Preliminary findings from a study published in The Lancet indicate that alternating doses of different covid-19 vaccines causes mild and moderate reactions more frequent than if the standard immunization schedules are followed with two injections of the same preparation.
A team from the Oxford University (United Kingdom) launched Com-Cov earlier this year, an investigation into the effects of alternating two vaccine regimens manufactured by different pharmaceutical companies. The authors found that this combination increased reactogenicity – adverse reactions when administering the vaccine, such as injection site pain, malaise, headache, fever, etc-.
The research found that applying mixed vaccination schedules generated more mild or moderate reactions after the second dose than if vaccination was done without mixing the preparations
The researchers found that when a four-week interval was left between doses, applying the “mixing schedules” (first dose of Pfizer / BionNTech and second dose of Oxford / AstraZeneca, and Oxford / AstraZeneca followed by Pfizer / BioNTech) generated more reactions. mild or moderate after the second dose than if the standard procedure of not combining vaccines from different manufacturers was followed.
They also reported that any adverse effect derived from the mixture was short-lived and clarified that no other safety-related complications were detected.
Mixed dose studies
“Although this is a secondary part of what we are exploring, it is important that we inform people about these data, especially since several countries are considering using these mixed dose schedules,” he says. Matthew snape, Associate Professor of Pediatrics and Vaccines at the University of Oxford and lead investigator of the work.
The CombivacS clinical trial in Spain, promoted by the Carlos III Health Institute (ISCIII), also analyzes the safety and the effect of giving different doses of vaccine.
It is important that we inform people about these data, especially as several countries are considering using these mixed dose schedules.
Matthew Snape, Lead Research Investigator
The study findings suggest that “mixed dose schedules could result in an increase in work absences the day after immunization, and it is important to consider when planning the vaccination of healthcare workers, ”says Snape.
“There are no concerns related to safety,” said the expert, noting that the study does not determine whether the immune response “will be affected.”
Snape also says the team is confident of showing that data in full “in the next few months,” as these results published in The Lancet are preliminary and data from participants who have not yet received the second dose of the vaccine have yet to be collected.
Data remains to be collected from trial participants who have not yet received the second dose of the vaccine.
“In the meantime, we have adapted the study to assess whether early and regular use of paracetamol it reduces the frequency of these reactions ”, reveals the chief researcher.
The experts also note that the data collected from their tests was drawn from participants over 50 years old, so there is a possibility that such reactions may be more prevalent in younger age groups.
Fountain: EFE / SINC
Rights: Creative Commons.