New research shows that waiting 3 months between the first and second dose of AstraZeneca vaccine leads to high efficacy.
And the study, which included more than 17,000 participants and was recently published in The Lancet according to a report by abc, found that the vaccine - which most people will receive in Australia - had an efficacy rate of 81% when a second dose was given three months after the first. This is up to a 55% efficacy rate if the second dose is given less than 6 weeks after the first.
Judy Macferon, director of epidemiology at the Peter Doherty Institute for Infection and Immunology in Australia, said that the result was not surprising, adding: This finding, of the late interval between the initial dose and the booster dose to give a better response to antibodies, is consistent with some other vaccines that we have seen before. She also cited the flu, Ebola and malaria vaccines that had greater protection and stronger immune responses after a longer period between doses.
But Professor Macferon said that the long waiting period between doses is not ideal for every vaccine, pointing out that each vaccine needs to be studied to determine those doses and the best period of time.
In Australia, the Medication Administration recommends waiting 12 weeks between doses, but why waiting longer leads to better results is still unclear.
Why waiting between doses boosts the immune response
According to the researchers, there are two theories as to why waiting 12 weeks between doses led to a higher efficiency rate: The first theory is based on the fact that after a person is vaccinated, their body has a reaction to the vaccine itself, and this reaction is the initiation of the body's immune system, and some of those The particles produced can be completely inflammatory and when you receive the vaccine (injection) in a short period, these inflammatory responses can limit the ability of the immune system to generate an enhanced immune response. "
The second theory concerns the synthesis of the AstraZeneca virus vector vaccine, which uses a harmless chimpanzee adenovirus to deliver DNA into our cells, as the vaccine contains a viral particle that contains the spiky protein gene, and adenovirus particles are on the surface of the particle.
High level of protection between doses
The researchers also found that the first dose provided 76% protection in the three months between doses, meaning that people enjoyed high coverage while waiting for their second dose.
The results published in The Lancet are also supported by a factual study from Scotland, and according to this research, which has not yet been reviewed, examined the effectiveness of the first dose of the Pfizer and AstraZeneca vaccine in a nationwide study of about 5.4 million people.
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