- Michelle Roberts
- Health Affairs Editor, BBC News Network
Image source,Getty Images
A variant of the new coronavirus, first discovered in India, is causing an increase in cases of infection in some parts of the UK. Experts are worried about this.
Experts say that this variant, named “Delta” by the World Health Organization (WHO), is even easier to spread than the “Kent” or “Alpha” variants, and has now become the dominant variant of the virus in the UK.
It may delay England’s decision to relax social restrictions on June 21, although the number of hospital admissions is still low.
What happened to the Indian variant that appeared in the UK?
There are several “Indian” variants, but a variant called “B.1.617.2” seems to spread faster in the UK.
Some areas are already carrying out large-scale “big wave” testing, including Bolton and Blackburn, to identify infected people-but this may not prevent the spread of the virus.
A second vaccine for people over 50 years old (and clinically susceptible people) in England is being implemented to protect more people faster. The second dose will be given eight weeks after the first dose, instead of 11-12 weeks.
The latest research shows that Pfizer and AstraZeneca’s new crown vaccines are highly effective against new variants after two doses of vaccination, but the protection after one dose seems to have declined.
What do we know about the different virus variants?
There are currently thousands of variants of the new coronavirus spreading all over the world.
Viruses have always mutated continuously, and most changes will bring no consequences. Some can even cause harm to the virus. But some may make the disease more infectious or more harmful-and these mutations often become dominant variants.
Those with the most worrying changes are called “variants of concern” and are closely monitored by official health personnel. Such variants include the following:
Mutant viruses are more dangerous?
There is currently no evidence that any variant of the virus will cause more serious diseases to the general population.
Like the original virus, the highest risk is still the elderly or people with serious underlying health problems.
But a more infectious and dangerous virus can cause more deaths among unvaccinated people.
For all variant viruses, the advice to prevent infection remains the same: wash your hands frequently, maintain social distancing, wear a mask, and stay alert to air circulation.
How do these mutations work?
The variant viruses that experts are worried about all have changes in the spike protein-this is the part where the virus connects to human cells.
The “Delta” variant has some potentially very important mutations (such as L452R), which may make it easier to spread.
British officials said that there is currently no evidence that it will cause more serious diseases or reduce the effectiveness of current vaccines.
At the same time, the World Health Organization has listed another similar variant virus circulating in India—the scientific name is “B.1.617″—as a variant of concern.
One of the mutations called “N501Y” appears in Alpha, Gamma, and Beta variants at the same time. It seems to make the virus more capable of infecting other cells and spreading.
The Beta and Gamma variants also have a key mutation called “E484K”, which may help the virus avoid antibodies, which are a key part of the immune system to help the body fight infection.
Experts recently discovered that a small number of Alpha variants have also seen this change.
Is the vaccine still effective against variant viruses?
The current vaccines are designed for earlier new coronaviruses, but scientists believe that they should be effective, although they may be less effective.
Laboratory studies have shown that antibodies that can fight infections triggered by vaccines or past infections may not be as effective for Delta variants to a certain extent.
However, two doses of Pfizer or AstraZeneca vaccines can still protect the infected from severe illness.
Real-world data shows that Pfizer vaccines can resist new variants, albeit with a slight decrease in effectiveness. Data from the Oxford-AstraZeneca vaccine team shows that this vaccine is still the same resistance to the Alpha variant. Its protection against the Beta variant has declined-but it should still be able to avoid severe illness.
A recent study showed that the Gamma variant may be able to resist antibodies in the body of people recovering from the new coronavirus.
Some early results show that the Moderna vaccine is effective against the Beta variant, but the immune response it provokes may be slightly weaker and the duration is short.
Does the variant mean additional injections?
Experts are confident that existing vaccines can be improved to better fight against new variants.
The British government has reached an agreement with the biomedical company CureVac to study vaccines for future variants, and 50 million doses have been ordered.
Based on the next development of the mutant virus, these vaccines may be used in the elderly or clinically susceptible people later this year.