AstraZeneca, Pfizer COVID Vaccines: Second Dose Provide High Immune Response!

According to published published published published published research, two doses of Pfizer and AstraZeneca vaccines give substantial protection against severe COVID-19 for up to six months following the second injection.

The team, led by researchers from the University of Bristol in the United Kingdom, examined National Health Service (NHS) health record data on over seven million persons, discovering protection in those over the age of 65 and clinically fragile adults.

AstraZeneca, Pfizer Vaccines Boost High Immune Response From Covid!

They also looked at how rapidly vaccination efficacy faded over time in patients without past SARS-CoV-2 infection who got two doses of Pfizer-BioNTech or AstraZeneca COVID-19 vaccine compared to unvaccinated people.

The researchers analyzed data from 1,951,866 (19.5 lakh) and 3,219,349 (32 lakh) persons who had two doses of Pfizer and AstraZeneca vaccines, respectively, as well as 2,422,980 (24 lakh) unvaccinated adults.

They discovered that the incidence of COVID-19 hospitalization and mortality were significantly lower in vaccinated people than in unvaccinated persons up to six months following their second dose.

According to the researchers, vaccination efficacy against these occurrences was determined to be at least 80% for Pfizer and at least 75% for AstraZeneca.

However, due to diminishing vaccination efficacy against SARS-CoV-2 infection, rates in vaccinated persons were comparable to or greater than rates in unvaccinated individuals six months following the second dose, they said.

“Until recently, there has been minimal and contradictory information about the rate of fading after the second dose of COVID-19 vaccinations, whether it extends to severe COVID-19, and if the rate varies by age and clinical susceptibility,” said Elsie Horne, the study’s lead author from the University of Bristol.

According to the researchers, this discovery was consistent across all participants, including older persons and those at risk of severe COVID-19.

“Understanding how long COVID-19 immunizations stay effective is critical for scheduling and targeting booster doses,” said Jonathan Sterne, a professor at Bristol Medical School.

The researchers want to conduct a follow-up study to assess vaccination efficacy one year after the second dosage and into the period of the Omicron version. They are also looking into the rate of fading in sensitive clinical groupings, such as individuals suffering from chronic renal disease or cancer.

Faced with insufficient COVID-19 vaccination supply and unanticipated side effects, some governments have embraced an experimental strategy: switching injections midway.

The majority of approved vaccinations require two doses given weeks or months apart, however, Canada and some European countries are now proposing an alternative vaccine for the second dose in some individuals. Early evidence suggests that the strategy, which arose out of need, may be advantageous.

Researchers discovered that following one dosage of the AstraZeneca vaccine with a dose of the Pfizer-BioNTech vaccine generates robust immunological responses, as determined by blood tests in three recent experiments.

Two studies even show that the combined vaccination response will be at least as effective as two doses of the Pfizer-BioNTech product, which is one of the most effective COVID-19 vaccines. Only a few of the possible vaccination combinations have been evaluated.

However, if combining vaccinations is proven to be safe and effective, it might accelerate the endeavor to protect billions of people. “This creates fresh prospects for many countries.,” Cristóbal Belda-Iniesta, clinical research expert at the Carlos III Health Institute, agrees.

Governments, for example, may distribute fresh doses instantly without having to worry about keeping aside second shots of certain vaccinations to deliver to patients weeks or months later.