Advertisement
Monday, Jun 27, 2022
Outlook.com
Outlook.com

Covid-19: Pfizer Vaccine Not Effective Against Omicron Like Delta, Finds South Africa Analysis

Covid-19 Omicron variant was first detected in South Africa. The large-scale analysis of Pfizer vaccine effectiveness seems to support early indications that the the vaccine shot effective against Omicron like Delta variant.

Covid-19: Pfizer Vaccine Not Effective Against Omicron Like Delta, Finds South Africa Analysis
People wait for Covid-19 vaccination at Soweto's Baragwanath hospital in South Africa. | AP
Covid-19: Pfizer Vaccine Not Effective Against Omicron Like Delta, Finds South Africa Analysis
outlookindia.com
2021-12-14T17:22:35+05:30

A two-dose Pfizer/BioNTech vaccination provides just 33 per cent protection against infection by the omicron variant of the coronavirus, but 70 per cent protection against hospitalisation, according to a large-scale analysis in South Africa released Tuesday.

The first large-scale analysis of vaccine effectiveness in the region where the new variant was discovered appears to support early indications that omicron is more easily transmissible and that the Pfizer shot isn't as effective in protecting against infection as it was against the delta variant.

The analysis was based on more than 211,000 positive Covid-19 test results, 41 per cent from adults who had received two doses of the Pfizer vaccine. About 78,000 of these positive Covid-19 test results between Nov. 15 and Dec. 7 were attributed to omicron infections.

The study was carried out by Discovery Health, South Africa's largest private health insurer, and the South African Medical Research Council.

The study has been carried out in the weeks since omicron was first announced in November by scientists in South Africa and Botswana. The researchers emphasized that its findings are preliminary and not peer reviewed.

The data are gathered from the first three weeks of South Africa's omicron-driven wave and may change as time passes. South Africa is the first country to experience a surge in Covid-19 driven by the omicron variant.

South Africa has experienced rapid community spread — concentrated in its most populous province, Gauteng — dominated by the omicron variant.

The seven-day rolling average of daily new cases in South Africa has risen over the past two weeks from 8.07 new cases per 100,000 people on Nov. 29 to 34.37 new cases per 100,000 people on Dec. 13, according to Johns Hopkins University. The death rate hasn't increased during that same period.

“Superb genetic surveillance by the Network for Genomic Surveillance in South Africa identified that omicron infection accounts for over 90% of new infections in South Africa, and has displaced the formerly dominant delta variant,” Discovery Health chief executive Dr. Ryan Noach said.

“The omicron-driven fourth wave has a significantly steeper trajectory of new infections relative to prior waves. National data show an exponential increase in both new infections and test positivity rates during the first three weeks of this wave, indicating a highly transmissible variant with rapid community spread of infection,” Noach said.

The result shows that vaccinated individuals who received two doses of the Pfizer vaccine have 33 per cent protection against infection from omicron, relative to those who were unvaccinated in the first weeks of South Africa's current omicron-driven wave.

This represents a significant drop from the 80 per cent protection against infection afforded during the earlier period, probably on the basis of lower antibody susceptibility, following the extensive spike protein mutations in the omicron variant.

Encouragingly though, the result shows that these same vaccinated individuals who received two doses of the Pfizer vaccine have 70 per cent protection against hospital admission in this same time period. This protection against hospital admission is reduced from the highs of 93 per cent in South Africa's delta-driven variant.

The study shows that the protection against hospital admission is maintained across all ages, in people from 18 to 79 years old, with slightly lower levels of protection for older people, with 67 per cent in people age 60 to 69 and 60 per cent for people age 70 to 79.

Protection against admission is also consistent across a range of chronic illnesses including diabetes, hypertension, hypercholesterolemia, and other cardiovascular diseases.

The study also found:

1. Omicron poses a higher risk of reinfection. For individuals who have previously had COVID-19, the risk of reinfection with omicron is significantly higher than that of earlier variants.

2. Risk of hospitalisation from omicron is lower. Hospital admissions among adults diagnosed with Covid-19 attributed to omicron is 29 per cent lower compared to the Covid-19 wave that South Africa experienced in mid-2020, after adjusting for vaccination status. (AP)

Advertisement

Outlook Newsletters

Advertisement
Advertisement
Advertisement

Read More from Outlook

Lament Of Separation: Songs Of Habba Khatun, Last Queen Of Kashmir, Still Echo In Valley

Lament Of Separation: Songs Of Habba Khatun, Last Queen Of Kashmir, Still Echo In Valley

In happy times and sad, Habba Khatun’s sensuous songs make both young and old emotional. With the never-ending conflict bringing tragedies to every doorstep, Habba’s lyrics of separation amplify their mourning.

How Indian Laws Govern People’s Right To Love And Live

How Indian Laws Govern People’s Right To Love And Live

In India, only those relationships between a man and a woman are considered to be legitimate when there is a marriage between the two.

Kohli Quits Test Captaincy, Leaves Leadership Vacuum

Kohli Quits Test Captaincy, Leaves Leadership Vacuum

Virat Kohli, 33, had recently stepped down as India's T20I captain and was subsequently removed as the ODI captain.

UP Elections 2022: How Congress Is Harnessing Power Of 'Persecuted' Women To Counter BJP

UP Elections 2022: How Congress Is Harnessing Power Of 'Persecuted' Women To Counter BJP

A Mahila Congress leader, who is the face of the ‘Ladki Hoon, Lad Sakti Hoon’ campaign, however, has accused the party of anti-women bias after she was denied a ticket.

Advertisement