Monday, 27 April 2020

Immunity and the Virus: Cause for Concern













Can you catch the Coronavirus Twice? As Jersey considers how to lift the lockdown, this is a question of critical importance.

Despite the comments by the World Health Organisation that it is uncertain, the science of immunity is pretty solid,  so if you’ve had the virus it is extremely unlikely you can catch it again. While there’s a lot of uncertainly about coronavirus, how the body's immune responses work is almost 100% certain. 

But what may not be so certain is whether there are several strains of Coronavirus out in the wild, so different that immunity from one may not mean immunity from another.

Back in January 2020, Insider Magazine reported on influenza – coronavirus was then a distant cloud on the horizon:

A double-barreled flu season occurs when two flu outbreaks overlap one another, a pattern which is very unusual, according to flu experts.

Last year, for example, we saw A/H1N1 infections peak early, followed by another wave of A/H3N2 infections. Though the predominant strains are different this year, we’re seeing the same pattern play out: Activity took off with B/Victoria and now that second wave of A/H1N1 is coming for us, according to Schaffner. “Around the country, my colleagues and I are seeing H1N1 come up strong, and it’s now about 50-50 [with B/Victoria],” Schaffner told Healthline. The most worrisome part of a double-barreled flu season is that you can get sick twice.

Just because you caught a B-strain flu doesn’t mean that you’re immune from the A strains. “There will be the rare person who gets two flu infections in the same season — one with B and one with H1N1,” Schaffner said. Though there will be some protection within each strain — in that contracting an A strain will protect you against other A strains, and B strains will protect against other B’s — there’s not much cross protection.


Now the South China Morning Post – April 2020 – has this to note on Coronavirus. Firstly, there are at least 30 variants, but these come down to three main strands:

Geneticists from Britain and Germany have mapped the evolutionary path of the coronavirus that causes Covid-19 and determined there are currently three versions of it spreading around the world

Type A was also found in Americans who had lived in Wuhan, and in other patients diagnosed in the United States and Australia. 

The most common variant found in Wuhan was type B, the study said, though this appeared not to have travelled much beyond East Asia before mutating, which the researchers said was probably due to some form of resistance to it outside that region. 

Finally, type C was the variant found most often in Europe based on cases in France, Italy, Sweden and England. It had not been detected in any patients in mainland China, though had been found in samples from Singapore, Hong Kong and South Korea, the study said. 

The researchers concluded that variant A was the root of the outbreak as it was most closely related to the virus found in bats and pangolins. Type B was derived from A, separated by two mutations, while type C was the “daughter” of variant B.

Lu Jiahai, an epidemiologist at Sun Yat-sen University Guangzhou, the capital of Guangdong, said the study had provided a preliminary analysis of genomics and molecular variation. “The virus mutates during spreading and has become more adapted to transmission among humans in different populations from different countries,” he said. 

But as the variants were related to each other, tracking mutations within different groups could help to determine the origin of the virus, he said. “This research indicates that the spread of the virus is increasingly adapted to different populations and therefore the pandemic needs to be taken seriously,” Lu said. “People need to pay more attention to prevention and control … the virus may coexist with humans for a long time.”

So no – you can’t easily catch the same variant twice, but you could catch an alternative variant! And it is still mutating.

That is a cause for concern.

References
https://www.insider.com/can-you-get-the-flu-more-than-once
https://www.scmp.com/news/china/science/article/3079491/deadly-coronavirus-comes-three-variants-researchers-find
https://gulfnews.com/world/asia/coronavirus-has-mutated-into-at-least-30-variants-of-which-19-are-new-and-previously-undetected-1.1587559316992