post-vaccination 6, 7

Patients with cardiovascular comorbidities require closer monitoring given the association between cardiovascular system involvement and higher mortality in serious adverse events 5