theconversation | At the end of 2020, there was a strong hope that high levels of vaccination would see humanity finally gain the upper hand over SARS-CoV-2, the virus that causes COVID-19. In an ideal scenario, the virus would then be contained at very low levels without further societal disruption or significant numbers of deaths.
But since then, new “variants of concern” have emerged and spread worldwide, putting current pandemic control efforts, including vaccination, at risk of being derailed.
Put simply, the game has changed, and a successful global rollout of current vaccines by itself is no longer a guarantee of victory.
No one is truly safe from COVID-19 until everyone is safe. We are in a race against time to get global transmission rates low enough to prevent the emergence and spread of new variants. The danger is that variants will arise that can overcome the immunity conferred by vaccinations or prior infection.
What’s more, many countries lack the capacity to track emerging variants via genomic surveillance. This means the situation may be even more serious than it appears.
As members of the Lancet COVID-19 Commission Taskforce on Public Health, we call for urgent action in response to the new variants. These new variants mean we cannot rely on the vaccines alone to provide protection but must maintain strong public health measures to reduce the risk from these variants. At the same time, we need to accelerate the vaccine program in all countries in an equitable way.
Together, these strategies will deliver “maximum suppression” of the virus.
What are ‘variants of concern’?
Genetic mutations of viruses like SARS-CoV-2 emerge frequently, but some variants are labelled “variants of concern”, because they can reinfect people who have had a previous infection or vaccination, or are more transmissible or can lead to more severe disease.
There are currently at least three documented SARS-CoV-2 variants of concern:
B.1.351, first reported in South Africa in December 2020
B.1.1.7, first reported in the United Kingdom in December 2020
P.1, first identified in Japan among travellers from Brazil in January 2021.
Similar mutations are arising in different countries simultaneously, meaning not even border controls and high vaccination rates can necessarily protect countries from home-grown variants, including variants of concern, where there is substantial community transmission.
If there are high transmission levels, and hence extensive replication of SARS-CoV-2, anywhere in the world, more variants of concern will inevitably arise and the more infectious variants will dominate. With international mobility, these variants will spread.
0 comments:
Post a Comment