The US Centers for Disease Control and Prevention announced declared in May that people fully vaccinated against Covid-19 could go into public places without a mask.
Not anymore. The data that informed the revised CDC mask guidelines in May was based on the then-dominant alpha variant. We must all continue to wear masks in all public gatherings. I know for the vaccinated it is not the freedom we all expected. Delta, the highly transmissible variant, has caused a devastating surge in Covid-19 infections in Africa, Asia, the UK and the US.
Studies show that the delta variant replicates sooner and faster, making it much easier to spread than the original coronavirus that first emerged in China in late 2019. Moreover, the level of the dominant delta variant in the nasal pharynx is estimated at about 1,000 times higher than in the alpha variant.
Some 65 countries have detected Covid-19 cases caused by the delta variant in the four weeks to August 5. In 55 out of the 65 countries, the delta variant accounts for more than 50 per cent of Covid-19 cases. First detected in India in October 2020, the delta variant is now present in 135 countries. But data on the prevalence of the delta variant is perhaps underestimated because many countries don’t share sequenced samples.
The delta variant is now dominant in Israel where more than 62 per cent of the population is vaccinated. Similarly, the delta variant now accounts for 50 to 80 per cent of Covid-19 cases in the US.
The good news is that vaccines provide effective protection against severe illness. Using real world data, a study published in the New England Journal of Medicine found that two doses of Pfizer-BioNTech vaccine are 88 per cent effective against the delta variant. The AstraZeneca-Oxford vaccine was found to be 67 per cent effective against the delta variant.
As the delta variant gets out of control, people already vaccinated are getting infected. Rich countries are contemplating administering booster shots or a third dose for the elderly and those whose immune conditions are compromised. This would be morally outrageous considering that only 1.85 per cent of the entire African population is vaccinated, compared to 49-61 per cent of Americans and Europeans who are fully vaccinated.
The delta variant is so prevalent because there is little commitment to distribute vaccines equitably among all countries. It is estimated that rich countries have a stockpile of 1.9 billion vaccine doses more than they need to protect their populations.
For example, Canada secured 409 million doses of vaccines and vaccine candidates for Canadian citizens. Similarly, based on existing authorisations and purchase agreements, the US has 300 million or more excess vaccine doses.
Given the inequity in vaccine access, it is highly likely that a variant far deadlier than delta will soon emerge. Either wealthy nations export excess vaccine doses and expand vaccine production capacity in low-and-middle-income countries or import more virulent Covid-19 strains. One unvaccinated person anywhere is a threat to vaccinated people everywhere.
Views expressed are the writer’s
