Coronavirus: UK banking on herd immunity to save it, but it could leave more than a million dead, say experts
With 1,143 infections and 21 deaths, the UK's approach to tackling the coronavirus spread is to sit back and surrender, thereby allowing millions to catch the disease.
This controversial approach builds on people developing "herd immunity" to the virus. This means that the government will allow at least 40 million of its citizens to develop the disease believing that those infected will resist a second attack from the virus. When such a high proportion of individuals in a population are immune, the virus will struggle to survive, limiting its spread.
"I do worry that making plans that assume such a large proportion of the population will become infected (and hopefully recovered and immune) may not be the very best that we can do,” Martin Hibberd, professor of emerging infectious disease at the London School of Hygiene & Tropical Medicine, told the Guardian.
The strategy has drawn flak from some scientists: the approach could endanger the lives of the vulnerable population — the elderly and those with other health conditions such as diabetes or heart ailments.
While the UK plans to sit back, other European countries such as Italy, Spain, and France are implementing aggressive measures to contain the spread: From lockdowns to shutting down schools and other public spaces.
Besides, the UK's strategy goes against the World Health Organization's (WHO) stance. The United Nation's health arm has time and again stressed on aggressively containing the virus's spread by widespread testing, tracing contacts of those with possible exposure to the virus, and social distancing. This worked for China, South Korea, and Singapore.
What is herd immunity?
People fight infections, thanks to the immune system. In addition to fighting, our immune system holds records of previous attacks from intruders such as viruses or bacteria. These records help people ward off a second attack from the same intruder.
The idea behind herd immunity is to let a majority of the population develop the disease and eventually become immune to a virus. And when this happens, "the disease will stop spreading, even if some of the population is not immune," Jeremy Rossman, from the University of Kent, wrote in The Conversation.
Herd immunity protects against measles and other diseases — but through vaccines
It is herd immunity that makes vaccines more effective. Vaccines contain a weakened pathogen that cannot launch an attack on people — but strong enough to help the immune system keep a record of the intruder. This helps vaccinated people actively ward off a second attack.
For instance, people who receive MMR shots are protected against Measles, Mumps, and Rubella. If most individuals in a population are vaccinated, then the virus is less likely to encounter an unvaccinated individual, thus limiting its spread.
The unvaccinated people are usually with a weak immune system: the weakened virus in the vaccine could make them sick. This includes babies, people with vaccine allergies, and anyone with an immune-suppressing disease like HIV or cancer.
But COVID-19 has no vaccine yet. It could take a year and a half before they reach the markets. Until then, if the UK goes ahead with its strategy, it could put the lives of many at stake.
Why are experts wary?
To reach herd immunity, about 60% of the population would need to get ill and become immune, according to Sir Patrick Vallance, the government’s chief scientific adviser.
But experts say this percentage could be higher: 70% or more. This depends on how contagious the virus is. For now, estimates put the number between 3 and 4. This measure called the Reproduction number or R0. An R0 between 3 and 4 means three or four people can contract the infection from an infected person.
According to the WHO, 3.4% of those who contracted the disease died. Other estimates say the disease kills 2.3% of those infected and 19% of those develop severe disease.
"This means that achieving herd immunity to COVID-19 in the UK could result in the deaths of more a million people with a further eight million severe infections requiring critical care," Jeremy Rossman, from the University of Kent, wrote in The Conversation.
He added that even if the UK government manages to protect the vulnerable, the death rate among the healthy population might be 0.5% or higher. "This means that even in this unlikely 'best case' scenario we would still be looking at more than 236,000 deaths," he wrote.
Your immunity to the virus may not last
This approach could end up counterproductive because the virus is mysterious. We do not know if immunity against the virus lasts.
What is more, a woman in Japan fell sick after recovering from the virus, opening up questions on whether the virus is capable of reinfecting people. In China, a few tested positive for the virus even after recovery. They, however, did not get sick again.
While we still await the verdict, a group of scientists has predicted that through 2025, we could see recurrent outbreaks. But this will depend on our immunity against the virus.
"If immunity isn’t permanent, SARS-CoV-2 (the new coronavirus) will likely enter seasonal circulation," tweeted Dr. Stephen Kissler from Harvard T.H. Chan School of Public Health and one of the authors of a preprint study.
What is the UK government saying?
According to ITV journalist Robert Peston, the government’s strategy to minimize the impact of COVID-19 “is to allow the virus to pass through the entire population so that we acquire herd immunity". But they intend on doing it at a much-delayed speed so that those who suffer the most can receive the medical support they need. They believe this strategy could prevent hospitals from getting overwhelmed and crushed.
The government has pushed back on taking aggressive measures. The reason, according to Vallance, is the public will get fatigued and may not comply as a result.
But experts disagree. “When there is a real health crisis people’s ability to accept and act is greater,” Helen Ward at Imperial College London, told the New Scientist.
Defending the government's move, Patrick Vallance, the UK’s chief scientific adviser, said that in the coming days the government will explain the rationale behind the approach.
According to Mark Woolhouse at the University of Edinburgh, learning to live with the virus, instead of eradicating it, is a more sustainable option. “At some point, I suspect the WHO is going to have to change its position to something like the UK government’s, and not the other way around,” he told the New Scientist.
What are other European countries doing?
Europe has emerged as the new epicenter of the outbreak, with infections rapidly proliferating in Italy, Spain, Germany, France, and Switzerland. More than 20,000 people have contracted the disease in Italy.
Sensing that the situation was going out of hand, Italy locked down its country, following China's example. Spain has also followed suit: The government has declared a two-week state of emergency which will start from Monday at 07:00 GMT. And France is closing all cafés, restaurants, clubs, and cinemas.
Some of these approaches, though difficult, may work. “Other countries have shown speed is crucial. There is a middle path between complete shutdown and carrying on as normal,” Dr. Devi Sridhar from the University of Edinburgh tweeted, citing examples of stopping large public gatherings, stopping non-essential travel and urging employers to allow home working.
Another expert also found the UK's strategy disappointing. "Test, trace contacts, quarantine, social distancing. DO IT ALL. China did this and suppressed its epidemic in 7 weeks. Yes, it could flare up again there, but we are all playing for time in the hope of developing a vaccine to bring herd immunity," tweeted Anthony Costello, professor of Global Health and Sustainable Development at University College London, who worked with WHO between 2015 and 2018.