The latest figures show that cases are increasing in Germany, France, the UK, Italy, Spain, Greece and Denmark. Portugal, a popular holiday destination for many people every summer, is experiencing the biggest rise. Hospital admissions have risen in several countries, including France and England, according to data analyzed by the Financial Times. In the UK, figures from the Office for National Statistics (ONS), published on June 17, show that COVID infections are increasing by 43 percent each week. Noting the ONS data while speaking at a meeting of Independent SAGE (a group of scientists that advises the UK government) on June 17, Kit Yates, a senior lecturer in the mathematics department at the University of Bath, said: “It’s pretty much official from the latest ONS data that the UK has entered the next wave of COVID. It is very worrying to see that there has been an increase in COVID infections in older age groups and the 50-59 age group, who have not yet been offered another reminder.”
What is driving the new waves of COVID-19?
The rise in new COVID cases and hospital admissions is believed to be largely driven by new sub-variants of the Omicron variant of SARS-CoV-2, known as BA.4 and BA.5. Omicron’s BA.5 sub-variant is now the dominant variant in Portugal. In Germany, where imports have been rising for over a week, the share of COVID infections attributed to BA.5 doubled at the end of last month. And according to the US Centers for Disease Control and Prevention (CDC), BA.4 and BA.5 are now likely the dominant variants in the country, accounting for about 52 percent of new cases in the US, numbers that experts say are rising in the coming weeks. BA.4 and BA.5 are two newly characterized Omicron lines, meaning they are Omicron viruses with a new combination of mutations. Both were first spotted in South Africa – BA.4 in January and BA.5 in February 2022 – and are now the dominant variants there. South Africa performs genetic sequencing on more SARS-CoV-2 samples than many other countries, so it’s possible that these variants arose somewhere else and the South African scientists were just the first to spot them. New mutations are expected in a virus as widespread as SARS-CoV-2. they occur as the virus divides within hosts and random errors occur in copying the genetic material. The further the virus spreads and the more people it infects, the more likely mutations will occur. Mutations only matter if they enhance the severity of the disease the virus causes, greatly enhance its ability to overcome immunity provided by vaccines or previous infection, or make diagnostic tests less effective, making it harder to control the spread of the disease. The fact that BA.4 and BA.5 quickly became dominant over earlier Omicron subvariants would indicate that they contain mutations that make them more transmissible, either because of these mutations or because of reduced protection from vaccines and previous infections. It’s likely a combination of both, though it’s too early to say for sure. The two subvariants are often discussed together because the mutations in the spike protein gene are identical, even though they differ in mutations located elsewhere. The spike protein is key, as this is what the virus uses to infect and enter human cells, and changes here that make the process easier and faster will make the virus more contagious. The spike protein is also the part of the virus targeted by the majority of COVID-19 vaccines. The European Center for Disease Prevention and Control (ECDC) – which regularly assesses new evidence on variants detected through epidemic intelligence, rule-based genomic variant screening or other scientific sources – has designated the BA.4 and BA.5 subvariants as “variants of concern’, indicating a significant effect on transmissibility, severity and/or immunity that is likely to have an impact on the epidemiological situation in Europe. Both new variants carry an L452R mutation, which was also previously detected in the Delta variant, and is thought to make the virus more transmissible by enhancing the virus’ ability to attach to human cells. It may also help it partially avoid destruction by immune cells. They also have a genetic change, called the F486V mutation, near where their spike protein binds to human cells. This may also help them partially evade our immune response. They also contain a change in their genetic sequence, known as an S gene dropout, which means they won’t show up in some PCR tests that look for the S gene to give a positive result. So far, there is no evidence that BA.4 or BA.5 are associated with new symptoms or more severe disease. This is to be expected, given that the majority of mutations are similar to those found in other Omicron lineages, although it is something that will continue to be closely monitored by the World Health Organization (WHO). Research is still ongoing as to whether the new subvariants can evade the protection afforded by vaccines and/or previous infections from other variants. A small study showed that anti-BA.2 Omicron antibodies were less effective in neutralizing the BA.4 and BA.5 subvariants. He also found that antibodies elicited by the COVID-19 vaccines were more effective against these new subvariants than those raised from previous infection. Another study, not yet peer-reviewed, found that unvaccinated individuals previously infected with the BA.1 subvariant of Omicron were more likely to be reinfected with BA.4 and BA.5 compared with those who had been vaccinated.
What can we do?
Most experts agree that we are likely to see more cases of COVID as a result of the combination of the new sub-variants, the reduction in protection and the relaxation of safety measures. To prevent healthcare systems from being overwhelmed with patients suffering severe symptoms as a result of infections from these subvariants, it is wise to take preventive measures. Many countries offer a second booster, or fourth dose, to elderly or at-risk groups to boost their protection and protect against severe symptoms. Drug companies are also working to make Omicron-specific vaccines, although these may now need to be modified to protect against these new subvariants. It is good to remember that this virus, regardless of its variants, is airborne. Maintaining airflow and good ventilation indoors to keep the air moving is a good way to reduce your chances of becoming infected. Although many countries have abandoned mask mandates, wearing a mask such as an N95 or FFP2 mask in crowded indoor spaces or on public transportation is a good way to reduce your risk of contracting the virus. Testing is a key part of tracking new variants. some countries have restricted free testing or only made it available to certain groups of people, such as health and social care professionals, but to accurately track numbers and variations, we need to consider making testing more readily available.
