WThere is still only a week to go by 2021 and there are already urgent warnings about a new strain of pandemic virus spreading surreptitiously and exponentially around the world.
This looks like déjà vu. But in a way, this is good: this is not just another chapter in the exhaustive saga of SARS-CoV-2, the virus that causes Covid-19, which the new vaccines available are gradually controlling.
Humanity was not even remotely prepared for our fight with SARS-Cov-2 when it emerged in late 2019. So, we lost to him.
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But be better prepared for this new enemy, called B.1.1.7 or B-117 for short.
We already understand how this new virus spreads, what public health strategies can help contain it and how to effectively treat people infected with it. We are already conducting millions of diagnostic tests each day that can sensitively detect the new pathogen and distinguish it from our old enemy.
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Anyone who already has Covid-19 is highly resistant to B-117, a variant of SARS-CoV-2. So, in one respect, the old virus is helping us against the new one. Most importantly, the new vaccines that have been developed against SARS-CoV-2 and are being launched in the United States and in several other countries around the world are likely to protect us against B-117, which means that vaccination campaigns can defeat both viruses.
Still, the B-117 has two critical advantages. One is that we are exhausted from fighting Covid-19. People may find it difficult to gather energy to respond to a new viral threat, especially when the emergence of the new virus is hidden in the larger sea of SARS-CoV-2 cases. The other is that cases of B-117 can increase much faster than those of our enemy in 2020. In the United Kingdom, where B-117 appears to have evolved, most districts that have imposed conditions of stay at Tier 1 home 4 kept the SARS-CoV-2 cases unchanged just to see B-117 increase 10 times every three or more weeks. The same pattern of exponential growth appears to have started in Denmark.
What can this mean for at least 32 countries outside the UK with confirmed cases of B-117?
Suppose your community is using masks and distance to keep SARS-CoV-2 transmission levels flat, but it has detected a single case of B-117 (plus 1,000 cases of SARS-CoV-2). In three weeks, your community can have ten daily cases of B-117 (plus 1,000 cases of SARS-CoV-2). Within six weeks, there may be 100 cases of the new variant (plus 1,000 SARS-CoV-2). In nine weeks, half of all cases can be B-117, and the number will continue to increase, even when the spread of both viruses decreases due to infection and vaccination, increasing immunity in the population. These estimates are intended to illustrate what may happen, but are consistent with what we know about the comparative spread of B-117 and other strains of SARS-CoV-2.
Since B-117 can grow exponentially even in communities that keep SARS-CoV-2 under control, the situation is extremely urgent. If vaccination is to win this new race, we must slow down the new virus while it is still rare.
The first step is to find the enemy. Each week, Thermo Fisher manufactures twenty million TaqPath test kits capable of detecting B-117, which exhibits a “loss of the S gene” pattern that distinguishes it from SARS-CoV-2. These kits, an equivalent to the PCR tests used to detect SARS-CoV-2 infection and / or genetic sequencing, can be used on samples that have already tested positive for SARS-CoV-2 to see which ones were really B-117. No emergency use authorization is needed to analyze more positive samples.
The second step is to redirect resources to the new threat that spreads more quickly. Testing and contact tracking can slow the spread of rare pathogens, such as B-117, but become comparatively ineffective when there are many cases. Several models (including one developed by one of us, KE) show that bidirectional screening to find the sources of infection and also those exposed to it can prevent more than twice as many cases as standard methods.
This suggests that as soon as the first person is diagnosed with B-117 in a community, local contact trackers must abandon everything else to map the complete transmission chain of the new strain using all available resources. Veteran trackers can visit contacts’ homes to provide medical advice, take samples to be sent to labs to be tested for B-117 with results the next day, and offer supplies to people who need self-quarantine.
Widely publicized guarantees of legal disclaimer for anything revealed in the course of the search for contacts could help combat distrust. Governments should also offer financial compensation and job preservation to exposed individuals who self-quarantine at home and B-117-positive people who isolate themselves, if necessary, in publicly provided hotel rooms or other accommodations. As this new threat remains rare in most parts of the world, we have a second chance to apply the testing and tracking countermeasures that helped stem the initial spread in some locations and that faltered in many others because SARS-CoV-2 had already become very widespread.
The third step is to consider deviating Covid-19 vaccine doses to any region with large groups of vaccination cases for the entire community. To be clear, we have very limited data showing how current vaccines prevent infection or transmission of B117. Still, the data we have suggests that the effect can be substantial, as with virtually all other viral vaccines.
Given the enormous importance of blocking the exponential growth of B-117 in advance, it seems worthwhile to try this approach quickly, monitoring the results and adapting as we discover how well it is working. We didn’t have that potential silver bullet last time. Now it could turn the tide.
Two other steps are necessary. In the immediate term, the diagnosis should be developed to detect other SARS-CoV-2 variants of concern, such as the 501.V2 strain that appeared in South Africa, but is not yet known to have spread to the US or many other countries that harbor B-117. This variant does not yet appear to be as transmissible as B-117, but the questions about how vulnerable it is to Covid-19 vaccines have not yet been resolved.
From now on, in the coming years, we must build a genomic monitoring system to detect evolutionary changes in viruses, bacteria and other pathogens that may require new measures to protect public health and that can detect new pandemic pathogens from any source with sufficient advance notice. to intervene. The need is global, so as the United States updates domestic systems, we must learn from the experience of countries that have been more agile in detecting new variants, such as the United Kingdom and South Africa, and helping others to configure their systems themselves.
Genomic monitoring will be a central pillar of the larger project to massively update public health information systems that have failed at many stages in the current Covid-19 pandemic.
Those who are tired and impatient for the end of the pandemic drama – a category that includes both of us – can take comfort in the fact that the light at the end of the tunnel is still getting stronger, although the appearance of the B-117 adds an extra measure of urgency. Biologically, the new virus is an evolved variant of SARS-CoV-2. Epidemiologically, it appears to be a distinct and more formidable enemy, but for which we are much better prepared.
It’s 2021 and a different race has started. Let’s win this one.
Kevin Esvelt is an assistant professor in the Media Lab at the Massachusetts Institute of Technology, where he directs the Sculpting Evolution Group. Marc Lipsitch is a professor in the Departments of Epidemiology and Immunology and Infectious Diseases at Harvard School of Public Health TH Chan, where he also directs the Center for Communicable Disease Dynamics.