Cut risk of Covid-19 death by 20 times with double jab

Discovery study shows Pfizer vaccine offers 90% protection against dying

05 November 2021 - 12:01
By Claire Keeton
Pfizer's double-dose vaccine provides 94% protection against death, a Discovery Health study has found.
Image: SEBABATSO MOSAMO Pfizer's double-dose vaccine provides 94% protection against death, a Discovery Health study has found.

The risk of dying from Covid-19 is 20 times higher among people who are not vaccinated than those who had the double dose Pfizer vaccine, a new study by Discovery Health shows.

Unvaccinated adults faced a 20 times higher risk of death and a five times higher risk of infection than vaccinated members, their records reveal. From May to September 1.2-million Discovery members got the jab.

People who had received both shots had 94% protection against death 14 days after the second dose, and 92% protection against hospital admission.

After the first dose, people’s risk of death was reduced by 79% and of hospital admission by 73%.

Reassuring people with concerns about the vaccine’s safety, Discovery CEO Dr Ryan Noach said: “There have been zero vaccine-related deaths recorded [by Discovery Health]. The risk of a severe adverse event is extremely low.”

In the study, the Pfizer vaccine was found to be as effective at protecting people with two comorbidities, like diabetes, and equally beneficial to men and women.

People older than 80 and those with three comorbidities experienced a 5% to 7% decline in vaccine effectiveness.

Three months after the second dose — the vaccinations were being delivered during the third wave of infections driven by the contagious Delta variant — no waning in vaccine effectiveness was found.

These results on Pfizer’s effectiveness match international studies, SA hospital records and research.

Wits University infectious diseases specialist Dr Jeremy Nel said: “The exact protection against death depends on the specific vaccine, the specific virus variant, and the time point at which it is measured, but on average, with Delta, people can probably expect to see 70% to 95% protection from hospitalisation, and about a 90% to 95% or higher reduction in the risk of death.”

In the latest study, people who had recovered from Covid-19 and got both Pfizer jabs had a 98% drop in the risk of being admitted to hospital.

“While immunity following an infection provides some protection from future Covid-19 complications, the risk of reinfection remains,” said Noach.

“More than 11,500 Discovery Health-administered members have experienced reinfections during the three waves of the pandemic.”

Three easily treatable side-effects which occurred after vaccination were lymphadenopathy (a benign enlargement of lymph nodes), myositis (inflammation of the muscles presenting as general muscle pain) and paraesthesia (a tingling sensation).

The “manageable adverse” effects which occurred rarely after vaccination presented a much higher risk to people who got Covid-19:

  • There is a 40-fold increased risk of pulmonary embolism (40 times higher chance of experiencing pulmonary embolism after a Covid-19 infection).
  • There is a 22-fold increased risk of myocarditis.
  • There is a 16-fold increased risk of acute kidney injury.

More than 80% of Discovery members older than 60 have received at least one dose and more than 60% of its adult members had a single shot.

By Thursday night, 32% of South Africans had been fully vaccinated.

Noach predicted the country, which has secured enough vaccine doses for 80% of its population, was likely to tip just over 50% by the end of this year.

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