COVID-19: Prevention of coronavirus vaccines diminishes within six months | UK news

A new study finds that protection against COVID-19 from two doses of the Pfizer or AstraZeneca vaccine begins to wear off within six months.

In a plausible ‘worst-case scenario’, protection could drop below 50% for seniors and health care workers by winter, analysis from Zoe Corona virus disease study found.

The Pfizer-Biwantech The vaccine was 88% effective in preventing Corona Virus Infection a month after the second dose.

But protection fell to 74% after five to six months – indicating a protection drop of 14 percentage points in four months.

Meanwhile, protection from Oxford AstraZeneca The vaccine dropped to 77% just one month after the second dose.

It fell to 67% after four to five months – indicating a 10 percentage point decrease in protection over three months.

The large study included more than 1.2 million test results and participants, although no vaccines have been tried against the currently prevalent Delta type of virus.

PfizerA medium-term efficacy trial noted an initial 96.2% risk reduction in infection for up to 2 months after the second dose.

There was an 83.7% decrease about four months after the second dose – a 12.5 percentage point increase in risk.

Corona virus disease The vaccines were rolled out across the UK among the elderly and most vulnerable in the community along with health workers first, before being given to younger age groups.

So the majority of people who took their second dose five to six months ago will be older or considered at risk for other health reasons — indicating that they are likely now to be at greater risk of contracting COVID-19 than those who were recently vaccinated.

Professor Tim Spector, chief scientist for the Zoe COVID Study App, said: “In my opinion, a reasonable worst-case scenario could see less than 50% protection for older adults and healthcare workers by winter.

“If high levels of infection in the UK, driven by relaxed social restrictions and a highly transmissible variant, this scenario could mean increased hospitalizations and deaths.”

We urgently need to make plans to boost vaccines, he said, as well as determine whether a strategy to vaccinate children is reasonable if the goal is to reduce deaths and hospital admissions.

Professor Spector continued: “Diminished protection is to be expected and not a reason not to receive the vaccination.

“Vaccines still provide high levels of protection for the majority of the population, especially against the delta variant, so we still need as many people as possible to get fully vaccinated.”

The Zoe COVID study launched the app feature last December to enable registration of coronavirus vaccines and monitoring of real-world side effects and efficacy in its group of more than one million users.

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Younger age groups were recently vaccinated against COVID-19

It used data from vaccines recorded from December 8, 2020 to July 3, 2021, and from infections that occurred between May 26 of this year when the delta variant became prevalent, and July 31.

Study results were slightly modified to give the average risk of infection in the population.

The researchers claim that while protection appears to be steadily decreasing, individual risks may vary due to individual difference in antibody duration.

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