KUALA LUMPUR, Sept 23 — Complete inoculation with Covid-19 vaccines is 83 per cent effective against admission into intensive care and can prevent death by 88 per cent, a study led by the Institute of Clinical Research (ICR) found.
ICR director Dr Kalaiarasu Peariasamy told a media briefing today that complete vaccinations can reduce one intensive care unit (ICU) admission for every 67 persons infected with Covid-19, and one death for every 97 individuals who contract the virus.
Complete vaccination reduces the risk of coronavirus infection by 88 per cent and symptomatic disease by 86 per cent, but Dr Kalaiarasu did not provide details on vaccine efficacy by vaccine type.
By vaccine brand, Dr Kalaiarasu said AstraZeneca-Oxford’s vaccine was the most effective at reducing both ICU admission risks and deaths among breakthrough Covid-19 cases by 96 per cent.
Pfizer-BioNTech’s vaccine is 92 per cent effective at reducing ICU admissions and 93 per cent effective at preventing deaths among fully vaccinated Covid-19 patients. The Sinovac vaccine is 77 per cent and 84 per cent effective at curbing ICU admissions and deaths, respectively.
Dr Kalaiarasu said findings by the Real-World Evaluation of Covid-19 Vaccines Under the Malaysia National Covid-19 Immunisation Program (RECoVaM) showed that the overall ICU rate among fully vaccinated individuals — 14 days after the second vaccine dose in a two-dose regime — stood at only 0.0066 per cent.
This is equivalent to 953 ICU admissions in 14,500,984 fully vaccinated individuals tracked from April 1 to September 12 who received two doses of either Pfizer-BioNTech, AstraZeneca, or Sinovac.
Out of 7,223,897 individuals double-jabbed with Sinovac, 799 entered ICU, or 0.011 per cent, slightly exceeding the average 0.0066 per cent ICU admission rate across vaccine types.
This was followed by Pfizer’s 0.002 per cent ICU rate at 147 admissions of 6,530,943 people who completed inoculation with the mRNA vaccine. AstraZeneca showed a 0.001 per cent ICU rate at seven admissions of 744,958 people who received two doses of the viral vector vaccine.
However, it was pointed out that 50.4 per cent of the 953 breakthrough ICU admissions were aged 60 or older and 88.6 per cent had comorbidities.
The RECoVaM survey also found that breakthrough Covid-19 death rates were low among fully vaccinated individuals at 0.010 per cent or 1,445 deaths out of 14.5 million people in the study.
Sinovac slightly exceeded the 0.010 per cent breakthrough mortality rate across vaccine types at 0.015 per cent, with 1,108 deaths among the 7.2 million people fully inoculated with the inactivated vaccine.
A total of 323 breakthrough deaths were recorded among the 6.5 million fully vaccinated with Pfizer, or 0.005 per cent. This was followed by 14 breakthrough deaths among the 744,958 individuals fully inoculated with AstraZeneca, or 0.002 per cent.
Among the breakthrough mortality cases, 76.3 per cent were aged 60 years and above, while 92 per cent had comorbidities.
Dr Kalaiarasu told reporters that AstraZeneca showed a lower breakthrough mortality rate because the majority of its vaccine recipients were young adults, while the proportion of AstraZeneca recipients is also substantially smaller than those who received Pfizer and Sinovac.
Pfizer and Sinovac vaccines, said the RECoVaM lead researcher, were generally given to individuals across age group, including the vulnerable. All Covid-19 vaccines are effective, said Dr Kalaiarasu.
Citing a recently published article by the British Medical Journal, Dr Kalaiarasu said unvaccinated people are 11 times at risk of death from the Delta variant.
Dr Kalaiarasu further noted that the risk of breakthrough infections increases with every passing day after completing the vaccination course.
The same RECoVaM survey indicated that the Covid-19 infection risk among fully vaccinated people was at 5.2 to 5.32 per cent within 120 days after full vaccination, versus 0.53 to 0.54 per cent within 30 days after being fully vaccinated.
This is consistent with recent findings by the United States’ Centers for Disease Control and Prevention (CDC) which point to the waning of vaccine-induced immunity with increased time since vaccination.
Update: This article was updated with Dr Kalaiarasu’s comments in the 15th and 16th paragraphs.