Systemic reactogenicity increased with heterologous COVID-19 vaccine doses

HealthDay News – Participants who received heterologous prime and boost doses of COVID-19 vaccines experienced an increase in systemic reactogenicity after the boost dose compared to participants who received homologous vaccination schedules. This is evident from an online research letter published in The Lancet on May 12th.

Robert H. Shaw, MBBS of Oxford University in the UK, and colleagues present the first reactogenicity and safety data for the Com-COV study, which compares all four prime-boost permutations of the ChAd and BNT vaccines, both at 28- and 84-day Prime Boost intervals. Data were included for 463 participants in the 28-day prime boost interval group.

The researchers found that both heterologous vaccination schedules induced greater systemic reactogenicity after the boost dose compared to their homologous counterparts. 34 percent of patients who received ChAd for Prime and BNT for Boost reported a fever versus 10 percent of those who received ChAd for Prime and Boost and 41 percent of those who received BNT for Prime and ChAd for Boost, versus 21 percent of those who have favourited BNT for Prime and Boost. Similar increases were seen in chills, fatigue, headache, joint pain, malaise, and muscle pain. No hospitalizations occurred due to the symptoms requested. Most of the increase in reactogenicity occurred in the 48 hours after immunization. The hematological and biochemical profiles were similar for heterologous and homologous vaccination schedules. On day 7 after the boost dose, no thrombocytopenia occurred in any group.

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“The important thing is that there are no safety concerns or signals, and this doesn’t tell us whether the immune response will be affected,” a co-author said in a statement. “We hope to be able to report this data in the coming months.”

One author disclosed financial relationships with vaccine manufacturers, including vaccines from AstraZeneca, GlaxoSmithKline, Pfizer, Novavax, Janssen, Medimmune, and MCM.

Abstract / full text


COVID19 COVID19 Vaccine General Infectious Disease General Neurology

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