6.3mil lives saved thanks to AstraZeneca Covid-19 jab

 

From Dr Musa Nordin and Dr Tan Hui Siu

The AstraZeneca (AZ) Covid-19 vaccine has been in the news lately, but the press reports have not been investigative and precise enough, let alone fair, giving rise to anti-vaccine proponents thinking they have been right all along.

One particular anti-vaccine doctor was bold enough to suggest that other Covid-19 vaccine manufacturers would eventually come clean with their safety data and withdraw all their vaccines. This same doctor once claimed that “…this pandemic is the greatest hoax of human history.”

Any investigative reporting would have considered in detail the benefits and risks of the AZ Covid-19 vaccine and its role in saving most lives in a larger context of the then-raging pandemic.

The story of the AZ vaccine begins with how the vaccine experts at the Jenner Institute, University of Oxford, were futuristically designing a vaccine model to defeat an unknown pandemic pathogen.

They infected chimpanzees with the common cold virus (adenovirus), and re-engineered it to be the backbone of a vaccine against any pathogen. They named it Chimpanzee Adenovirus Oxford One, or ChAdOx1.

When Chinese scientists shared the complete genome of SARS-CoV-2 on Jan 11, 2020, the Oxford team inserted the genetic code of the spike protein into ChAdOx1 and developed a vaccine against SARS-CoV-2 in a record time of 10 months.

Phase 3 ChAdOx1 Covid-19 vaccine randomised control trials demonstrated a vaccine efficacy of 76%, which increased to 82% with a second dose 12 weeks later.

In just a year, in January 2021, the UK, which had the second highest Covid-19 death toll in Europe, became the first country to roll out this vaccine, co-developed by the University of Oxford and AZ.

A month later, the World Health Organization approved the Oxford/AZ Covid-19 vaccine for emergency use, and the jabs were rolled out globally.

The vaccine was one of the most affordable in the market – almost five to 10 times cheaper than the mRNA vaccines. It would have been interesting to know the exact price tags in various countries, including Malaysia.

Apart from being affordable, the AZ Covid-19 vaccine was easier to transport, distribute, and administer since it did not require storage at arctic low temperatures.

The rare but serious adverse effects of the AZ Covid-19 vaccine were known as thrombosis thrombocytopenia syndrome (TTS), which is the presence of blood clots (thrombosis) developing in unusual locations such as the cerebral veins, and low platelet levels (thrombocytopenia).

The adverse effects following immunisation (AEFI) monitoring and pharmacovigilance data showed that in those under 70 years of age, the rate of hospitalisation due to TTS was higher after the vaccination compared to those unvaccinated and those aged above 70.

However, in general, the risks of venous thrombosis, thrombocytopenia and cerebral venous thrombosis from Covid-19 infection had been quoted as 190, nine, and three times higher, respectively, than those associated with the vaccination.

With the emergence of this data, many countries limited the AZ Covid-19 to elderly persons, but not Malaysia.

Malaysia’s health ministry and vaccine supply committee sanctioned the voluntary uptake of the AZ Covid-19 vaccine among younger persons.

Some of us raised a red flag in 2021, asking how the ministry could scientifically and ethically justify giving the AZ vaccine to younger adults when the UK, and later Europe, with the most extensive AZ Covid-19 vaccine experience, had advised otherwise.

Some 5,698,292 doses of the AZ Covid-19 vaccine were administered in Malaysia up until Nov 30, 2023, with 151 (or 0.0027% of the total AZ jabs) reports of severe AEFI following the vaccine.

Of this figure, up to March 31, 2024, the National Pharmaceutical Regulatory Agency reported five cases of TTS or 0.88 cases per one million doses of AZ vaccine given.

Comparatively, the European Medicines Agency reported a rate of five cases per million among those above the age of 70 and 20 cases per million among those below 50.

An Imperial College London study calculated that Covid-19 vaccines saved 20 million lives between December 2020 and December 2021.

UK-based analytics firm Airfinity’s further analysis of this data showed that the AZ Covid-19 vaccine saved 6.3 million lives, Pfizer 5.9 million lives, Sinovac two million lives and Moderna 1.7 million lives.

Yes, the mRNA Covid-19 vaccines were more robust, easier, and faster to update than the AZ Covid-19 vaccine, while AstraZeneca initiated a worldwide withdrawal of its vaccine due to a “surplus of updated vaccines”.

But notwithstanding the pending court cases against AZ, we must not dismiss the role the AZ vaccine played in the early days of the pandemic in saving many lives.

The benefits of vaccination in preventing severe Covid-19 disease and deaths outweighed the risks of TTP if considered independently and in the proper age category.

The efficacy and safety data of the AZ vaccine was published from the start. It was up to each country to critically appraise the scientific evidence and tailor the roll-out according to emergency needs and the benefits and risks calculation of different populations. - FMT

Dr Musa Nordin and Dr Tan Hui Siu are paediatricians.

The views expressed are those of the writers and do not necessarily reflect those of MMKtT.