Is the Lambda variant more infectious than Delta?

lambda variant infectious, delta variant
© Dimitar Marinov

The Lambda variant, originating in Peru, has been found in 32 countries – but for the moment, it remains classified as a less threatening Variant of Interest

The World Health Organisation (WHO) named the variant, in the new Greek style, on 14 June, 2021: but it first emerged in Peru as early as August, 2020.

When it comes to new variants, Delta has become an easy comparison. Currently, the Delta variant is projected by the WHO to become globally dominant – if it isn’t already. Originating in India, the Delta variant quickly made the leap from Variant of Interest to Variant of Concern.

What is the Lambda variant?

The Lambda variant, scientifically known as C.37, is currently responsible for 21% of cases in Chile and 17% in Peru. It has been discovered in 42 US States alongside 32 countries, but is particularly present in South America.

In their latest update, the WHO said: “Lambda has been associated with substantive rates of community transmission in multiple countries, with rising prevalence over time concurrent with increased COVID-19 incidence.

“Further studies are also required to validate the continued effectiveness of vaccines.”

So is it more infectious than Delta?

The Delta variant is known to be twice as infectious as the Alpha variant, which originated in the UK. It decreases the power of vaccines, bringing two doses of Pfizer down to 64% efficacy.

There is not enough data to compare the Lambda variant to what we know about Delta – so the short answer is, not yet.

But it is marked as a Variant of Interest, which means the WHO believes it to be the cause of increased community transmissions.

Only 10.4% of people in Peru have been double-vaccinated so far. Now, as several countries in the West begin to loosen restrictions, new variants remain an external anxiety for healthcare professionals and policy-makers.

How long until herd immunity?

Possibly 2027, according to some calculations. Some countries can’t start vaccinating until 2023.

Despite the UKs’ population being 64% double-vaccinated, a mere 6% away from the infamous herd immunity concept, the Delta variant is still creating a significant rise in infections. Around 180,000 people tested positive for COVID-19 last week, which is an immense increase of 61,000 from the week before. The advice group, SAGE, predict that a merciless fourth wave is coming – and this prediction comes without the knowledge of Lambda.

Even as vaccines prove their relative efficacy against Delta, new mutations are quietly writhing into life across the globe. While some countries like the UK over 60% double-vaccinated, others are struggling to simply get to 3% on single doses.

A race of acquisition, not science

The race to re-open post-COVID has become a race of acquisition, with richer countries securing contracts with drugmakers like Pfizer and AstraZeneca. Meanwhile, countries in the Global South wait on the mercies of the WHO’s COVAX programme – which is struggling to meet demand.

The TRIPS Agreement, an intellectual property law, continues to make it implausible for some countries to afford to make their own version of the vaccine. Factories in Bangladesh stand empty, waiting for legal confirmation of right to manufacture. If they go ahead and make the generic vaccine anyway, they face being sued heavily by the pharmaceutical industry. The World Trade Organisation has been debating waiving this law for the entirety of the pandemic, but countries like Australia and the UK remain opposed to the relaxation of the law.


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